Composite metal oxide fuel additives

Abstract

The present invention provides a composite material, which comprises a metal oxide core capped with a modified chlorophyll, and used thereof as a fuel additive.

Description

RELATED APPLICATIONS

[0001] This application is a bypass continuation of International Application No. PCT / IL2025 / 050523, filed Jun. 17, 2025, titled “COMPOSITE METAL OXIDE FUEL ADDITIVES,” which claims the benefit of U.S. Provisional Patent Application No. 63 / 661,588, filed Jun. 19, 2024, titled “COMPOSITE METAL OXIDE FUEL ADDITIVES,” the entirety of the disclosures of which are hereby incorporated by this reference.FIELD OF THE INVENTION

[0002] The present invention provides a composite material, which comprises a metal oxide core capped with a modified chlorophyll and used thereof as a fuel additive.BACKGROUND OF THE INVENTION

[0003] The increasing world population and the level of prosperity have led to an increase in the need for transportation. A pivotal role in the progress of transportation and the increased speed of vehicles is attributed to internal combustion engines that use different fuels as an energy source. Fuel additives are chemical compounds that can help to optimize emissions and engine power and torque. Moreover, fuel additives are mixed with raw fuel, to get improved combustion efficiency, lower fuel consumption, decreasing engine wear, preventing failures, and better running in cold weather. Fuel additives considered to be a cost-effective and simple approach to improve combustion and reduce the harmful emissions of internal combustion engines.

[0004] One of the main uses of using fuel additives is the improvement in fuel efficiency. Fuel additives such as cetane and octane boosters alter the combustion properties of fuel. This, in turn, allows for smoother and more effective fuel burning. By enabling more of the fuel to be efficiently burned in the combustion chamber, less is wasted, and therefore more energy is obtained from each unit of fuel. This results in better fuel economy and less frequent refills, providing direct cost savings to the user.

[0005] Known fuel additives typically consist of different alcohols, which are commonly short alcohols, such as methanol and ethanol, or small hydrocarbons, such as petroleum ether, hexanes, benzene toluene and the like.

[0006] Nevertheless, there remains a need in the art for more suitable and efficient fuel additives that effectively increase the combustion efficiency of fuels, in particular diesel fuels, and thereby reduce the associated carbon emissions.SUMMARY OF THE INVENTION

[0007] The present invention relates to composite materials comprising a metal oxide core and an organic coating, which were surprisingly found to be highly useful as fuel additives (e.g., diesel fuel additives). The terms “fuel”, fuel additive” and “diesel fuel” are defined herein in the definitions section.

[0008] Specifically, it was found that the present composite materials significantly improved the combustion efficiency of fuel, which is highly useful in reducing carbon emissions caused by operation of fuel-powered engines. Without wishing to be bound by any theory of mechanism of action it is hypothesized that the composite fuel additive of the present invention efficiently binds dioxygen (O2), thus improving the combustion efficiency of the fuel in the presence of the bound oxygen.

[0009] The composite material of the present invention generally includes, according to some embodiments, a metal oxide core coated or capped with an organic coating. The metal oxide core may be particulate (micro / nano particles and / or quantum dots), according to some embodiments. The terms “particulate”, “micro particles”, “nanoparticles”, “small nanoparticles” and “quantum dots” are defined herein in the definitions section. The organic coating of the present composite material includes, according to some embodiments, a chlorophyll molecule. According to some embodiments, the organic coating of the present composite material includes a cation exchanged chlorophyll, a term which is further defined herein, and generally refers to a chlorophyll molecule that in bound to a cation other than magnesium (Mg+2). In particular, the cation exchanged chlorophyll coating of the present invention may include chelated divalent metal cation, such as, but not limited to iron cation (e.g., Fe+2), copper cation (e.g., Cu+2), cobalt cation (e.g., Co+2) and manganese cation (e.g., Mn+2). According to some embodiments, the cation exchanged chlorophyll coating includes a copper cation (e.g., Cu+2).

[0010] Thus, according to some embodiments, the present invention provides a composite material, which comprises a metal oxide core, coated with an organic coating. According to some embodiments, the organic coating comprises a cation exchanged chlorophyll. According to some embodiments, the cation exchanged chlorophyll comprises a chelated metal cation. According to some embodiments, the cation exchanged chlorophyll comprises a copper cation (e.g., Cu+2).

[0011] According to some embodiments, the metal oxide core comprises a metal oxide selected from the group consisting of: cerium oxide, aluminum oxide, titanium oxide, zinc oxide, copper oxide, iron oxide, manganese oxide, cobalt oxide, nickel oxide, vanadium oxide, molybdenum oxide, tungsten oxide, chromium oxide and a combination thereof. Each possibility represents a separate embodiment of the invention.

[0012] According to some embodiments, the metal oxide core comprises a metal oxide selected from the group consisting of: CeO2, AlO3 and MnO2. Each possibility represents a separate embodiment of the invention. According to some embodiments, the metal oxide core comprises CeO2.

[0013] According to some embodiments, the metal oxide core is particulate.

[0014] According to some embodiments, the metal oxide core has a particle size in the range of 1 nm to 500 nm.

[0015] According to some embodiments, the metal oxide core has a particle size in the range of 1 nm to 300 nm. According to some embodiments, the metal oxide core has a particle size in the range of 3 nm to 300 nm.

[0016] According to some embodiments, the metal oxide core is in the form of a nanoparticle(s) having particle size in the range of 100 nm to 300 nm.

[0017] According to some embodiments, the metal oxide core is in the form of a small nanoparticle(s) having particle size in the range of 10 nm to 50 nm.

[0018] According to some embodiments, the metal oxide core is in the form of a quantum dot(s) having particle size in the range of 1 nm to 20 nm. According to some embodiments, the metal oxide core is in the form of a quantum dot(s) having particle size in the range of 1 nm to 10 nm. According to some embodiments, the metal oxide core is in the form of a quantum dot(s) having particle size in the range of 2 nm to 10 nm. According to some embodiments, the metal oxide core is in the form of a quantum dot(s) having particle size in the range of 3 nm to 10 nm.

[0019] According to some embodiments, cation exchanged chlorophyll is selected from the group consisting of: chlorophyll a, chlorophyll b, chlorophyll c1, chlorophyll c2, chlorophyll c3, chlorophyll d, chlorophyll f and a combination thereof.

[0020] According to some embodiments, cation exchanged chlorophyll is selected from the group consisting of: synthetic chlorophyll or native modified chlorophyl such as chlorophyll c1 bound to long chain alcohol of C4-C24 carbon long at the carboxylic group of the chlorophyll, chlorophyll c2 bound to long chain alcohol of C4-C24 carbon long at the carboxylic group of the chlorophyll, synthetic cation exchanged chlorophyll, and a combination of synthetic and native cation exchanged chlorophyll thereof.

[0021] According to some embodiments, the chelated metal cation is coordinately bonded to the chlorophyll at the central coordination cavity / core of the chlorin-type macrocycle. Without wishing to be bound by any theory of mechanism of action it is hypothesized that the chlorophyll of the present invention efficiently may bind dioxygen, and it is further hypothesized that a strong binding of the exchanged metal improves the efficacy of the binding and overall performance of the present composite material as a fuel additive.

[0022] Thus, according to some embodiments, the chelated metal cation has a stronger binding to dioxygen than Mg+2.

[0023] According to some embodiments, the chelated metal cation is selected from the group consisting of: cobalt cation, copper cation, iron cation, manganese cation, nickel cation, ruthenium cation, rhodium cation, silver cation, vanadium cation, chromium cation, zinc cation, nickel cation, cerium cation, tungsten cation, molybdenum cation, rhenium cation, iridium cation, palladium cation, osmium cation, technetium cation, platinum cation, titanium cation, zirconium cation, hafnium cation, niobium cation, tantalum cation, gallium cation, indium cation, tin cation, lead cation, antimony cation, bismuth cation, thulium cation, thorium cation, boron cation arsenic cation and a combination thereof. Each possibility represents a separate embodiment of the invention.

[0024] According to some embodiments, the chelated metal cation is a divalent cation.

[0025] According to some embodiments, the chelated metal cation is selected from the group consisting of: Co+2, Cu+2, Mn+2, Fe+2, Zn+2. Each possibility represents a separate embodiment of the invention. According to some embodiments, the chelated metal cation is Cu+2

[0026] According to some embodiments, the composite material is in a particulate form.

[0027] According to some embodiments, the composite material comprises a composite particle having particle size in the range of 1 nm to 500 nm, including each value and sub-range within the specified range. According to some embodiments, the composite material comprises a composite particle having particle size in the range of 3 nm to 400 nm, including each value and sub-range within the specified range. According to some embodiments, the composite particle has a particle size in the range of 3 nm to 300 nm. According to some embodiments, the composite particle has a particle size in the range of 5 nm to 200 nm.

[0028] According to some embodiments, the composite particle is in the form of a quantum dot having particle size in the range of 4 nm to 12 nm. According to some embodiments, the composite particle is in the form of a quantum dot having particle size in the range of 5 nm to 10 nm. According to some embodiments, the composite particle is in the form of a quantum dot having particle size in the range of 5 nm to 7 nm.

[0029] According to some embodiments, the composite particle is in the form of a small nanoparticle having particle size in the range of 10 nm to 50 nm. According to some embodiments, the composite particle is in the form of a small nanoparticle having particle size in the range of 12 nm to 55 nm.

[0030] According to some embodiments, the composite particle is in the form of a nanoparticle having particle size in the range of 100 nm to 300 nm. According to some embodiments, the composite particle is in the form of a nanoparticle having particle size in the range of 105 nm to 330 nm.

[0031] According to some embodiments, the composite material further comprises at least one surface ligand. According to seme embodiments, the at least one surface ligand is selected from the group consisting of: a carboxylic acid, an amine, an alcohol, a thiol, a phosphine, a phosphine oxide and a combination thereof. Each possibility represents a separate embodiment of the invention.

[0032] According to some embodiments, the composite material comprises at least one carboxylic acid ligand.

[0033] According to some embodiments, the carboxylic acid ligand comprises a C4-C28 fatty acid.

[0034] According to some embodiments, the carboxylic acid ligand is selected from the group consisting of: oleic acid, palmitic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, elaidic acid, erucic acid linoleic acid, linoelaidic acid, α-linolenic acid, myristoleic acid, palmitoleic acid, sapienic acid, vaccenic acid and a combination thereof. Each possibility represents a separate embodiment of the invention.

[0035] According to some embodiments, the carboxylic acid ligand comprises oleic acid, palmitic acid or both. According to some embodiments, the carboxylic acid ligand comprises oleic acid. According to some embodiments, the carboxylic acid ligand is oleic acid.

[0036] According to some embodiments, the composite material comprises at least one amine ligand.

[0037] According to some embodiments, the amine ligand is selected from the group consisting of: oleylamine, butylamine, methylamine, ethylenediamine, dimethylamine, diphenylamine, an amino acid, biogenic amines, triethylamine, trimethylamine, aniline, imidazole, pyridine, pyrazole, pyrole, pyroline, piperidine, and a combination thereof.

[0038] According to some embodiments, the amine ligand comprises oleylamine, butylamine, ethylenediamine or a combination thereof.

[0039] According to some embodiments, the composite material comprises at least one alcohol ligand.

[0040] According to some embodiments, the alcohol ligand comprises a C1-C24 alcohol.

[0041] According to some embodiments, the alcohol ligand is selected from the group consisting of ethylene glycol, propylene glycol, glycerol, methanol, ethanol, propanol, butanol, pentanol, hexanol, octanol, decanol, hexadecanol, allyl alcohol, geraniol, and a combination thereof. Each possibility represents a separate embodiment of the invention.

[0042] According to some embodiments, the composite material comprises at least one thiol ligand.

[0043] According to some embodiments, the thiol ligand is selected from the group consisting of: 1-dodecanethiol, thioglycolic acid and a combination thereof. Each possibility represents a separate embodiment of the invention.

[0044] According to some embodiments, the composite material comprises at least one phosphine ligand.

[0045] According to some embodiments, the phosphine ligand comprises trioctylphosphine.

[0046] According to some embodiments, the composite material comprises at least one phosphine oxide ligand.

[0047] According to some embodiments, the phosphine ligand comprises trioctylphosphine oxide.

[0048] According to some embodiments, the composite material has solubility of at least 1 gr per liter in diesel fuel. According to some embodiments, the composite material has solubility of at least 5 gr per liter in diesel fuel. According to some embodiments, the composite material has solubility of at least 10 gr per liter in diesel fuel.

[0049] According to some embodiments, the metal oxide core of the composite material comprises CeO2, the metal oxide core is in the form of a quantum dot having particle size in the range of 1 nm to 20 nm, and the chelated metal cation comprises Cu+2.

[0050] According to some embodiments, the metal oxide core of the composite material comprises CeO2, is coated with an organic coating, and the organic coating comprises a Cu+2 exchanged chlorophyll and oleic acid; the CeO2 core is particulate in the form of a quantum dot and has a diameter in the range of 1 nm to 4 nm; and the composite material is particulate in the form of a quantum dot and has a diameter in the range of 4 nm to 10 nm.

[0051] According to a further aspect of the present invention, the composite material as described herein is prepared by a method comprising subjecting a core metal salt to sonication to form a nanoparticulate metal oxide; and subjecting the nanoparticulate metal oxide to sonication together with a cation exchanged chlorophyll, to form the composite material.

[0052] It is to be understood by a person of ordinary skill in the art that, although the current optional method for forming the present composite material involves one or more sonication steps, other methods for producing nanoparticulate materials are known in the art and may likewise be employed in the preparation of the present composite material. According to some embodiments, the method further comprises, a step of contacting Mg-chlorophyll with a chelating metal salt to form the cation exchanged chlorophyll, which is performed before the step of subjecting the nanoparticulate metal oxide and cation exchanged chlorophyll to sonication.

[0053] According to some embodiments, the method further comprises a step of subjecting the nanoparticulate metal oxide to sonication together with at least one surface ligand. According to some embodiments, the at least one surface ligand is selected from the group consisting of: a carboxylic acid, an amine, an alcohol, a thiol, a phosphine, a phosphine oxide and a combination thereof,

[0054] According to some embodiments, the step of subjecting the nanoparticulate metal oxide to sonication together with the at least one surface ligand is performed before, together with, or after the step of subjecting the nanoparticulate metal oxide and the cation exchanged chlorophyll to sonication. Each possibility represents a separate embodiment of the invention.

[0055] In a further aspect of the invention, there is provided a composite material comprising a metal oxide core, coated with an organic coating, wherein the organic coating comprises a chlorophyll and a ligand. In a further aspect of the invention, there is provided a composite material comprising a metal oxide core, coated with an organic coating, wherein the organic coating comprises a chlorophyll and a fatty acid ligand.

[0056] It is to be understood that any embodiment above, may equally apply to the composite material comprising the metal oxide core, coated with the organic coating, wherein the organic coating comprises the chlorophyll and the fatty acid ligand

[0057] According to some embodiments, the chlorophyll is a cation exchanged chlorophyll, which comprises chelated metal cation.

[0058] According to some embodiments, the chelated metal cation is a divalent cation. According to some embodiments, the chelated metal cation is Cu+2.

[0059] According to some embodiments, the metal oxide core comprises a metal oxide selected from the group consisting of CeO2, AlO3 and MnO2. According to some embodiments, the metal oxide core is particulate, and has a particle size in the range of 1 nm to 500 nm. According to some embodiments, the metal oxide core is in the form of a quantum dot having particle size in the range of 1 nm to 20 nm.

[0060] According to some embodiments, the fatty acid ligand comprises an oleic acid.

[0061] According to some embodiments, the composite material is prepared by a method comprising subjecting a core metal salt to sonication to form a nanoparticulate metal oxide; subjecting the nanoparticulate metal oxide to sonication together with a chlorophyll; and subjecting the nanoparticulate metal oxide to sonication together with a fatty acid; wherein the step of subjecting the nanoparticulate metal oxide to sonication together with the fatty acid is performed before, together with, or after the step of subjecting the nanoparticulate metal oxide and the chlorophyll to sonication, to form the composite material.

[0062] According to some embodiments, the method further comprises a step of contacting Mg-chlorophyll with a chelating metal salt to form the cation exchanged chlorophyll, wherein the forming of the cation exchanged chlorophyll is performed before the step of subjecting the nanoparticulate metal oxide and cation exchanged chlorophyll to sonication.

[0063] In a further aspect of the invention, there is provided a composite material comprising a metal oxide core, coated with an organic coating, wherein the organic coating comprises a chlorophyll and a fatty acid.

[0064] According to some embodiments, the chlorophyll is a cation exchanged chlorophyll.

[0065] According to some embodiments, the composite material is prepared by a method comprising subjecting a core metal salt to sonication to form a nanoparticulate metal oxide; subjecting the nanoparticulate metal oxide to sonication together with a chlorophyll; and subjecting the nanoparticulate metal oxide to sonication together with a fatty acid; wherein the step of subjecting the nanoparticulate metal oxide to sonication together with the fatty acid is performed before, together with, or after the step of subjecting the nanoparticulate metal oxide and the chlorophyll to sonication, to form the composite material.

[0066] According to some embodiments, the method further comprises a step of contacting Mg-chlorophyll with a chelating metal salt to forms the cation exchanged chlorophyll, wherein the step of forming the cation exchanged chlorophyll is performed before the step of subjecting the nanoparticulate metal oxide and cation exchanged chlorophyll to sonication.

[0067] According to some embodiments, there is provided a fuel composition comprising a motor fuel and a fuel additive, wherein the fuel additive comprises a composite material comprising a metal oxide core, coated with an organic coating, wherein the organic coating comprises a chlorophyll.

[0068] According to some embodiments, the composite material comprises the composite material according to the present invention.

[0069] According to some embodiments, the fuel composition comprises a plurality of composite particles having average particle size in the range of 1 nm to 500 nm, including each value and sub-range within the specified range. According to some embodiments, the fuel composition comprises a plurality of composite particles having average particle size in the range of 3 nm to 400 nm, including each value and sub-range within the specified range.

[0070] According to some embodiments, the plurality of composite particles have an average particle size in the range of 3 nm to 300 nm. According to some embodiments, the plurality of composite particles have an average particle size in the range of 5 nm to 200 nm.

[0071] According to some embodiments, the plurality of composite particles are in a form of quantum dots, which have an average particle size in the range of 5 nm to 10 nm. According to some embodiments, the plurality of composite particles are in a form of quantum dots, which have an average particle size in the range of 1 nm to 20 nm. According to some embodiments, the plurality of composite particles are in a form of quantum dots, which have an average particle size in the range of 1 nm to 10 nm. According to some embodiments, the plurality of composite particles are in a form of quantum dots, which have an average particle size in the range of 3 nm to 12 nm. According to some embodiments, the plurality of composite particles are in a form of quantum dots, which have an average particle size in the range of 7 nm to 12 nm.

[0072] According to some embodiments, the plurality of composite particles are in a form of small nanoparticles having an average particle size in the range of 10 nm to 50 nm. According to some embodiments, the plurality of composite particles are in a form of small nanoparticles having an average particle size in the range of 12 nm to 55 nm.

[0073] According to some embodiments, the plurality of composite particles are in a form of nanoparticles having an average particle size in the range of 100 nm to 300 nm. According to some embodiments, the plurality of composite particles are in a form of nanoparticles having an average particle size in the range of 105 nm to 330 nm.

[0074] According to some embodiments, at least 50% of the plurality of composite particles are in a form of quantum dots, which have an average particle size in the range of 5 nm to 7 nm.

[0075] According to some embodiments, the fuel composition is in a form of solution or suspension. Each possibility represents a separate embodiment of the invention.

[0076] According to some embodiments, the motor fuel comprises a hydrocarbon fuel. According to some embodiments, the hydrocarbon fuel comprises diesel fuel. According to some embodiments, the motor fuel comprises diesel fuel. According to some embodiments, the diesel fuel is standard diesel fuel. According to some embodiments, the diesel fuel is untreated diesel fuel.

[0077] According to some embodiments, the fuel composition comprises 1×10−6 gr (0.001 mg) to 25 gr of the composite material per liter of the motor fuel, including each value and sub-range within the specified range. According to some embodiments, the fuel composition comprises 10−4 gr to 1 gr of the composite material per liter of the motor fuel. According to some embodiments, the fuel composition comprises 10−3 gr to 0.04 gr of the composite material per liter of the motor fuel.

[0078] According to some embodiments, the fuel additive comprises a CeO2 core, coated with an organic coating, wherein the organic coating comprises a Cu+2 exchanged chlorophyll and oleic acid; wherein the CeO2 core is particulate in the form of a quantum dot and has a diameter in the range of 1 nm to 4 nm; and wherein the composite material is particulate in the form of a quantum dot and has a diameter in the range of 4 nm to 10 nm.

[0079] According to some embodiments, the composite material is present in the fuel at a concentration of 10−3 gr to 0.04 gr per liter.

[0080] In a further aspect of the invention, there is provided a liquid fuel additive formulation comprising a solvent and a fuel additive, wherein the fuel additive comprises a composite material comprising a metal oxide core, coated with an organic coating, wherein the organic coating comprises a chlorophyll.

[0081] According to some embodiments, the composite material comprises any composite material disclosed herein. According to some embodiments, the liquid fuel additive formulation comprises 0.5% to 10% composite material in the solvent w / v. According to some embodiments, the liquid fuel additive formulation comprises 2% to 6% composite material in the solvent w / v. According to some embodiments, the liquid fuel additive formulation comprises about 4% composite material in the solvent w / v.

[0082] According to some embodiments, the solvent comprises kerosene, TBME, or a mixture thereof.

[0083] Further embodiments and the full scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.BRIEF DESCRIPTION OF THE DRAWINGS

[0084] For a better understanding of the invention and to show how the same may be carried into effect which will now be made, purely by way of example, to the accompanying drawings in which like numerals designate corresponding sections or elements throughout.

[0085] With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred examples of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how several forms of the invention may be embodied in practice. In the accompanying drawings:

[0086] FIG. 1 illustrates a simplified schematic perspective view of a chlorophyll-nanoparticle, according to some embodiments.

[0087] FIG. 2 illustrates a simplified schematic perspective view of a lipophilic chlorophyll-quantum-dot, according to some embodiments.

[0088] FIG. 3 shows absorbance comparison of CeO2-QD (cerium oxide quantum dots; dashed line) versus CeO2-NP (cerium oxide nanoparticles; solid line).

[0089] FIG. 4 shows absorbance comparison of CeO2-QD (cerium oxide quantum dots, long dashes) versus copper-chlorophyl-CeO2-QD (cerium oxide quantum dots coated with copper-modified chlorophyll; solid line) and Cu-chlorophyll (free copper-modified chlorophyll; short dashes).

[0090] FIG. 5 show absorbance comparison of copper chlorophyl bound to CeO2-QD (dashes) versus free copper-chlorophyl (solid line).

[0091] FIG. 6A shows results of oxygen release from diesel compositions: oxygen saturated hexane (dark blue), cerium-oxide quantum dots (light blue), copper-chlorophyl (orange), copper-chlorophyl coated cerium-oxide quantum dots (purple), copper-chlorophyll-cerium-oxide quantum dots (dark green) and copper-chlorophyll-cerium-oxide quantum dots+hexane (light green).

[0092] FIG. 6B shows results of oxygen desorption rates of diesel+hexane (dark orange), diesel+copper-chlorophyll-cerium-oxide quantum dots (brown), diesel+cerium-oxide quantum dots+copper-chlorophyl+hexane (light orange), diesel+copper-chlorophyl (light purple), diesel+cerium-oxide quantum dots (dark purple), and diesel+copper-chlorophyll-cerium-oxide quantum dots+hexane (pink).

[0093] FIG. 7 shows results of oxygen desorption and in Oxygen saturated diesel fuel of the following: copper-chlorophyll-cerium-oxide quantum dots (dark blue), diesel alone (orange), copper-chlorophyll (dark green), cerium-oxide quantum dots (light blue) aerated diesel (purple) and cerium-oxide quantum dots+Magnesium-chlorophyll] (light green).

[0094] FIGS. 8A and 8B show results of temperature (FIG. 8A) and normalized temperature (FIG. 8B) after sample injection and of the following diesel compositions: copper-chlorophyll-cerium-oxide quantum dots (dark blue), diesel alone (orange), copper-chlorophyl (dark green), cerium-oxide quantum dots (light blue) aerated diesel (purple) and cerium-oxide quantum dots+Magnesium-chlorophyll] (light green).

[0095] FIG. 9 shows a Spectrophotometer analysis of Cu-Chlorophyll-CeO-FA-QDs.

[0096] FIGS. 10A-B show results of a Dynamic Light Scattering analyses of Cu-Chlorophyll-CeO-FA-QDs by volume (FIG. 10A) and by number (FIG. 10B).

[0097] FIGS. 11A-C are Transmission Electron Microscopy analyses of Cu-Chlorophyll-CeO-FA-QDs, FIG. 11C is an enlarged view of a portion of FIG. 11B.

[0098] FIGS. 12A-12B show results of fuel consumption per hour (ml) (FIG. 12A) and fuel consumption percent improvement (FIG. 12B) for diesel fuels comprising Cu-Chlorophyll-CeO-FA-QDs additives at a concentration of 1:250,000, 1:125,000, and 1:50,000, respectively, as compared to diesel fuel without additives.

[0099] FIGS. 13A-13B show results of Nox emissions (ppm) (FIG. 13A) and Nox percent reduction (FIG. 13B) for diesel fuels comprising Cu-Chlorophyll-CeO-FA-QDs additives at a concentration of 1:250,000, 1:125,000, and 1:50,000, respectively, as compared to diesel fuel without additives.

