Population of particles, method for preparation and uses thereof

Abstract

The present disclosure provides a population of particles, method of producing the same and uses thereof. In the disclosed population of particles, each particle comprising a construct comprising (i) at least one solid core having an outer surface comprising an inorganic composition, (ii) a scaffold secured in place with respect to said solid core, the scaffold being suitable for support growth of photosynthesizing aquatic organism; and (iii) gas entrapped within plurality of voids in said at least one solid core, wherein said inorganic composition has a water solubility configured to allow controlled exchange between the entrapped gas and water external to said construct; wherein said gas has a first specific gravity less than that of water and present in an amount sufficient to provide floatation of said particle, once the particle is brought into contact with the water; and wherein said construct having a second specific gravity greater than that of water.

Description

[0001] POPULATION OF PARTICLES, METHOD FOR PREPARATION AND USES THEREOF

[0002] TECHNOLOGICAL FIELD

[0003] The present disclosure is in the field of chemistry and carbon dioxide sequestration.

[0004] BACKGROUND ART

[0005] References considered to be relevant as background to the presently disclosed subject matter are listed below:

[0006] International Patent Application Publication No. WO2021126315

[0007] - US Patent No. 8,033,879

[0008] US Patent Application Publication No. 20080236033

[0009] - US Patent No. 5,965,117

[0010] - US Patent No. 1,0752,528

[0011] European Patent No. EP1207743

[0012] Chinese Patent Application No. CN 115428726

[0013] - US Patent No. 8,753,863

[0014] - US Patent Application publication No. 2022 / 295761

[0015] German Patent application no. DE 10 2012 106610

[0016] - US Patent Application publication No. 2008 / 029039

[0017] European Patent No. EP 1114219 B 1

[0018] Grimes, C.J. et al. " Calcium Carbonate Particle Formation through Precipitation in a Stagnant Bubble and a Bubble Column Reactor" Crystal Growth Science 20:5572-5582 (2000) Seo, Y.B., et al., "Upgrading waste paper by in-situ calcium carbonate formation", Journal of Cleaner Production (2016).

[0019] Acknowledgement of the above references herein is not to be inferred as meaning that these are in any way relevant to the patentability of the presently disclosed subject matter.

[0020] BACKGROUND

[0021] WO2021126315 describes a nano bio-composite nutrient carrier containing a water-soluble polymer with an iron nutrient, nourishing an aquatic organism. The water- soluble polymer includes a hydrogen bonded interpenetrating polymer network entrapping the iron nutrient. The nutrient carrier is buoyant having a density of < 1.0 grams per cubic centimeter.

[0022] US8,033,879 describes compositions, methods, and equipment for biological and physical geoengineering. It introduces inorganic particles or floats designed for dispersal on water bodies.

[0023] US20080236033 describes floating slow-release fertilizer which enables the growth of phytoplankton in ocean thereby removing CO2 from atmosphere.

[0024] US5,965,117 describes water-buoyant compositions comprising a source of micronutrients for photosynthetic phytoplankton growth which are useful for stimulating photosynthetic phytoplankton growth in ocean areas devoid of such growth when deployed on ocean surfaces as floating particles.

[0025] CN115428726 describes a method for sequestering carbon dioxide in the ocean using phosphorus supplementation. The method involves transporting a phosphorus source loader to a nutrient-poor area, releasing it on a continental shelf, and dispersing phosphorus into the ocean. The nutrient mix promotes phytoplankton growth in the euphotic layer, which converts atmospheric carbon dioxide into organic matter thereby reducing atmospheric concentration of carbon dioxide.

[0026] US8,753,863 describes a method for removing carbon dioxide from the atmosphere. The method comprises delivering urea from a floating vessel to a region of a photic zone of the ocean, whereby the number of phytoplankton is caused to increase in the region upon addition of the urea. US 2022 / 295761 describes systems and methods for cultivating or accumulating climate-focused marine target products. The target product may be microalgae, macroalgae, plankton, marine bacteria or archaea, filter feeders (such as oysters or clams), or crustaceans either for the purpose of bioremediation, eventual cultivation or for sequestering carbon dioxide; or the target product may be direct chemical or biological accumulation of carbon or carbon containing organisms. The system is primarily a floating apparatus designed to hold the target product in a region of the water column and in a spatial region of the water where it will best accumulate target product mass. The system is designed to achieve an eventual passive sinking into the deep ocean.

[0027] DE 102012 106610 describes a method for producing fertilizer from fermentation residues by means of encapsulation of the fermentation residues, in which the ingredients from the obtained preparations are released in a long-lasting manner.

[0028] US 2008 / 029039 describes a composite particle, comprising: an absorbent core; an absorbent material surrounding the core and forming a particle; and at least one performance-enhancing active added to the absorbent material.

[0029] EP 1114219 describes process for obtaining fibres integral with calcium carbonate particles, in which the fibres to be treated are contacted with carbon dioxide generator means and at least one composition comprising Ca++ions capable of reacting with the carbon dioxide so as to give "in fine" a precipitation of calcium carbonate "in situ" on the fibres, characterized in that it comprises: - a step of preparing a first composition comprising calcium bicarbonate. - a step of preparing a second composition comprising calcium hydroxide. Complex product containing fibres and fillers which are crystallized on their contact, is also described.

[0030] Further, Grimes C.J. et al., describe calcium carbonate particle formation through precipitation in a stagnant bubble and a bubble column reactor.

[0031] Finally, Seo Y.B. et al., describe upgrading waste paper by in situ calcium carbonate formation.

[0032] GENERAL DESCRIPTION

[0033] The present disclosure provides, in accordance with a first of its aspects, a population of particles, essentially each particle comprising: a construct comprising: at least one solid core having an outer surface comprising an inorganic composition, a scaffold secured in place with respect to said solid core, the scaffold being suitable for support growth of photosynthesizing aquatic organism; gas entrapped within plurality of voids in said at least one solid core, wherein said inorganic composition has a water solubility configured to allow controlled exchange between the entrapped gas and water external to said construct; wherein said gas has a first specific gravity less than that of water and present in an amount sufficient to provide floatation of said particle, once the particle is brought into contact with the water; and wherein said construct having a second specific gravity greater than that of water.

[0034] In accordance with a second of its aspects, the present disclosure provides a method of preparing particles, the method comprising: in situ formation of an inorganic composition over an entire surface of a solid core; securing to at least the inorganic composition a scaffold suitable for support growth of photosynthesizing aquatic organism to thereby provide a construct, wherein said construct carries gas entrapped within a plurality of voids of said solid core; wherein the inorganic composition has a water solubility configured to allow controlled exchange between the gas entrapped within said voids and water external to said construct; wherein said gas has a first specific gravity less than that of water and present in an amount sufficient to provide floatation of said particles, once the particles are brought into contact with the water; and wherein said construct having a second specific gravity greater than that of water.

[0035] In accordance with a third of its aspects, the present disclosure provides a method of preparing particles, the method comprising: providing solid particulates of inorganic composition, the particulates having a plurality of voids distributed therein, and suitable for accommodating a gas; securing onto the solid particulates a scaffold suitable for support growth of photosynthesizing aquatic organism to thereby provide a construct; wherein said construct carries gas entrapped within a plurality of voids of said solid core; wherein the inorganic composition has a water solubility configured to allow controlled exchange between the gas entrapped within said voids and water external to said construct; wherein said gas has a first specific gravity less than that of water and present in an amount sufficient to provide floatation of said particles, once the particles are brought into contact with the water; and wherein said construct having a second specific gravity greater than that of water.

[0036] In accordance with yet a fourth of its aspects, the present disclosure provides a method for carbon dioxide sequestration, comprising distributing a population of particles according to the presently disclosed first aspect, or prepared or preparable according to the second or third disclosed aspects, over a selected area of body of water comprising at least one photosynthesizing aquatic organism and being open to a source of carbon dioxide to be sequestered.

[0037] BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0039] Figures 1A-1H are schematic illustrations of particles according to some nonlimiting examples of the presently disclosed subject matter.

[0040] Figures 2A-2J are microscope images of uncoated vermiculite and coated vermiculite. Figures 3A-3D are microscope images of uncoated vermiculite and coated vermiculite obtained by in situ coating with Ca(0H)2 solution and CO2 gas.

[0041] Figures 4A-4D are microscope images of inorganic coated vermiculite obtained by two sequential in situ coatings with Na2CCh solution and CaCh solution to form two layers of coating.

[0042] Figures 5A-5B are microscope images of inorganic coated vermiculite obtained by first submerging in CaCh solution, filtered ad then submerging in Na2COs solution.

[0043] Figures 6A-6B are microscope images of inorganic coated vermiculite obtained by spraying first with CaCh solution followed by spraying with Na?CO3 solution.

[0044] DETAILED DESCRIPTION

[0045] Generally, the present disclosure is based on the development of particles having, inter alia, a control floatation or buoyancy property, resulting in floatation of the particles over water, and a pre-designed and controllable settling or sedimentation property, triggering the particles to settle within the water.

[0046] Further, the developed particles are designed to support growth of a photosynthesizing aquatic organism which contributes on the one hand to the sequestration of carbon dioxide, and on the other hand, can contribute to the settling of the particles in the water. Thus, when in proximity with photosynthesizing aquatic organisms, e.g. those harboring the sunlight zone (photic zone) of bodies of water, the presently disclosed floating particles can serve as a support scaffold for these algae until actuation of the pre-designed settling trigger, which then results in the process of particles' settling within the body of water, together with the harboring algae.

[0047] Thus, in the context of a first aspect of the presently disclosed subject matter, there is provided a population of particles, essentially each particles in the population of particles comprises a construct including:

[0048] (i) at least one solid core having at least an outer sealing of inorganic composition;

[0049] (ii) a scaffold secured in place with respect to the solid core, the scaffold being suitable for support growth of photosynthesizing aquatic organism; and the particles further comprise gas entrapped within plurality of voids in the at least one solid core.

[0050] In the disclosed population of particles the inorganic composition has a water solubility configured to allow controlled exchange between the entrapped gas and water external to the construct.

[0051] In the disclosed population of particles the gas has a first specific gravity less than that of water and the gas is present in an amount sufficient to provide floatation of the particle, once the particle is brought into contact with the water.

[0052] Further, In the disclosed population of particles the construct has a specific gravity (referred to as a second specific gravity) that is greater than that of water.

[0053] In the context of the presently disclosed subject matter the term "population of particles" denote two or more particles, preferably multiplicity of particles, which while all have the same construction as defined herein, may not be necessarily the same in the population. In other words, while all have a solid core, gas entrapped at least in the core, and a scaffold secured to the solid core, some may differ in the type / dimensions of the solid core, some may differ in the type of gas entrapped, some may differ in the type of scaffold, some may differ in the number of solid cores per particle, some may differ in dimensions, etc.

[0054] Further, in the context of the presently disclosed subject matter, it is to be understood that while the population of particles is defined such that each particle has the herein defined constructions, some, typically insignificant amount of particles may deviate from the defined constructions (e.g. lack scaffold, lack gas etc.), such insignificant amount being ineffective to fault the functionality of the population of particles as a whole. Accordingly, at times, when referring to essentially each particle, it is to be understood that the population may include an insignificant amount of particles may deviate from the defined properties of the particles, as further discussed hereinbelow.

[0055] The particles are an assembly of components. Thus, it is appreciated that term "construct" as used herein, denotes a structured solid object formed by an organized assembly of the indicated components, including at least the solid core with an inorganic composition, at least surrounding its outer surface, the gas and the scaffold. The particles in the population of particles comprise at least one solid core. In the context of the presently disclosed subject matter, the term "solid core" should be understood to encompass any non-flowing substance / solids, including, rocks, minerals, glass.

[0056] In some examples, the solid core can be a gel like materials, as further discussed below.

[0057] The solid core is a discrete solid entity within the construct, that is distinguishable (e.g. visually or using imaging techniques) at least from the growth supporting scaffold secured thereto.

[0058] In the context of the presently disclosed subject matter, it is understood that the term “ solid core" encompasses structures having dimensions within any size scale as further defined hereinbelow.

[0059] In some examples, the solid core has dimensions within the sub-micron to micron range.

[0060] In some examples, the solid core has dimensions within the micron range.

[0061] In some examples, the solid core has dimensions within the micro to millimeter range.

[0062] In some examples, the solid core has dimensions within the micrometer or millimeter to centimeter range.

[0063] In some examples, the solid core has dimensions within the centimeter range, and typically up to 10cm, or up to 9cm, or up to 8cm, or up to 7cm, or up to 6cm, or up to 5cm.

[0064] In some examples, the solid core has dimensions of up to 10cm.

[0065] In some examples, the solid core has dimensions of up to 5cm.

[0066] In some examples of the presently disclosed subject matter, the solid core is a water insoluble particulate matter. This means that once brought into contact with water, the solid core per se will not dissolve immediately.

[0067] In some examples of the presently disclosed subject matter, the solid core is an expanded particulate. In some examples of the presently disclosed subject matter, the solid core is a porous particulate.

[0068] In the context of the presently disclosed subject matter, the terms "expanded" or "porous", with reference to the solid core, may be understood to refer to having voids, preferably suitable for / capable of holding entrapped gas. Thus, when referring to an expanded and / or porous particulate it is to be understood to encompass any particulate that contains voids / open gas-containing spaces. These voids can be distributed throughout the material, and the size, shape, distribution, and interconnectivity of the voids can vary between the particulates. The voids can have a shape of cavities within the substance, can represent spaces between layers in a layered substance or any other form of voids within the particulate.

[0069] In some examples of the presently disclosed subject matter, the term "expanded" denotes a material, e.g. a mineral that has undergone a thermal process resulting in its expansion. Accordingly, and as an example, expanded vermiculite is raw vermiculite that underwent a process involving exposure to high temperatures (also known by the term exfoliation) causing expansion of its inner layers and turning into a form of lightweight, porous material with layered structure.

[0070] Thus, in some examples of the presently disclosed subject matter, the solid core is an expanded particulate (e.g. where the raw material underwent the exfoliation process, resulting in a porous layered structure that can hold the said gas).

[0071] In the context of the presently disclosed subject matter, when referring to an expanded particulate, it is to be understood to refer to particulate matter that has expanded as a result of treatment, e.g. heat treatment. In some examples, the particulate material is expanded due to a process of exfoliation.

[0072] In some examples of the presently disclosed subject matter, the solid core is an expanded particulate mineral.

[0073] In the context of the presently disclosed subject matter, the term "mineral" should be understood to have its regular meaning, as known in the art. For example, the term "mineral" can be understood to pertain to inorganic, crystalline substance, including singular crystalline entities and aggregates thereof. In some examples of the presently disclosed subject matter, the term "mineral" includes compounds that constitute geological formations and substrates. It is acknowledged that "minerals" may also arise from the alteration or fusion of their constituent components, resulting in the formation of new chemical entities within the context of rocks.

[0074] A non-limiting list of expanded and / or porous particulate minerals include vermiculite (including specifically expanded vermiculite), montmorillonite, bentonite, hectorite, saponite, kaolinite, halloysite, illite, palygorskite, sepiolite and nontronite.

[0075] In some examples of the presently disclosed subject matter, the solid core is expanded vermiculite mineral.

[0076] In some examples of the presently disclosed subject matter, the solid core is an expanded particulate volcanic glass.

[0077] A non-limiting list of expandable particulate volcanic glass includes perlite and pumice.

[0078] In some examples of the presently disclosed subject matter, the solid core is expanded particulate perlite.

[0079] In some examples of the presently disclosed subject matter, the solid core is expanded particulate pumice.

[0080] In some examples of the presently disclosed subject matter, the solid core is a porous core comprising a second inorganic composition which may be the same or different from the inorganic composition present at and surrounding the surface of the solid core (as a sealing layer).

[0081] In some examples of the presently disclosed subject matter, the solid core is comprised of an inorganic composition which is the same also at the outer surface. As such, there is no distinct coating or sealing layer of inorganic composition over the solid core and the core and outer surface are considered an integral unit.

[0082] In some examples of the presently disclosed subject matter, the solid core is or comprises an inorganic composition that is different from the inorganic composition at its outer surface.

[0083] When the solid core is coated with (sealed within) a different inorganic composition, the inorganic composition forming the outer surface (as if it is a coating / sealing layer) and the inorganic composition forming the solid core may differ in any one of their chemistries, their water solubility, and / or their density / porosity.

[0084] The outer surface including the inorganic composition, is preferably in a form of a continuous sealed layer over a solid core.

[0085] In the context of the presently disclosed subject matter, the term "continuous layer" is to be understood to encompass at least the presence of no gaps in the surface, visible to the naked eye (i.e. visual inspection without the aid of magnifying tools). In some examples of the presently disclosed subject matter, the continuous layer may include gaps (invisible to the naked eye) that are insufficient or insignificant to cause immediate (e.g. within less than about 2 days) exchange between the entrapped gas and external water.

[0086] In some examples of the presently disclosed subject matter, the solid core is coated with two or more layers, of the same or different, inorganic composition.

[0087] When coated with a plurality of layers of inorganic composition, the plurality of layers can be achieved, for example, by stepwise coating of the particles.

[0088] In some examples of the presently disclosed subject matter, when the solid core is coated by two or more layers of (the same or different) inorganic compositions, the layering can be distinguished by the use of suitable magnifying equipment, such as scanning electron microscope (SEM).

[0089] In some examples of the presently disclosed subject matter, the solid core is coated by two or more layers of different inorganic compositions.

[0090] Yet, it may occur that the two or more layers cannot be visualized, even by the aid of a magnifying equipment. In such cases, the presence of two or more layers can be deduced by other parameters, such as thickness of the coating layer, e.g. a thick coating layer can be a result of applying, in situ, more than one coating layer.

[0091] In some examples of the presently disclosed subject matter, the solid core is a porous organic particulate.

[0092] The organic core can be syntenic or non- synthetic.

[0093] In some examples of the presently disclosed subject matter, the organic solid core is a carbon-based sponge. In some examples of the presently disclosed subject matter, the solid core is a natural / non-synthetic carbon-based sponge.

[0094] A non-limiting list of organic (non- synthetic) sponge that can be utilized in the context of the presently disclosed subject matter include sea sponge, cellulose based sponge, loofah sponge and combinations of same.

[0095] In some examples of the presently disclosed subject matter, the organic solid core is a carbon-based foam.

[0096] A non-limiting list of carbon-based foams that can be utilized in the context of the presently disclosed subject matter, include foamed polyurethane or latex (yet, preferably polyurethane).

[0097] In some examples of the presently disclosed subject matter, the organic solid core comprises a carbon-based fibrous (porous) material.

[0098] A non-limiting list of carbon-based fibrous material that can be used as the solid core in the context of the presently disclosed subject matter include coir fibers, rise husk, wood fibers, hemp fibers, palm fibers, bamboo fibers, jute, cotton fibers and viscose. some examples of the presently disclosed subject matter, the solid core comprises cotton fibers.

[0099] In some examples of the presently disclosed subject matter, the solid core comprises viscose fibers.

[0100] In some examples of the presently disclosed subject matter, the solid core comprises jute fibers.

[0101] In some examples of the presently disclosed subject matter, the solid core comprises bamboo fibers.

[0102] In some examples of the presently disclosed subject matter, the solid core comprises wood fibers.

[0103] In some examples of the presently disclosed subject matter, the solid core comprises a particulate hydrocolloid.

[0104] In the context of the presently disclosed subject matter, the term "hydrocolloid' is to be understood to encompass any substance that is capable of forming a viscous, yet, non-flowing, dispersion or a non-flowing gel when mixed with water or other aqueous solutions.

[0105] In some examples of the presently disclosed subject matter, the hydrocolloid is or forms (e.g. in contact with water) a hydrogel.

[0106] In some examples of the presently disclosed subject matter, the particulate hydrocolloid comprises a polysaccharide.