[0100] FIGS. 14A-14B show results of particulate matter emissions (mg / m{circumflex over ( )}3) (FIG. 14A) and particulate matter percent reduction (FIG. 14B) for diesel fuels comprising Cu-Chlorophyll-CeO-FA-QDs additives at a concentration of 1:250,000, 1:125,000, and 1:50,000, respectively, as compared to diesel fuel without additives.

[0101] FIGS. 15A-15B show results of hydrocarbon emissions (ppm) (FIG. 15A) and hydrocarbon percent reduction (FIG. 15B) for diesel fuels comprising Cu-Chlorophyll-CeO-FA-QDs additives at a concentration of 1:250,000, 1:125,000, and 1:50,000, respectively, as compared to diesel fuel without additives.

[0102] FIGS. 16A-16B show results of fuel consumption per hour (gram) (FIG. 16A) and fuel consumption percent improvement (FIG. 16B) for untreated diesel fuel comprising Cu-Chlorophyll-CeO-FA-QDs additives at a concentration of 1:125,000 as compared to untreated diesel fuel without additives.

[0103] FIGS. 17A-17B show results of Nox emissions (ppm) (FIG. 17A) and Nox percent reduction (FIG. 17B) for untreated diesel fuels comprising Cu-Chlorophyll-CeO-FA-QDs additives at a concentration of 1:125,000 as compared to untreated diesel fuel without additives.

[0104] FIGS. 18A-18B show results of hydrocarbon emissions (ppm) (FIG. 18A) and hydrocarbon percent reduction (FIG. 18B) for untreated diesel fuels comprising Cu-Chlorophyll-CeO-FA-QDs additives at a concentration 1:125,000 as compared to untreated diesel fuel without additives.

[0105] FIGS. 19A-19B show results of particulate matter emissions (mg / m{circumflex over ( )}3) (FIG. 19A) and particulate matter percent reduction (FIG. 19B) for diesel fuels comprising Cu-Chlorophyll-CeO-FA-QDs additives at a concentration of 1:125,000 as compared to untreated diesel fuel without additives.

[0106] FIGS. 20A-20B show results of the engine temperature (° C.) over the course of the experiment (subtracting the room temperature) for untreated diesel fuel with and without the Cu-Chlorophyll-CeO-FA-QD fuel additives (1:125,000); FIG. 20B shows the temperature difference (ΔT) between the formula with the Cu-Chlorophyll-CeO-FA-QDs additives and the formula without the additives.

[0107] FIG. 21 is a schematic representation of an experimental setup for determination of oxygen saturation.DETAILED DESCRIPTION OF THE PRESENT INVENTION

[0108] In the following description, various aspects of the disclosure will be described. For explanation, specific configurations and details are set forth to provide a thorough understanding of the different aspects of the disclosure. However, it will also be apparent to one skilled in the art that the disclosure may be practiced without specific details being presented herein. Furthermore, well-known features may be omitted or simplified in order not to obscure the disclosure. In the figures, like reference numerals refer to like parts throughout. To avoid undue clutter from having too many reference numbers and lead lines on a particular drawing, some components will be introduced via one or more drawings and not explicitly identified in every subsequent drawing that contains that component.

[0109] The present invention is based on the discovery that a composite material, which comprises a specific metal oxide core, capped with an organic coating can be a highly efficient fuel additive that significantly improves the combustion efficiency of motor fuels (e.g., hydrocarbon fuels, such as diesel fuel).

[0110] Thus, according to some embodiments, the present invention provides a composite material, which comprises a metal oxide core, coated with an organic coating. According to some embodiments, the organic coating comprises a cation exchanged chlorophyll. According to some embodiments, the cation exchanged chlorophyll comprises a chelated metal cation. According to some embodiments, there is provided a composite material comprising a metal oxide core, coated with an organic coating, wherein the organic coating comprises a cation exchanged chlorophyll, which comprises a chelated metal cation. According to some embodiments, the organic coating comprises a surface ligand. According to some embodiments, the surface ligand comprises a fatty acid. According to some embodiments, there is provided a composite material comprising a metal oxide core, coated with an organic coating, wherein the organic coating comprises a chlorophyll and a fatty acid ligand. According to some embodiments, there is provided a composite material comprising a metal oxide core, coated with an organic coating, wherein the organic coating comprises a cation exchanged chlorophyll and a fatty acid ligand, wherein the cation exchanged chlorophyll comprises a chelated metal cation.

[0111] According to some embodiments, the composite material is in a particulate form. According to some embodiments, the composite material comprises a composite particle.

[0112] According to some embodiments, the composite particle has a particle size in the range of 1 nm to 500 nm, including each value and sub-range within the specified range. According to some embodiments, the composite particle has a particle size in the range of 2 nm to 400 nm. According to some embodiments, the composite particle has a particle size in the range of 3 nm to 300 nm. According to some embodiments, the composite particle has a particle size in the range of 4 nm to 300 nm. According to some embodiments, the composite particle has a particle size in the range of 5 nm to 300 nm.

[0113] According to some embodiments, the composite particle is in the form of a nanoparticle. The term “nanoparticle” is defined herein the definitions section.

[0114] According to some embodiments, the nanoparticle has particle size in the range of 100 nm to 300 nm, including each value and sub-range within the specified range.

[0115] According to some embodiments, the composite particle is in the form of small nanoparticle. The term “small nanoparticle” is defined herein the definitions section.

[0116] According to some embodiments, the small nanoparticle has particle size in the range of 10 nm to 50 nm, including each value and sub-range within the specified range.

[0117] According to some embodiments, the composite particle is in the form of quantum dot. The term “quantum dot” is defined herein the definitions section.

[0118] According to some embodiments, the quantum dot has particle size in the range of 3 nm to 10 nm, including each value and sub-range within the specified range. According to some embodiments, the quantum dot has particle size in the range of 4 nm to 10 nm. According to some embodiments, the quantum dot has particle size in the range of 5 nm to 10 nm.

[0119] Referring now to the core of the present composite material. According to some embodiments, the core is a metal oxide core.

[0120] It is hypothesized that the metal oxide core stabilizes the chlorophyll coating, which in it turn, is responsible for dioxygen binding. Indeed, as shown in the Examples, chlorophyl alone did not show significant decrease of fuel consumption or increase of combustion efficiency, and is therefore not an efficient fuel additive on its own.

[0121] In addition to the particle size of the composite material of the present invention itself, according to some embodiments, the metal oxide core can be defined by its size.

[0122] According to some embodiments, the metal oxide core is particulate.

[0123] According to some embodiments, the metal oxide core has a particle size in the range of 1 nm to 500 nm, including each value and sub-range within the specified range. According to some embodiments, the metal oxide core has a particle size in the range of 3 nm to 500 nm. According to some embodiments, the metal oxide core has a particle size in the range of 5 nm to 500 nm. According to some embodiments, the metal oxide core has a particle size in the range of 10 nm to 500 nm. According to some embodiments, the metal oxide core has a particle size in the range of 2 nm to 400 nm. According to some embodiments, the metal oxide core has a particle size in the range of 4 nm to 400 nm. According to some embodiments, the metal oxide core has a particle size in the range of 10 nm to 400 nm. According to some embodiments, the metal oxide core has a particle size in the range of 3 nm to 300 nm. According to some embodiments, the metal oxide core has a particle size in the range of 10 nm to 300 nm.

[0124] According to some embodiments, the metal oxide core is in the form of nanoparticles. The term “nanoparticles” is defined herein the definitions section.

[0125] According to some embodiments, the nanoparticles have particle size in the range of 100 nm to 300 nm, including each value and sub-range within the specified range. According to some embodiments, the nanoparticles have particle size in the range of 75 nm to 500 nm. According to some embodiments, the nanoparticles have particle size in the range of 75 nm to 200 nm. According to some embodiments, the nanoparticles have particle size in the range of 100 nm to 500 nm. According to some embodiments, the nanoparticles have particle size in the range of 100 nm to 200 nm. According to some embodiments, the nanoparticles have particle size in the range of 50 nm to 400 nm. According to some embodiments, the nanoparticles have particle size in the range of 50 nm to 300 nm. According to some embodiments, the nanoparticles have particle size in the range of 50 nm to 250 nm. According to some embodiments, the nanoparticles have particle size in the range of 50 nm to 200 nm. According to some embodiments, the nanoparticles have particle size in the range of 50 nm to 150 nm.

[0126] According to some embodiments, the metal oxide core is in the form of small nanoparticles. The term “small nanoparticles” is defined herein the definitions section.

[0127] According to some embodiments, the small nanoparticles have particle size in the range of 10 nm to 50 nm, including each value and sub-range within the specified range. According to some embodiments, the small nanoparticles have particle size in the range of 10 nm to 75 nm. According to some embodiments, the small nanoparticles have particle size in the range of 10 nm to 40 nm. According to some embodiments, the small nanoparticles have particle size in the range of 10 nm to 30 nm. According to some embodiments, the small nanoparticles have particle size in the range of 10 nm to 25 nm. According to some embodiments, the small nanoparticles have particle size in the range of 10 nm to 20 nm. According to some embodiments, the small nanoparticles have particle size in the range of 15 nm to 75 nm. According to some embodiments, the small nanoparticles have particle size in the range of 15 nm to 50 nm. According to some embodiments, the small nanoparticles have particle size in the range of 15 nm to 30 nm. According to some embodiments, the small nanoparticles have particle size in the range of 20 nm to 60 nm. According to some embodiments, the small nanoparticles have particle size in the range of 20 nm to 50 nm. According to some embodiments, the small nanoparticles have particle size in the range of 20 nm to 40 nm. According to some embodiments, the small nanoparticles have particle size in the range of 25 nm to 50 nm.

[0128] According to some embodiments, the metal oxide core is in the form of quantum dots. The term “quantum dots” is defined herein the definitions section.

[0129] According to some embodiments, the quantum dots have particle size in the range of 3 nm to 10 nm, including each value and sub-range within the specified range. According to some embodiments, the quantum dots have particle size in the range of 1 nm to 20 nm. According to some embodiments, the quantum dots have particle size in the range of 1 nm to 10 nm. According to some embodiments, the quantum dots have particle size in the range of 1 nm to 3 nm. According to some embodiments, the quantum dots have particle size in the range of 1 nm to 4 nm. According to some embodiments, the quantum dots have particle size in the range of 1 nm to 5 nm. According to some embodiments, the quantum dots have particle size in the range of 1 nm to 7 nm. According to some embodiments, the quantum dots have particle size in the range of 2 nm to 12 nm. According to some embodiments, the quantum dots have particle size in the range of 2 nm to 8 nm. According to some embodiments, the quantum dots have particle size in the range of 2 nm to 6 nm. According to some embodiments, the quantum dots have particle size in the range of 5 nm to 15 nm. According to some embodiments, the quantum dots have particle size in the range of 5 nm to 10 nm. According to some embodiments, the quantum dots have particle size in the range of 3 nm to 12 nm. According to some embodiments, the quantum dots have particle size in the range of 3 nm to 9 nm. According to some embodiments, the quantum dots have particle size in the range of 3 nm to 7 nm. According to some embodiments, the quantum dots have particle size in the range of 4 nm to 8 nm. According to some embodiments, the quantum dots have particle size in the range of 4 nm to 6 nm.

[0130] According to some embodiments, the metal oxide core is in a form selected from the group consisting of: nanoparticles, small nanoparticles and quantum dots.

[0131] According to some embodiments, the metal oxide core comprises a metal oxide selected from the group consisting of: cerium oxide, aluminum oxide, titanium oxide, zinc oxide, copper oxide, iron oxide, manganese oxide, cobalt oxide, nickel oxide, vanadium oxide, molybdenum oxide, tungsten oxide, chromium oxide and a combination thereof. Each possibility represents a separate embodiment of the invention.

[0132] According to some embodiments, the metal oxide comprises cerium oxide. The term “cerium oxide” includes, without limitation, cerium(III) oxide, Ce2O3, cerium(III, IV) oxide, Ce3O4 and cerium(IV) oxide and CeO2, also known as ceric oxide. According to some embodiments, the metal oxide comprises CeO2. According to some embodiments, the cerium oxide comprises CeO2.

[0133] Cerium oxide (e.g., CeO2) quantum dots are known for their excellent redox properties and oxygen storage capacity. They readily transition between Ce+4 and Ce+3 oxidation states, making them highly effective in catalyzing the oxidation of CO and the reduction of NOx. CeO2 QDs are widely used in automotive catalytic converters and other applications requiring CO oxidation and NOx reduction. The excellent redox properties and oxygen storage capacity render the cerium oxide CeO2 QDs are among the most efficient catalysts for CO oxidation and NOx reduction, achieving up to 90-95% conversion rates for CO oxidation in practical applications.

[0134] According to some embodiments, the metal oxide comprises aluminum oxide. The term “aluminum oxide” includes, without limitation, aluminum(I) oxide, Al2O, aluminum(II) oxide, AlO and aluminum(III) oxide, AlO3, the most common form of aluminum oxide. According to some embodiments, the metal oxide comprises AlO3. According to some embodiments, the aluminum oxide comprises AlO3.

[0135] According to some embodiments, the metal oxide comprises titanium oxide. The term “titanium oxide” includes, without limitation, titanium dioxide, TiO2, titanium(II) oxide, TiO titanium(III) oxide, T2O3, as well as Ti3O, Ti2O, TinO2n-1 where n ranges from 3-9 inclusive and non-stoichiometric titanium oxides. According to some embodiments, the metal oxide comprises TiO2. According to some embodiments, the titanium oxide comprises TiO2.

[0136] Titanium oxide (e.g., TiO2) QDs exhibit strong photocatalytic activity under UV light. Their ability to generate reactive oxygen species makes them suitable for the degradation of NOx. TiO2 QDs are used in environmental purification processes, including air and water treatment, due to their photocatalytic properties. TiO2 QDs exhibit strong photocatalytic activity under UV light, making them effective for NOx degradation. Their efficiency in CO oxidation is also notable but can be limited by light availability. The typical efficiency range of TiO2 QDs is in the range of 70-90% for NOx degradation under UV light, displaying a somewhat lower efficiency for CO oxidation without light.

[0137] According to some embodiments, the metal oxide comprises zinc oxide. The term “zinc oxide” includes, without limitation, zinc(II) oxide, ZnO, the most common form of zinc oxide. According to some embodiments, the metal oxide comprises ZnO. According to some embodiments, the zinc oxide comprises ZnO.

[0138] Zinc oxide (e.g., ZnO) QDs have high electron mobility and excellent photocatalytic properties. They are effective in both the oxidation of CO and the degradation of NOx under UV light. ZnO QDs are employed in various photocatalytic applications, including environmental remediation and air purification. ZnO QDs have good photocatalytic properties, particularly under UV light, but their efficiency for CO oxidation may not be as high as some other metal oxides. The typical Efficiency Range of titanium oxide QDs is in the range of 60-85% for NOx degradation under UV light.

[0139] According to some embodiments, the metal oxide comprises copper oxide. The term “copper oxide” includes, without limitation, copper(I) oxide, Cu2O, copper(II) oxide, CuO and copper(I, II) oxide, Cu4O3. According to some embodiments, the metal oxide comprises CuO. According to some embodiments, the copper oxide comprises CuO.

[0140] Copper oxide (e.g., CuO) QDs possess good catalytic properties for CO oxidation and NOx reduction due to their ability to facilitate redox reactions. CuO QDs are used in catalytic converters and other catalytic processes aimed at reducing CO and NOx emissions. CuO QDs have good catalytic properties for both CO oxidation and NOx reduction. They are particularly effective in combination with other catalysts. The typical efficiency of copper oxide is in the range of 75-90% for CO oxidation and NOx reduction in optimal conditions.

[0141] According to some embodiments, the metal oxide comprises iron oxide. The term “iron oxide” includes, without limitation, iron(II) oxide, FeO, iron(II, III) oxide, Fe3O4 and iron(III) oxide, Fe2O3. According to some embodiments, the metal oxide comprises Fe3O4. According to some embodiments, the iron oxide comprises Fe3O4.

[0142] Iron oxide (e.g., Fe3O4) QDs have magnetic properties and exhibit good catalytic activity for CO oxidation and NOx reduction, especially when combined with other metal oxides. Fe3O4 QDs are used in various catalytic and environmental applications, including heterogeneous catalysis and pollution control. Fe3O4 QDs are effective catalysts, especially when combined with other metal oxides, but their standalone efficiency can vary. The typical efficiency of iron oxide QDs is in the range of 65-80% for CO oxidation and NOx reduction.

[0143] According to some embodiments, the metal oxide comprises manganese oxide. The term “manganese oxide” includes, without limitation, manganese(II) oxide, MnO, manganese(II, III) oxide, Mn3O4, manganese(III) oxide, Mn2O3, manganese dioxide, MnO2, manganese(VI) oxide, MnO3, and manganese(VII) oxide, Mn2O7. According to some embodiments, the metal oxide comprises MnO2. According to some embodiments, the manganese oxide comprises MnO2.

[0144] Manganese oxide (e.g., MnO2) QDs have strong oxidative properties and are effective in catalyzing the oxidation of CO and the reduction of NOx. They readily transition between different oxidation states, enhancing their catalytic activity. MnO2 QDs are used in environmental remediation and catalytic converters due to their high redox activity. MnO2 QDs are very effective due to their strong oxidative properties and ability to transition between different oxidation states. The typical efficiency of manganese oxide QDs is in the range of 85-95% for CO oxidation and NOx reduction.

[0145] According to some embodiments, the metal oxide comprises cobalt oxide. The term “cobalt oxide” includes, without limitation, cobalt(II) oxide, CoO, cobalt(III) oxide, Co2O3 and cobalt(II, III) oxide, Co3O4. According to some embodiments, the metal oxide comprises Co3O4. According to some embodiments, the cobalt oxide comprises Co3O4.

[0146] Cobalt oxide (e.g., Co3O4) QDs exhibit high catalytic activity for both CO oxidation and NOx reduction. They are known for their stability and ability to function effectively at lower temperatures compared to some other metal oxides. Co3O4 QDs are used in air purification systems and catalytic converters. Co3O4 QDs exhibit high catalytic activity and are effective at lower temperatures, making them efficient for both CO oxidation and NOx reduction. The typical efficiency of cobalt oxide QDs is in the range of 80-95% for both CO oxidation and NOx reduction.

[0147] According to some embodiments, the metal oxide comprises nickel oxide. The term “nickel oxide” includes, without limitation, nickel(II) oxide, NiO and nickel(III) oxide, Ni2O3. According to some embodiments, the metal oxide comprises NiO. According to some embodiments, the nickel oxide comprises NiO.

[0148] Nickel oxide (e.g., NiO) QDs have good catalytic properties and can facilitate the oxidation of CO and degradation of NOx. They are particularly noted for their ability to work in a variety of environmental conditions. NiO QDs are employed in environmental catalysis and energy conversion processes. NiO QDs have good catalytic properties and can perform well in various environmental conditions. The typical efficiency of nickel oxide QDs is in the range of 70-90% for CO oxidation and NOx reduction.

[0149] According to some embodiments, the metal oxide comprises vanadium oxide. The term “vanadium oxide” includes, without limitation, vanadium(II) oxide, VO, vanadium(III) oxide, V2O3, vanadium(IV) oxide, VO2, and vanadium(V) oxide, V2O5. According to some embodiments, the metal oxide comprises V2O5. According to some embodiments, the vanadium oxide comprises V2O5.

[0150] Vanadium oxide (e.g., V2O5) QDs are effective catalysts for the oxidation of CO and the reduction of NOx due to their strong oxidative properties and ability to undergo multiple oxidation states. V2O5 QDs are used in industrial catalytic processes, including the selective catalytic reduction (SCR) of NOx. V2O5 QDs are known for their strong oxidative properties and high catalytic efficiency. The typical efficiency of vanadium oxide QDs is in the range of 85-95% for NOx reduction and CO oxidation in optimal conditions.

[0151] According to some embodiments, the metal oxide comprises molybdenum oxide. The term “molybdenum oxide” includes, without limitation, molybdenum(IV) oxide, MoO2, and molybdenum(VI) oxide, MoO3. According to some embodiments, the metal oxide comprises MoO3. According to some embodiments, the molybdenum oxide comprises MoO3.

[0152] Molybdenum oxide (e.g., MoO3) QDs have high catalytic activity and are known for their ability to oxidize CO and reduce NOx. Their unique electronic properties make them effective in various catalytic applications. MoO3 QDs are used in catalytic converters and other industrial catalysis applications. MoO3 QDs have good catalytic activity and are effective in various applications. The typical efficiency of molybdenum oxide QDs is in the range of 75-90% for CO oxidation and NOx reduction.

[0153] According to some embodiments, the metal oxide comprises tungsten oxide. The term “tungsten oxide” includes, without limitation, tungsten(III) oxide, W2O3, tungsten(IV) oxide, WO2 and tungsten(VI) oxide, WO3. According to some embodiments, the metal oxide comprises AlO3. According to some embodiments, the tungsten oxide comprises WO3.

[0154] Tungsten oxide (e.g., WO3) QDs exhibit strong photocatalytic activity and are effective in the oxidation of CO and degradation of NOx under UV or visible light. WO3 QDs are used in photocatalytic applications, including air and water purification systems. WO3 QDs are effective under UV or visible light, particularly for photocatalytic applications. The typical efficiency of tungsten oxide QDs is in the range of 70-90% for NOx degradation under light conditions.

[0155] According to some embodiments, the metal oxide comprises chromium oxide. The term “chromium oxide” includes, without limitation, chromium(II) oxide, CrO, chromium(III) oxide, Cr2O3, chromium dioxide CrO2, and chromium(VI) oxide, CrO3. According to some embodiments, the metal oxide comprises Cr2O3. According to some embodiments, the chromium oxide comprises Cr2O3.

[0156] Chromium oxide (e.g., Cr2O3) QDs have excellent thermal stability and catalytic properties, making them suitable for high-temperature applications involving CO oxidation and NOx reduction. Cr2O3 QDs are used in industrial catalysis and environmental remediation processes. Cr2O3 QDs are stable and effective in high-temperature applications but may have lower efficiency compared to other metal oxides. The typical efficiency of chromium oxide XDs is in the range of 65-85% for CO oxidation and NOx reduction.

[0157] According to some embodiments, the metal oxide core comprises a metal oxide selected from the group consisting of: CeO2, AlO3, TiO2, ZnO, CuO, Fe3O4, MnO2, Co3O4, NiO, V2O5, MoO3, WO3, Cr2O3 and a combination thereof. Each possibility represents a separate embodiment of the invention.

[0158] According to some embodiments, the metal oxide core comprises a metal oxide selected from the group consisting of: CeO2, AlO3 and MnO2. According to some embodiments, the metal oxide comprises CeO2. According to some embodiments, the metal oxide consists of CeO2.

[0159] Reference is now made to the coating of the present composite material. According to some embodiments, the coating is an organic coating, comprising a cation exchanged chlorophyll. According to some embodiments, the cation exchanged chlorophyll comprises a chelated metal cation. The term “cation exchanged chlorophyll” is defined in the definitions section herein.

[0160] It is hypothesized that the chlorophyll binds the chelated metal cation using its chlorin ring, wherein the chelated metal cation is responsible for dioxygen binding. The dioxygen binding allows significant improvement of combustion efficiency of fuel compositions, in which the composite material of the present invention is incorporated.

[0161] In addition it is hypothesized that the chlorophyll coating prevents aggregation of the metal oxide nanoparticles.

[0162] According to some embodiments, cation exchanged chlorophyll is a natural or synthetic chlorophyll. According to some embodiments, cation exchanged chlorophyll is a natural chlorophyll. According to some embodiments, cation exchanged chlorophyll is a synthetic chlorophyll. It is to be understood that reference to “natural chlorophyll” is intended to mean that the organic structure thereof with a bound Mg+2 is naturally occurring, whereas the cation exchanged natural chlorophyll is not required to be natural per se, and, for example can be the cation exchanged product of a natural chlorophyll.

[0163] According to some embodiments, cation exchanged chlorophyll is selected from the group consisting of: chlorophyll a, chlorophyll b, chlorophyll c1, chlorophyll c2, chlorophyll c3, chlorophyll d, chlorophyll f and a combination thereof. Each possibility represents a separate embodiment of the invention.

[0164] According to some embodiments, the chlorophyll comprises chlorophyll a. According to some embodiments, the chlorophyll comprises chlorophyll b. According to some embodiments, the chlorophyll comprises chlorophyll c1. According to some embodiments, the chlorophyll comprises chlorophyll c2. According to some embodiments, the chlorophyll comprises chlorophyll c3. According to some embodiments, the chlorophyll comprises chlorophyll d. According to some embodiments, the chlorophyll comprises chlorophyll f.

[0165] According to some embodiments, cation exchanged chlorophyll is selected from the group consisting of: synthetic chlorophyll comprises modified chlorophyll c1 bound to long chain alcohol of C4-C24 carbon long at the carboxylic group of chlorophyll c1, modified chlorophyll c2 bound to long chain alcohol of C4-C24 carbon long at the carboxylic group of the chlorophyll, synthetic cation exchanged chlorophyll, and a combination of synthetic and native cation exchanged chlorophyll thereof.

[0166] According to some embodiments, the chelated metal cation has a substantially equal or stronger binding to dioxygen than Mg+2. According to some embodiments, the chelated metal cation has a stronger binding to dioxygen than Mg+2. According to some embodiments, the chelated metal cation can create stronger and more stable oxo center and superoxide (O2) bond as compared to Mg+2.