[0107] In some examples of the presently disclosed subject matter, the particulate hydrocolloid comprises a polysaccharide selected from the group consisting of alginate, agar-agar, agarose, carrageenan, pectin, methylcellulose, hydroxypropyl methylcellulose (HPMC), ethylcellulose, carboxymethyl cellulose (CMC), microcrystalline cellulose, hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), carboxymethyl hydroxyethylcellulose (CMHEC), carboxymethyl hydroxypropylcellulose (CMHPC), chitosan, carboxymethyl chitosan, xanthan gum, guar gum, locust bean gum, galactomannan, konjac gum, glucomannan, tara gum, gellan gum, acacia gum (Gum Arabic), curdlan, fucoidan, pullulan, hyaluronic acid and any combination of same.

[0108] It is to be appreciated that the hydrocolloids according to the presently disclosed subject matter can be self-linked (also known, at times, as "self-cross linked") or cross linked.

[0109] In some examples of the presently disclosed subject matter, the particulate hydrocolloid comprises a self-linked polysaccharide.

[0110] A non-limiting list of self-linked polysaccharides includes self-linked alginate, self-linked agarose, self-linked chitosan.

[0111] In some examples of the presently disclosed subject matter, the particulate hydrocolloid comprises a cross-linked polysaccharide.

[0112] A non-limiting list of cross-linked polysaccharides includes cross-linked alginate, cross-linked starch, cross-linked cellulose, cross-linked Chitosan, cross-linked Xanthan Gum, cross-linked Pectin, and cross-linked Guar Gum.

[0113] In some examples of the presently disclosed subject matter, the particulate hydrocolloid comprises or is cross-linked alginate. Cross linked alginate can be obtained using any one of a divalent or trivalent metal cation. This may include, without being limited thereto, any one or combination of Ca2+, Mg2+, Fe2+, Fe3+, Mn2+.

[0114] In some examples of the presently disclosed subject matter, the particulate hydrocolloid comprises or is alginate crosslinked with Ca2+, referred to as calcium alginate, or Ca-alginate.

[0115] In some examples of the presently disclosed subject matter, the particulate hydrocolloid comprises or is gelatin.

[0116] In some examples of the presently disclosed subject matter, the population of particles can comprise a combination of the above solid core materials.

[0117] It is to be appreciated that the particles in the population of particles can include a single solid core, or two or more solid cores held together by the inorganic composition material or held together, entrapped / surrounded by the scaffold (such as in a net cage).

[0118] In some examples of the presently disclosed subject matter, at least some of the particles in the population of particles include a single solid core.

[0119] In some examples of the presently disclosed subject matter, at least some of the particles in the population of particles include two or more solid cores.

[0120] In some examples of the presently disclosed subject matter, essentially each particle in the population of particles includes a single solid core.

[0121] As used herein, the term "essentially" refers to a feature, characteristic, or parameter that is as specified, while allowing for deviations that do not materially affect the intended function or purpose. Unless otherwise indicated, such deviations are understood to include up to 10% variation relative to the specified value, feature, or population.

[0122] For example, the phrase "essentially each particle in the population of particles includes a single solid core" should be understood to mean that while some particles may not contain a single solid core, e.g. not more than 10%, this does not affect the overall characteristics or function of the population. The outer surface of the solid core comprises or is an inorganic composition (e.g. in a form of a coating layer).

[0123] The inorganic composition forming part of the particle, e.g. in a form of a coating layer over the solid core or as part of the solid core, is poorly water soluble. Thus, in the context of the presently disclosed subject matter, when referring to the inorganic composition, be it that forming the outer surface over a solid core or that constituting the solid core, it is to be understood to encompass a poorly water-soluble composition.

[0124] In the context of the presently disclosed subject matter, when referring to a poorly water-soluble composition it is to be understood to refer to an inorganic composition having a solubility in tap water, at 25°C, of up to 5gr / L.

[0125] In some examples of the presently disclosed subject matter, the inorganic composition has tap water solubility, at 25°C, of up to 4.5gr / L; at times, of up to 4.0gr / L; at times, of up to 3.5r / L; at times, of up to 3.0gr / L; at times, of up to 2.8gr / L; at times, of up to 2.6gr / L; at times, of up to 2.5gr / L; at times, of up to 2.4gr / L; at times, of up to 2.3gr / L; at times, of up to 2.2gr / L; at times, of up to 2. Igr / L; at times, of up to 1 ,8gr / L; at times, of up to 1.6gr / L; at times, of up to 1.4gr / L; at times, of up to 1.2gr / L; at times, of up to l.Ogr / L; at times, of up to 0.8gr / L; at times, of up to 0.6gr / L; at times, of up to 0.5gr / L; at times, of up to 0.4gr / L; at times, of up to 0.3gr / L; at times, of up to 0.2gr / L; at times, of up to 0. Igr / L; at times, of up to 0.05gr / L; at times, of up to 0.02gr / L.

[0126] In some examples of the presently disclosed subject matter, the inorganic composition comprises at least one inorganic compound selected from the group consisting of inorganic salt, inorganic oxide, inorganic hydroxide, and amorphous silicate and combination of same.

[0127] In some examples of the presently disclosed subject matter, the inorganic composition comprises an inorganic salt.

[0128] In some examples of the presently disclosed subject matter, the inorganic composition comprises inorganic hydroxide.

[0129] In some examples of the presently disclosed subject matter, the inorganic composition comprises at least one inorganic salt or hydroxide selected from the group consisting of calcium carbonate (CaCCh), calcium sulphate (CaSCh), calcium hydroxide (Ca(OH)2), barium hydroxide (Ba(OH)2), calcium phosphate (Cax(PO4)y)-based mineral, magnesium carbonate (MgCCh), magnesium phosphate (Mg3(PO4)2), magnesium hydroxide (Mg(0H)2), and any hydrate and / or any combination of same.

[0130] As used herein, the term "calcium phosphate-based mineraF refers to any material comprising calcium and phosphate ions, optionally further comprising hydroxide, oxide, carbonate, or water moieties, and encompassing, without limitation, naturally occurring or synthetic apatites (including but not limited to hydroxyapatite, fluoroapatite, and chloroapatite), amorphous calcium phosphates, calcium phosphate hydrates, calcium phosphate hydroxides, and any crystalline or amorphous phase variants thereof.

[0131] In some examples, the inorganic composition comprises carbonate salt. In some examples of the presently disclosed subject matter, the in situ formation of the carbonate salt can be achieved by the following general reaction:

[0132] XCO3+CaY‘> CaCO3(s) + XY2

[0133] In some examples, the inorganic composition comprising carbonate salts can be obtained, in situ, according to the following scheme of reactions:

[0134] X being any alkaline-earth metal, preferably calcium or magnesium and Y being any halogen, preferably, chlorine or bromine.

[0135] In some examples of the presently disclosed subject matter, the inorganic composition comprises calcium carbonate (CaCO3).

[0136] In some examples of the presently disclosed subject matter, the inorganic composition comprises magnesium carbonate (MgCO3).

[0137] In some examples of the presently disclosed subject matter, the inorganic composition comprises an inorganic oxide.

[0138] In some examples of the presently disclosed subject matter, the inorganic composition comprises at least one inorganic oxide selected from the group consisting of calcium oxide (CaO), magnesium oxide (MgO), manganese oxide (MnCh), copper oxide (CuO), iron oxides and any combination of same.

[0139] As used herein the term “iron oxide" refers to any compound or material comprising iron and oxygen, including, without limitation, naturally occurring or synthetic oxides and oxyhydroxides of iron, in any oxidation state or combination thereof. This includes magnetite (FesC^), ferric oxide (Fe2O3), hematite (a-Fe2O3), maghemite (y- FeiOs), wiistite (FeO), goethite (a-FeOOH), lepidocrocite (y-FeOOH), ferrihydrite, and any hydrated, amorphous, partially oxidized, or mixed-valence forms thereof, whether crystalline or non-crystalline.

[0140] In some examples of the presently disclosed subject matter, the inorganic composition comprises calcium oxide (CaO).

[0141] In some examples of the presently disclosed subject matter, the inorganic composition comprises magnesium oxide (MgO).

[0142] In some examples of the presently disclosed subject matter, the inorganic composition comprises an amorphous silicate.

[0143] In some examples of the presently disclosed subject matter, the at least one inorganic composition comprises sodium silicate.

[0144] In some examples of the presently disclosed subject matter, the amorphous silicate comprises or is fumed silica.

[0145] When the particle has a solid core coated with a layer of the inorganic composition, a unique feature of the outer surface of inorganic composition is that it is an in situ formed layer of inorganic composition over the solid core.

[0146] In the context of the presently disclosed subject matter, when referring to an "in situ" formation of an outer layer, it is to be understood to refer to the layer or more than one such layers where the inorganic compound constituting the outer surface, over the solid core, is formed on the surface of the solid particle. The in situ formation of the inorganic compound is further elaborated hereinbelow.

[0147] The population of particles disclosed herein comprise the scaffold that is configured and / or constructed to support the growth of photosynthesizing aquatic organisms.

[0148] In some examples of the presently disclosed subject matter, the scaffold is secured to the coated solid core.

[0149] In the context of the presently disclosed subject matter, the term "secured" refers to any form of fixation in place with respect to the coated solid core. The fixation can be chemical fixation or physical fixation or spatial fixation. To this end, it is to be understood that the securing of the scaffold can be, without being limited thereto, by any one of bonding, adhesion, entanglement, entrapment, and attachment. In some examples of the presently disclosed subject matter, the securing of the scaffold is by having the scaffold entangled over (surrounding) the coated solid core. The entanglement may be such that there is no physical attachment of the scaffold to the coated solid core, and the scaffold has spatial freedom to move (i.e. free movement) with respect to the coated solid core, while being detached therefrom.

[0150] In some examples of the presently disclosed subject matter, the securing of the scaffold to the coated solid core is by physical forces, such as electrostatic forces, van der Waals forces, ionic interactions, mechanical forces (e.g. the scaffold partially anchored in the outer surface formed of the inorganic composition) etc.

[0151] In some examples of the presently disclosed subject matter, the scaffold is physically anchored to the at least one coated solid core at one or more locations.

[0152] In some examples of the presently disclosed subject matter, the securing of the scaffold to the coated solid core is by chemical linkage.

[0153] In some examples of the presently disclosed subject matter, the securing of the scaffold to the coated solid core is via a linker that is associated both to the scaffold material and to the solid core, e.g. in a form of a bridge. For illustration, reference is made to Figure 1G, further discussed hereinbelow.

[0154] In some examples of the presently disclosed subject matter, the scaffold is secured to one or more areas / zones over the coated solid core.

[0155] In some examples of the presently disclosed subject matter, the scaffold envelops / surrounds the entire coated solid core.

[0156] In some examples of the presently disclosed subject matter, the scaffold comprises water insoluble fibers.

[0157] When referring to "fibers" it is to be understood to include any fibrous material, as known in the art. In this context, the term "fibers" also be understood to encompasses lint fibers.

[0158] As used herein the term "lint" or "lint fibers" pertains to lose or fine fibers, threads, or small fragments of material that have become detached or separated from textiles or fabrics due to wear, friction, or mechanical action. In some examples lint manifests as lightweight, entangled, and accumulative structures, comprising individual fibers or particles loosely adhering to one another. In some examples of the presently disclosed subject matter, the water insoluble fibers are organic, non-synthetic fibers. It is to be understood that by the term "organic, non-synthetic" it is meant also fibers that are formed from original / natural source, that have been subjected to manipulations, to obtain therefrom fibers. As such, the term "organic non synthetic" can be referred to as "semi-synthetic" or "regenerated" fibers.

[0159] In some examples, the regenerated fibers are regenerated cellulose fibers (also known as viscose fibers). Viscose fibers are formed from natural material, such as wood, bamboo or cotton linters) and are chemically reacted to form a viscous solution, which is then extended and regenerated into fibers.

[0160] A non-limiting list of organic, non-synthetic fibers that can form part of the scaffold includes abaca fibers, banana fibers, bamboo fibers, broom fibers, coir fibers, cotton fibers, cannabus fibers, elephant fibers, flax fibers, hemp fibers, jute fibers, kenaf fibers, linseed fibers, oil palm fruit fibers, ramie fibers, rice husk fibers, roselle fibers, sisal fibers, sun hemp fibers, wheat fibers, wood fibers and any combination of same.

[0161] In some examples of the presently disclosed subject matter, the scaffold comprises cotton fibers.

[0162] In some examples of the presently disclosed subject matter, the scaffold comprises cannabus fibers.

[0163] In some examples of the presently disclosed subject matter, the scaffold comprises viscose fibers.

[0164] In some examples of the presently disclosed subject matter, the water insoluble fibers are synthetic fibers. Examples of synthetic fibers include polyester fibers.

[0165] In some examples of the presently disclosed subject matter, the water insoluble fibers are recycled fibers, as available and known in the art.

[0166] In some examples of the presently disclosed subject matter, the scaffold comprises water insoluble porous particulate material entrapped, bound, and / or entangled within the fibers.

[0167] In the context of the presently disclosed subject matter, when referring to water insoluble porous particulate material it is to be understood to refer to particulate matter, having open voids / cells and with no known or detectable water solubility at 25°C. In some examples, the water insoluble porous particulate material is fixedly attached at least to the fibers. For illustration, reference is made to Figures 1C and IF, further discussed hereinbelow.

[0168] In the above and below description, when referring to the fixation of the water insoluble porous particulate material as part of the scaffold, it is to be understood to encompass any form of entrapment of the water insoluble porous particulate matter, as part of the scaffold.

[0169] In some examples, the water insoluble porous particulate material is directly fixed at least to the outer surface comprising the inorganic composition.

[0170] The fixation of the water insoluble porous particulate material can be by the aid of the binder, as described herein, the binder being further defined and / or exemplified hereinbelow.

[0171] The water insoluble particulate material forming part of the scaffold can comprise, in accordance with some examples of the presently disclosed subject matter, particulate minerals and / or particulate rock.

[0172] In some examples of the presently disclosed subject matter, the water insoluble porous particulate material comprises or is a clay mineral.

[0173] In some examples of the presently disclosed subject matter, the water insoluble porous particulate material comprises or is aluminosilicate mineral.

[0174] In some examples of the presently disclosed subject matter, the water insoluble porous particulate material comprises or is carbonate mineral.

[0175] In some examples of the presently disclosed subject matter, the water insoluble porous particulate material comprises or is a mineral selected from the group consisting of montmorillonite, bentonite, halloysite, sepiolite, attapulgite and dolomite.

[0176] In some other examples of the presently disclosed subject matter, the water insoluble porous particulate material forming part of the scaffold comprises bentonite.

[0177] In some other examples of the presently disclosed subject matter, the water insoluble porous particulate material forming part of the scaffold comprises montmorillonite. In accordance with some other examples of the presently disclosed subject matter, the water insoluble porous particulate material forming part of the scaffold can comprise particulate porous rock.

[0178] In some other examples of the presently disclosed subject matter, the water insoluble porous particulate material forming part of the scaffold is selected from the group consisting of tuff, sandstone, diatomaceous earth, shale, marl and vesicular basalt.

[0179] In some other examples of the presently disclosed subject matter, the water insoluble porous particulate material forming part of the scaffold comprises or is tuff.

[0180] In accordance with yet other examples of the presently disclosed subject matter, the water insoluble particulate material forming part of the scaffold, can comprise any combination of such minerals and rocks.

[0181] In some examples, the scaffold provides physical support for the growth of the said photosynthesizing aquatic organisms.

[0182] In some examples, the scaffold provides nutritional support for the growth of the said photosynthesizing aquatic organisms.

[0183] In some examples, the scaffold is constructed to allow growth of the organisms on and / or within the scaffold.

[0184] In its broadest context, the term "photosynthesizing aquatic organisms" denotes any aquatic primary producer.

[0185] In some examples of the presently disclosed subject matter, the organisms comprise at least one photosynthesizing microorganism.

[0186] In some examples of the presently disclosed subject matter, the organisms comprise algae.

[0187] In some examples of the presently disclosed subject matter, the organisms comprise microalgae.

[0188] In some examples of the presently disclosed subject matter, the organisms comprise at least phytoplankton. In some examples of the presently disclosed subject matter, the organisms comprise at least phytoplankton and the scaffold supports growth of the phytoplankton thereon and / or thereby.

[0189] Thus, more specifically, the term "scaffold supporting growth of photosynthesizing aquatic organism", or "growth scaffold" or "scaffold" refers to a framework, physical structure / substrate that provides at least physical support and a conducive environment for at least the growth / proliferation and preferably also attachment of the photosynthesizing aquatic organism.

[0190] In some examples of the presently disclosed subject matter, that scaffold comprises at least one nutrient, preferably a nutrient composition, suitable or selected for supporting growth of the photosynthesizing aquatic organism.

[0191] In the context of the presently disclosed subject matter when referring to a nutrient, it is to be understood to encompass both micronutrients and macronutrients.

[0192] In the context of the presently disclosed subject matter, when referring to a nutrient, it is to be understood to encompass any state of the nutrient, be it ionic state or elemental state, even if not explicitly mentioned hereinabove or below. Thus, it is to be appreciated that when referring herein to a nutrient, it is not to be limited to a particular state.

[0193] A non-limiting list of nutrients that can be utilized for the support of growth photosynthesizing aquatic organism, in the context of the presently disclosed subject matter, includes Iron (Fe), Zinc (Zn), Copper (Cu), Manganese (Mn), Molybdenum (Mo), Selenium (Se), Chromium (Cr), Cobalt (Co), Iodine (I), Fluorine (F), Magnesium (Mg), Silicon (Si), Nitrogen (N), Phosphorus (P), Sulfur (S), Strontium (Sr), Nickel (Ni), Vanadium (V) and any combination of same.

[0194] In some examples of the presently disclosed subject matter, the scaffold is supplemented with at least one nutrient.

[0195] In some examples of the presently disclosed subject matter, the scaffold is supplemented at least with iron, e.g. Fe2+, Fe3+.

[0196] In some examples of the presently disclosed subject matter, the scaffold is supplemented at least with manganese, e.g. Mn2+. In some examples of the presently disclosed subject matter, the scaffold is supplemented at least with a composition comprising iron and manganese.

[0197] In some examples of the presently disclosed subject matter, the scaffold is supplemented with a composition comprising at least nitrogen containing compound, e.g. NO3’.

[0198] In some examples of the presently disclosed subject matter, the scaffold is supplemented with a composition comprising at least phosphorus containing compound, e g. PO43'.

[0199] In some examples of the presently disclosed subject matter, the scaffold is supplemented with a composition comprising at least iron, manganese, nitrogen containing compounds, and phosphorous containing compounds.

[0200] Without being bound thereto, it is assumed that the nutrients are adsorbed onto the fibers and / or onto the water insoluble particulates forming part of the scaffold.

[0201] When a binder is used, as described hereinabove, the binder is preferably a biobased and / or biodegradable binder.

[0202] In some examples of the presently disclosed subject matter, the binder is a synthetic binder.

[0203] Examples of bio-based binders include starch-based binders; plant-based adhesives; protein-based binders, such as gelatin; polysaccharide-based binders, such as alginate; cellulose based binders, such as lignin; as well as biobased waxes.

[0204] In some examples of the presently disclosed subject matter, the binder is or comprises a hydrocolloid.

[0205] In some examples of the presently disclosed subject matter, the binder comprises alginate.

[0206] The binder can be used for different functionalities, in addition or other than the property of securing / associating / binding per se.

[0207] In some examples of the presently disclosed subject matter, the binder is used to bind between the scaffold fibers and the outer surface of the coated solid core. In some examples of the presently disclosed subject matter, the binder is used to bind between the fibers forming part of the scaffold.

[0208] In some examples of the presently disclosed subject matter, the binder is used to bind between the scaffold's fibers and the water-insoluble particulate material, when also forming part of the scaffold.