[0167] According to some embodiments, the chelated metal cation is selected from the group consisting of: cobalt cation, copper cation, iron cation, manganese cation, nickel cation, ruthenium cation, rhodium cation, silver cation, vanadium cation, chromium cation, zinc cation, nickel cation, cerium cation, tungsten cation, molybdenum cation, rhenium cation, iridium cation, palladium cation, osmium cation, technetium cation, platinum cation, titanium cation, zirconium cation, hafnium cation, niobium cation, tantalum cation, gallium cation, indium cation, tin cation, lead cation, antimony cation, bismuth cation, thulium cation, thorium cation, boron cation arsenic cation and a combination thereof. Each possibility represents a separate embodiment of the invention.

[0168] According to some specific embodiments, the chelated metal cation comprises a copper cation. According to some specific embodiments, the chelated metal cation consists of a copper cation.

[0169] Metal ions bind dioxygen through coordination chemistry, forming metal-oxygen complexes. This process typically involves the following steps:

[0170] Coordination: Dioxygen coordinates to the metal center through its lone pairs of electrons.

[0171] Electron Transfer: There may be partial or complete electron transfer from the metal ion to the dioxygen molecule, leading to different oxidation states of both the metal and the dioxygen.

[0172] Bond Formation: This interaction can lead to the formation of metal-oxygen bonds, which can be of various types, including side-on (η2) or end-on (η1) coordination.

[0173] Without wishing to be bound by any theory of mechanism of action, the nature of the metal ion, its oxidation state, and the surrounding ligands significantly influence the binding mode and stability of the metal-dioxygen complex. In synthetic chemistry, metal-dioxygen complexes are vital for catalysis, especially in oxidation reactions. They enable the activation of dioxygen, facilitating its use as an oxidizing agent in various chemical transformations.

[0174] Reference is now made to each of the metal cations specified herein.Iron (Fe)

[0175] In hemoglobin and myoglobin, iron is coordinated in a heme group, a porphyrin ring that allows iron to bind dioxygen reversibly. The iron ion switches between the Fe+2 (ferrous) state when binding O2 and Fe+3 (ferric) state when releasing O2. In the Fe+2 state, the iron ion binds dioxygen in a bent end-on configuration, forming an Fe—Fe+2 complex. The bond is partially covalent and partially ionic, allowing for reversible binding and release of dioxygen.Copper (Cu)

[0176] In hemocyanin, found in some invertebrates, dioxygen binds to two copper ions (Cu+2) within a protein complex. The resulting Cu+2—O2—Cu+2 complex facilitates oxygen transport. Dioxygen can bind side-on (η2) to each copper ion, forming a bridged peroxo (O2−2) species. The complex undergoes a color change from colorless to blue upon binding dioxygen.Cobalt (Co)

[0177] Vitamin B12 (Cobalamin): while cobalamin doesn't directly bind dioxygen, cobalt in a +3 oxidation state is involved in oxygen-dependent enzymatic reactions. Some synthetic cobalt complexes can reversibly bind dioxygen, similar to hemoglobin, through end-on coordination.Manganese (Mn)

[0178] Manganese-containing enzymes, like Superoxide Dismutase (Mn-SOD), catalyze the conversion of superoxide radicals (O2−) to dioxygen and hydrogen peroxide, protecting cells from oxidative damage. Manganese in different oxidation states (Mn2+ / Mn3+) can facilitate redox reactions involving dioxygen and reactive oxygen species.Nickel (Ni)

[0179] Nickel-containing enzymes like urease do not directly bind dioxygen but participate in reactions that involve oxygen transfer, such as the hydrolysis of urea.Ruthenium (Ru) and Rhodium (Rh)

[0180] Synthetic complexes od Ru and Rh bind dioxygen, catalysis for oxidation reactions.Silver (Ag) and Platinum (Pt)

[0181] Silver and platinum complexes bind and activate dioxygen, primarily in catalytic applications.Vanadium (V)

[0182] Vanadium-dependent Haloperoxidases are enzymes that contain vanadium and bind dioxygen to catalyze the formation of halogenated organic compounds. Vanadium ions in the +4 and +5 oxidation states can facilitate the activation of dioxygen, forming vanadium-peroxo species that participate in halogenation reactions.Chromium (Cr)

[0183] Chromium complexes bind dioxygen, used in oxidation catalysis.Zinc Zn

[0184] Carbonic anhydrase plays a crucial role in enzymes like carbonic anhydrase, which facilitate the rapid interconversion of carbon dioxide and water to bicarbonate and protons.Nickel (Ni)

[0185] Nickel-containing oxygenases are enzymes that contain nickel and participate in oxygenation reactions. Nickel ions in these enzymes can facilitate the activation of dioxygen, often forming superoxo or peroxo intermediates.Lanthanides (e.g., Cerium, Ce)

[0186] Cerium complexes bind dioxygen, particularly in oxidation reactions and materials science. Cerium in the +3 or +4 oxidation state forms coordination complexes with dioxygen, used in catalytic oxidation processes.Tungsten (W)

[0187] Enzymes that contain tungsten, such as aldehyde oxidoreductase, participate in oxidation reactions involving oxygen. Tungsten ions can facilitate redox reactions, often involving oxygen transfer to organic substrates.Molybdenum (Mo)

[0188] Molybdenum-dependent enzymes are enzymes like xanthine oxidase that contain molybdenum and are involved in oxygen transfer reactions. Molybdenum ions in these enzymes can facilitate the activation of dioxygen, leading to the formation of reactive oxygen species used in metabolic processes.Rhenium (Re)

[0189] Rhenium complexes can bind dioxygen, and are used in oxidation catalysis.Iridium Ir

[0190] Iridium complexes can bind dioxygen, and are used in advanced oxidation catalysis.Palladium (Pd)

[0191] Palladium complexes can bind dioxygen, and are used in catalytic oxidation reactions.Osmium (Os)

[0192] Osmium can form dioxygen complexes, which are used in oxidation catalysis.Technetium (Tc)

[0193] Technetium complexes can bind dioxygen in coordination complexes.Silver (Ag)

[0194] Silver complexes can bind dioxygen, particularly in coordination complexes used in catalysis.Platinum (Pt)

[0195] Platinum complexes can bind dioxygen, particularly in oxidation catalysis.Titanium (Ti)

[0196] Titanium complexes can form complexes with dioxygen, particularly in the context of materials science and catalysis. Titanium in the +3 or +4 oxidation state can form side-on (η2) or end-on (η1) peroxo complexes, facilitating the activation of dioxygen for various oxidation reactions.Zirconium (Zr)

[0197] Zirconium complexes can bind dioxygen in coordination complexes, used in catalysis and materials science.Hafnium (Hf)

[0198] Hafnium complexes can form dioxygen complexes, similar to zirconium, used in advanced materials and catalysis.Niobium (Nb)

[0199] Niobium complexes: bind dioxygen, particularly in synthetic and catalytic applications.Tantalum (Ta)

[0200] Tantalum can form complexes with dioxygen, which are used in catalysis and materials science.Gallium (Ga)

[0201] Gallium complexes can bind dioxygen in coordination complexes, explored in materials science.Indium (In)

[0202] Indium complexes can form complexes with dioxygen, used in organometallic chemistry and catalysis.Tin Sn

[0203] Tin complexes can bind dioxygen, particularly in synthetic applications.Lead Pb

[0204] Lead complexes can form coordination complexes with dioxygen.Antimony (Sb)

[0205] Antimony complexes can bind dioxygen in synthetic contexts, as studied in organometallic chemistry.Bismuth (Bi)

[0206] Bismuth complexes can form dioxygen complexes, used in catalysis and materials applications.Thulium (Tm)

[0207] Thulium complexes can bind dioxygen in coordination complexes, which are used in advanced materials science.Thorium (Th)

[0208] Thorium complexes can bind dioxygen, particularly in nuclear chemistry and materials science.Boron B

[0209] Boron, particularly in borane compounds, interact with dioxygen.Arsenic (As)

[0210] Arsenic can bind dioxygen in coordination complexes. Arsenic forms stable dioxygen complexes, facilitating oxidation reactions.

[0211] As the natural chlorophylls include a divalent Mg+2 cation, it may be more convenient to exchange the Mg+2 with another divalent cation.

[0212] According to some embodiments, the chelated metal cation is a divalent metal cation.

[0213] According to some embodiments, the chelated metal cation is selected from the group consisting of: Co+2, Cu+2, Mn+2, Fe+2, Zn+2. Each possibility represents a separate embodiment of the invention. According to some embodiments, the chelatedmetal cation comprises Cu+2. According to some embodiments, the chelatedmetal cation comprises Co+2. According to some embodiments, the chelatedmetal cation comprises Mn+2. According to some embodiments, the chelatedmetal cation comprises Fe+2. According to some embodiments, the chelatedmetal cation comprises Zn+2.

[0214] According to some embodiments, the composite particle is in a form selected from the group consisting of nanoparticles, small nanoparticles and quantum dots.

[0215] Reference is now made to additional components, according to some embodiments, of the present composite material, which are surface ligand(s).

[0216] Without wishing to be bound by any theory of mechanism of action, surface ligands may play a crucial role in stabilizing nanoparticulate colloids, such as colloidal quantum dots, preventing agglomeration, and ensuring dispersibility in liquid media (e.g., organic liquid mixtures, such as solvents or and fuel compositions). Ligands can also impact the electronic properties and biocompatibility of quantum dots. Selecting the best surface ligands for quantum dots (QDs) nanoparticles depends on the intended application and the desired properties, such as stability, solubility, and optical properties.

[0217] According to some embodiments, the composite material further comprises at least one surface ligand. According to some embodiments, the at least one surface ligand is selected from the group consisting of: a carboxylic acid, an amine, an alcohol, a thiol, a phosphine, a phosphine oxide and a combination thereof. Each possibility represents a separate embodiment of the invention.

[0218] According to some embodiments, the composite material comprises at least one carboxylic acid ligand. According to some embodiments, the at least one surface ligand comprises at least one carboxylic acid ligand.

[0219] According to some embodiments, the carboxylic acid comprises a saturated carboxylic acid, an unsaturated carboxylic acid or both. The terms “saturated carboxylic acid” and “unsaturated carboxylic acid” are as defined herein in the definitions section.

[0220] According to some embodiments, the carboxylic acid ligand comprises at least one saturated fatty acid. The term “fatty acid” is as defined herein in the definitions section.

[0221] According to some embodiments, the saturated fatty acid is selected from the group consisting of: caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid and a combination thereof. Each possibility represents a separate embodiment of the invention.

[0222] According to some embodiments, the carboxylic acid ligand comprises at least one unsaturated fatty acid. According to some embodiments, the unsaturated fatty acid is selected from the group consisting of: arachidonic acid, docosahexaenoic acid, eicosapentaenoic acid, elaidic acid, erucic acid linoleic acid, linoelaidic acid, α-linolenic acid, myristoleic acid, oleic acid, palmitoleic acid, sapienic acid, vaccenic acid and a combination thereof. Each possibility represents a separate embodiment of the invention.

[0223] According to some embodiments, the carboxylic acid ligand comprises a C4-C28 fatty acid.

[0224] According to some embodiments, the carboxylic acid ligand is selected from the group consisting of: oleic acid, palmitic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, elaidic acid, erucic acid linoleic acid, linoelaidic acid, α-linolenic acid, myristoleic acid, palmitoleic acid, sapienic acid, vaccenic acid and a combination thereof. Each possibility represents a separate embodiment of the invention.

[0225] The chemical structures of each of the specific carboxylic acids referred herein are known in the art.

[0226] According to some embodiments, the carboxylic acid ligand comprises oleic acid, palmitic acid or both. According to some embodiments, the carboxylic acid ligand comprises oleic acid. According to some embodiments, the surface ligand is oleic acid.

[0227] Specifically, without wishing to be bound by any theory of mechanism of action, oleic acid, CH3—(CH2)7—CH═CH—(CH2)7—COOH or (9Z)-Octadec-9-enoic acid, is a long-chain unsaturated carboxylic acid that can bind strongly to the surface of quantum dots, providing excellent solubility in non-polar solvents, commonly used in the synthesis of QDs.

[0228] According to some embodiments, the composite material comprises at least one amine ligand. The term “amine” is as defined herein in the definitions section. According to some embodiments, the at least one surface ligand comprises at least one amine ligand.

[0229] According to some embodiments, the amine is a primary amine. Primary amines include, but not limited to: oleylamine, butylamine, methylamine, ethylenediamine, amino acids (other than proline) and aniline.

[0230] According to some embodiments, the amine is a secondary amine. Secondary amines include, but not limited to: dimethylamine, diphenylamine and proline

[0231] According to some embodiments, the amine is a tertiary amine. Tertiary amines include, but not limited to: triethylamine and trimethylamine.

[0232] According to some embodiments, the amine ligand is selected from the group consisting of: oleylamine, butylamine, methylamine, ethylenediamine, dimethylamine, diphenylamine, an amino acid, biogenic amines, triethylamine, trimethylamine, aniline imidazole, pyridine, pyrazole, pyrole, pyroline, piperidine, and a combination thereof. Each possibility represents a separate embodiment of the invention.

[0233] The chemical structures of each of the specific amines referred herein are known in the art.

[0234] According to some embodiments, the amine ligand comprises oleylamine, butylamine, ethylenediamine or a combination thereof.

[0235] Specifically, without wishing to be bound by any theory of mechanism of action, ethylenediamine can act both as a ligand and as a solvent in the synthesis of QDs. It is good for controlling particle size and morphology, helps in stabilizing the QDs and can be easily exchanged with other functional ligands.

[0236] According to some embodiments, the composite material comprises at least one alcohol ligand. The term “alcohol” is as defined herein in the definitions section. According to some embodiments, the at least one surface ligand comprises at least one alcohol ligand.

[0237] According to some embodiments, the alcohol ligand comprises a C1-C24 alcohol.

[0238] According to some embodiments, alcohol is a monohydric alcohol. Monohydric alcohols include, but not limited to: methanol, ethanol, propanol, butanol, pentanol, hexanol, octanol, decanol, hexadecanol, allyl alcohol, and geraniol.

[0239] According to some embodiments, alcohol is a polyhydric alcohol. polyhydric alcohols include, but not limited to: ethylene glycol, propylene glycol, and glycerol.

[0240] According to some embodiments, the alcohol ligand is selected from the group consisting of ethylene glycol, propylene glycol, glycerol, methanol, ethanol, propanol, butanol, pentanol, hexanol, octanol, decanol, hexadecanol, allyl alcohol, geraniol, and a combination thereof. Each possibility represents a separate embodiment of the invention.

[0241] The chemical structures of each of the specific alcohols referred herein are known in the art.

[0242] Specifically, without wishing to be bound by any theory of mechanism of action, ethylene glycol can act both as a ligand and as a solvent in the synthesis of QDs. It is good for controlling particle size and morphology, helps in stabilizing the QDs and can be easily exchanged with other functional ligands.

[0243] According to some embodiments, the composite material comprises at least one thiol ligand. The term “thiol” is as defined herein in the definitions section. According to some embodiments, the at least one surface ligand comprises at least one thiol ligand.

[0244] Without wishing to be bound by any theory of mechanism of action, thiols (e.g., 1-dodecanethiol) can bind strongly to the surface of the composite material, e.g., to the surface of the particle. They can be used for their strong anchoring ability, and be good for stabilizing coated particles in non-polar organic media, such as hydrocarbon fuels.

[0245] According to some embodiments, the thiol ligand is 1-dodecanethiol, thioglycolic acid or both. Each possibility represents a separate embodiment of the invention.

[0246] Thioglycolic acid, HSCH2COOH, also known as mercaptoacetic acid, may be regarded as a thiol and / or as a carboxylic acid according to the present definitions. It is not, however, considered to be a fatty acid.

[0247] According to some embodiments, the composite material comprises at least one phosphine ligand. The term “phosphine” is as defined herein in the definitions section. According to some embodiments, the at least one surface ligand comprises at least one phosphine ligand.

[0248] According to some embodiments, the phosphine ligand comprises trioctylphosphine.

[0249] According to some embodiments, the composite material comprises at least one phosphine oxide ligand. The term “phosphine oxide” is as defined herein in the definitions section. According to some embodiments, the at least one surface ligand comprises at least one phosphine oxide ligand.

[0250] According to some embodiments, the phosphine ligand comprises trioctylphosphine oxide.

[0251] In general, trioctylphosphine (TOP) and trioctylphosphine oxide (TOPO) can be used in the synthesis of QDs, providing strong binding and stabilizing effects to the QD products.

[0252] According to some embodiments, the composite material comprises at least one surfactant. According to some embodiments, the at least one surface ligand comprises at least one surfactant ligand.

[0253] According to some embodiments, the surfactant ligand comprises Sodium dodecyl sulfate (SDS).

[0254] Specifically, SDS may be used to improve dispersion and stability in various solvents, and it is useful in colloidal synthesis.

[0255] According to some embodiments, the composite material comprises at least one coupling agent. According to some embodiments, the at least one surface ligand comprises at least one coupling agent.

[0256] According to some embodiments, the coupling agent comprises a carbodiimide. According to some embodiments, the coupling agent comprises 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC).

[0257] Specifically, coupling agents such as EDC may be used for coupling reactions to attach other functional groups or biomolecules.

[0258] According to some embodiments, the composite material comprises at least one phosphonate. According to some embodiments, the at least one surface ligand comprises at least one phosphonate.

[0259] According to some embodiments, the phosphonate comprises phosphonic acid, aminomethylphosphonic acid or both.

[0260] Specifically, phosphonates: as phosphonic acid and aminomethylphosphonic acid, may provide strong binding to metal oxide surfaces, and can enhance stability in polar and non-polar media.

[0261] According to some embodiments, the composite material comprises at least one phospholipid. According to some embodiments, the at least one surface ligand comprises at least one phospholipid.

[0262] Specifically, amphiphilic molecules, such as phospholipids, and amphiphilic block copolymers, may enhance solubility in both polar and non-polar solvents, and can be useful for creating lipid bilayers and micelles.

[0263] According to some embodiments, the metal oxide core comprises a plurality of metal oxide units. According to some embodiments, the particle comprises 5 to 13,000 metal oxide units, including each value and sub-range within the specified range. According to some embodiments, the particle comprises 10 to 4600 metal oxide units. According to some embodiments, the particle comprises 10 to 3100 metal oxide units. According to some embodiments, the particle comprises 10 to 1680 metal oxide units. According to some embodiments, the particle comprises 10 to 860 metal oxide units. According to some embodiments, the particle comprises 10 to 36 metal oxide units. According to some embodiments, the particle comprises 13 to 1600 metal oxide units. According to some embodiments, the particle comprises 13 to 860 metal oxide units. According to some embodiments, the particle comprises 13 to 36 metal oxide units. According to some embodiments, the particle comprises 36 to 1680 metal oxide units. According to some embodiments, the particle comprises 36 to 860 metal oxide units.

[0264] According to some embodiments, the organic coating comprises a plurality of cation exchanged chlorophyll ligands. According to some embodiments, the particle comprises 5 to 250 cation exchanged chlorophyll ligand units, including each value and sub-range within the specified range. According to some embodiments, the particle comprises 10 to 300 cation exchanged chlorophyll ligand units. According to some embodiments, the particle comprises 10 to 200 cation exchanged chlorophyll ligand units. According to some embodiments, the particle comprises 10 to 150 cation exchanged chlorophyll ligand units. According to some embodiments, the particle comprises 10 to 100 cation exchanged chlorophyll ligand units. According to some embodiments, the particle comprises 10 to 50 cation exchanged chlorophyll ligand units. According to some embodiments, the particle comprises 25 to 500 cation exchanged chlorophyll ligand units. According to some embodiments, the particle comprises 25 to 250 cation exchanged chlorophyll ligand units. According to some embodiments, the particle comprises 25 to 150 cation exchanged chlorophyll ligand units. According to some embodiments, the particle comprises 25 to 100 cation exchanged chlorophyll ligand units. According to some embodiments, the particle comprises 50 to 250 cation exchanged chlorophyll ligand units. According to some embodiments, the particle comprises 100 to 250 cation exchanged chlorophyll ligand units. According to some embodiments, each particle comprises 10 to 250 cation exchanged chlorophyll ligand units.

[0265] According to some embodiments, the organic coating comprises a plurality of surface ligands. According to some embodiments, the particle comprises 5 to 700 surface ligand units, including each value and sub-range within the specified range. According to some embodiments, the particle comprises 10 to 500 surface ligand units. According to some embodiments, the particle comprises 10 to 200 surface ligand units. According to some embodiments, the particle comprises 10 to 150 surface ligand units. According to some embodiments, the particle comprises 10 to 100 surface ligand units. According to some embodiments, the particle comprises 10 to 50 surface ligand units. According to some embodiments, the particle comprises 25 to 500 surface ligand units. According to some embodiments, the particle comprises 25 to 250 surface ligand units. According to some embodiments, the particle comprises 25 to 150 surface ligand units. According to some embodiments, the particle comprises 25 to 100 surface ligand units. According to some embodiments, the particle comprises 50 to 250 surface ligand units. According to some embodiments, the particle comprises 100 to 250 surface ligand units. According to some embodiments, each particle comprises 10 to 250 surface ligand units.

[0266] According to some embodiments, the composite material of the present invention is represented by the following formula: (Chlorophyll)z-(metal-oxide)x-(L)y, wherein

[0267] z is the number of chlorophyll (e.g., cation-exchanged chlorophyll) molecules in a unit of the composite material,

[0268] x is the number of metal oxide units in a unit of the composite material, and

[0269] y is the number of surface ligand units in a unit of the composite material.

[0270] According to some embodiments, z is in the range of 5 to 260, including each value and sub-range within the specified range. According to some embodiments, z is in the range of 5 to 50. According to some embodiments, z is in the range of 5 to 100. According to some embodiments, z is in the range of 20 to 100. According to some embodiments, z is in the range of 20 to 200. According to some embodiments, z is in the range of 50 to 250.

[0271] According to some embodiments, x, y and z are variable, and may indicate the ratios, particularly for composite material in the form of small nanoparticles (quantum dots) sized 1-10 nm.

[0272] According to some embodiments, x is in the range of 10 to 13,000, including each value and sub-range within the specified range. According to some embodiments, x is in the range of 10 to 100. According to some embodiments, x is in the range of 500. According to some embodiments, x is in the range of 50 to 500. According to some embodiments, x is in the range of 50 to 1,000. According to some embodiments, x is in the range of 100 to 1,000. According to some embodiments, the metal oxide is selected from the group consisting of cerium oxide, titanium oxide, zinc oxide, copper oxide, iron oxide, manganese oxide, cobalt oxide, nickel oxide, vanadium oxide, molybdenum oxide, tungsten oxide, chromium oxide and a combination thereof, According to some particular embodiments, the metal oxide comprises cerium oxide.

[0273] According to some embodiments, y is in the range of 0 to 700 surface ligand units, including each value and sub-range within the specified range. It is to be understood that when y is 0, the composite does not include a surface ligand. According to some embodiments, y is in the range of 5 to 700 surface ligand units. According to some embodiments, y is in the range of 5 to 50. According to some embodiments, y is in the range of 10 to 100. According to some embodiments, y is in the range of 20 to 200. According to some embodiments y is in the range of 50 to 500. According to some embodiments, y is in the range of 50 to 250. According to some embodiments, y is in the range of 100 to 700. According to some embodiments, the surface ligand is selected from the group consisting of a carboxylic acid, an amine, a thiol, a phosphine, a phosphine oxide and a combination thereof. according to some particular embodiments, the surface ligand comprises a carboxylic acid. According to some embodiments, the carboxylic acid comprises oleic acid.

[0274] According to some embodiments, z is in the range of 5 to 260, and / or x is in the range of 10 to 13,000, and / or y is in the range of 0 to 700. According to some embodiments, z is in the range of 5 to 260, and / or x is in the range of 10 to 13,000, and / or y is in the range of 5 to 700.

[0275] According to some embodiments, z is in the range of 5 to 260, and x is in the range of 10 to 13,000.

[0276] According to some embodiments, z is in the range of 5 to 260, and y is in the range of 0 to 700. According to some embodiments, z is in the range of 5 to 260, and y is in the range of 5 to 700.

[0277] According to some embodiments, x is in the range of 10 to 13,000, and y is in the range of 0 to 700. According to some embodiments, x is in the range of 10 to 13,000, and y is in the range of 5 to 700.

[0278] According to some embodiments, z is in the range of 5 to 260, x is in the range of 10 to 13,000, and y is in the range of 0 to 700. According to some embodiments, z is in the range of 5 to 260, x is in the range of 10 to 13,000, and y is in the range of 5 to 700.

[0279] Advantageously, one of the improved properties imparted by the organic components of the present composite material (e.g., the chlorophyll, the surface ligand(s) etc.) is improved solubility in fuel. Solubility in non-polar organic liquids, such as diesel fuel, is usually not enabled with unmodified metal-oxides, however, it was found that the composite material of the present invention is diesel freely soluble, even at high concentrations (up to 6%) which can be an important advantage to fuel additive. The submicron size of the nanoparticles is also an important feature since fuel injectors in diesel engines that have holes of several micrometers cannot be blocked by the small nanoparticles.

[0280] The solubility of oxygen in organic solvents is an important property for the development of chemical plants and the quality control of solvents in many industries, such as the petroleum, food, and semiconductor industries. For example, molecular oxygen in hydrocarbon feed stocks plays a key role in fouling and corrosion of refinery units. Dissolved oxygen also contributes to shortening of the shelf life of refinery fuel products owing to deposit and sediment formation. The solubilities of gases in alcohols have attracted particular attention in connection with the mechanism of general anesthesia. In the liquid-phase oxidation of toluene, the oxygen partial pressure in the industrial reactors must be controlled at a very low concentration for safety. Hence, the solubility of oxygen is essential information for the design of chlorophyll-metal-oxide QD fuel additives, especially the oxygen solubility data under reaction pressure and temperature. The content of oxygen and its delivery in fuel additives can be extremely important to improve combustion efficiency and emissions levels.