[0209] In some examples of the presently disclosed subject matter, the binder is used to connect / bind between the fibers and the outer surface of the coated solid core and between the insoluble particulates forming part of the scaffold and the fibers forming part of the same scaffold.

[0210] In some examples of the presently disclosed subject matter, the water-insoluble particulates forming part of the scaffold, hold the at least one nutrient. In this context, the "hold" can encompass adsorption (e.g. to the porous particulates), or embedment (e.g. into the binder material).

[0211] The adsorption or embedment of the at least one nutrient to the particles can be determined by any one of the X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDS), Fourier- Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Energy Dispersive X-ray Fluorescence (ED-XRF), Electron Spectroscopy for Chemical Analysis (ESCA), UV-Visible Spectroscopy, Raman Spectroscopy any Inductive Coupled Plasma (ICP) methodology including Inductive Coupled Plasma Optical Emission Spectroscopy (ICP- OES) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS).

[0212] It is noted that while it is preferable that the at least one nutrient is held by the scaffold, it can also be located / held by other components of the particulate matter, e.g. embedded within the core and / or as part of the inorganic coating.

[0213] The particles of the presently disclosed population of particles hold gas that is entrapped within voids of the at least one solid core. The gas is one having a specific gravity that is less than that of water and is present in an amount sufficient to provide floatation of the particle, at least at the moment the particle is brought into contact with the water.

[0214] Without being limited thereto, the gas can be any one of air, carbon dioxide (CO2) and nitrogen (N2), oxygen (O2). In one specific example, the gas comprises or is air.

[0215] In one specific example, the gas comprises, or is, any gaseous mixture other than ambient air.

[0216] In one specific example, the gas comprises or is CO2.

[0217] In one specific example, the gas comprises or is N2.

[0218] In one specific example, the gas comprises or is O2.

[0219] In some examples of the presently disclosed subject matter, the amount / volume of gas present in the voids provides flotation for a time sufficient to allow growth of photosynthesizing aquatic organism on the scaffold, and thereby consumption (sequestration) of CO2. This floatation duration is referred to herein as the positive buoyancy effect.

[0220] In some examples of the presently disclosed subject matter, the amount / volume of gas present in the voids is sufficient to allow floatation for at least about 2 days from deposition into the water.

[0221] The amount of gas required to make a particle float in the water (for a time sufficient to allow growth of the photosynthesizing aquatic organism) can be determined by mathematical and / or experimental methods.

[0222] Without being limited thereto and by way of illustration only, the volume of gas required to provide a desired positive buoyancy effect can be calculated according to the Archimedean principle.

[0223] In some examples of the presently disclosed subject matter, the volume of gas required to provide a desired positive buoyancy effect can be calculated by applying Equations 1 to 4 hereinbelow:.

[0224] The overall density of the raw particle Pparticle can be defined in equation 1.

[0225] Pparticle is the overall density of a particle components in gr cm'3, where rm is the mass and Vi is the volume of component i. The minimum required volume of air (Van) to float a raw particle is described in the following equation 2.

[0226] Equation 2: air > Pparticle ~ Psw particle Psw ~ Pair(T,P)

[0227] Where, Vair / Vparticie is the minimum fraction of air (in volume) from the total volume of the raw particle; pSwis the density of seawater (or any other aqueous solution); pSw is the density of air under temperature T and pressure P.

[0228] The overall density of particles applied for time t, with addition of dry weight (dw) is described in the following equation 3:

[0229] The minimum air required to allow floating with addition of dry weight in time t described in the following equation 4:

[0230] Equation 4:

[0231] In this context, a "positive buoyancy" can be understood to refer to the condition where the disclosed particles exhibit a density lower than that of the water in which they are distributed, resulting in an upward buoyant force exceeding the particles' gravitational weight, thereby inducing a floating or ascending behavior within the water.

[0232] In accordance with the presently disclosed subject matter, the particles, after a predefined duration following their distribution in the body of water, undergo a transition to negative buoyancy.

[0233] In this context, a "negative buoyancy" pertains to a state in which the particles turn to have a density higher than that of the surrounding water. In this state, the upward buoyant force exerted by the water on the particles is less than the particle's gravitational weight, thereby inducing a settling or sinking or descending behavior within the water. In some examples of the presently disclosed subject matter, the transition to a negative buoyancy is facilitated by expulsion or removal of gas from the particle, typically due to diffusion / infiltration of surrounding water into the particle.

[0234] Thus, in the context of the presently disclosed subject matter, the controlled exchange between the entrapped gas and water external to the construct can be a result of the water infiltration.

[0235] In some examples of the presently disclosed subject matter, the exchange between the entrapped gas and the water to the construct is controlled by any parameter selected from the group consisting of type material of core, dimension of core, surface area of core, porosity of core, specific gravity of core, surface energy of core, wettability of core, number of layers of the inorganic composition over the solid core; gas permeability of the inorganic composition, water permeability of the inorganic composition, solubility of the inorganic composition, composition of the inorganic composition; wettability of the inorganic composition, overall wettability of the inorganic composition, type of entrapped gas, amount of entrapped gas, water resistance of the inorganic composition, gas permeability of the inorganic composition, gas resistance of the inorganic composition, outer surface charge, outer surface polarity and outer surface free energy.

[0236] In some examples of the presently disclosed subject matter, the exchange between the entrapped gas and external water is controlled by a combination of two or more of the above parameters.

[0237] In some examples of the presently disclosed subject matter, the controlled exchange between the entrapped gas and water external to said construct is determinable by a settling test, also known by the term "sedimentation test" or "sedimentation analysis" designed to assess the behavior of suspended solid particles in a liquid medium when subjected to gravitational forces. It involves the observation and measurement of the rate at which particles settle, % particles settling under defined test conditions. In the context of the presently disclosed subject matter, the "settling test" involves the assessment of the population of particles when suspended in water (as defined herein) including the organism that can grow on the scaffold, preferably, photosynthesizing organism / primary producers that typically harbor a photic zone of a body of water. Without being bound by theory, it is assumed that the settling of the particles is affected by any one or combination of gas / water exchange, growth of photosynthesizing aquatic organism on the scaffold. Thus, it is to be understood that while floating at distribution over the body of water, with time, and as a result of any one or combination of gas / water exchange, growth of photosynthesizing aquatic organism on the scaffold as well as possibly other parameters, the particles will eventually settle to deeper zones of the body of water. This is one unique feature of the presently disclosed subject matter, as this will allow the capturing of carbon dioxide at the photic zone of the body of water and "removal" of the particles from the photic zone once the particles have fulfilled their purpose of carbon dioxide capturing, leaving the upper water level uncontaminated by the particles.

[0238] The amount of photosynthesizing aquatic organism grown on and / or due to the scaffold, namely, biomass, can be determined using, for example, hemocytometer or Fluorescence Activated Cell Sorter (FACS).

[0239] In some examples, the amount of biomass can be determined by the change on Total Organic Carbon (TOC) content of the particles.

[0240] Without being limited by theory, the amount of biomass can be indicative of the amount of carbon dioxide sequestration.

[0241] The particles of the presently disclosed subject matter can have any size within the range from micrometers to centimeters.

[0242] In some examples, the particles have a dimension, along their longest dimension, of up to 10cm.

[0243] In some examples, the solid core has dimensions within the centimeter range, and typically up to 10cm, or up to 9cm, or up to 8cm, or up to 7cm, or up to 6cm, or up to 5cm.

[0244] In some examples, the solid core has dimensions of up to 10cm.

[0245] In some examples, the solid core has dimensions of up to 5cm.

[0246] In some examples, the particles have a dimension ranging from micrometers to millimeters. In some examples of the presently disclosed subject matter, the particles have, along their longest dimension, a size ranging from about 1pm and about 10 millimeters; at times, between about 1pm and about 9 mm; at times, between about 1pm and about 8mm; at times, between about 1pm and about 7 mm; at times, between about 1pm and about 6mm; at times, between about 1pm and about 5mm.

[0247] The dimensions of the particles can be dictated by any one of the dimensions of the solid core, the thickness of the inorganic composition at the outer surface of the solid core, the thickness of the scaffold.

[0248] The dimensions of the different particle's component can be determined analytically, using, for example, any one of Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Confocal Laser Scanning Microscopy (CLSM), Sample Cross-Sectioning, Differential Weighing, Ellipsometry, Reflectance Spectroscopy, Nuclear Magnetic Resonance (NMR) Relaxometry, White Light Interferometry, X-ray Photoelectron Spectroscopy (XPS) Depth Profiling, Quartz Crystal Microbalance (QCM) with Dissipation Monitoring (QCM-D).

[0249] In some examples of the presently disclosed subject matter, the solid core dimension is in the range of between about 1pm and about 10 millimeters; at times, between about 1pm and about 9mm; at times, between about 1pm and about 8mm; at times, between about 1pm and about 7mm; at times, between about 1pm and about 6mm; at times, between about 1pm and about 5mm.

[0250] In some examples of the presently disclosed subject matter, the thickness of the inorganic composition sealing layer over the solid core (be it one or several layers together) is in the range of between about 1pm and about 1 millimeter.

[0251] The population of particles can be utilized for distribution in any type of body of water. In this context, the term "water" encompasses freshwater (lakes, rivers), saltwater (oceans, seas), brackish water, saline lakes, glacier lakes, lagoons, Fjords.

[0252] As noted above, one unique feature of the presently disclosed subject matter, is that the construction and properties of the particles allow on the one hand the capturing of carbon dioxide at the photic zone of the body of water and on the other hand, "removal" of the particles from the photic zone once the particles have fulfilled their purpose of carbon dioxide capturing, leaving the upper water level uncontaminated by the particles. In some examples of the presently disclosed subject matter, the water is saltwater.

[0253] In some examples of the presently disclosed subject matter, the water is freshwater.

[0254] In some examples of the presently disclosed subject matter, the disclosed population of particles is characterized by a combination of all the following properties:

[0255] - the solid core comprises or is expanded or porous particulate;

[0256] - the inorganic composition has a solubility in water, at 25°C, of up to 5gr / L;

[0257] - the scaffold comprises a nutrient composition suitable for supporting growth of photosynthesizing aquatic organism.

[0258] In some examples of the presently disclosed subject matter, the disclosed population of particles is characterized by a combination of all the following properties:

[0259] - the solid core comprises or is expanded or porous particulate;

[0260] - the inorganic composition has a solubility in water, at 25°C, of up to 5gr / L;

[0261] - the scaffold comprises a nutrient composition suitable for supporting growth of photosynthesizing aquatic organism; and

[0262] - the particles have dimensions in a range of between micrometers to milimeters, along the longest dimension.

[0263] In some examples of the presently disclosed subject matter, the disclosed population of particles is characterized by a combination of the following properties:

[0264] - the solid core comprises or is expanded or porous particulate;

[0265] - the inorganic composition comprises at least one substance selected from the group consisting of calcium carbonate (CaCCh), calcium sulphate (CaSO4), calcium hydroxide (Ca(OH)2), barium hydroxide (BaO), calcium phosphate (Cax(PO4)y), magnesium carbonate (MgCCh), magnesium phosphate (Mg3(PO4)2), magnesium hydroxide (Mg(OH)2), and any combination of same;

[0266] - the scaffold comprises water insoluble, semi-synthetic fibers; - the scaffold comprises a nutrient composition suitable for supporting growth of photosynthesizing aquatic organism and

[0267] - the particles have dimensions of up to 10cm, along the longest dimension.

[0268] In some examples of the presently disclosed subject matter, the disclosed population of particles is characterized by a combination of the following properties:

[0269] - the solid core comprises or is expanded particulate mineral, preferably expanded vermiculite;

[0270] - the inorganic composition has a solubility in water, at 25°C, of up to 5gr / L;

[0271] - the scaffold comprises a nutrient composition suitable for supporting growth of photosynthesizing aquatic organism.

[0272] In some examples of the presently disclosed subject matter, the disclosed population of particles is characterized by a combination of the following properties:

[0273] - the solid core comprises or is a particulate organic core, preferably carbon based fibrous material;

[0274] - the inorganic composition has a solubility in water, at 25°C, of up to 5gr / L; and

[0275] - the scaffold comprises a nutrient composition suitable for supporting growth of photosynthesizing aquatic organism.

[0276] In some examples of the presently disclosed subject matter, the disclosed population of particles is characterized by a combination of the following properties:

[0277] - the solid core comprises or is a particulate hydrocolloid;

[0278] - the inorganic composition has a solubility in water, at 25°C, of up to 5gr / L; and the scaffold comprises a nutrient composition suitable for supporting growth of photosynthesizing aquatic organism.

[0279] Reference is made to Figures 1A-1H providing schematic illustrations of different particles according to some examples of the presently disclosed subject matter. For simplicity, Figures 1A-1H share the same reference numerals to identify the same components of the particle. For example, unless specifically indicated, solid core is identified by the reference number 102.

[0280] Figure 1A provides an illustration of a particle 100A having a single solid core 102, that is entirely surrounded with a layer 104 of an inorganic composition. Solid core 102 together with surrounding layer 104 entrap gas in voids inherently presented in the solid core (e.g. when the core is expanded vermiculite, the voids not illustrated). Over a segment 110 of layer 104 there are distributed fibers 106 forming a scaffold. While not illustrated as such, the plurality of fibers 106 may be entangled. The plurality of fibers 106 holds growth nutrients (not illustrated).

[0281] Figure IB provides an illustration of a particle 100B having a single solid core 102, that is entirely surrounded with a layer 104 of an inorganic composition. Solid core 102 together with surrounding layer 104 entrap gas (not illustrated). The solid core 102 and layer 104 are surrounded by fibers 106 forming a scaffold. The plurality of fibers 106 holds growth nutrients (not illustrated).

[0282] Figure 1C provides an illustration of another particle, particle 100C, having a single solid core 102, that is entirely coated with a layer 104. Solid core 102 together with surrounding layer 104 entrap gas (not illustrated). Solid core 102 including layer 104 are surrounded by fibers 106 that form a scaffold. Fibers 106 carry water insoluble porous particulates 108. Fibers 106 together with the porous particulates 108 hold growth nutrients (not illustrated).

[0283] Figure ID provides another illustration of a particle 100D having a plurality of solid cores 102a, 102b, 102c, 102d, which are fully surrounded by a layer 104. Solid cores 102a, 102b, 102c, 102d together with surrounding layer 104 entrap gas (not illustrated). It is noted that the plurality of solid cores 102a, 102b, 102c, 102d need not to be spaced apart and it may occur that within layer 104, two solid cores are in contact, as illustrated for solid core 102a and solid core 102c while solid core 102b and solid core 102d are isolated one from the other, layer 104 is surrounded by a plurality of fibers 106, forming a scaffold. The plurality of fibers 106 hold growth nutrients (not illustrated).

[0284] Figure IE provides another illustration of a particle 100E having a solid core 102 made of an inorganic composition. Inorganic particle 102 is formed to include a plurality of internal void 112, accommodating gas (not illustrated). Internal voids 112 are sealed from the surrounding. Solid core 102, including voids 112, carry a plurality of fibers 106.

[0285] The plurality of fibers 106 holds growth nutrients (not illustrated).

[0286] Figure IF provides another illustration of a particle 100F having a solid core 102 made of an inorganic composition as defined herein. The particle 102 of the inorganic composition are formed in a manner to intentionally include a plurality of internal void 112, accommodating gas (not illustrated). Internal voids 112 are sealed from the surrounding by the solid inorganic composition material. Solid core 102, including the voids 112, are also surrounded by and carry a plurality of fibers 106. The plurality of fibers 106 have attached thereto, water insoluble porous particulates 108. Fibers 106 and particulates 108 form together the growth scaffold. The plurality of fibers 106 together with the porous particulates 108 hold growth nutrients (not illustrated).

[0287] Figure 1G provides yet another illustration of particle 100G, including a single solid core 102 fully coated by a layer of inorganic composition 104 and entrap gas within the solid core and inorganic composition layer (the gas entrapped is not illustrated). Surrounding and enveloping the inorganic composition layer, but without physical attachment to the inorganic composition there are a plurality of bundled fibers 106 spaced apart (120) from the inorganic coating. The plurality of fibers are secured in place with respect to solid core 102, similar to free moving ball within a ball. The plurality of fibers 106 holds growth nutrients (not illustrated).

[0288] Figure 1H provides another illustration of a particle 100H having a single solid core 102 fully coated by a layer 104 and entrap gas (not illustrated). Solid core 102 together with the layer 104 is linked to a first end of a linker 116 forming a bridge to a plurality of fibers 106. Linker 116 can be a fiber similar to or integral part of fibers 106 or a different synthetic or non-synthetic fibrous material associated with fiber 106 in a chemical or non-chemical manner.

[0289] In some examples, the solid core 102 as illustrated in Figures 1A-1D and 1G -1H is a porous or expanded inorganic material and the layer 104 is of CaCCh and the scaffold can comprise cotton fibers.

[0290] In some examples, the solid core 102, as illustrated in Figures 1A-1D and 1G-1H is vermiculite and / or perlite and / or pumice and / or natural sponge, the layer 104 is of CaCCh and the scaffold can comprise cotton fibers. In some examples, the solid core 102, as illustrated in Figure 1G is composed of a solid inorganic composition, such as CaCCh, and the scaffold can comprise cotton fibers. In some examples, the solid core 102 as illustrated in Figures 1E-1F is comprised of CaCCh, and the scaffold can comprise cotton fibers.

[0291] In some examples, the linker 116 as illustrated in Figure 1H can also be cotton fibers.

[0292] In some examples, the water insoluble porous particulates 108 can be made of Tuff and / or bentonite and / or montmorillonite.

[0293] It is to be appreciated that in the context of the presently disclosed subject matter, the population of particles can include particles of different constructs, e.g. including different solid cores material (e.g. some made of vermiculite, some made of inorganic composition), different number of layers of inorganic composition (e.g. some being formed by applying a single layer of the inorganic composition, some being formed by applying a plurality of layers of the inorganic composition), different scaffold composition (e.g. some with insoluble porous particulates, some without the water insoluble porous particulates), different nutrient composition, different dimensions, different type of water insoluble fibers etc. The selection of particles to form a population can be dictated by the specific needs.

[0294] The presently disclosed population of particles can have different uses.

[0295] In some examples of the presently disclosed subject matter, the population of particles are suitable for use or are used in a method for carbon dioxide sequestration, the method being as disclosed herein. Thus, the presently disclosed subject matter also discloses the use of the presently disclosed population of particles for carbon dioxide sequestration.

[0296] The presently disclosed subject matter also provides methods of producing a population of particles. In some examples, the particles have a core-shell structure and the method comprises coating of the surface of a solid core with the inorganic composition. This method is referred to herein as the core-shell method.

[0297] When the solid core is coated with / sealed by at least one layer of inorganic composition, namely by the core-shell method, the method comprises: in situ forming of an inorganic composition over an entire surface of the solid core; securing to at least the inorganic composition a scaffold forming material suitable for support growth of photosynthesizing aquatic organism to thereby provide a construct.

[0298] In some examples of the core-shell method, the inorganic composition comprises an inorganic compound and the in situ formation of the inorganic composition over the core comprises in situ sedimentation of a first component of said inorganic compound, followed by sedimentation of a second component of said inorganic compound, to thereby form said inorganic compound onto said solid core.

[0299] The "two step" sedimentation of the inorganic compound, to form over the solid core a coating layer (referred to as the inorganic composition) results in the formation of any one of inorganic salt, inorganic hydroxide and inorganic oxide.

[0300] In some examples of the presently disclosed subject matter, when the coating layer is applied in more than one step, the layers may be the same or different in their composition.

[0301] In some examples of the presently disclosed method for forming the presently disclosed particles, the inorganic compound is amorphous silicate or sodium silicate, and the in situ forming comprises sedimentation of the amorphous silicate or sodium silicate.