[0281] According to some embodiments, the composite material has solubility of at least 0.1 gr per liter in diesel fuel. The term diesel fuel is defined in the definitions section. According to some embodiments, the composite material has solubility of at least 0.25 gr per liter in diesel fuel. According to some embodiments, the composite material has solubility of at least 0.5 gr per liter in diesel fuel. According to some embodiments, the composite material has solubility of at least 0.75 gr per liter in diesel fuel. According to some embodiments, the composite material has solubility of at least 1 gr per liter in diesel fuel. According to some embodiments, the composite material has solubility of at least 5 gr per liter in diesel fuel. According to some embodiments, the composite material has solubility of at least 6 gr, at least 7 gr, at least 8 gr, or at least 9 gr per liter in diesel fuel. Each possibility represents a separate embodiment. According to some embodiments, the composite material has solubility of at least 10 gr per liter (1%) in diesel fuel. According to some embodiments, the composite material has solubility of at least 25 gr per liter (2.5%) in diesel fuel. According to some embodiments, the composite material has solubility of at least 60 gr per liter (6%) in diesel fuel.

[0282] Conveniently, some solubility properties in non-polar organic media are measured in hexane.

[0283] According to some embodiments, the composite material has solubility of at least 0.1 gr per liter in hexane. According to some embodiments, the composite material has solubility of at least 0.25 gr per liter in hexane. According to some embodiments, the composite material has solubility of at least 0.5 gr per liter in hexane. According to some embodiments, the composite material has solubility of at least 0.75 gr per liter in hexane. According to some embodiments, the composite material has solubility of at least 1 gr per liter in hexane. According to some embodiments, the composite material has solubility of at least 10 gr per liter in hexane. According to some embodiments, the composite material has solubility of at least 25 gr per liter in hexane. According to some embodiments, the composite material has solubility of at least 60 gr per liter (6%) in hexane.

[0284] Reference is now made to FIG. 1 and FIG. 2, which are non-limiting examples that can assist in understanding several embodiments related to optional structures of the present composite material, in a form of a particle.

[0285] FIG. 1 shows a chlorophyll-metal-oxide nanocomposites, optionally constructed of nanocrystal 10 coated with chlorophyll 11 and chlorophyll 12. Both chlorophyll 11 and chlorophyll 12 can have a metal core 13. Chlorophyll 11 can have a lipophilic tail 15.

[0286] FIG. 2 shows chlorophyll-metal-oxide QD constructed of nanocrystal 10 constructed of Chlorophyll 11, Fatty acid 16, and blocker 17. All Chlorophylls have Metal core 13. Chlorophyll 11 has a lipophilic tail 15.

[0287] Chlorophylls 11 and 12 can serve as a native structure for metal core binding, oxygen binding, and energy transition. Chlorophyll 11 can be selected from Chlorophyll a, Chlorophyll b, Chlorophyll d, Chlorophyll f, and other native or synthetic chlorophylls having a lipophilic tail. Chlorophyll 12 can be selected from Chlorophyll c1, Chlorophyll c2, Chlorophyll c3 and other native or synthetic chlorophylls which do not have a lipophilic tail.

[0288] The lipophilic tail 15 of the chlorophylls is optionally C4-C24 carbon long.

[0289] The chlorophyll metal core 13 can have a positive charge +2 metal ion such as Mg+2, Cu+2, Co+2, Mn+2, Fe+2, Zn+2, etc. The metal ion can optionally bind and transmit oxygen for the combustion process in diesel.

[0290] Metal-Oxide that can optionally create QD, such as cerium oxide, manganese oxide, aluminum oxide, etc. Cerium oxide optionally serves as QD matrix for chlorophyl absorption, but also as a catalysator of combustion, oxidation of hydrocarbons (HC) and carbon oxide (CO) and nitric oxides (NOx) reduction.

[0291] Fatty acid 16 can include oleic acid, but any fatty acid having 4-28 or 8-28 carbon atoms can be applied. The fatty acid 16 is optionally used to increase the lipophilic features of the QD and help them solubilize in organic solvents such as diesel fuel.

[0292] Blocker 17 can be ethylenediamine, ethylene glycol, or any other blocker 17 such as other di-amines and / or di-alcohol, that can also serve as good leaving groups.

[0293] According to a further aspect of the present invention, there is provided a fuel composition comprising a motor fuel and a fuel additive, wherein the fuel additive comprises a composite material comprising a metal oxide core, coated with an organic coating, wherein the organic coating comprises a chlorophyll.

[0294] It is to be understood that any of the embodiments above, may apply to the composite material of the fuel additive. According to some embodiments, the composite material comprises the composite material according to the present invention.

[0295] According to some embodiments, the fuel composition comprises a plurality of composite particles.

[0296] According to some embodiments, the composite particles have an average particle size in the range of 1 nm to 500 nm, including each value and sub-range within the specified range. According to some embodiments, the composite particles have an average particle size in the range of 3 nm to 400 nm. According to some embodiments, the composite particles have an average particle size in the range of 2 nm to 400 nm. According to some embodiments, the composite particles have an average particle size in the range of 3 nm to 300 nm. According to some embodiments, the composite particles have an average particle size in the range of 4 nm to 300 nm. According to some embodiments, the composite particles have an average particle size in the range of 5 nm to 300 nm. According to some embodiments, the composite particles have an average particle size in the range of 5 nm to 200 nm.

[0297] According to some embodiments, the composite particles have a mean particle size in the range of 1 nm to 500 nm, including each value and sub-range within the specified range. According to some embodiments, the composite particles have a mean particle size in the range of 3 nm to 400 nm. According to some embodiments, the composite particles have a mean particle size in the range of 2 nm to 400 nm. According to some embodiments, the composite particles have a mean particle size in the range of 3 nm to 300 nm. According to some embodiments, the composite particles have a mean particle size in the range of 4 nm to 300 nm. According to some embodiments, the composite particles have a mean particle size in the range of 5 nm to 300 nm. According to some embodiments, the composite particles have a mean particle size in the range of 5 nm to 200 nm.

[0298] According to some embodiments, the composite particles are in the form of small nanoparticles. According to some embodiments, the small nanoparticles have an average particle size in the range of 10 nm to 50 nm, including each value and sub-range within the specified range. According to some embodiments, the small nanoparticles have an average particle size in the range of 12 nm to 55 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 15 nm to 90 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 13 nm to 45 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 12 nm to 35 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 12 nm to 30 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 12 nm to 22 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 20 nm to 80 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 20 nm to 55 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 18 nm to 35 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 25 nm to 65 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 25 nm to 55 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 22 nm to 44 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 30 nm to 55 nm.

[0299] According to some embodiments, the small nanoparticles have a mean particle size in the range of 10 nm to 50 nm, including each value and sub-range within the specified range. According to some embodiments, the small nanoparticles have a mean particle size in the range of 12 nm to 55 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 15 nm to 90 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 13 nm to 45 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 12 nm to 35 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 12 nm to 30 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 12 nm to 22 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 20 nm to 80 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 20 nm to 55 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 18 nm to 35 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 25 nm to 65 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 25 nm to 55 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 22 nm to 44 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 30 nm to 55 nm.

[0300] According to some embodiments, the composite particles are in the form of quantum dots. According to some embodiments, the quantum dots have an average particle size in the range of 1 nm to 20 nm, including each value and sub-range within the specified range. According to some embodiments, the quantum dots have an average particle size in the range of 1 nm to 10 nm. According to some embodiments, the quantum dots have an average particle size in the range of 2 nm to 10 nm. According to some embodiments, the quantum dots have an average particle size in the range of 3 nm to 10 nm. According to some embodiments, the quantum dots have an average particle size in the range of 4 nm to 10 nm. According to some embodiments, the quantum dots have an average particle size in the range of 5 nm to 10 nm. According to some embodiments, the quantum dots have an average particle size in the range of 5 nm to 12 nm. According to some embodiments, the quantum dots have an average particle size in the range of 4 nm to 14 nm. According to some embodiments, the quantum dots have an average particle size in the range of 4 nm to 12 nm. According to some embodiments, the quantum dots have an average particle size in the range of 3 nm to 7 nm. According to some embodiments, the quantum dots have an average particle size in the range of 7 nm to 17 nm. According to some embodiments, the quantum dots have an average particle size in the range of 7 nm to 12 nm. According to some embodiments, the quantum dots have an average particle size in the range of 7 nm to 10 nm. According to some embodiments, the quantum dots have an average particle size in the range of 5 nm to 15 nm. According to some embodiments, the quantum dots have an average particle size in the range of 6 nm to 14 nm. According to some embodiments, the quantum dots have an average particle size in the range of 6 nm to 10 nm. According to some embodiments, the quantum dots have an average particle size in the range of 6 nm to 8 nm. According to some embodiments, the quantum dots have an average particle size in the range of 5 nm to 9 nm. According to some embodiments, the quantum dots have an average particle size in the range of 4 nm to 8 nm. According to some embodiments, the quantum dots have an average particle size in the range of 5 nm to 7 nm. According to some particular embodiments, the quantum dots have an average particle size of about 7 nm.

[0301] According to some embodiments, the quantum dots have a mean particle size in the range of 1 nm to 20 nm, including each value and sub-range within the specified range. According to some embodiments, the quantum dots have a mean particle size in the range of 1 nm to 10 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 2 nm to 10 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 3 nm to 10 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 4 nm to 10 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 5 nm to 10 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 5 nm to 12 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 4 nm to 14 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 4 nm to 12 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 3 nm to 7 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 7 nm to 17 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 7 nm to 12 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 5 nm to 15 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 6 nm to 14 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 5 nm to 9 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 4 nm to 8 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 5 nm to 7 nm.

[0302] According to some embodiments, at least 50% of the plurality of composite particles have an average particle size, or a mean particle size, in the range of 1 nm to 500 nm. According to some embodiments, at least 60%, at least 75%, at least 80%, at least 90%, at least 95%, or at least 98% of the plurality of composite particles have an average particle size, or a mean particle size, in the range of 1 nm to 500 nm. Each possibility represents a separate embodiment. According to some embodiments, at least 50% of the plurality of composite particles have an average particle size, or a mean particle size, in the range of 1 nm to 100 nm. According to some embodiments, at least 60%, at least 75%, at least 80%, at least 90%, at least 95%, or at least 98% of the plurality of composite particles have an average particle size, or a mean particle size, in the range of 1 nm to 100 nm. Each possibility represents a separate embodiment. According to some embodiments, at least 50% of the plurality of composite particles have an average particle size, or a mean particle size, in the range of 1 nm to 50 nm. According to some embodiments, at least 60%, at least 75%, at least 80%, at least 90%, at least 95%, or at least 98% of the plurality of composite particles have an average particle size, or a mean particle size, in the range of 1 nm to 50 nm. Each possibility represents a separate embodiment.

[0303] According to some embodiments, at least 50% of the plurality of composite particles are in a form of quantum dots, which have an average particle size in the range of 1 nm to 15 nm. According to some embodiments, at least 60%, at least 75%, at least 80%, at least 90%, at least 95%, or at least 98% of the plurality of composite particles are in a form of quantum dots, which have an average particle size in the range of 1 nm to 15 nm. Each possibility represents a separate embodiment. According to some embodiments, at least 50% of the plurality of composite particles are in a form of quantum dots, which have an average particle size in the range of 3 nm to 12 nm. According to some embodiments, at least 60%, at least 75%, at least 80%, at least 90%, at least 95%, or at least 98% of the plurality of composite particles are in a form of quantum dots, which have an average particle size in the range of 3 nm to 12 nm. Each possibility represents a separate embodiment. According to some embodiments, at least 50% of the plurality of composite particles are in a form of quantum dots, which have an average particle size in the range of 4 nm to 8 nm. According to some embodiments, at least 60%, at least 75%, at least 80%, at least 90%, at least 95%, or at least 98% of the plurality of composite particles are in a form of quantum dots, which have an average particle size in the range of 4 nm to 8 nm. Each possibility represents a separate embodiment. According to some embodiments, at least 50% of the plurality of composite particles are in a form of quantum dots, which have an average particle size in the range of 5 nm to 7 nm. According to some embodiments, at least 60%, at least 75%, at least 80%, at least 90%, at least 95%, or at least 98% of the plurality of composite particles are in a form of quantum dots, which have an average particle size in the range of 5 nm to 7 nm. Each possibility represents a separate embodiment.

[0304] According to some embodiments, the fuel composition is in a form of solution or suspension. According to some embodiments, the fuel composition is in a form of a solution. According to some embodiments, the fuel composition is in a form of a suspension.

[0305] According to some embodiments, the motor fuel comprises hydrocarbon fuel. According to some embodiments, the motor fuel comprises diesel fuel or gasoline fuel. According to some embodiments, the motor fuel comprises diesel fuel. The term “diesel fuel” is defined in the definitions section

[0306] According to some embodiments, the fuel composition comprises 0.000001 (1×10−6) gr (0.001 mg) to 25 gr of the composite material per liter of the motor fuel. According to some embodiments, the fuel composition comprises 1×10−4 gr to 10 gr of the composite material per liter of the motor fuel. According to some embodiments, the fuel composition comprises 10−4 gr to 5 gr of the composite material per liter of the motor fuel. According to some embodiments, the fuel composition comprises 2*10−4 gr to 1 gr of the composite material per liter of the motor fuel. According to some embodiments, the fuel composition comprises 5*10−4 gr to 0.5 gr of the composite material per liter of the motor fuel. According to some embodiments, the fuel composition comprises 10−3 gr to 0.1 gr of the composite material per liter of the motor fuel. According to some embodiments, the fuel composition comprises 2*10−3 gr to 0.05 gr of the composite material per liter of the motor fuel. According to some embodiments, the fuel composition comprises 2*10−3 gr to 0.02 gr of the composite material per liter of the motor fuel. According to some embodiments, the fuel composition comprises 2*10−3 gr to 0.015 gr of the composite material per liter of the motor fuel. According to some embodiments, the fuel composition comprises 3*10−3 gr to 0.015 gr of the composite material per liter of the motor fuel. According to some embodiments, the fuel composition comprises 4*10−3 gr to 0.0125 gr of the composite material per liter of the motor fuel. According to some embodiments, the fuel composition comprises about 0.008 gr of the composite material per liter of the motor fuel.

[0307] According to some embodiments, the ratio (w / v) of the composite material to the fuel is in the range of 1:500,000-1:500, including each value and sub-range within the specified range. According to some embodiments, the ratio (w / v) of the composite material to the fuel is in the range of 1:250,000-1:5000, 1:200,000-1:5000, 1:175,000-1:10000, 1:175,000-1:20,000, 1:170,000-1:30,000, 1:170,000-1:40,000, 1:160,000-1:50,000, 1:160,000-1:60,000, 1:160,000-1:70,000, 1:155,000-1:80,000, 1:150,000-1:90,000, 1:150,000-1:100,000, 1:140,000-1:110,000, 1:135,000-1:115,000 or 1:120,000-1:110,000. Each possibility represents a separate embodiment.

[0308] According to some embodiments, the fuel additive comprises a CeO2 core, coated with an organic coating, wherein the organic coating comprises a Cu+2 exchanged chlorophyll and oleic acid; wherein the CeO2 core is particulate in the form of a quantum dot and has a diameter in the range of 1 nm to 4 nm; and wherein the composite material is particulate in the form of a quantum dot and has a diameter in the range of 4 nm to 10 nm. According to some embodiments, the composite material is present in the motor fuel at a concentration of 10−1 gr to 1 gr per liter.

[0309] According to some embodiments, the fuel composition according to the present invention, is characterized by a water content in the range of no more than 200 mg / kg, including each value and sub-range within the stated range. According to some embodiments, the fuel composition is characterized by a water content in the range of no more than 150 mg / kg. According to some embodiments, the fuel composition is characterized by a water content in the range of no more than 120 mg / kg. According to some embodiments, the fuel composition is characterized by a water content in the range of no more than 100 mg / kg.

[0310] According to a further aspect of the present invention, there is provided a liquid fuel additive formulation comprising a solvent and a fuel additive, wherein the fuel additive comprises a composite material comprising a metal oxide core, coated with an organic coating, wherein the organic coating comprises a chlorophyll.

[0311] According to some embodiments, the solvent is an organic solvent. According to some embodiments, the solvent is a non-polar organic solvent.

[0312] According to some embodiments, the solvent is selected from the group consisting of: kerosen, pentanes, hexanes, heptanes, octanes, nonanes, decanes, cyclopentane, cyclohexane, cycloheptane, benzene, toluene, xylene, methanol, ethanol, propanol, isopropanol, 1-butanol, 2-butanol, sec-butanol, t-butanol, 1-pentanol, 2-pentanol, 3-pentanol, neopentanol, 3-methyl-1-butanol, 2-methyl-1-butanol, 3-methyl-2-butanol, 2-methyl-2-butanol, ethyleneglycol, tert-butyl methyl ether (TBME), ethyleneglycol monomethyl ether, diethyl ether, methylethyl ether, ethylpropyl ether, methylpropyl ether, 1,2-dimethoxyethane, tetrahydrofuran, dihydrofuran, furan, pyran, dihydropyran, tetrahydropyran, methyl acetate, ethyl acetate, propyl acetate, acetaldehyde, methylformate, ethylformate, ethyl propionate, methyl propionate, dichloromethane, chloroform, dimethylformamide, acetamide, dimethylacetamide, N-methylpyrrolidone, acetone, ethylmethyl ketone, diethyl ketone, acetonitrile, propionitrile and mixtures thereof.

[0313] According to some embodiments, the solvent comprises kerosene. According to some embodiments, the solvent comprises TBME. According to some embodiments, the solvent comprises kerosene, TBME, or a mixture thereof. According to some embodiments, the solvent comprises a mixture of kerosene and TBMA.

[0314] It is to be understood that any of the embodiments above, may apply to the composite material of the liquid fuel additive formulation. According to some embodiments, the composite material of the liquid fuel additive formulation comprises the composite material according to the present invention.

[0315] According to some embodiments, the composite material of the liquid fuel additive formulation comprises a plurality of composite particles.

[0316] According to some embodiments, the composite particles within the liquid fuel additive formulation have an average particle size in the range of 1 nm to 500 nm, including each value and sub-range within the specified range. According to some embodiments, the composite particles have an average particle size in the range of 3 nm to 400 nm. According to some embodiments, the composite particles have an average particle size in the range of 2 nm to 400 nm. According to some embodiments, the composite particles have an average particle size in the range of 3 nm to 300 nm. According to some embodiments, the composite particles have an average particle size in the range of 4 nm to 300 nm. According to some embodiments, the composite particles have an average particle size in the range of 5 nm to 300 nm. According to some embodiments, the composite particles have an average particle size in the range of 5 nm to 200 nm. According to some embodiments, the composite particles have a mean particle size in the range of 1 nm to 500 nm, including each value and sub-range within the specified range. According to some embodiments, the composite particles have a mean particle size in the range of 3 nm to 400 nm. According to some embodiments, the composite particles have a mean particle size in the range of 2 nm to 400 nm. According to some embodiments, the composite particles have a mean particle size in the range of 3 nm to 300 nm. According to some embodiments, the composite particles have a mean particle size in the range of 4 nm to 300 nm. According to some embodiments, the composite particles have a mean particle size in the range of 5 nm to 300 nm. According to some embodiments, the composite particles have a mean particle size in the range of 5 nm to 200 nm.

[0317] According to some embodiments, the composite particles within the liquid fuel additive formulation are in the form of small nanoparticles. According to some embodiments, the small nanoparticles have an average particle size in the range of 10 nm to 50 nm, including each value and sub-range within the specified range. According to some embodiments, the small nanoparticles have an average particle size in the range of 12 nm to 55 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 15 nm to 90 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 13 nm to 45 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 12 nm to 35 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 12 nm to 30 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 12 nm to 22 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 20 nm to 80 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 20 nm to 55 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 18 nm to 35 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 25 nm to 65 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 25 nm to 55 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 22 nm to 44 nm. According to some embodiments, the small nanoparticles have an average particle size in the range of 30 nm to 55 nm.

[0318] According to some embodiments, the small nanoparticles within the liquid fuel additive formulation have a mean particle size in the range of 10 nm to 50 nm, including each value and sub-range within the specified range. According to some embodiments, the small nanoparticles have a mean particle size in the range of 12 nm to 55 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 15 nm to 90 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 13 nm to 45 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 12 nm to 35 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 12 nm to 30 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 12 nm to 22 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 20 nm to 80 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 20 nm to 55 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 18 nm to 35 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 25 nm to 65 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 25 nm to 55 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 22 nm to 44 nm. According to some embodiments, the small nanoparticles have a mean particle size in the range of 30 nm to 55 nm.

[0319] According to some embodiments, the composite particles within the liquid fuel additive formulation are in the form of quantum dots. According to some embodiments, the quantum dots have an average particle size in the range of 1 nm to 20 nm, including each value and sub-range within the specified range. According to some embodiments, the quantum dots have an average particle size in the range of 1 nm to 10 nm. According to some embodiments, the quantum dots have an average particle size in the range of 2 nm to 10 nm. According to some embodiments, the quantum dots have an average particle size in the range of 3 nm to 10 nm. According to some embodiments, the quantum dots have an average particle size in the range of 4 nm to 10 nm. According to some embodiments, the quantum dots have an average particle size in the range of 5 nm to 10 nm. According to some embodiments, the quantum dots have an average particle size in the range of 5 nm to 12 nm. According to some embodiments, the quantum dots have an average particle size in the range of 4 nm to 14 nm. According to some embodiments, the quantum dots have an average particle size in the range of 4 nm to 12 nm. According to some embodiments, the quantum dots have an average particle size in the range of 3 nm to 7 nm. According to some embodiments, the quantum dots have an average particle size in the range of 7 nm to 17 nm. According to some embodiments, the quantum dots have an average particle size in the range of 7 nm to 12 nm. According to some embodiments, the quantum dots have an average particle size in the range of 7 nm to 10 nm. According to some embodiments, the quantum dots have an average particle size in the range of 5 nm to 15 nm. According to some embodiments, the quantum dots have an average particle size in the range of 6 nm to 14 nm. According to some embodiments, the quantum dots have an average particle size in the range of 6 nm to 10 nm. According to some embodiments, the quantum dots have an average particle size in the range of 6 nm to 8 nm. According to some embodiments, the quantum dots have an average particle size in the range of 5 nm to 9 nm. According to some embodiments, the quantum dots have an average particle size in the range of 4 nm to 8 nm. According to some embodiments, the quantum dots have an average particle size in the range of 5 nm to 7 nm. According to some particular embodiments, the quantum dots have an average particle size of about 7 nm.

[0320] According to some embodiments, the quantum dots within the liquid fuel additive formulation have a mean particle size in the range of 1 nm to 20 nm, including each value and sub-range within the specified range. According to some embodiments, the quantum dots within the liquid fuel additive formulation have a mean particle size in the range of 1 nm to 10 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 2 nm to 10 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 3 nm to 10 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 4 nm to 10 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 5 nm to 10 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 5 nm to 12 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 4 nm to 14 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 4 nm to 12 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 3 nm to 7 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 7 nm to 17 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 7 nm to 12 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 5 nm to 15 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 6 nm to 14 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 5 nm to 9 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 4 nm to 8 nm. According to some embodiments, the quantum dots have a mean particle size in the range of 5 nm to 7 nm.

[0321] According to some embodiments, at least 50% of the plurality of composite particles within the liquid fuel additive formulation have an average particle size, or a mean particle size, in the range of 1 nm to 500 nm. According to some embodiments, at least 60%, at least 75%, at least 80%, at least 90%, at least 95%, or at least 98% of the plurality of composite particles have an average particle size, or a mean particle size, in the range of 1 nm to 500 nm. Each possibility represents a separate embodiment. According to some embodiments, at least 50% of the plurality of composite particles have an average particle size, or a mean particle size, in the range of 1 nm to 100 nm. According to some embodiments, at least 60%, at least 75%, at least 80%, at least 90%, at least 95%, or at least 98% of the plurality of composite particles have an average particle size, or a mean particle size, in the range of 1 nm to 100 nm. Each possibility represents a separate embodiment. According to some embodiments, at least 50% of the plurality of composite particles have an average particle size, or a mean particle size, in the range of 1 nm to 50 nm. According to some embodiments, at least 60%, at least 75%, at least 80%, at least 90%, at least 95%, or at least 98% of the plurality of composite particles have an average particle size, or a mean particle size, in the range of 1 nm to 50 nm. Each possibility represents a separate embodiment.

[0322] According to some embodiments, at least 50% of the plurality of composite particles within the liquid fuel additive formulation are in a form of quantum dots, which have an average particle size in the range of 1 nm to 15 nm. According to some embodiments, at least 60%, at least 75%, at least 80%, at least 90%, at least 95%, or at least 98% of the plurality of composite particles are in a form of quantum dots, which have an average particle size in the range of 1 nm to 15 nm. Each possibility represents a separate embodiment. According to some embodiments, at least 50% of the plurality of composite particles are in a form of quantum dots, which have an average particle size in the range of 3 nm to 12 nm. According to some embodiments, at least 60%, at least 75%, at least 80%, at least 90%, at least 95%, or at least 98% of the plurality of composite particles are in a form of quantum dots, which have an average particle size in the range of 3 nm to 12 nm. Each possibility represents a separate embodiment. According to some embodiments, at least 50% of the plurality of composite particles are in a form of quantum dots, which have an average particle size in the range of 4 nm to 8 nm. According to some embodiments, at least 60%, at least 75%, at least 80%, at least 90%, at least 95%, or at least 98% of the plurality of composite particles are in a form of quantum dots, which have an average particle size in the range of 4 nm to 8 nm. Each possibility represents a separate embodiment. According to some embodiments, at least 50% of the plurality of composite particles are in a form of quantum dots, which have an average particle size in the range of 5 nm to 7 nm. According to some embodiments, at least 60%, at least 75%, at least 80%, at least 90%, at least 95%, or at least 98% of the plurality of composite particles are in a form of quantum dots, which have an average particle size in the range of 5 nm to 7 nm. Each possibility represents a separate embodiment.