[0302] When the solid core is made entirely from the inorganic composition (a solid core comprising the inorganic compound) a scaffold forming material suitable for support growth of photosynthesizing aquatic organism to thereby provide a construct.

[0303] In some examples of the presently disclosed methods for forming the presently disclosed particles, the inorganic compound is an inorganic salt, having the meaning and definitions and non-limiting examples as provided with respect to the presently disclosed population of particles.

[0304] In some examples of the presently disclosed methods for forming the presently disclosed particles, the inorganic compound is an inorganic hydroxide, having the meaning and definitions and non-limiting examples as provided with respect to the presently disclosed population of particles. In some examples of the presently disclosed methods for forming the presently disclosed particles, the inorganic compound is an inorganic oxide, having the meaning and definitions and non-limiting examples as provided with respect to the presently disclosed population of particles.

[0305] In some examples of the presently disclosed methods for forming the presently disclosed particles, the

[0306] Irrespective of whether the solid core is made of the inorganic composition, or the inorganic composition embeds and seals solid core(s) the following are fulfilled: the construct carries gas entrapped within a plurality of voids of said solid core; the inorganic composition has a water solubility configured to allow controlled exchange between the gas entrapped within said voids and water external to said construct a construct; the gas has a first specific gravity less than that of water and present in an amount sufficient to provide floatation of said particles, once the particles are brought into contact with the water; and the construct having a second specific gravity greater than that of water.

[0307] The presently disclosed method provides, inter alia, the presently disclosed population of particles. Thus, for the sake of simplicity, all terms and definitions provided in connection with the population of particles also apply to the presently disclosed method of producing the population of particles, mutatis mutandis.

[0308] Accordingly, in the context of the presently disclosed subject matter, the solid core material has the same meaning of the solid core forming part of the presently disclosed particles, and in the context of the presently disclosed method the solid core material is to be understood to encompass a material that allows the formation of a plurality of solid cores forming part of a population of particles, as disclosed herein.

[0309] Further accordingly, the growth scaffold forming material has the same meaning of the growth scaffold forming part of the presently disclosed particles. To this end, it is to be understood that the scaffold forming material includes water insoluble fibers as defined herein and optionally also the water insoluble porous particulate material, fixedly attached to the fibers. The fixation of the water insoluble porous particulates can be by the aid of a binder, as described herein.

[0310] Further accordingly, the entrapped gas has the same meaning as the gas forming part of the presently disclosed particles.

[0311] Further accordingly, the algae have the same meaning as the algae forming part of the presently disclosed particles.

[0312] The presently disclosed method comprises mixing the solid core of inorganic composition, or coated with the inorganic composition, at least at its surface, with a scaffold forming material under conditions suitable to allow securing of a scaffold to at least the inorganic composition.

[0313] In some examples of the presently disclosed subject matter, the mixing of the solid core with the scaffold forming material may be in the presence of a binder to facilitate adherence of the scaffold forming material to at least the inorganic composition.

[0314] In the context of the presently disclosed method, the binder has the same meaning as provided with respect to the presently disclosed population of particles.

[0315] In some other examples, the securing of the scaffold forming material can be mixing with the scaffold forming material with the solid core including inorganic composition at least at its surface. The mixing can be, for example, by rolling the solid core (with the inorganic composition) over the scaffold forming material.

[0316] In some examples of the presently disclosed subject matter, the scaffold forming material is secured to the solid core by causing in situ enlargement of the scaffold forming material over the solid core including the inorganic composition at least at its surface.

[0317] In some examples of the presently disclosed subject matter, the solid core is embedded in at least one layer of an in situ formed inorganic composition. This is typically, although not exclusively, prior to the securing of the scaffold material.

[0318] As noted above, in some examples of the presently disclosed subject matter, the scaffold comprises at least one nutrient suitable for growth of the photosynthesizing aquatic organism (also referred to as aquatic primary producers). To this end, the presently disclosed method comprises mixing the scaffold forming material with a nutrient composition to allow adsorption of the nutrient composition to the scaffold forming material.

[0319] It is to be understood that the at least one nutrient and / or the nutrient composition has the same meaning as defined with respect to the presently disclosed population of particles.

[0320] In some examples of the presently disclosed subject matter, the mixing of the nutrient composition is with the scaffold forming material, e.g. the water insoluble fibers forming the scaffold. The mixing of the fibers with the nutrient composition can be before or after associating the scaffold forming material, e.g. the fibers to the solid core or to the barrier coating / binder layer, if present.

[0321] In some examples of the presently disclosed subject matter, the mixing of the nutrient composition is with the water insoluble porous particulates, either before the water insoluble porous particulates are associated to the fibers forming the scaffold or after said association.

[0322] It is to be appreciated that the water insoluble fibers and the water insoluble porous material have the same meaning as provided with respect to the population of particles.

[0323] In some examples of the presently disclosed subject matter, the method comprises associating (preferably, fixedly attaching) the water insoluble porous particulate material to the water insoluble fibers (forming together the scaffold). The association can be before or after securing the water insoluble fibers to at least the inorganic composition at the surface. The association between the water insoluble fibers and the water insoluble porous particulates can be achieved with the aid of a binder as defined herein.

[0324] In some examples of the presently disclosed subject matter, the method comprises applying a binder over the water insoluble fibers forming part of the scaffold, prior to contacting the fibers with the water insoluble porous particulates.

[0325] In some examples of the presently disclosed subject matter, the method comprises actively introducing gas into the solid core. In the context of the presently disclosed subject matter the term "active introducing" is to be understood to mean applying an action that results in entrapping within the core, an amount of gas, that would not be present in the core under passive conditions. In some examples of the presently disclosed subject matter, the active introducing involves bubbling of gas.

[0326] In some examples of the presently disclosed subject matter, the active introducing involves gas permeation.

[0327] In some examples of the presently disclosed subject matter, the active introducing involves gas injection.

[0328] In some examples of the presently disclosed subject matter, the active introducing involves gas releasing chemical reaction. Non-limiting example of gas released by a chemical reaction includes the release of CO2 gas by the chemical decomposition of carbonate salts.

[0329] In some examples of the presently disclosed subject matter, the method comprises controlling dimension of the particles within the population of particles.

[0330] In some examples of the presently disclosed subject matter, the control of dimension of the particles can be by sieving, to select a size threshold.

[0331] In some examples of the presently disclosed subject matter, the control of dimension of the particles can be by downsizing the particles, e.g. by grinding the solid core material to a desired size, prior to in situ formation of the inorganic composition over the solid core.

[0332] In some examples of the presently disclosed subject matter, the control of dimensions of the particles is to a size of less than about 1cm.

[0333] The presently disclosed subject matter also provides, in accordance with a third of its aspects, a method for carbon dioxide sequestration, the method comprising distribution a population of particles over a selected area of body of water comprising at least one photosynthesizing aquatic organism, having the meaning as provided herein, and being open to a source of carbon dioxide to be sequestered; wherein the population of particles are as defined herein with respect to the first aspect of the presently disclosed subject matter.

[0334] The presently disclosed sequestration method employs, inter alia, the presently disclosed population of particles. Thus, for the sake of simplicity, all terms and definitions provided in connection with the population of particles also apply to the presently disclosed method of carbon dioxide sequestration, mutatis mutandis.

[0335] In some examples of the presently disclosed subject matter, the sequestration method comprises receiving data relating to the selected area of body of water prior to particles distribution and determining success rate of sequestration based on the data.

[0336] All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0337] The term "about" as used herein indicates values that may deviate up to 1%, more specifically 5%, more specifically 10%, more specifically 15%, and in some cases up to 20% higher or lower than the value referred to, the deviation range including integer values, and, if applicable, non-integer values as well, constituting a continuous range. In some embodiments, the term "about" refers to ± 10 %.

[0338] The indefinite articles “a” and “an” as used herein in the description and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one”. It must be noted that, as used in this description and the appended claims, the singular forms “a”, “an” and “the” include plural referents unless the content clearly dictates otherwise.

[0339] The clause “and / or” as used herein in the description and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and / or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and / or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and / or B”, when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0340] As used herein in the description and in the claims, “or” should be understood to have the same meaning as “and / or” as defined above. For example, when separating items in a list, “or” or “and / or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of’ or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e., “one or the other but not both”) when preceded by terms of exclusivity, such as “either” “one of’ “only one of’ or “exactly one of’ “consisting essentially of’ when used in the claims, shall have its ordinary meaning as used in the field of patent law.

[0341] As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and / or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

[0342] It should also be understood that, unless clearly indicated to the contrary, in any methods claimed herein that include more than one step or act, the order of the steps or acts of the method is not necessarily limited to the order in which the steps or acts of the method are recited.

[0343] Throughout this description (including the Examples) and claims which follow, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Specifically, it should be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. Only the transitional phrases “consisting of’ and “consisting essentially of’ shall be closed or semiclosed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures. More specifically, the terms "comprises", "comprising", "includes", "including", “having” and their conjugates mean "including but not limited to". The term “consisting of means “including and limited to”. The term "consisting essentially of' means that the composition, method or structure may include additional ingredients, steps and / or parts, but only if the additional ingredients, steps and / or parts do not materially alter the basic and novel characteristics of the claimed composition, method or structure.

[0344] It should be noted that various embodiments of the presently disclosed subject matter may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the presently disclosed subject matter. Accordingly, the description of a range should be considered to have specifically disclosed all the possible sub ranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed sub ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range. Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the indicated range. The phrases "ranging / ranges between" a first indicate number and a second indicate number and "ranging / ranges from" a first indicate number "to" a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numerals there between.

[0345] As used herein the term "method" refers to manners, means, techniques and procedures for accomplishing a given task including, but not limited to, those manners, means, techniques and procedures either known to, or readily developed from known manners, means, techniques and procedures by practitioners of the chemical, pharmacological, biological, biochemical and medical arts. It is appreciated that certain features of the presently disclosed subject matter, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the presently disclosed subject matter, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub combination or as suitable in any other described embodiment of the presently disclosed subject matter. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.

[0346] Various embodiments and aspects of the presently disclosed subject matter as delineated herein above and as claimed in the claims section below find experimental support in the following examples.