[0323] According to some embodiments, the liquid fuel additive formulation is in a form of solution or suspension. According to some embodiments, the liquid fuel additive formulation is in a form of a solution. According to some embodiments, the liquid fuel additive formulation is in a form of a suspension.

[0324] According to some embodiments, the liquid fuel additive formulation comprises 0.5% w / v to 10% w / v of the fuel additive, including each value and sub-range within the specified range. According to some embodiments, the liquid fuel additive formulation comprises 1% w / v to 8% w / v of the fuel additive. According to some embodiments, the liquid fuel additive formulation comprises 2% w / v to 6% w / v of the fuel additive. According to some embodiments, the liquid fuel additive formulation comprises 3% w / v to 5% w / v of the fuel additive.

[0325] According to some embodiments, the liquid fuel additive formulation comprises 0.5% w / v to 10% w / v of the composite material, including each value and sub-range within the specified range. According to some embodiments, the liquid fuel additive formulation comprises 1% w / v to 8% w / v of the composite material. According to some embodiments, the liquid fuel additive formulation comprises 2% w / v to 6% w / v of the composite material. According to some embodiments, the liquid fuel additive formulation comprises 3% w / v to 5% w / v of the composite material.

[0326] According to some embodiments, the fuel additive of the liquid fuel additive formulation comprises a CeO2 core, coated with an organic coating, wherein the organic coating comprises a Cu+2 exchanged chlorophyll and oleic acid; wherein the CeO2 core is particulate in the form of a quantum dot and has a diameter in the range of 1 nm to 4 nm; and wherein the composite material is particulate in the form of a quantum dot and has a diameter in the range of 4 nm to 10 nm. According to some embodiments, the composite material is present in the motor fuel at a concentration of 10 gr to 150 gr per liter.

[0327] According to some embodiments, the liquid fuel additive formulation according to the present invention, is characterized by a water content in the range of no more than 200 mg / kg, including each value and sub-range within the stated range. According to some embodiments, the liquid fuel additive formulation is characterized by a water content in the range of no more than 150 mg / kg. According to some embodiments, the liquid fuel additive formulation is characterized by a water content in the range of no more than 120 mg / kg. According to some embodiments, the liquid fuel additive formulation is characterized by a water content in the range of no more than 100 mg / kg. According to some further aspects of the preset invention, there is provided a composite material prepared by a method comprising the steps of.

[0328] subjecting a core metal salt to sonication, to form a metal oxide; and

[0329] subjecting the nanoparticulate metal oxide to sonication together with a chlorophyll, optionally a cation exchanged chlorophyll, to form the composite material.

[0330] According to some embodiments, the chlorophyll comprises a cation exchanged chlorophyll.

[0331] According to some embodiments, the metal of the metal salt is selected from the group consisting of cerium, aluminum, titanium, zinc, copper, iron, manganese, cobalt, nickel, vanadium, molybdenum, tungsten, chromium and a combination thereof. Each possibility represents a separate embodiment of the invention. According to some particular embodiments, the metal of the metal salt is cerium.

[0332] According to some embodiments, the metal salt comprises a group selected from a halide (including, for example, chloride, fluoride, bromide, iodide), oxide, nitrate, tetrafluoroborate, sulfate, sulfonate, cyanide, and phosphate. The term “salt” is described in the definitions section. It is to be understood that the salts, as described herein, include solvates and hydrates thereof.

[0333] According to some specific examples, the metal salt comprises metal nitrate. According to some examples, the nitrate consists of NO−3. According to some embodiments, the nitrate comprises a nitrate hydrate. According to some embodiments, the nitrate hydrate is selected from nitrate monohydrate, nitrate dihydrate, nitrate trihydrate, nitrate tetrahydrate, nitrate pentahydrate, nitrate hexahydrate, or more.

[0334] According to some specific embodiments, the metal salt comprises cerium nitrate hexahydrate.

[0335] According to some embodiments, the formed metal oxide comprises a metal oxide selected from the group consisting of: cerium oxide, aluminum oxide, titanium oxide, zinc oxide, copper oxide, iron oxide, manganese oxide, cobalt oxide, nickel oxide, vanadium oxide, molybdenum oxide, tungsten oxide, chromium oxide and a combination thereof. Each possibility represents a separate embodiment of the invention. According to some particular embodiments, the metal oxide is selected from cerium oxide, aluminum oxide, and manganese oxide. According to further particular embodiments, the metal oxide comprises cerium oxide.

[0336] According to some embodiments, the metal oxide is in a particulate form, i.e., a particulate metal oxide. According to some embodiments, the particulate form is a nanoparticulate form, i.e., a nanoparticulate metal oxide. According to some embodiments, the particulate form is in the form of QDs. According to some embodiments, the particulate metal oxide has a diameter in the range of 1-100 nm, 1-10 nm, 1-5 nm, 3-10 nm, 1-4 nm, or 1-3 nm. Each possibility represents a separate embodiment.

[0337] According to some embodiments, the cation exchanged chlorophyll comprises chelated metal cation that has a stronger binding to dioxygen than Mg+2. According to some embodiments, the chelated metal cation is selected from the group consisting of: cobalt cation, copper cation, iron cation, manganese cation, nickel cation, ruthenium cation, rhodium cation, silver cation, vanadium cation, chromium cation, zinc cation, nickel cation, cerium cation, tungsten cation, molybdenum cation, rhenium cation, iridium cation, palladium cation, osmium cation, technetium cation, platinum cation, titanium cation, zirconium cation, hafnium cation, niobium cation, tantalum cation, gallium cation, indium cation, tin cation, lead cation, antimony cation, bismuth cation, thulium cation, thorium cation, boron cation arsenic cation and a combination thereof. Each possibility represents a separate embodiment of the invention.

[0338] According to some embodiments, the chelated metal cation is a divalent cation. According to some embodiments, the chelated metal cation is selected from the group consisting of: Co+2, Cu+2, Mn+2, Fe+2, Zn+2. Each possibility represents a separate embodiment of the invention. According to some specific embodiments, the chelated metal cation is Cu+2.

[0339] According to some embodiments, the method further comprises a step of contacting Mg-chlorophyll with a chelating metal salt to form the cation exchanged chlorophyll, before the step of subjecting the nanoparticulate metal oxide and cation exchanged chlorophyll to sonication.

[0340] According to some embodiments, the step of contacting Mg-chlorophyll with a chelating metal salt comprises boiling a solution comprising the Mg-chlorophyll and the chelating metal salt for a time period of 0.5-60 minutes, optionally for a time period of 1-15 minutes.

[0341] According to some embodiments, the chelating metal salt comprises a metal selected from cobalt, copper, iron, manganese, nickel, ruthenium, rhodium, silver, vanadium, chromium, zinc, nickel, cerium, tungsten, molybdenum, rhenium, iridium, palladium, osmium, technetium, platinum, titanium, zirconium, hafnium, niobium, tantalum, gallium, indium, tin, lead, antimony, bismuth, thulium, thorium, boron arsenic and a combination thereof. Each possibility represents a separate embodiment of the invention. According to some particular embodiments, the chelating metal salt comprises copper.

[0342] According to some embodiments, the chelating metal salt comprises a group selected from a halide (including, for example, chloride, fluoride, bromide, iodide), oxide, nitrate, tetrafluoroborate, sulfate, sulfonate, cyanide, and phosphate. According to some particular embodiments, metal salt comprises a group selected from nitrate, halide (e.g., chloride), and sulfate. According to some embodiments, the salt comprises solvates and hydrates thereof.

[0343] According to some embodiments, the method further comprises a step of subjecting the nanoparticulate metal oxide to sonication together with at least one surface ligand. According to some embodiments, the at least one surface ligand is selected from the group consisting of: a carboxylic acid, an amine, an alcohol, a thiol, a phosphine, a phosphine oxide and a combination thereof.

[0344] According to some embodiments, the surface ligand comprises a fatty acid ligand. According to some embodiments, the surface ligand comprises a carboxylic acid ligand. According to some embodiments, the carboxylic acid ligand comprises a C4-C28 fatty acid.

[0345] According to some embodiments, the carboxylic acid ligand is selected from the group consisting of: oleic acid, palmitic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, elaidic acid, erucic acid linoleic acid, linoelaidic acid, α-linolenic acid, myristoleic acid, palmitoleic acid, sapienic acid, vaccenic acid and a combination thereof. Each possibility represents a separate embodiment of the invention.

[0346] According to some embodiments, the carboxylic acid ligand comprises oleic acid, palmitic acid or both. According to some embodiments, the carboxylic acid ligand comprises oleic acid. According to some embodiments, the carboxylic acid ligand consists of oleic acid.

[0347] According to some embodiments, the step of subjecting the nanoparticulate metal oxide to sonication together with the at least one surface ligand is performed before the step of subjecting the nanoparticulate metal oxide and the cation exchanged chlorophyll to sonication. According to some embodiments, the step of subjecting the nanoparticulate metal oxide to sonication together with the at least one surface ligand is performed together with the step of subjecting the nanoparticulate metal oxide and the cation exchanged chlorophyll to sonication. According to some embodiments, the step of subjecting the nanoparticulate metal oxide to sonication together with the at least one surface ligand is performed after the step of subjecting the nanoparticulate metal oxide and the cation exchanged chlorophyll to sonication. According to some embodiments, the step of subjecting the nanoparticulate metal oxide to sonication together with the at least one surface ligand is performed at least one of before, together with, or after the step of subjecting the nanoparticulate metal oxide and the cation exchanged chlorophyll to sonication.

[0348] According to some further aspects of the preset invention, there is provided a method for preparing a composite material, the method comprising the steps of:

[0349] subjecting a core metal salt to sonication, to form a metal oxide; and

[0350] subjecting the nanoparticulate metal oxide to sonication together with a chlorophyll, optionally a cation exchanged chlorophyll, to form the composite material.

[0351] According to some embodiments, the core metal salt comprises nitrate. According to some embodiments, the metal oxide comprises cerium oxide. According to some embodiments, the metal oxide is nanoparticulate. According to some embodiments, the metal oxide is in the form of quantum dots, having an average diameter in the range of 1 nm to 4 nm.

[0352] According to some embodiments, the cation exchanged chlorophyll comprises a chelated metal cation, which is optionally a divalent cation. According to some embodiments, the chelated metal cation is selected from the group consisting of: Co+2, Cu+2, Mn+2, Fe+2, Zn+2. Each possibility represents a separate embodiment of the invention. According to some embodiments, the chelated metal cation is Cu+2.

[0353] According to some embodiments, the method further comprises, before the step of subjecting the nanoparticulate metal oxide and cation exchanged chlorophyll to sonication, a step of contacting Mg-chlorophyll with a chelating metal salt to form the cation exchanged chlorophyll.

[0354] According to some embodiments, the method further comprises a step of subjecting the nanoparticulate metal oxide to sonication together with at least one surface ligand. According to some embodiments, the at least one surface ligand comprises a fatty acid ligand. According to some embodiments, the fatty acid ligand comprises oleic acid. It is to be understood that further embodiments of a method for preparing a composite material according to the present invention, which are disclosed throughout the specification, apply also to the presently described method. Similarly, embodiments disclosed with relation to the presently described method for preparing a composite material, apply equally to any such method described throughout the specification. In particular, embodiments that are disclosed herein in relation to a composite material prepared by a method, apply equally, wherever relevant, also to a method for preparing a composite material according to the present invention.

[0355] According to some embodiments, the composite material is prepared by a method comprising the steps of:

[0356] subjecting a core metal salt to sonication to form a particulate metal oxide;

[0357] subjecting the particulate metal oxide to sonication together with a chlorophyll; and

[0358] subjecting the particulate metal oxide to sonication together with a fatty acid,

[0359] wherein the step of subjecting the particulate metal oxide to sonication together with the fatty acid is performed before, together with, or after the step of subjecting the particulate metal oxide and the chlorophyll to sonication;

[0360] to form the composite material.

[0361] According to some embodiments, the particulate metal oxide is a nanoparticulate metal oxide.

[0362] According to some embodiments, the metal of the core metal salt is selected from the group consisting of cerium, aluminum, titanium, zinc, copper, iron, manganese, cobalt, nickel, vanadium, molybdenum, tungsten, chromium and a combination thereof. Each possibility represents a separate embodiment of the invention. According to some particular embodiments, the metal of the metal salt is cerium.

[0363] According to some embodiments, the core metal salt comprises a group selected from a halide (including, for example, chloride, fluoride, bromide, iodide), oxide, nitrate, tetrafluoroborate, sulfate, sulfonate, cyanide, and phosphate. The term “salt” is described in the definitions section. It is to be understood that the salts, as described herein, include solvates and hydrates thereof.

[0364] According to some specific examples, the metal salt comprises metal nitrate. According to some specific embodiments, the metal salt comprises cerium nitrate hexahydrate.

[0365] According to some embodiments, the method further comprises, before the step of subjecting the particulate metal oxide and chlorophyll to sonication, a step of contacting Mg-chlorophyll with a chelating metal salt to form the cation exchanged chlorophyll.

[0366] According to some embodiments, the step of contacting Mg-chlorophyll with a chelating metal salt comprises boiling a solution comprising the Mg-chlorophyll and the chelating metal salt for a time period of 0.5-60 minutes, optionally for a time period of 1-15 minutes.

[0367] According to some embodiments, the chelating metal salt comprises a group selected from a halide (including, for example, chloride, fluoride, bromide, iodide), oxide, nitrate, tetrafluoroborate, sulfate, sulfonate, cyanide, and phosphate. According to some particular embodiments, metal salt comprises a group selected from nitrate, halide (e.g., chloride), and sulfate. According to some embodiments, the salt comprises solvates and hydrates thereof.

[0368] According to some embodiments, the step of subjecting the nanoparticulate metal oxide to sonication together with the at least one surface ligand is performed at least one of before, together with, or after the step of subjecting the nanoparticulate metal oxide and the cation exchanged chlorophyll to sonication. According to some particular embodiments, the step of subjecting the nanoparticulate metal oxide to sonication together with the at least one surface ligand is performed before the step of subjecting the nanoparticulate metal oxide and the cation exchanged chlorophyll to sonication.

[0369] In some further aspects of the present invention, there is provided a method for preparing a composite material, the method comprising the steps of:

[0370] subjecting a core metal salt to sonication to form a particulate metal oxide;

[0371] subjecting the particulate metal oxide to sonication together with a chlorophyll; and

[0372] subjecting the particulate metal oxide to sonication together with a fatty acid,

[0373] wherein the step of subjecting the particulate metal oxide to sonication together with the fatty acid is performed before, together with, or after the step of subjecting the particulate metal oxide and the chlorophyll to sonication.

[0374] According to some embodiments, the step of subjecting the particulate metal oxide to sonication together with the fatty acid is performed before the step of subjecting the particulate metal oxide and the chlorophyll to sonication.

[0375] According to some embodiments, the metal salt comprises nitrate. According to some embodiments, the metal oxide comprises cerium oxide. According to some embodiments, the metal oxide is nanoparticulate. According to some embodiments, the metal oxide is in the form of quantum dots, having an average diameter in the range of 1 nm to 4 nm.

[0376] According to some embodiments, the method further comprises, before the step of subjecting the particulate metal oxide and chlorophyll to sonication, a step of contacting Mg-chlorophyll with a chelating metal salt to form the cation exchanged chlorophyll.

[0377] According to some embodiments, the cation exchanged chlorophyll comprises a chelated metal cation, which is optionally a divalent cation. According to some embodiments, the chelated metal cation is selected from the group consisting of: Co+2, Cu+2, Mn+2, Fe+2, Zn+2. Each possibility represents a separate embodiment of the invention. According to some embodiments, the chelated metal cation is Cu+2.

[0378] According to some embodiments, the method further comprises, before the step of subjecting the nanoparticulate metal oxide and cation exchanged chlorophyll to sonication, a step of contacting Mg-chlorophyll with a chelating metal salt to form the cation exchanged chlorophyll.

[0379] It is to be understood that further embodiments of a method for preparing a composite material according to the present invention, which are disclosed throughout the specification, apply also to the presently described method. Similarly, embodiments disclosed with relation to the presently described method for preparing a composite material, apply equally to any such method described throughout the specification. In particular, embodiments that are disclosed herein in relation to a composite material prepared by a method, apply equally, wherever relevant, also to a method for preparing a composite material according to the present invention.

[0380] According to some embodiments, there is provided a composite material prepared by any one of the methods disclosed herein.

[0381] According to some embodiments, there is provided composite material as disclosed herein for use in enhancing motor fuel efficiency.

[0382] According to some embodiments, there is provided composite material as disclosed herein, which is suitable for use in enhancing motor fuel efficiency.

[0383] According to some embodiments, there is provided a means for enhancing motor fuel efficiency, which comprises adding the composite material as disclosed herein to a motor fuel.EXEMPLARY EMBODIMENTSEmbodiment 1. A composite material comprising a metal oxide core, coated with an organic coating, wherein the organic coating comprises a cation exchanged chlorophyll, which comprises a chelated metal cation.

[0385] Embodiment 2. The composite material of any embodiment herein, particularly of embodiment 1, wherein the metal oxide core comprises a metal oxide selected from the group consisting of: cerium oxide, titanium oxide, zinc oxide, copper oxide, iron oxide, manganese oxide, cobalt oxide, nickel oxide, vanadium oxide, molybdenum oxide, tungsten oxide, chromium oxide and a combination thereof.

[0386] Embodiment 3. The composite material of any embodiment herein, particularly of embodiment 2, wherein the metal oxide core comprises a metal oxide selected from the group consisting of: CeO2, AlO3 and MnO2.

[0387] Embodiment 4. The composite material of any embodiment herein, particularly of embodiment 3, wherein the metal oxide core comprises CeO2.

[0388] Embodiment 5. The composite material of any embodiment herein, particularly of any one of embodiments 1 to 4, wherein the metal oxide core is particulate, and has a particle size in the range of 1 nm to 500 nm.

[0389] Embodiment 6. The composite material of any embodiment herein, particularly of embodiment 5, wherein the metal oxide core is in the form of a quantum dot having particle size in the range of 1 nm to 20 nm.

[0390] Embodiment 7. The composite material of any embodiment herein, particularly of any one of embodiments 1 to 6, wherein the cation exchanged chlorophyll is selected from the group consisting of: chlorophyll a, chlorophyll b, chlorophyll c1, chlorophyll c2, chlorophyll c3, chlorophyll d, chlorophyll f and a combination thereof.

[0391] Embodiment 8. The composite material of any embodiment herein, particularly of any one of embodiments 1 to 7, wherein the chelated metal cation has a stronger binding to dioxygen than Mg+2.

[0392] Embodiment 9. The composite material of any embodiment herein, particularly of any one of embodiments 1 to 7, wherein the chelated metal cation is selected from the group consisting of: cobalt cation, copper cation, iron cation, manganese cation, nickel cation, ruthenium cation, rhodium cation, silver cation, vanadium cation, chromium cation, zinc cation, nickel cation, cerium cation, tungsten cation, molybdenum cation, rhenium cation, iridium cation, palladium cation, osmium cation, technetium cation, platinum cation, titanium cation, zirconium cation, hafnium cation, niobium cation, tantalum cation, gallium cation, indium cation, tin cation, lead cation, antimony cation, bismuth cation, thulium cation, thorium cation, boron cation arsenic cation and a combination thereof.

[0393] Embodiment 10. The composite material of any embodiment herein, particularly of any one of embodiments 1 to 9, wherein the chelated metal cation is a divalent cation.

[0394] Embodiment 11. The composite material of any embodiment herein, particularly of embodiment 10, wherein the chelated metal cation is Cu+2.

[0395] Embodiment 12. The composite material of any embodiment herein, particularly of any one of embodiments 1 to 11, which is in a particulate form and has a particle size in the range of 3 nm to 400 nm.

[0396] Embodiment 13. The composite material of any embodiment herein, particularly of embodiment 12, wherein the composite particle is in the form of a quantum dot having particle size in the range of 4 nm to 12 nm.

[0397] Embodiment 14. The composite material of any embodiment herein, particularly of any one of embodiments 1 to 13, which further comprises at least one surface ligand selected from the group consisting of: a carboxylic acid, an amine, an alcohol, a thiol, a phosphine, a phosphine oxide and a combination thereof.

[0398] Embodiment 15. The composite material of any embodiment herein, particularly of embodiment 14, comprising at least one carboxylic acid ligand.

[0399] Embodiment 16. The composite material of any embodiment herein, particularly of embodiment 15, wherein the carboxylic acid ligand comprises a C4-C28 fatty acid.

[0400] Embodiment 17. The composite material of any embodiment herein, particularly of any one of embodiments 15 to 16, wherein the carboxylic acid ligand is selected from the group consisting of: oleic acid, palmitic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, elaidic acid, erucic acid linoleic acid, linoelaidic acid, α-linolenic acid, myristoleic acid, palmitoleic acid, sapienic acid, vaccenic acid and a combination thereof.

[0401] Embodiment 18. The composite material of any embodiment herein, particularly of embodiment 17, wherein the carboxylic acid ligand comprises oleic acid.

[0402] Embodiment 19. The composite material of any embodiment herein, particularly of any one of embodiments 1 to 18, which has solubility of at least 1 gr per liter in diesel fuel.

[0403] Embodiment 20. The composite material of any embodiment herein, particularly of embodiment 19, which has solubility of at least 5 gr per liter in diesel fuel.

[0404] Embodiment 21. The composite material of any embodiment herein, particularly of embodiment 1, wherein the metal oxide comprises CeO2 and the metal oxide core is in the form of a quantum dot having particle size in the range of 1 nm to 20 nm, and wherein the chelated metal cation comprises Cu+2.

[0405] Embodiment 22. The composite material of any embodiment herein, particularly of embodiment 1, comprising a CeO2 core, coated with an organic coating, wherein the organic coating comprises a Cu+2 exchanged chlorophyll and oleic acid; wherein the CeO2 core is particulate in the form of a quantum dot and has a diameter in the range of 1 nm to 4 nm; and wherein the composite material is particulate in the form of a quantum dot and has a diameter in the range of 4 nm to 10 nm.

[0406] Embodiment 23. The composite material of any embodiment herein, particularly of any one of embodiments 1 to 22, which is prepared by a method comprising:

[0407] subjecting a core metal salt to sonication to form a nanoparticulate metal oxide; and

[0408] subjecting the nanoparticulate metal oxide to sonication together with a cation exchanged chlorophyll, to form the composite material.

[0409] Embodiment 24. The composite material of any embodiment herein, particularly of embodiment 23, wherein the method further comprises a step of contacting Mg-chlorophyll with a chelating metal salt to form the cation exchanged chlorophyll, wherein the cation exchanged chlorophyll is performed before the step of subjecting the nanoparticulate metal oxide and cation exchanged chlorophyll to sonication.

[0410] Embodiment 25. The composite material of any embodiment herein, particularly of any one of embodiments 23 to 24, wherein the method further comprises a step of subjecting the nanoparticulate metal oxide to sonication together with at least one surface ligand selected from the group consisting of: a carboxylic acid, an amine, an alcohol, a thiol, a phosphine, a phosphine oxide and a combination thereof,

[0411] wherein the step of subjecting the nanoparticulate metal oxide to sonication together with the at least one surface ligand is performed before, together with, or after the step of subjecting the nanoparticulate metal oxide and the cation exchanged chlorophyll to sonication.

[0412] Embodiment 26. A composite material comprising a metal oxide core, coated with an organic coating, wherein the organic coating comprises a chlorophyll and a fatty acid ligand.

[0413] Embodiment 27. The composite material of any embodiment herein, particularly of embodiment 26, wherein the chlorophyll is a cation exchanged chlorophyll, which comprises a chelated metal cation.

[0414] Embodiment 28. The composite material of any embodiment herein, particularly of embodiment 27, wherein the chelated metal cation is a divalent cation.

[0415] Embodiment 29. The composite material of any embodiment herein, particularly of embodiment 28, wherein the chelated metal cation is Cu+2.

[0416] Embodiment 30. The composite material of any embodiment herein, particularly of any one of embodiments 26 to 29, wherein the metal oxide core comprises a metal oxide selected from the group consisting of: CeO2, AlO3 and MnO2.

[0417] Embodiment 31. The composite material of any embodiment herein, particularly of any one of embodiments 26 to 30, wherein the metal oxide core is particulate, and has a particle size in the range of 1 nm to 500 nm.

[0418] Embodiment 32. The composite material of any embodiment herein, particularly of embodiment 31, wherein the metal oxide core is in the form of a quantum dot having particle size in the range of 1 nm to 20 nm.

[0419] Embodiment 33. The composite material of any embodiment herein, particularly of any one of embodiments 26 to 32, wherein the fatty acid ligand comprises an oleic acid.

[0420] Embodiment 34. The composite material of any embodiment herein, particularly of any one of embodiments 26 to 33, which is prepared by a method comprising:

[0421] subjecting a core metal salt to sonication to form a nanoparticulate metal oxide;

[0422] subjecting the nanoparticulate metal oxide to sonication together with a chlorophyll; and

[0423] subjecting the nanoparticulate metal oxide to sonication together with a fatty acid;

[0424] wherein the step of subjecting the nanoparticulate metal oxide to sonication together with the fatty acid is performed before, together with, or after the step of subjecting the nanoparticulate metal oxide and the chlorophyll to sonication;

[0425] to form the composite material.

[0426] Embodiment 35. The composite material of any embodiment herein, particularly of embodiment 34, wherein the method further comprises, before the step of subjecting the nanoparticulate metal oxide and chlorophyll to sonication, a step of contacting Mg-chlorophyll with a chelating metal salt to form the cation exchanged chlorophyll.

[0427] Embodiment 36. The composite material of any embodiment herein, particularly of any one of embodiments 1 to 35, represented by the formula:z is the number of chlorophyll molecules in a unit of the composite material, and is in the range of 5 to 260,

[0429] x is the number of metal oxide units in a unit of the composite material, and is in the range of 10 to 13,000, and

[0430] y is the number of surface ligand units in a unit of the composite material, and is in the range of 0 to 700.

[0431] Embodiment 37. A fuel composition comprising a motor fuel and a fuel additive, wherein the fuel additive comprises a composite material comprising a metal oxide core, coated with an organic coating, wherein the organic coating comprises a chlorophyll.

[0432] Embodiment 38. The fuel composition of any embodiment herein, particularly of embodiments 37, wherein the composite material comprises the composite material according to any one of any embodiment herein, particularly of embodiments 1 to 36.

[0433] Embodiment 39. The fuel composition of any embodiment herein, particularly of embodiments 37 or 38, wherein the composite material comprises a plurality of composite particles in a form of quantum dots, which have an average particle size in the range of 1 nm to 20 nm.

[0434] Embodiment 40. The fuel composition of any embodiment herein, particularly of embodiment 39, wherein at least 50% of the plurality of composite particles are in a form of quantum dots, which have an average particle size in the range of 5 nm to 7 nm.

[0435] Embodiment 41. The fuel composition of any embodiment herein, particularly of any one of embodiments 37 to 40, which is in a form of solution or suspension.

[0436] Embodiment 42. The fuel composition of any embodiment herein, particularly of any one of embodiments 37 to 41, wherein the motor fuel comprises diesel fuel.

[0437] Embodiment 43. The fuel composition of any embodiment herein, particularly of embodiment 42, wherein the diesel fuel comprises untreated diesel fuel.

[0438] Embodiment 44. The fuel composition of any embodiment herein, particularly of any one of embodiments 37 to 43, comprising 1×10−6 gr to 25 gr of the composite material per liter of the motor fuel.

[0439] Embodiment 45. The fuel composition of any embodiment herein, particularly of embodiment 44, comprising 10−3 gr to 0.04 gr of the composite material per liter of the motor fuel.

[0440] Embodiment 46. The fuel composition of any embodiment herein, particularly of embodiment 37, wherein the a fuel additive comprises a CeO2 core, coated with an organic coating, wherein the organic coating comprises a Cu+2 exchanged chlorophyll and oleic acid; wherein the CeO2 core is particulate in the form of a quantum dot and has a diameter in the range of 1 nm to 4 nm; and wherein the composite material is particulate in the form of a quantum dot and has a diameter in the range of 4 nm to 10 nm.

[0441] Embodiment 47. A composite material prepared by a method comprising the steps of:

[0442] subjecting a core metal salt to sonication, to form a metal oxide; and

[0443] subjecting the metal oxide to sonication together with a chlorophyll, optionally a cation exchanged chlorophyll, to form the composite material.

[0444] Embodiment 48. The composite material of any embodiment herein, particularly of embodiment 47, wherein the chlorophyll comprises a cation exchanged chlorophyll.

[0445] Embodiment 49. The composite material of any embodiment herein, particularly of embodiments 47 or 48, wherein the metal of the metal salt is selected from the group consisting of cerium, aluminum, titanium, zinc, copper, iron, manganese, cobalt, nickel, vanadium, molybdenum, tungsten, chromium and a combination thereof.

[0446] Embodiment 50. The composite material of any embodiment herein, particularly of embodiment 49, wherein the metal of the metal salt is cerium.

[0447] Embodiment 51. The composite material of any embodiment herein, particularly of any one of embodiments 47 to 50, wherein the metal salt comprises a group selected from a halide, oxide, nitrate, tetrafluoroborate, sulfate, sulfonate, cyanide, and phosphate.

[0448] Embodiment 52. The composite material of any embodiment herein, particularly of embodiment 51, wherein the metal salt comprises metal nitrate.

[0449] Embodiment 53. The composite material of any embodiment herein, particularly of embodiment 52, wherein the nitrate consists of NO−3.

[0450] Embodiment 54. The composite material of any embodiment herein, particularly of any one of embodiments 52 to 53, wherein the metal salt comprises cerium nitrate hexahydrate.

[0451] Embodiment 55. The composite material of any embodiment herein, particularly of any one of embodiments 47 to 54, wherein the formed metal oxide comprises a metal oxide selected from the group consisting of: cerium oxide, aluminum oxide, titanium oxide, zinc oxide, copper oxide, iron oxide, manganese oxide, cobalt oxide, nickel oxide, vanadium oxide, molybdenum oxide, tungsten oxide, chromium oxide and a combination thereof. Each possibility represents a separate embodiment of the invention.

[0452] Embodiment 56. The composite material of any embodiment herein, particularly of embodiment 55, wherein the metal oxide is selected from CeO2, AlO3 and MnO2.

[0453] Embodiment 57. The composite material of any embodiment herein, particularly of embodiment 56, wherein the metal oxide comprises CeO2.

[0454] Embodiment 58. The composite material of any embodiment herein, particularly of any one of embodiments 47 to 57, wherein the chlorophyll is selected from the group consisting of: chlorophyll a, chlorophyll b, chlorophyll c1, chlorophyll c2, chlorophyll c3, chlorophyll d, chlorophyll f and a combination thereof.

[0455] Embodiment 59. The composite material of any embodiment herein, particularly of any one of embodiments 47 to 58, wherein the cation exchanged chlorophyll comprises chelated metal cation that has a stronger binding to dioxygen than Mg+2.

[0456] Embodiment 60. The composite material of any embodiment herein, particularly of embodiment 59, wherein the chelated metal cation is selected from the group consisting of: cobalt cation, copper cation, iron cation, manganese cation, nickel cation, ruthenium cation, rhodium cation, silver cation, vanadium cation, chromium cation, zinc cation, nickel cation, cerium cation, tungsten cation, molybdenum cation, rhenium cation, iridium cation, palladium cation, osmium cation, technetium cation, platinum cation, titanium cation, zirconium cation, hafnium cation, niobium cation, tantalum cation, gallium cation, indium cation, tin cation, lead cation, antimony cation, bismuth cation, thulium cation, thorium cation, boron cation arsenic cation and a combination thereof.

[0457] Embodiment 61. The composite material of any embodiment herein, particularly of embodiment 60, wherein the chelated metal cation is a divalent cation.

[0458] Embodiment 62. The composite material of any embodiment herein, particularly of embodiment 61, wherein the chelated metal cation is selected from the group consisting of: Co+2, Cu+2, Mn+2, Fe+2, Zn+2.

[0459] Embodiment 63. The composite material of any embodiment herein, particularly of embodiment 62, wherein the chelated metal cation is Cu+2.

[0460] Embodiment 64. The composite material of any embodiment herein, particularly of any one of embodiments 47 to 63, wherein the metal oxide is in a particulate form.

[0461] Embodiment 65. The composite material of any embodiment herein, particularly of embodiment 64, wherein the metal oxide core has a particle size in the range of 1 nm to 500 nm.

[0462] Embodiment 66. The composite material of any embodiment herein, particularly of embodiment 65, wherein the particulate form is in the form of QDs having particle size in the range of 1-10 nm.

[0463] Embodiment 67. The composite material of any embodiment herein, particularly of any one of embodiments 47 to 65, which is in a particulate form and has a particle size in the range of 3 nm to 400 nm.

[0464] Embodiment 68. The composite material of any embodiment herein, particularly of embodiment 67, wherein the composite particle is in the form of a quantum dot having particle size in the range of 4 nm to 12 nm.

[0465] Embodiment 69. The composite material of any embodiment herein, particularly of any one of embodiments 47 to 68, wherein the method further comprises a step of subjecting the metal oxide to sonication together with at least one surface ligand.

[0466] Embodiment 70. The composite material of any embodiment herein, particularly of embodiment 69, wherein the step of subjecting the metal oxide to sonication together with the at least one surface ligand is performed before the step of subjecting the metal oxide and the cation exchanged chlorophyll to sonication.

[0467] Embodiment 71. The composite material of any embodiment herein, particularly of embodiment 69, wherein the step of subjecting the metal oxide to sonication together with the at least one surface ligand is performed together with the step of subjecting the metal oxide and the cation exchanged chlorophyll to sonication.

[0468] Embodiment 72. The composite material of any embodiment herein, particularly of embodiment 69, wherein the step of subjecting the metal oxide to sonication together with the at least one surface ligand is performed after the step of subjecting the metal oxide and the cation exchanged chlorophyll to sonication.

[0469] Embodiment 73. The composite material of any embodiment herein, particularly of embodiment 69, wherein the step of subjecting the metal oxide to sonication together with the at least one surface ligand is performed at least one of before, together with, or after the step of subjecting the metal oxide and the cation exchanged chlorophyll to sonication.

[0470] Embodiment 74. The composite material of any embodiment herein, particularly of any one of embodiments 47 to 73, which further comprises at least one surface ligand selected from the group consisting of: a carboxylic acid, an amine, an alcohol, a thiol, a phosphine, a phosphine oxide and a combination thereof.

[0471] Embodiment 75. The composite material of any embodiment herein, particularly of embodiment 74, wherein the at least one surface ligand comprises at least one carboxylic acid ligand.

[0472] Embodiment 76. The composite material of any embodiment herein, particularly of embodiment 75, wherein the carboxylic acid ligand comprises a C4-C28 fatty acid.

[0473] Embodiment 77. The composite material of any embodiment herein, particularly of any one of embodiments 75 to 76, wherein the carboxylic acid ligand is selected from the group consisting of: oleic acid, palmitic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, elaidic acid, erucic acid linoleic acid, linoelaidic acid, α-linolenic acid, myristoleic acid, palmitoleic acid, sapienic acid, vaccenic acid and a combination thereof.

[0474] Embodiment 78. The composite material of any embodiment herein, particularly of embodiment 77, wherein the carboxylic acid ligand comprises oleic acid.

[0475] Embodiment 79. The composite material of any embodiment herein, particularly of any one of embodiments 47 to 78, which has solubility of at least 1 gr per liter in diesel fuel.

[0476] Embodiment 80. The composite material of any embodiment herein, particularly of embodiment 79, which has solubility of at least 5 gr per liter in diesel fuel.

[0477] Embodiment 81. The composite material of any embodiment herein, particularly of embodiment 80, which has solubility of at least 60 gr per liter in diesel fuel.

[0478] Embodiment 82. The composite material of any embodiment herein, particularly of any one of embodiments 47 to 81, which has solubility of at least 1 gr per liter in hexane.

[0479] Embodiment 83. The composite material of any embodiment herein, particularly of embodiment 82, which has solubility of at least 5 gr per liter in hexane.

[0480] Embodiment 84. The composite material of any embodiment herein, particularly of embodiment 83, which has solubility of at least 60 gr per liter in hexane.

[0481] Embodiment 85. The composite material of any embodiment herein, particularly of embodiment 47, wherein the metal oxide comprises CeO2 and the metal oxide core is in the form of a quantum dot having particle size in the range of 1 nm to 20 nm, and wherein the chlorophyll is a cation exchanged chlorophyll comprising the chelated metal cation Cu+2.

[0482] Embodiment 86. The composite material of any embodiment herein, particularly of any one of embodiments 47 to 85, wherein the method further comprises a step of contacting Mg-chlorophyll with a chelating metal salt to form the cation exchanged chlorophyll, before the step of subjecting the metal oxide and cation exchanged chlorophyll to sonication.

[0483] Embodiment 87. The composite material of any embodiment herein, particularly of embodiment 86, wherein the step of contacting Mg-chlorophyll with a chelating metal salt comprises boiling a solution comprising the Mg-chlorophyll and the chelating metal salt for a time period of 0.5-60 minutes, optionally for a time period of 1-15 minutes.

[0484] Embodiment 88. The composite material of any embodiment herein, particularly of embodiments 86 or 87, wherein the chelating metal salt comprises a metal selected from cobalt, copper, iron, manganese, nickel, ruthenium, rhodium, silver, vanadium, chromium, zinc, nickel, cerium, tungsten, molybdenum, rhenium, iridium, palladium, osmium, technetium, platinum, titanium, zirconium, hafnium, niobium, tantalum, gallium, indium, tin, lead, antimony, bismuth, thulium, thorium, boron arsenic and a combination thereof.

[0485] Embodiment 89. The composite material of any embodiment herein, particularly of embodiment 88, wherein the chelating metal salt comprises copper.

[0486] Embodiment 90. The composite material of any embodiment herein, particularly of any one of embodiments 86 to 89, wherein the chelating metal salt comprises a group selected from a halide (including, for example, chloride, fluoride, bromide, iodide), oxide, nitrate, tetrafluoroborate, sulfate, sulfonate, cyanide, and phosphate. According to some particular embodiments, metal salt comprises a group selected from nitrate, halide, and sulfate.

[0487] Embodiment 91. The composite material of any embodiment herein, particularly of embodiment 47, comprising a CeO2 core, coated with an organic coating, wherein the organic coating comprises a Cu+2 exchanged chlorophyll and oleic acid; wherein the CeO2 core is particulate in the form of a quantum dot and has a diameter in the range of 1 nm to 4 nm; and wherein the composite material is particulate in the form of a quantum dot and has a diameter in the range of 4 nm to 10 nm.

[0488] Embodiment 92. The composite material of any embodiment herein, particularly of embodiment 20, which has solubility of at least 60 gr per liter in diesel fuel.

[0489] Embodiment 93. The composite material of any embodiment herein, particularly of any one of embodiments 1 to 20, which has solubility of at least 1 gr per liter in hexane.

[0490] Embodiment 94. The composite material of any embodiment herein, particularly of embodiment 93, which has solubility of at least 5 gr per liter in hexane.

[0491] Embodiment 95. The composite material of any embodiment herein, particularly of embodiment 94, which has solubility of at least 60 gr per liter in hexane.

[0492] Embodiment 95. A means for enhancing fuel efficiency, comprising adding the composite material of any embodiment herein, particularly of any one of embodiments 1 to 36 and 47 to 94 to a motor fuel.

[0493] Embodiment 96. The means for enhancing fuel efficiency of any embodiment herein, particularly of embodiment 95, wherein the motor fuel comprises diesel fuel.

[0494] Embodiment 97. The means for enhancing fuel efficiency of any embodiment herein, particularly of embodiments 95 or 96, wherein the diesel fuel comprises untreated diesel fuel.

[0495] Embodiment 98. The means for enhancing fuel efficiency of any embodiment herein, particularly of any one of embodiments 95 to 97, wherein the composite material is added to achieve a concentration of 1×10−6 gr to 25 gr of the composite material per liter of the motor fuel.

[0496] Embodiment 99. The means for enhancing fuel efficiency of any embodiment herein, particularly of embodiment 98, wherein the composite material is added to achieve a concentration of 10−3 gr to 0.04 gr of the composite material per liter of the motor fuel.

[0497] Embodiment 100. The composite material of any embodiment herein, particularly of any one of embodiments 1 to 36 and 47 to 94, for use in enhancing fuel efficiency.

[0498] Embodiment 101. A method for preparing a composite material comprising the steps of:

[0499] subjecting a core metal salt to sonication, to form a metal oxide; and

[0500] subjecting the metal oxide to sonication together with a chlorophyll, optionally a cation exchanged chlorophyll, to form the composite material.

[0501] Embodiment 102. The method of any embodiment herein, particularly of embodiment 101, wherein the chlorophyll comprises a cation exchanged chlorophyll.

[0502] Embodiment 103. The method of any embodiment herein, particularly of embodiments 101 or 102, wherein the metal of the metal salt is selected from the group consisting of cerium, aluminum, titanium, zinc, copper, iron, manganese, cobalt, nickel, vanadium, molybdenum, tungsten, chromium and a combination thereof.

[0503] Embodiment 104. The method of any embodiment herein, particularly of embodiment 102, wherein the metal of the metal salt is cerium.

[0504] Embodiment 105. The method of any embodiment herein, particularly of any one of embodiments 101 to 104, wherein the metal salt comprises a group selected from a halide, oxide, nitrate, tetrafluoroborate, sulfate, sulfonate, cyanide, and phosphate.

[0505] Embodiment 106. The method of any embodiment herein, particularly of embodiment 105, wherein the metal salt comprises metal nitrate.

[0506] Embodiment 107. The method of any embodiment herein, particularly of embodiment 106, wherein the nitrate consists of NO−3.

[0507] Embodiment 108. The method of any embodiment herein, particularly of any one of embodiments 106 to 107, wherein the metal salt comprises cerium nitrate hexahydrate.

[0508] Embodiment 109. The method of any embodiment herein, particularly of any one of embodiments 101 to 108, wherein the formed metal oxide comprises a metal oxide selected from the group consisting of: cerium oxide, aluminum oxide, titanium oxide, zinc oxide, copper oxide, iron oxide, manganese oxide, cobalt oxide, nickel oxide, vanadium oxide, molybdenum oxide, tungsten oxide, chromium oxide and a combination thereof. Each possibility represents a separate embodiment of the invention.

[0509] Embodiment 110. The method of any embodiment herein, particularly of embodiment 109, wherein the metal oxide is selected from CeO2, AlO3 and MnO2.

[0510] Embodiment 111. The method of any embodiment herein, particularly of embodiment 110, wherein the metal oxide comprises CeO2.

[0511] Embodiment 112. The method of any embodiment herein, particularly of any one of embodiments 101 to 111, wherein the chlorophyll is selected from the group consisting of: chlorophyll a, chlorophyll b, chlorophyll c1, chlorophyll c2, chlorophyll c3, chlorophyll d, chlorophyll f and a combination thereof.

[0512] Embodiment 113. The method of any embodiment herein, particularly of any one of embodiments 101 to 112, wherein the cation exchanged chlorophyll comprises chelated metal cation that has a stronger binding to dioxygen than Mg+2.

[0513] Embodiment 114. The method of any embodiment herein, particularly of embodiment 113, wherein the chelated metal cation is selected from the group consisting of: cobalt cation, copper cation, iron cation, manganese cation, nickel cation, ruthenium cation, rhodium cation, silver cation, vanadium cation, chromium cation, zinc cation, nickel cation, cerium cation, tungsten cation, molybdenum cation, rhenium cation, iridium cation, palladium cation, osmium cation, technetium cation, platinum cation, titanium cation, zirconium cation, hafnium cation, niobium cation, tantalum cation, gallium cation, indium cation, tin cation, lead cation, antimony cation, bismuth cation, thulium cation, thorium cation, boron cation arsenic cation and a combination thereof.

[0514] Embodiment 115. The method of any embodiment herein, particularly of embodiments 113, wherein the chelated metal cation is a divalent cation.

[0515] Embodiment 116. The method of any embodiment herein, particularly of embodiment 115, wherein the chelated metal cation is selected from the group consisting of: Co+2, Cu+2, Mn+2, Fe+2, Zn+2.

[0516] Embodiment 117. The method of any embodiment herein, particularly of embodiment 116, wherein the chelated metal cation is Cu+2.

[0517] Embodiment 118. The method of any embodiment herein, particularly of any one of embodiments 101 to 117, wherein the metal oxide is in a particulate form.

[0518] Embodiment 119. The method of any embodiment herein, particularly of embodiment 118, wherein the metal oxide core has a particle size in the range of 1 nm to 500 nm.

[0519] Embodiment 120. The method of any embodiment herein, particularly of embodiment 119, wherein the particulate form is in the form of QDs having particle size in the range of 1-10 nm.

[0520] Embodiment 121. The method of any embodiment herein, particularly of any one of embodiments 101 to 120, wherein the formed composite material is in a particulate form and has a particle size in the range of 3 nm to 400 nm.

[0521] Embodiment 122. The method of any embodiment herein, particularly of embodiment 121, wherein the composite particle is in the form of a quantum dot having particle size in the range of 4 nm to 12 nm.

[0522] Embodiment 123. The method of any embodiment herein, particularly of any one of embodiments 101 to 122, further comprising a step of subjecting the metal oxide to sonication together with at least one surface ligand.

[0523] Embodiment 124. The method of any embodiment herein, particularly of embodiment 123, wherein the step of subjecting the metal oxide to sonication together with the at least one surface ligand is performed before the step of subjecting the metal oxide and the cation exchanged chlorophyll to sonication.

[0524] Embodiment 125. The method of any embodiment herein, particularly of embodiment 123, wherein the step of subjecting the metal oxide to sonication together with the at least one surface ligand is performed together with the step of subjecting the metal oxide and the cation exchanged chlorophyll to sonication.

[0525] Embodiment 126. The method of any embodiment herein, particularly of embodiment 123, wherein the step of subjecting the metal oxide to sonication together with the at least one surface ligand is performed after the step of subjecting the metal oxide and the cation exchanged chlorophyll to sonication.

[0526] Embodiment 127. The method of any embodiment herein, particularly of embodiment 123, wherein the step of subjecting the metal oxide to sonication together with the at least one surface ligand is performed at least one of before, together with, or after the step of subjecting the metal oxide and the cation exchanged chlorophyll to sonication.

[0527] Embodiment 128. The method of any embodiment herein, particularly of any one of embodiments 123 to 127, wherein the at least one surface ligand is selected from the group consisting of: a carboxylic acid, an amine, an alcohol, a thiol, a phosphine, a phosphine oxide and a combination thereof.

[0528] Embodiment 129. The method of any embodiment herein, particularly of embodiment 128, wherein the at least one surface ligand comprises at least one carboxylic acid ligand.

[0529] Embodiment 130. The method of any embodiment herein, particularly of embodiment 129, wherein the carboxylic acid ligand comprises a C4-C28 fatty acid.

[0530] Embodiment 131. The method of any embodiment herein, particularly of any one of embodiments 129 to 130, wherein the carboxylic acid ligand is selected from the group consisting of: oleic acid, palmitic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, elaidic acid, erucic acid linoleic acid, linoelaidic acid, α-linolenic acid, myristoleic acid, palmitoleic acid, sapienic acid, vaccenic acid and a combination thereof.

[0531] Embodiment 132. The method of any embodiment herein, particularly of embodiment 131, wherein the carboxylic acid ligand comprises oleic acid.

[0532] Embodiment 133. The method of any embodiment herein, particularly of any one of embodiments 101 to 132, wherein the formed composite material has a solubility of at least 1 gr per liter in diesel fuel.

[0533] Embodiment 134. The method of any embodiment herein, particularly of embodiment 133, wherein the formed composite material has a solubility of at least 5 gr per liter in diesel fuel.

[0534] Embodiment 135. The method of any embodiment herein, particularly of embodiment 134, wherein the formed composite material has a solubility of at least 60 gr per liter in diesel fuel.

[0535] Embodiment 136. The method of any embodiment herein, particularly of any one of embodiments 101 to 135, wherein the formed composite material has a solubility of at least 1 gr per liter in hexane.

[0536] Embodiment 137. The method of any embodiment herein, particularly of embodiment 136, wherein the formed composite material has a solubility of at least 5 gr per liter in hexane.

[0537] Embodiment 138. The method of any embodiment herein, particularly of embodiment 137, wherein the formed composite material has a solubility of at least 60 gr per liter in hexane.

[0538] Embodiment 139. The method of any embodiment herein, particularly of embodiment 101, wherein the metal oxide comprises CeO2 and the metal oxide core is in the form of a quantum dot having particle size in the range of 2 nm to 10 nm, and wherein the chlorophyll is a cation exchanged chlorophyll comprising the chelated metal cation Cu+2.

[0539] Embodiment 140. The method of any embodiment herein, particularly of any one of embodiments 101 to 139, further comprising a step of contacting Mg-chlorophyll with a chelating metal salt to form the cation exchanged chlorophyll, before the step of subjecting the metal oxide and cation exchanged chlorophyll to sonication.

[0540] Embodiment 141. The method of any embodiment herein, particularly of embodiment 140, wherein the step of contacting Mg-chlorophyll with a chelating metal salt comprises boiling a solution comprising the Mg-chlorophyll and the chelating metal salt for a time period of 0.5-60 minutes, optionally for a time period of 1-15 minutes.

[0541] Embodiment 142. The method of any embodiment herein, particularly of embodiments 140 or 141, wherein the chelating metal salt comprises a metal selected from cobalt, copper, iron, manganese, nickel, ruthenium, rhodium, silver, vanadium, chromium, zinc, nickel, cerium, tungsten, molybdenum, rhenium, iridium, palladium, osmium, technetium, platinum, titanium, zirconium, hafnium, niobium, tantalum, gallium, indium, tin, lead, antimony, bismuth, thulium, thorium, boron arsenic and a combination thereof.

[0542] Embodiment 143. The method of any embodiment herein, particularly of embodiment 142, wherein the chelating metal salt comprises copper.

[0543] Embodiment 144. The method of any embodiment herein, particularly of any one of embodiments 140 to 143, wherein the chelating metal salt comprises a group selected from a halide (including, for example, chloride, fluoride, bromide, iodide), oxide, nitrate, tetrafluoroborate, sulfate, sulfonate, cyanide, and phosphate. According to some particular embodiments, metal salt comprises a group selected from nitrate, halide, and sulfate.

[0544] Embodiment 145. The method of any embodiment herein, particularly of embodiment 101, wherein the formed composite material comprises a CeO2 core, coated with an organic coating, wherein the organic coating comprises a Cu+2 exchanged chlorophyll and oleic acid; wherein the CeO2 core is particulate in the form of a quantum dot and has a diameter in the range of 1 nm to 4 nm; and wherein the composite material is particulate in the form of a quantum dot and has a diameter in the range of 4 nm to 10 nm.

[0545] Embodiment 145. A composite material prepared according to a method of any embodiment herein, particularly according to any one of embodiments 101 to 144.

[0546] Embodiment 146. A liquid fuel additive formulation comprising a solvent and a fuel additive, wherein the fuel additive comprises a composite material comprising a metal oxide core, coated with an organic coating, wherein the organic coating comprises a chlorophyll.

[0547] Embodiment 147. The liquid fuel additive formulation of any embodiment herein, particularly of embodiment 146, wherein the composite material comprises the composite material of any one of embodiments 1 to 36 and 47 to 94.

[0548] Embodiment 148. The liquid fuel additive formulation of any embodiment herein, particularly of embodiments 146 or 147, comprising 0.5% to 10% composite material in the solvent w / v.

[0549] Embodiment 149. The liquid fuel additive formulation of any embodiment herein, particularly of any one of embodiments 146 to 148, wherein the solvent is a non-polar organic solvent.

[0550] Embodiment 150. The liquid fuel additive formulation of any embodiment herein, particularly of embodiment 149, wherein the solvent comprises kerosene, TBME, or a mixture thereof.

[0551] Embodiment 151. The liquid fuel additive formulation of any embodiment herein, particularly of any one of embodiments 146 to 150, wherein the metal oxide core comprises CeO2.

[0552] Embodiment 152. The liquid fuel additive formulation of any embodiment herein, particularly of any one of embodiments 146 to 151, wherein the metal oxide core is particulate, and has a particle size in the range of 1 nm to 500 nm.

[0553] Embodiment 153. The liquid fuel additive formulation of any embodiment herein, particularly of embodiment 152, wherein the metal oxide core is in the form of a quantum dot having particle size in the range of 1 nm to 20 nm.

[0554] Embodiment 154. The liquid fuel additive formulation of any embodiment herein, particularly of any one of embodiments 146 to 153, wherein the chlorophyll is selected from the group consisting of: chlorophyll a, chlorophyll b, chlorophyll c1, chlorophyll c2, chlorophyll c3, chlorophyll d, chlorophyll f and a combination thereof.

[0555] Embodiment 155. The liquid fuel additive formulation of any embodiment herein, particularly of any one of embodiments 146 to 154, wherein the chlorophyll is a cation exchanged chlorophyll, which comprises a chelated metal cation.

[0556] Embodiment 156. The liquid fuel additive formulation of any embodiment herein, particularly of 155, wherein the chelated metal cation is a divalent cation.

[0557] Embodiment 157. The liquid fuel additive formulation of any embodiment herein, particularly of embodiment 156, wherein the chelated metal cation is Cu+2.

[0558] Embodiment 158. The liquid fuel additive formulation of any embodiment herein, particularly of any one of embodiments 146 to 157, wherein the composite material is in a particulate form and has a particle size in the range of 3 nm to 400 nm.

[0559] Embodiment 159. The liquid fuel additive formulation of any embodiment herein, particularly of embodiment 158, wherein the composite particle is in the form of a quantum dot having particle size in the range of 4 nm to 12 nm.

[0560] Embodiment 160. The liquid fuel additive formulation of any embodiment herein, particularly of any one of embodiments 146 to 159, wherein the composite material has solubility of at least 1 gr per liter in diesel fuel.

[0561] Embodiment 161. The liquid fuel additive formulation of any embodiment herein, particularly of any one of embodiments 146 to 160, wherein the composite material has solubility of at least 1 gr per liter in hexane.

[0562] Embodiment 162. A means for enhancing fuel efficiency, comprising adding the liquid fuel additive formulation of any embodiment herein, particularly of any one of embodiments 146 to 161, to a motor fuel.

[0563] Embodiment 163. The means for enhancing fuel efficiency of any embodiment herein, particularly of embodiment 162, wherein the motor fuel comprises diesel fuel.

[0564] Embodiment 164. The composite material of any embodiment herein, particularly of any one of embodiments 1 to 36 and 47 to 94, which is suitable for use in enhancing fuel efficiency.Definitions

[0565] To facilitate an understanding of the present invention, a number of terms and phrases are defined below. It is to be understood that these terms and phrases are for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance presented herein, in combination with the knowledge of one of ordinary skill in the art.

[0566] The term “about” means ±20%, ±15%, ±10% or ±5% or a specified value. Each possibility represents a separate embodiment of the invention.

[0567] The term “fuel” as used herein refers to compositions (e.g., liquid compositions and mixtures) that include one or more alcohols, one or more hydrocarbons, one or more fatty esters, or a mixture thereof. The fuel disclosed herein can be used to power internal combustion engines such as reciprocating engines (e.g., gasoline engines and diesel engines), jet engines, and gas turbine engines.

[0568] The term “fuel composition”, as used herein, refers to a composition comprising one or more fuel components and one or more fuel additives.

[0569] As used herein, the term “motor fuel” refers to any combustible vehicle fuel suitable for powering internal combustion engines in motorized vehicles, including but not limited to automobiles, trucks, motorcycles, aircraft, and marine vessels. The term encompasses both conventional and alternative fuels, including gasoline, diesel fuel, kerosene or any other fraction of crude oil or extract thereof, biodiesel, jet fuel, ethanol-containing fuels, renewable diesel, and synthetic fuels derived from biomass or other feedstocks. The term includes both hydrocarbon fuels and oxygenated fuels, whether of fossil origin or bio-based. Motor fuel may be liquid, including in emulsion, dispersion or suspension forms, provided it is suitable for combustion in a vehicle engine.

[0570] As used herein, the term “hydrocarbon fuel” refers to any combustible fuel comprising primarily hydrocarbons, including alkanes, alkenes, cycloalkanes, aromatics, or mixtures thereof. Hydrocarbon fuel includes, but is not limited to, gasoline, diesel fuel, jet fuel, marine fuel, kerosene, or any other fraction of crude oil or extract thereof, natural gas, liquefied petroleum gas (LPG), and synthetic hydrocarbons. Hydrocarbon fuels may be derived from crude oil, petroleum, coal, natural gas, biomass, or other feedstocks.

[0571] The term “Fuel component”, as used herein, refers to any compound or a mixture of compounds that are used to formulate a fuel composition. There are “major fuel components” and “minor fuel components.” A major fuel component is present in a fuel composition in at least 5% by weight or volume; and a minor fuel component is present in a fuel composition in less than 5%. Fuel additives are minor fuel components.

[0572] The term “diesel fuel”, as used herein, is defined as a fraction of crude oil mainly contains mixture of hydrocarbons which boil at atmospheric pressure over a temperature range within about 150° C. to 380° C., optionally from about 160° C. to 350° C.

[0573] The term “gasoline fuel”, as used herein, is defined as a fraction of crude oil mainly contains mixture of hydrocarbons which boil at atmospheric pressure over a temperature range within about 25° C. to 220° C., optionally, from about 62° C. to 151° C.

[0574] The term “Fuel additive”, as used herein, refers to a minor fuel component (in weight), such as chemical components added to fuels to alter the properties of the fuel, e.g., to improve engine performance, combustion efficiency, fuel handling, fuel stability, or for contaminant control.

[0575] The term “particulate”, as used herein refers to a collection of divided particles. The particulate has a range of sizes and morphologies. Particulate forms include, but are not limited to microparticles, nanoparticles (including small nanoparticles) and quantum dots.

[0576] The term “microparticle”, as used herein, means a microscopic particle whose size is typically measured in micrometers (m). A microparticle usually has a particle size of greater than 0.1 m, and more typically has a particle size of greater than 0.5 m. The particle size of a microparticle is typically up to 500 m. Often, however, a microparticle has a particle size of up to 100 m.

[0577] The term “nanoparticle”, as used herein, means a microscopic particle whose size is typically measured in nanometers (nm). A nanoparticle typically has a particle size of from 10 nm to 500 nm, for instance from 10 nm to 250 nm. A nanoparticle may for instance be a particle having size of from 10 nm to 300 nm, or for example from 10 nm to 200 nm. Often, a nanoparticle has a particle size of from 10 nm to 150 nm, for instance from 10 nm to 100 nm. The term “nanoparticle” includes larger nanoparticles, which have particle size closer to the upper limit of the term, as well as “small nanoparticles”, which have particle size closer to the lower limit of the term “nanoparticle”.

[0578] The term “small nanoparticle”, as used herein, means a nanoparticle having a particle size in the range of 10 nm to 50 nm.

[0579] The term “quantum dot” or “QD”, as used herein refers to nanocrystals that exhibit quantum confinement or exciton confinement. The quantum dots may be substantially uniform in material properties or, according to some embodiments, may be non-uniform, for example, including a core and at least one shell. The optical properties of quantum dots can be affected by their particle size, chemical composition, and / or surface composition, and can be determined by suitable optical tests available in the art. A QD typically has a particle size of from 1 nm to 20 nm, for instance from 3 nm to 10 nm.

[0580] The term “composite material”, as used herein, refers to a macro-structure comprising two or more distinct materials with varying physical or chemical properties, e.g., metal-oxide and chlorophyll, which, when combined, produce enhanced performance characteristics that are superior to those of the individual constituents.

[0581] The term “salt”, as used herein, refers to a chemical compound consisting of an assembly of positively charged ions (cations) and negatively charged ions (anions), which results in a compound with no net electric charge (electrically neutral). The term “metal salt”, as used herein, refers to a salt comprising a metal cation and a complementary anion.

[0582] As used herein, the term “chelated metal cation” refers to a metal ion that is coordinated by two or more electron donor atoms from a single organic ligand to form a stable complex. In particular, the term encompasses metal cations that are bound within the central coordination cavity of a macrocyclic ligand, such as a chlorin or porphyrin ring system, through coordination to multiple (e.g., four) nitrogen atoms located at the core of the macrocycle. For example, in natural chlorophylls, the chelated metal cation is typically magnesium (Mg2+), coordinated by the inner nitrogen atoms of the tetrapyrrolic chlorin structure. In metal-cation-exchanged chlorophyll, the magnesium ion may be replaced by another metal cation, such as copper (Cu2+), zinc (Zn2+), or other transition or main-group metal ions capable of forming a stable chelate with the core nitrogen atoms of the macrocyclic ring. The chelation may contribute to structural stability, electronic properties, or functional performance of the composite material, including its interaction external molecules or with light, redox activity, or catalytic behavior.

[0583] The term “chlorophyll”, as used herein, refer to a biomolecule that is critical in photosynthesis, and which allows plants and other photosynthetic organisms to absorb energy from light. Chlorophyll absorbs light most strongly in the blue portion, and to a lesser degree, in the red portion of the electromagnetic spectrum. The green color of chlorophyll is due to the biomolecule's poor absorption of green and near-green light. Chlorophyll is structurally similar and produced through the same metabolic pathway as other porphyrin pigments such as heme, an iron compound of protoporphyrin constituting the pigmental or protein-free part of the hemoglobin molecule, responsible for the molecule's oxygen-carrying properties. The term “chlorophyll”, as used herein, includes, but is not limited to, Chlorophyll a, Chlorophyll b, Chlorophyll c1, Chlorophyll c2, Chlorophyll c3, Chlorophyll d and Chlorophyll f. Unless explicitly stated otherwise, the term “Chlorophyll” as used herein encompasses also cation exchanged chlorophyll, defined herein below. The chemical structures of Chlorophyll a, Chlorophyll b, Chlorophyll c1, Chlorophyll c2, Chlorophyll c3, Chlorophyll d and Chlorophyll f are provided below:

[0584] The most widely distributed form that occurs in terrestrial plants is chlorophyll a. As also can be witnessed from the above chemical structures, the natural chlorophylls bind Mg+2 cation.

[0585] The term “cation exchanged chlorophyll” refers to a chlorophyll molecule, which binds a cation other than magnesium, Mg+2. Similarly, the terms “cation exchanged chlorophyll a”, “cation exchanged chlorophyll b”, “cation exchanged chlorophyll c1”, “cation exchanged chlorophyll c2”, “cation exchanged chlorophyll c3”, “cation exchanged chlorophyll d” and “cation exchanged chlorophyll f”, refer to the specific chlorophyll type, with the Mg+2 substituted for a cation other than Mg+2

[0586] The term “divalent cation” as used herein refers to a cation, which has a +2 positive electrical charge.

[0587] The term “unsaturated carboxylic acid”, as used herein, means a compound having both an unsaturated bond (e.g., a carbon-carbon double bond and / or triple bond) and a carboxylate group, —COOH, or in its deprotonated from, —COO−. Unsaturated carboxylic acids may contain more than a single unsaturated bond and more than a single carboxylic acid groups. The term “saturated carboxylic acid” is also to be understood as meaning aromatic acids, for example benzoic acid, terephthalic acid, isophthalic acid, phthalic acid and their anhydrides.

[0588] The term “saturated carboxylic acid”, as used herein, means a compound having and a carboxylate group, —COOH, or in its deprotonated from, —COO−, wherein each of its carbon-carbon bonds is saturated, i.e., carbon-carbon single, or sigma bonds.

[0589] The term “fatty acid”, as used herein, refers to a carboxylic acid with an aliphatic chain, which may be saturated or unsaturated. Fatty acids have the general formula CnHm—COOH or deprotonated equivalents, CnHm—COO−, wherein n is an integer, which is equal or greater than 4. The relative ratio between n and m depend on the level of saturation of the fatty acid. When using the phrase “C4-C28 fatty acid”, it is intended to mean that the total number of carbon atoms in the fatty acid (including the carboxylic carbon) is at least 4 and not more than 28. For example, butyric acid, CH3CH2CH2COOH is defined under the C4-C28 fatty acid definition.

[0590] The term “amine”, as used herein, refers to primary, secondary, and tertiary amines having, e.g., the formula N(group)3 wherein each group can independently be H or non-H, such as optionally substituted alkyl, optionally substituted aryl, and the like. Amines include but are not limited to R—NH2, for example, alkylamines, arylamines, alkylarylamines; R2NH wherein each R is independently selected, such as dialkylamines, diarylamines, aralkylamines, heterocyclylamines and the like; and R3N wherein each R is independently selected, such as trialkylamines, dialkylarylamines, alkyldiarylamines, triarylamines, and the like. The term “amine” also includes ammonium ions and polyamines, such as diamines (e.g., ethylene diamine), triamines and the like.

[0591] The term “amino acid” or “amino acids”, as used herein, is understood to include the 20 naturally occurring amino acids, i.e., alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine and valine. Each possibility represents a separate embodiment of the invention. According to other embodiments, the term “amino acids” refers to non-natural amino acids or synthetic amino acids.

[0592] The term “biogenic amine”, as used herein, includes a biogenic substance with one or more amine groups. Biogenic amines are basic nitrogenous compounds formed mainly by decarboxylation of amino acids or by amination and transamination of aldehydes and ketones. Biogenic amines are organic bases with low molecular weight and are synthesized by microbial, vegetable and animal metabolisms. In food and beverages, they are formed by the enzymes of raw material or are generated by microbial decarboxylation of amino acids. There are two major categories of biogenic amines, Monoamines and Polyamines. Notable examples of Monoamines include histamine, serotonin, norepinephrine, epinephrine, dopamine, phenethylamines, tryptamines, trimethylamine, indoleamines and melatonin. Notable examples of Polyamines include agmatine, cadaverine, putrescine, spermine and spermidine.

[0593] The term “alcohol”, as used herein, refers to an organic compound comprising one or more hydroxy (—OH) groups each bonded to a saturated carbon atom (i.e., a carbon atom having single bonds only, typically sp3-hybridized). The alcohol may be a monohydric alcohol, containing a single hydroxy group, or a polyhydric alcohol (also referred to as a polyol), containing two or more hydroxy groups. Unless specified otherwise, the term alcohol includes compounds in which the hydroxy-bearing carbon is part of an alkyl, cycloalkyl, aryl, heteroaryl, or heterocyclyl group, each of which may be unsubstituted or substituted as defined for those respective terms. The alcohol may further comprise one or more additional functional groups, provided that the compound retains at least one non-carboxylic acid hydroxy group. For the avoidance of doubt, compounds in which the only hydroxy group(s) is part of a carboxyl group (—COOH) are excluded from the definition of alcohol as used herein. Representative examples of monohydric alcohols include, without limitation: methanol, ethanol, propanol (e.g., isopropanol), butanol, pentanol, hexanol, cyclohexanol, octanol, decanol, hexadecanol, allyl alcohol, benzyl alcohol, 2-phenylethanol and geraniol. Representative examples of polyhydric alcohols (polyols) include, without limitation: ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, glycerol (1,2,3-propane-triol), pentaerythritol, sorbitol, and mannitol. References to specific alcohols are intended to cover each of their isomers, for example, “propanol” means n-propanol or isopropanol, butanol means, n-butanol, sec-butanol, isobutanol or tert-butanol, etc. The term “thiol”, as used herein, refers to an organic compound, which has the general formula R—SH, wherein R is an organic residue, such as optionally substituted alkyl, optionally substituted aryl and the like. According to some embodiments, the thiol is an aliphatic thiol. Polythiolated compounds are also covered under the “thiol” definition.

[0594] The term “phosphine”, as used herein, refers to primary, secondary, and tertiary phosphines having, e.g., the formula P(group)3 wherein each group can independently be H or non-H, such as optionally substituted alkyl, optionally substituted aryl, and the like. Phosphines include but are not limited to R—PH2, for example, alkylphosphines, arylphosphines, alkylarylphosphines; R2PH wherein each R is independently selected, such as dialkylphosphines, diarylphosphines, aralkylphosphines, heterocyclylphosphines and the like; and R3P wherein each R is independently selected, such as trialkylphosphines, dialkylarylphosphines, alkyldiarylphosphines, triarylphosphines, and the like. According to some embodiments, the phosphine is a tertiary phosphine.

[0595] The term “phosphine oxide”, as used herein, refers to primary, secondary, and tertiary phosphine oxides having, e.g., the formula O═P(group)3 wherein each group can independently be H or non-H, such as optionally substituted alkyl, optionally substituted aryl, and the like. Phosphine oxides include but are not limited to R—P(O)H2, for example, alkylphosphine oxides, arylphosphine oxides, alkylarylphosphine oxides; R2P(O)H wherein each R is independently selected, such as dialkylphosphine oxides, diarylphosphine oxides, aralkylphosphine oxides, heterocyclylphosphine oxides and the like; and R3P═O wherein each R is independently selected, such as trialkylphosphine oxides, dialkylarylphosphine oxides, alkyldiarylphosphine oxides, triarylphosphine oxides, and the like. According to some embodiments, the phosphine oxide is a tertiary phosphine oxide.EXAMPLESExample 1: Exchange of Metal in Chlorophyll-Mg+2 Extract to Produce Chlorophyll-Cu+2

[0596] 300 mg of Chlorophyll-Mg+2 pure fractions were placed in 50 ml Erlenmeyer flask, dissolved in 15 ml dichloromethane, and heated to 60° C. In parallel 102 mg of copper nitrate tetrahydrate (Cu(NO3)2·4H2O) were dissolved in 0.5 ml methanol, and the solution was added to the flask, and boiled under continuous stirring for 10 min. The mixture was cooled to room temperature and washed once in a separation funnel with deionized water. The organic phase was dried with sodium sulphate and evaporated under vacuum. The final product after evaporation was stored in a 5 ml vial at 0-5° C. The product Chlorophyll-Cu+2 has a blue-green color, with three absorbance peaks at 250-310 nm (max. at 270 nm), 380-440 nm (max. at 422 nm), and at 630-670 nm (max. at 650 nm). TLC on Silica gel aluminum plate in Hexane / acetone 7:3 solvent showed Rf 0.58. Table 1 depicts the color and absorbance comparison of copper modified chlorophyll and native magnesium chlorophyll.TABLE 1Color and absorbance of copper modified chlorophyll and magnesiumchlorophyllMetalColor of chlorophyllMax. Abs. (nm)Magnesiumyellow green665CopperBlue green650Example 2: Exchange of Metal in Chlorophyll-Mg+2 Extract to Produce Chlorophyll-Co+2

[0597] 300 mg of Chlorophyll-Mg+2 pure fractions were placed in 50 ml Erlenmeyer flask, dissolved in 15 ml dichloromethane, and heated to 60° C. In parallel 100 mg of Cobalt Nitrate hexahydrate (Co(NO3)2·6H2O) were dissolved in 0.5 ml methanol, and the solution was added to the flask, and boiled under continuous stirring for 10 min. The mixture was cooled to room temperature and washed once in a separation funnel with deionized water. The organic phase was dried with sodium sulphate and evaporated under vacuum. The final product after evaporation was stored in a 5 ml vial at 0-5° C. The product Chlorophyll-Co+2 has a black-green color, with three absorbance peaks at 250-310 nm (max. at 270 nm), 380-440 nm (max. at 420 nm), and at 630-670 nm (max. at 645 nm). TLC on Silica gel aluminum plate in Hexane / acetone 7:3 solvent show Rf 0.55. Table 2 depicts the color and absorbance comparison of cobalt modified chlorophyll and native magnesium chlorophyll.TABLE 2Color and absorbance of cobalt modified chlorophyll and magnesiumchlorophyllMetalColor of chlorophyllMax. Abs. (nm)Magnesiumyellow green665Cobaltdark green645Example 3: Exchange of Metal in Chlorophyll-Mg+2 Extract to Produce Chlorophyll-Mn+2

[0598] The procedure, as described in examples 1 and 2, was performed with 70 mg of Manganese Chloride (MnCl2) used for metal exchange. The achieved product Chlorophyll-Mn+2 has a brown-green color.Example 4: Exchange of Metal in Chlorophyll-Mg+2 Extract to Produce Chlorophyll-Fe+2

[0599] The procedure, as described in examples 1 and 2, was performed with 130 mg of (NH4)2Fe(SO4)2 used for metal exchange. The achieved product Chlorophyll-Fe+2 has a dark-green color.Example 5: Exchange of Metal in Chlorophyll-Mg+2 Extract to Produce Chlorophyll-Zn+2

[0600] The procedure, as described in examples 1 and 2, was performed with 100 mg of zink nitrate hexahydrate [Zn(NO3)2·6H2O] used for metal exchange. The achieved product Chlorophyll-Zn+2 has a green color.Example 6: Cerium Oxide Submicron Nanoparticles (NP)

[0601] In a round bottom flask, 40 ml of dimethylformamide and 30 ml propylene glycol were placed, and heated to 60° C. In parallel 3.18 g of ammonium cerium nitrate (NH4)2(Ce(NO3)6) were dissolved in 15 ml of water and added dropwise to the flask. The solution was stirred to complete dissolution and the solution was clear. 15 ml of NH4OH 28% were added to the solution. The solution was heated up to 90° C. under reflux and constant stirring for 6 h. The solution was then cooled down to room temperature, and yellowish clouds of cerium oxide nanoparticles were formed in the solution. The nanoparticles were precipitated by centrifugation at 4500 rpm for 5 min and washed three times with water forming a pale-yellow precipitate. The precipitate was lyophilized to produce a dry yellowish powder of cerium oxide (CeO2) submicron nanoparticles, having a size in the range of 100-300 nm.Example 7: Magnesium-Chlorophyll Coated Cerium Oxide Submicron Nanoparticles

[0602] 500 mg of cerium oxide submicron nanoparticles were placed in a 70 ml double jacket reactor and resuspend in 50 ml 1,4-dioxane and sonicated by UP200Ht horn titanium probe for 5 min at 90% amplitude at constant room temperature. 200 μl of concentrated Magnesium chlorophyl extract was added to the cerium oxide nanoparticles suspension and sonicated for 20 min under the same conditions. The precipitate was centrifuged and washed twice with dioxane and twice with deionized water, forming chlorophyll-coated cerium oxide. The cerium oxide nanoparticles coated with chlorophyll nanocomposite were lyophilized and stored at 0-5° C. The size range of the cerium oxide chlorophyll-coated nanocomposite was 100-300 nm, having a light-green color.Example 8: Copper-Chlorophyll Coated Cerium Oxide Submicron Nanoparticles

[0603] 500 mg of cerium oxide submicron nanoparticles were placed in a 70 ml double jacket reactor and resuspend in 50 ml 1,4-dioxane and sonicated by UP200Ht horn titanium probe for 5 min at 90% amplitude at constant room temperature. 100 mg of copper chlorophyll were added to the cerium oxide nanoparticles and sonicated for 20 min under the same conditions. The precipitate was centrifuged and washed twice with dioxane and twice with deionized water, forming copper-chlorophyll-coated cerium oxide. The cerium oxide nanoparticles coated with copper-chlorophyll nanocomposite were lyophilized and stored at 0-5° C. The size range of the cerium oxide Copper-chlorophyll coated nanocomposite was 100-300 nm, having a light-green color.Example 9: Cerium Oxide Small Nanoparticles (10-50 nm)

[0604] 45 ml ethylene-glycol was placed in a 70 ml double jacket reactor and sonicated at 90% amplitude under stable room temperature and sonicated by UP200Ht horn titanium probe. 1.6 g oleic acid and 1.3 g cerium nitrate were dissolved in 5 ml methanol and added to the reaction with continued sonication for 40 min. 50 ml deionized water was added to the reaction and the nanoparticles were extracted with 50 ml hexane. The hexane fraction was washed twice with deionized water and the solvent evaporated. The size range of the produced cerium oxide (CeO2) small nanoparticles was 10-50 nm, with absorbance peak at 275-340 nm (max. at 300 nm).Example 10: Cerium Oxide Quantum Dots (QD) (3-10 nm)

[0605] 45 ml ethylenediamine was placed in a 70 ml double jacket reactor and sonicated at 90% amplitude by UP200Ht horn titanium probe under stable room temperature. 0.8 g palmitic acid and 1.3 g cerium nitrate (Ce(NO3)3·6H2O) were dissolved in 5 ml methanol and added to the reaction with continued sonication for 40 min. 50 ml deionized water was added to the reaction and the QDs were extracted with 50 ml hexane. The hexane fraction was washed twice with deionized water and methanol the solvent evaporated. The size range of the produced cerium oxide (CeO2) quantum dots was 3-10 nm, with absorbance peak at 275-340 nm (max. at 294 nm). Absorbance comparison of CeO2-QD (quantum dots) v / s CeO2—NP submicron nanoparticles are shown in FIG. 3.Example 11: Magnesium-Chlorophyl Coated Cerium Oxide Quantum Dots

[0606] 50 ml of resuspended cerium oxide quantum dots in hexane were placed in 70 ml double jacket reactor and sonicated by UP200Ht horn titanium probe for 5 min at 90% amplitude at constant room temperature. 200 μl of concentrated chlorophyll extract was added and further sonicated for 20 min at the same conditions. The produced chlorophyl coated cerium oxide quantum dots were washed twice with methanol and the solvent evaporated. The chlorophyl coated cerium-oxide quantum dots nanocomposite had a size range of 5-10 nm. The product had a green color having two main absorbance peaks, one at 275-340 nm (max. at 294 nm), and another at 630-670 nm (max. at 654 nm).Example 12: Copper-Chlorophyll Coated Cerium Oxide Quantum Dots

[0607] 50 ml of resuspended cerium oxide quantum dots in hexane were placed in 70 ml double jacket reactor and sonicated by UP200Ht horn titanium probe for 5 min at 90% amplitude at constant room temperature. 100 mg of copper chlorophyll was dissolved in 0.5 ml dichloromethane, added to the reaction mix and further sonicated for 20 min at the same conditions. The produced copper-chlorophyl coated cerium oxide quantum dots were washed twice with methanol and the solvent evaporated. The copper-chlorophyl-cerium-oxide quantum dots had a size range of 5-10 nm. The product had a blue-green color having three absorbance peaks, one at 275-340 nm (max. at 294 nm), a second at 400-350 nm (max. at 430 nm) and a third at 630-670 nm (max. at 654 nm).Example 13: Direct Synthesis of Cerium Oxide Lipophilic Quantum Dots with Chlorophyll

[0608] 45 ml ethylenediamine was placed in a 70 ml double jacket reactor and sonicated at 90% amplitude by UP200Ht horn titanium probe under stable room temperature. 1.3 g cerium nitrate was dissolved in 5 ml methanol and added to the reaction, and after 15 min 200 μl of concentrated Chlorophyl extract were added and further sonicated for 15 min. 0.8 g oleic acid was added and sonicated for an additional 10 min. 50 ml deionized water was added and the product was extracted with 50 ml hexane and washed twice with deionized water. Finally, the solvent was evaporated to receive chlorophyll-cerium oxide lipophilic quantum dots. The product had a green color having three absorbance peaks, one at 275-340 nm (max. at 294 nm), second at 400-350 nm (max. at 430 nm), and a third at 630-670 nm (max. at 654 nm). The product was freely soluble in diesel.Example 14: Direct Synthesis of Copper-Chlorophyll-Cerium Oxide Lipophilic Quantum Dots

[0609] 45 ml ethylenediamine was placed in a 70 ml double jacket reactor and sonicated at 90% by UP200Ht horn titanium probe amplitude under stable room temperature. 1.3 g cerium nitrate was dissolved in 5 ml methanol and added to the reaction, after 15 min 100 mg of copper-chlorophyll dissolved in 0.5 ml ethanol were added and further sonicated for 15 min. 0.8 g oleic acid was added and sonicated for an additional 10 min. 50 ml deionized water was added and the product was extracted with 50 ml hexane and washed twice with deionized water. Finally, the solvent was evaporated to receive copper-chlorophyll-cerium oxide lipophilic quantum dots. The product had green color with three absorbance peaks, one at 275-340 nm (max. at 294 nm), a second peak at 400-450 nm (Max. at 430 nm) and a third at 630-670 nm (max. at 654 nm). The product is freely soluble in diesel. Results of absorbance shift are shown in FIG. 4 and FIG. 5, copper-chlorophyll-CeO2-QD show shift of absorbance at 654 nm as compared to free copper-chlorophyll, that shows absorbance at 650 nm.Example 15: Direct Synthesis of Cobalt-Chlorophyll-Cerium Oxide Lipophilic Quantum Dots

[0610] The procedure was performed as described in examples 13 and 14. 100 mg of cobalt-chlorophyll was dissolved in 0.5 ml ethanol and added to the reaction. The product received cobalt-chlorophyll-cerium oxide lipophilic quantum dots having green color.Example 16: Synthesis of Cobalt-Chlorophyll-Aluminum Oxide Quantum Dots

[0611] 45 ml ethylenediamine was placed in a 70 ml double jacket reactor and sonicated by UP200Ht horn titanium probe at 90% amplitude under stable room temperature. 1 g Aluminum nitrate nonahydrate [Al(NO3)3·9H2O] was dissolved in 5 ml methanol and added to the reaction, after 15 min 100 mg of Cobalt-chlorophyll dissolved in 0.5 ml ethanol was added and further sonicated for 15 min. 0.8 g oleic acid was added and sonicated for an additional 10 min. 50 ml deionized water was added and the product was extracted with 50 ml hexane and washed twice with deionized water. Finally, the solvent was evaporated to receive chlorophyll-cerium oxide lipophilic quantum dots. The product cobalt-chlorophyll-aluminum oxide quantum dots had green color.Example 17: Synthesis of Manganese Dioxide Nanoparticles

[0612] 45 ml water were placed in a 60 ml double jacket reactor and sonicated at 90% amplitude by UP200Ht horn titanium probe under 5° C. lg potassium permanganate KMnO4 (Potassium Permanganate) was dissolved in 5 ml potassium hydroxide 0.1M and added to the reaction, after 30 min the nanoparticles were precipitated by centrifugation at 4500 rpm for 5 min and washed three times with water to receive a brown precipitate. Finally, the precipitate was lyophilized to receive MnO2 submicron nanoparticles having a brown color. The manganese dioxide nanocomposites size range was 10-50 nm.Example 18: Chlorophyl Coated Manganese Dioxide Nanocomposite

[0613] 500 mg of resuspended Manganese dioxide nanoparticles in 45 ml hexane were placed in 70 ml double jacket reactor and sonicated by UP200Ht horn titanium probe for 5 min at 90% amplitude at constant room temperature. 200 μl of concentrated chlorophyll extract was added and further sonicated for 20 min at the same conditions. The chlorophyl coated Manganese dioxide nanocomposites were washed twice with methanol and the solvent evaporated. The chlorophyl-manganese dioxide nanocomposites size range was 10-50 nm. The product had brown-green color having two main absorbance peaks, one at 275-340 nm (max. at 375 nm), and another at 630-670 nm (max. at 654 nm).Example 19: Synthesis of Manganese Dioxide Lipophilic Quantum Dots

[0614] 40 ml methanol and 0.5 g oleic acid were placed in a 60 ml double jacket reactor and sonicated at 90% amplitude by UP200Ht horn titanium probe under 5° C. lg potassium permanganate KMnO4 and 1.3 g magnesium chloride MnCl2 were dissolved in 10 ml potassium hydroxide 0.1M and added to the reaction. After 30 min, 50 ml deionized water was added and the product was extracted with 50 ml hexane and washed twice with deionized water. Finally, the solvent was evaporated to receive oleic acid coated MnO2 nanoparticles having a red-brown color.Example 20: Synthesis of Chlorophyl-Manganese Dioxide Quantum Dots

[0615] 300 mg of Cu-Chlorophyl and 200 mg oleic acid were dissolved in 40 ml methanol placed in a 60 ml double jacket reactor and sonicated at 90% amplitude by UP200Ht horn titanium probe under 5° C. lg potassium permanganate KMnO4 and 1.3 g magnesium chloride MnCl2 were dissolved in 10 ml potassium hydroxide 0.1M and added to the reaction mix with continuous sonication. After 30 min, 50 ml deionized water was added and the product was extracted with 50 ml hexane and washed twice with deionized water. Finally, the solvent was evaporated to receive chlorophyl-manganese dioxide quantum dots having a dark-brown color.Example 21: Measurement of Oxygen Absorption / Release Capacity of Cu-Chlorophyl-CeO-QDs as Fuel Additives and their Impact on Diesel Oxygen LevelSample Preparation:Cu-Chlorophyl-CeO-QD Gas Depletion (Argon Gas):

[0616] In a 20 ml crimped vial 15 ml of 1% Cu-Chlorophyl-CeO-QD suspension were placed in a suitable solvent. The crimped cap was fitted to seal the vial and a needle was inserted through the rubber septa. The mixture was saturated with argon (to remove O2) for 30 minutes in a water bath at 30-37° C. The needle and the argon source were removed. The gas depleted Cu-Chlorophyl-CeO-QD suspension was stored at room temperature (20-25° C.).Cu-Chlorophyl-CeO-QD Gas Saturation (Oxygen or Air Gas).

[0617] The procedure above was repeated with oxygen or pressured air (20.9% oxygen) for 90 min, applied to the gas depleted Cu-Chlorophyl-CeO-QD suspension.Cu-Chlorophyl-CeO-QD Effect on Diesel

[0618] 50 ml of diesel was placed in the double jacket 20 reactor (FIG. 21) until temperature stabilization. The gas source 21 (argon, oxygen, air) was connected and bubbling started until the oxygen sensor stabilized. 1 ml of either materials cerium-oxide quantum dots (CeOQD), cerium-oxide nanoparticles (CeONp), copper-chlorophyll (CuChlo), copper-chlorophyll-cerium-oxide quantum dots (CuFx) or oxygen saturated hexane (O2 sat hex), subjected to the treatment above (gas depletion and saturation), were injected through injection septum 23 to the gas saturated diesel fuel. Oxygen was measured by the oxygen sensor 22 until stable signal was received. Results of oxygen measurements of Cu-Chlorophyl-CeO-QD in diesel are shown in FIGS. 6A, 6B and 7. Results of temperature measurements taken by temperature sensor 24 of Cu-Chlorophyl-CeO-QD in diesel are shown in FIGS. 8A and 8B.

[0619] The experimental results show improved oxygen absorption / release by chlorophyll-metal-oxide QD fuel additives in diesel fuel. The results also show endothermal temperature reduction by cation exchanged chlorophyll-metal oxide nanoparticles, specifically by cation exchanged chlorophyll-metal oxide QDs, which are proved to be effective fuel additives in diesel fuel. Moreover cation exchanged chlorophyll-metal oxide nanoparticles, specifically by cation exchanged chlorophyll-metal oxide QDs fuel additives, are freely soluble in diesel fuel and improve oxygen absorption. Advantageously, the additive neither causes an effect on the fuel composition, nor does it accumulate in and / or damage the engine.Example 22: Synthesis and Physical Characterization of Cu-Chlorophyll-CeO-FA-QDsExample 22A: Preparation of Activated CeO2 Nanoparticles

[0620] A suspension of cerium (III) nitrate hexahydrate has been subjected to sonochemical conditions in a double-jacket stainless-steel reactor, mixed with overhead stirrer until the reaction mixture became brown, indicating the formation of the activated cerium (IV) oxide, CeO2, nanoparticles (referred in this Example as CeO-QD).Example 22B: Preparation of CeO2 Nanoparticles Coated with Fatty Acid and Cu-Chlorophyll

[0621] A suspension of the cerium (IV) oxide nanoparticles prepared in Example 22A was added to a methanol solution of oleic acid (CH3—(CH2)7—CH═CH—(CH2)7—COOH, referred in this Example as FA, or fatty acid) and a methanol solution of Copper exchanged chlorophyll (Cu-Chlorophyll) and sonication was applied in a double-jacket stainless-steel reactor, mixed with overhead stirrer, until a green precipitate formed in the bottom of the reactor and the liquid phase clarified, indicating the formation of the CeO2 nanoparticles coated with Cu-chlorophyl and fatty acid (referred in this Example as Cu-Chlorophyl-CeO-FA-QD).

[0622] “z” indicates the number of chlorophyll ligand units in the nanocomposite, for small nanoparticles (quantum dots) sized 1-10 nm, “z” equals 5 to 260 chlorophyll ligand units. “x” indicates the number of cerium oxide units in the nanocomposite, for small nanoparticles (quantum dots) sized 1-10 nm, “x” equals 10 to 13,000 cerium oxide units. “y” indicates the number of fatty acid ligand units in the nanocomposite, for small nanoparticles (quantum dots) sized 1-10 nm, “y” equals 5 to 700 fatty acid ligand units.Example 22C: Characterization of Cu-Chlorophyll-CeO-FA-QDs—Spectrophotometry

[0623] The CeO2 nanoparticles coated with fatty acid and copper-exchanged chlorophyll (Cu-Chlorophyll-CeO-FA-QDs) were subjected to spectrophotometry. Spectrophotometer analysis was performed by scanning spectrum from 200 nm to 800 nm. The nanocomposite shows 3 main peaks, one at 298 nm, that indicate for CeO-QD at size of 2-20 nm, the metal oxide core of the nanoparticles, and 2 additional peaks at 420 nm, and at 650 nm respectively that are indicated and unique to this metal exchanged Cu-chlorophyll (FIG. 9).Example 22D: Characterization of Cu-Chlorophyll-CeO-FA-QDs—DLS

[0624] The CeO2 nanoparticles coated with fatty acid and copper-exchanged chlorophyll (Cu-Chlorophyll-CeO-FA-QDs) were subjected to DLS. Dynamic Light Scattering (DLS) studies were conducted on “Zetasizer Pro” DLS device. DLS results of the nanocomposite indicate particle size range between 4-12 nm with maximal peak at 5-7 nm for the product (FIGS. 10A and 10B).Example 22E: Characterization of Cu-Chlorophyll-CeO-FA-QDs—TEM

[0625] The CeO2 nanoparticles coated with fatty acid and copper-exchanged chlorophyll (Cu-Chlorophyll-CeO-FA-QDs) were subjected to TEM. Transmission Electron Microscopy (TEM) studies were conducted on two TEM microscopes. Both the Cyro-TEM and Dry-TEM show that the nanoparticles structures are rather uniform, with a generally spherical structure. The nanoparticles have a core-shell structure made of a dense core (metal oxide), size of 2-3 nm, surrounded by a light organic corona. The overall diameter of the nanoparticle is ~7 nm (FIGS. 11A to 11C).Example 22F: Physical Characterization of Cu-Chlorophyll-CeO-FA-QDs

[0626] Physical properties such as, density, viscosity, flash point, and water content, were analyzed by the “The Israeli Institute of Energy and Environment”, as well as the effect of the fuel additive on diesel stability parameters, studies conducted under the European Standard EN-590 and Israeli Standard SI-107 Part 1 (Gas-oil for diesel engines). It was found that Cu-Chlorophyll-CeO-FA-QDs, even when added at 1:2000 high ratio, does not change the diesel fuel properties.Example 23: Measurement of Diesel Combustion Parameters in the Presence of Cu-Chlorophyll-CeO-FA-QDs as Fuel Additive

[0627] To evaluate the performance of Chlorophyll coated metal-oxide QDs as fuel additive in a diesel engine / generator system, Cu-Chlorophyll-CeO-FA-QDs were tested at different ratios within diesel fuel. Diesel engine studies were conducted on diesel generator YAMAR 8000, 13.0 HP, a 4-stroke diesel generator with 2 L engine piston displacement, 0.485 L in volume, and direct fuel injection. Fuel consumption was measured by volume.

[0628] Five-gas measurement device (MAHA 6.3 with integrated NOx Sensor) was used to measure the exhaust gases of the engine. DS18B20 temperature sensors were used to measure engine and environment temperatures.

[0629] Four formulas of standard diesel fuel (purchased from SOS) were prepared, three with copper-chlorophyl-coated CeO-FA-QDs fuel additives at concentrations (v / v) of 1:50,000 (2 repetitions), 1:125,000 (3 repetitions) and 1:250,000 dilutions (2 repetitions), respectively, and one formula with no additives as a baseline control (6 repetitions).

[0630] To prepare the engine for the experiment, the engine oil was replaced with a 20 W-50 Engine oil (Liqui Moly). The engine then ran under a low 2200 W load for at least 20 hours using the standard diesel to remove any residues from prior fuels or additives. A certified car mechanic inspected the engine to confirm proper operation. The fuel storage tanks were weighed in an empty state and with 10 L of standard diesel, and the measured weights were recorded.

[0631] Prior to initiation of the experiment, the fuel tanks were confirmed empty, and the engine oil level checked. The exhaust extension (Stardonyx) was attached, and exactly 10,000 ml of clean diesel was added. A fuel level measurement was taken, and the 5-gas analyzer and temperature measurement devices were activated. The engine load was set to maximum (2200 W), and the engine was started. It was allowed to run for 60 minutes to warm up before measurements began.

[0632] Data was collected at T60, T90, T120, T150, T180, T210, T240, T270, and T300 (minutes after engine start). Exhaust gases were measured using the MAHA 6.3 5-gas analyzer, starting calibration 3-4 minutes before each time point. The gas analyzer probe was inserted into the exhaust extension, and readings were taken after a 1-3 minute stabilization period. Temperature and RPM values were recorded at the same time points. At T300, the engine was shut down, and after a 20-minute cooldown, fuel levels were measured again. Remaining fuel was extracted from the tanks using a lab hand pump and electronic pipette controller (RF3000), measured in graduated cylinders, returned to the respective tanks, and weighed.

[0633] As can be seen in FIGS. 12A-12B, at a Cu-Chlorophyll-CeO-FA-QD concentration of 1:125,000, an average improvement in fuel consumption (i.e., economy) of 8.9%, best performance at 9.8%, was achieved, as compared to fuel with no additives. At a concentration of 1:50,000, an average improvement in fuel consumption of 10.7%, best performance at 11.1%, was achieved.

[0634] As for the effect of the additives on harmful emissions, an average reduction in NOx emissions of 14.1% (best performance 14.2%) was achieved for the 1:125,000 fuel Cu-Chlorophyll-CeO-FA-QD formulation, and the 1:50,000 fuel additive formula showed an average reduction of 15.7% (best performance at 15.8%), as shown in FIGS. 13A-13B. An average reduction of particle matter (PM) emissions of 29.5%, with best performance at 33.4%, was achieved for the 1:125,000 formulation, while the 1:50,000 Cu-Chlorophyll-CeO-FA-QD fuel additive formula showed an average reduction of 35.4% (best performance at 36.8%), as shown in FIGS. 14A-14B. As for HC (Hydrocarbons) emissions, an average reduction of 18.3% (best performance of 20.5%) was achieved for the 1:125,000 Cu-Chlorophyll-CeO-FA-QD additive formulation, while the 1:50,000 formula showed an average reduction of 20.5% (best performance at 22.0%), as shown in FIGS. 15A-15B.

[0635] The 1:125,000 Cu-Chlorophyll-CeO-FA-QD fuel additive concentration was selected for further engine and vehicle experiments.Example 24: Measurement of Untreated Diesel Combustion Parameters in the Presence of Cu-Chlorophyll-CeO-FA-QDs as Fuel Additive

[0636] The performance of the Cu-Chlorophyll-CeO-FA-QDs particle fuel additive in a diesel engine / generator system fed with untreated fuel was tested. The diesel generator YAMAR 8000 was selected, as in the previous example. The MAHA 6.3 five-gas measurement device and DS18B20 temperature sensors were used for taking measurements. The untreated diesel fuel was provided by Bazan (Israeli Oil refineries). Fuel consumption was measured by weight.

[0637] Two formulas were prepared, one of untreated diesel fuel without any additives (3 repetitions), and one of untreated diesel fuel with Cu-Chlorophyll-CeO-FA-QD fuel additives at a ratio of 1:125,000 (3 repetitions).

[0638] The experiment was performed as set out in Example 23, with the standard diesel fuel being replaced by untreated diesel fuel (Bazan).

[0639] As can be seen in FIGS. 16A-16B, the Cu-Chlorophyll-CeO-FA-QD fuel additive in untreated diesel (1:125,000) produced an average improvement in fuel consumption of 12.7%, best performance at 13.2%, as compared to untreated fuel with no additives. As for the effect of the additives on harmful emissions, an average reduction in NOx emissions of 18.2% (best performance 23.6%) (FIGS. 17A-17B), an average reduction of PM emissions of 168.2% (best performance 182.2%)(FIGS. 18A-18B), and an average reduction of HC emissions of 57.1% (best performance 69.5%) (FIGS. 19A-19B) were achieved, as compared to untreated diesel with no additives.

[0640] As for the engine temperatures, FIG. 20A shows the engine temperature (° C.) over the course of the experiment (subtracting the room temperature) for the untreated diesel with and without the Cu-Chlorophyll-CeO-FA-QD fuel additives (1:125,000). FIG. 20B shows the temperature difference (ΔT) between the formula with the additives and the formula without the additives over the course of the experiment.

[0641] As can be seen, the Chlorophyll-coated metal-oxide QDs fuel additives formula achieved a substantial decrease in engine temperature of about −5.8° C. (average) in comparison to the untreated diesel with no additives, which is about −13% of the engine temperature (after subtracting RT therefrom). Of note, the temperature difference (ΔT) primarily increased over the duration of the experiment. While the temperature of the engine powered by the no-additives untreated diesel slowly increased throughout the experiment, the engine powered by Cu-Chlorophyll-CeO-FA-QD additives-enriched untreated diesel maintained a substantially fixed temperature.

[0642] The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the figures.

[0643] While the present invention has been particularly described, persons skilled in the art will appreciate that many variations and modifications can be made. Therefore, the invention is not to be construed as restricted to the particularly described embodiments, and the scope and concept of the invention will be more readily understood by reference to the claims, which follow.

Claims

1. A composite material comprising a metal oxide core, coated with an organic coating, wherein the organic coating comprises a cation exchanged chlorophyll, which comprises a chelated metal cation.

2. The composite material of claim 1, wherein the metal oxide core comprises a metal oxide selected from the group consisting of: CeO2, Al2O3 and MnO2.

3. The composite material of claim 1, wherein the metal oxide core is particulate, and has a particle size in the range of 0.5 nm to 500 nm.

4. The composite material of claim 3, wherein the metal oxide core is in the form of a quantum dot having particle size in the range of 1 nm to 20 nm.

5. The composite material of claim 1, wherein the cation exchanged chlorophyll is selected from the group consisting of: chlorophyll a, chlorophyll b, chlorophyll c1, chlorophyll c2, chlorophyll c3, chlorophyll d, chlorophyll f and a combination thereof.

6. The composite material of claim 1, wherein the chelated metal cation is Cu+2.

7. The composite material of claim 1, which is in a particulate form and has a particle size in the range of 3 nm to 400 nm.

8. The composite material of claim 1, which further comprises at least one lipophilic surface ligand selected from the group consisting of: a carboxylic acid, an amine, an alcohol, a thiol, a phosphine, a phosphine oxide and a combination thereof.

9. The composite material of claim 1, which has solubility of at least 1 gr per liter in diesel fuel.

10. The composite material of claim 9, which has solubility of at least 5 gr per liter in diesel fuel.

11. The composite material of claim 1, wherein the metal oxide comprises CeO2 and the metal oxide core is in the form of a quantum dot having particle size in the range of 1 nm to 20 nm, and wherein the chelated metal cation comprises Cu+2.

12. The composite material of claim 1, comprising a CeO2 core, coated with an organic coating, wherein the organic coating comprises a Cu+2 exchanged chlorophyll and oleic acid; wherein the CeO2 core is particulate in the form of a quantum dot and has a diameter in the range of 1 nm to 4 nm; and wherein the composite material is particulate in the form of a quantum dot and has a diameter in the range of 4 nm to 10 nm.

13. The composite material of claim 1, which is prepared by a method comprising:subjecting a core metal salt to sonication to form a nanoparticulate metal oxide; andsubjecting the nanoparticulate metal oxide to sonication together with a cation exchanged chlorophyll, to form the composite material.

14. The composite material of claim 13, wherein the method further comprises a step of contacting Mg-chlorophyll with a chelating metal salt to form the cation exchanged chlorophyll, wherein the cation exchanged chlorophyll is performed before the step of subjecting the nanoparticulate metal oxide and cation exchanged chlorophyll to sonication.

15. The composite material of claim 1, represented by the formula:(Chlorophyll)z-(metal-oxide)x-(L)y, whereinz is the number of chlorophyll molecules in a unit of the composite material, and is in the range of 5 to 260,x is the number of metal oxide units in a unit of the composite material, and is in the range of 10 to 13,000, andy is the number of surface ligand units in a unit of the composite material, and is in the range of 0 to 700.

16. A fuel composition comprising a motor fuel and a fuel additive, wherein the fuel additive comprises a composite material comprising a metal oxide core, coated with an organic coating, wherein the organic coating comprises a chlorophyll.

17. The fuel composition of claim 16, wherein the composite material comprises a metal oxide core, coated with an organic coating, wherein the organic coating comprises a cation exchanged chlorophyll, which comprises a chelated metal cation.

18. The fuel composition of claim 16, wherein the motor fuel comprises diesel fuel.

19. A liquid fuel additive formulation comprising a solvent and a fuel additive, wherein the fuel additive comprises a composite material comprising a metal oxide core, coated with an organic coating, wherein the organic coating comprises a chlorophyll.

20. The liquid fuel additive formulation of claim 19, comprising 0.5% to 10% composite material in the solvent w / v, wherein the solvent comprises kerosene, TBME, or a mixture thereof.

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