[0347] Disclosed and described, it is to be understood that the presently disclosed subject matter is not limited to the particular examples, methods steps, and compositions disclosed herein as such methods steps and compositions may vary somewhat. It is also to be understood that the terminology used herein is used for the purpose of describing particular embodiments only and not intended to be limiting since the scope of the presently disclosed subject matter will be limited only by the appended claims and equivalents thereof.

[0348] LIST OF PARAGRAPHS

[0349] The following statements / paragraphs disclose features and / or embodiments of the present disclosure. It is to be appreciated that any combination of these two or more of these paragraphs, or parts of paragraphs, constitute part of the invention and that there should be no limitation to the number of paragraphs that can be combined, as part of the presently disclosed subject matter:

[0350] 1. A population of particles, each particle comprising: a construct comprising: at least one solid core having an outer surface comprising an inorganic composition, a scaffold secured in place with respect to said solid core, the scaffold being suitable for support growth of photosynthesizing aquatic organism; gas entrapped within plurality of voids in said at least one solid core, wherein said inorganic composition has a water solubility configured to allow controlled exchange between the entrapped gas and water external to said construct; wherein said gas has a first specific gravity less than that of water and present in an amount sufficient to provide floatation of said particle, once the particle is brought into contact with the water; and wherein said construct having a second specific gravity greater than that of water.

[0351] 2. The population of particles according to paragraph 1, wherein said solid core comprises or is expanded or porous particulate.

[0352] 3. The population of particles according to any one or combination of the above paragraphs, wherein said core comprises expanded particulate mineral.

[0353] 4. The population of particles according to any one or any combination of the above paragraphs, wherein said particulate mineral is selected from the group consisting of vermiculite, montmorillonite, bentonite, hectorite, saponite, kaolinite, halloysite, illite, palygorskite, sepiolite, nontronite, and any combinations of same.

[0354] 5. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said expanded particulate mineral is expanded vermiculite.

[0355] 6. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, solid core is or comprises an expanded particulate volcanic glass.

[0356] 7. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said expanded particulate volcanic glass is or comprises expanded perlite. 8. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said particulate volcanic glass is or comprises expanded pumice.

[0357] 9. The population of particles according to any one or any combination of the above paragraphs, wherein said solid core is a porous core comprising a second inorganic composition which may be the same or different from the inorganic composition forming the at least one outer surface.

[0358] 10. The population of particles according to any one or any combination of the above paragraphs, wherein said solid core is a particulate organic core.

[0359] 11. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said particulate organic core is selected from the group consisting of carbon-based sponge, carbon-based foam, carbon-based fibrous material.

[0360] 12. The population of particles according to any one or any combination of the above paragraphs, wherein the particles comprise a single solid core embedded withing said inorganic composition.

[0361] 13. The population of particles according to any one or any combination of the above paragraphs, wherein the particles comprise two or more solid cores embedded within said inorganic composition.

[0362] 14. The population of particles according to any one or any combination of the above paragraphs, wherein said solid core comprises a particulate hydrocolloid.

[0363] 15. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said particulate hydrocolloid comprises a polysaccharide.

[0364] 16. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said particulate hydrocolloid comprises a polysaccharide selected from the group consisting of alginate, agar-agar, agarose, carrageenan, pectin, methylcellulose, hydroxypropyl methylcellulose (HPMC), ethylcellulose, carboxymethyl cellulose (CMC), microcrystalline cellulose, hydroxy ethyl cellulose (HEC), hydroxypropyl cellulose (HPC), carboxymethyl hydroxyethylcellulose (CMHEC), carboxymethyl hydroxypropylcellulose (CMHPC), chitosan, carboxymethyl chitosan, xanthan gum, guar gum, locust bean gum, galactomannan, konjac gum, glucomannan, tara gum, gellan gum, acacia gum (Gum Arabic), curdlan, fucoidan, pullulan, hyaluronic acid and any combination of same.

[0365] 17. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said particulate hydrocolloid comprises a self-linked or cross-linked polysaccharide.

[0366] 18. The population of particles according to any one or any combination of the above paragraphs, wherein said solid core has a size distribution characterized by dimensions between the micrometer range and millimeter range.

[0367] 19. The population of particles according to any one or any combination of the above paragraphs, wherein said inorganic composition is in a form of a continuous layer coating over the at least one solid core.

[0368] 20. The population of particles according to any one or any combination of the above paragraphs, wherein the inorganic composition has a solubility in water, at 25°C, of up to 5gr / L.

[0369] 21. The population of particles according to any one or any combination of the above paragraphs, wherein said at least one layer of the inorganic composition is an in situ layer.

[0370] 22. The population of particles according to any one or any combination of the above paragraphs, wherein the inorganic composition comprises at least one inorganic compound selected from the group consisting of inorganic salt, inorganic oxide, inorganic hydroxide, and amorphous silicate and combination of same.

[0371] 23. The population of particles according to any one or any combination of the above paragraphs, wherein the inorganic composition comprises at least one inorganic salt or hydroxide selected from the group consisting of calcium carbonate (CaCCh), calcium sulphate (CaSC ), calcium hydroxide (Ca(OH)2), barium hydroxide (BaO), calcium phosphate (Cax(PO4)y), magnesium carbonate (MgCCh), magnesium phosphate (Mg3(PO4)2), magnesium hydroxide (Mg(OH)2), and any combination of same.

[0372] 24. The population of particles according to any one or any combination of the above paragraphs, wherein the inorganic composition comprises at least one inorganic oxide selected from the group consisting of calcium oxide (CaO), magnesium oxide (MgO), manganese oxide (MnCh), ferric oxide (Fe2Ch), magnetite (FesC ), ferrous oxide (FeO), copper oxide (CuO), and any combination of same.

[0373] 25. The population of particles according to any one or any combination of the above paragraphs, wherein said at least one inorganic composition comprises amorphous silicate or sodium silicate.

[0374] 26. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said amorphous silicate is fumed silica.

[0375] 27. The population of particles according to any one or any combination of the above paragraphs, wherein said scaffold comprises any one or combination of fibers and waterinsoluble porous particulate material.

[0376] 28. The population of particles according to any one or any combination of the above paragraphs, wherein said scaffold comprises a nutrient composition suitable for supporting growth of photosynthesizing aquatic organism.

[0377] 29. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said nutrient composition comprises at least one nutrient selected from the group consisting of iron (Fe), Zinc (Zn), Copper (Cu), Manganese (Mn), Molybdenum (Mo), Selenium (Se), Chromium (Cr), Cobalt (Co), Iodine (I), Fluorine (F), Magnesium (Mg), Silicon (Si), Nitrogen (N), Phosphorus (P), Sulfur (S), Strontium (Sr), Nikel (Ni), Vanadium (V) and any combination of same.

[0378] 30. The population of particles according to any one or any combination of the above paragraphs, wherein said at least one nutrient, when relevant, comprises at least iron.

[0379] 31. The population of particles according to any one or any combination of the above paragraphs, wherein said at least one nutrient, when relevant, comprises at least manganese.

[0380] 32. The population of particles according to any one or any combination of the above paragraphs, wherein said scaffold, when relevant, comprises said fibers and said fibers are organic fibers.

[0381] 33. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said organic fibers are non-synthetic organic fibers. 34. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said organic fibers are selected from the group consisting of abaca fibers, banana fibers, bamboo fibers, broom fibers, coir fibers, cotton fibers, cannabus fibers, elephant fibers, flax fibers, hemp fibers, jute fibers, kenaf fibers, linseed fibers, oil palm fruit fibers, ramie fibers, rice husk fibers, roselle fibers, sisal fibers, sun hemp fibers, wheat fibers, wood fibers and any combination of same.

[0382] 35. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said organic fibers comprise cotton fibers.

[0383] 36. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said fibers comprise synthetic fibers.

[0384] 37. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said synthetic fibers comprise polyester fibers.

[0385] 38. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said synthetic fibers comprise recycled fibers.

[0386] 39. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said scaffold comprises the water insoluble porous particulate material.

[0387] 40. The population of particles according to any one or any combination of the above paragraphs, comprising a binder.

[0388] 41. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said binder is a bio-based binder and / or biodegradable binder.

[0389] 42. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said binder is a synthetic binder.

[0390] 43. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said binder binds between any one or combination of (i) the fibers and / or the water insoluble porous particulate matter the of the scaffold and the outer surface of the inorganic composition (ii) fibers of the scaffold; (iii) fibers of the scaffold and the water insoluble porous particulate material of the scaffold. 44. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said water-insoluble porous particulate material comprises minerals and / or particulate rock.

[0391] 45. The population to any one or any combination of the above paragraphs, wherein, when relevant, said water-insoluble porous particulate material comprises a clay mineral, aluminosilicate mineral and / or a carbonate mineral.

[0392] 46. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said water-insoluble porous particulate material is a mineral selected from the group consisting of zeolites, bentonite, montmorillonite, halloysite, sepiolite, attapulgite and dolomite.

[0393] 47. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said water insoluble porous particulate matter comprises bentonite and / or montmorillonite.

[0394] 48. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said water insoluble porous particulate material comprises particulate rock.

[0395] 49. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said particulate rock is selected from the group consisting of tuff, sandstone, diatomaceous earth, shale, marl and vesicular basalt.

[0396] 50. The population of particles according to any one or any combination of the above paragraphs, wherein, when relevant, said water-insoluble porous particulate material is tuff.

[0397] 51. The population of particles according to any one or combination of the above paragraphs, as relevant, wherein said water-insoluble porous particulate material holds said nutrient composition.

[0398] 52. The population of particles according to any one or any combination of the above paragraphs, wherein said scaffold is physically anchored into said inorganic composition, at one or more locations.

[0399] 53. The population of particles according to any one or any combination of the above paragraphs, wherein said scaffold has free movement with respect to said solid core. 54. The population of particles according to any one or any combination of the above paragraphs, wherein said scaffold surrounds said solid core.

[0400] 55. The population of particles according to any one or any combination of the above paragraphs, wherein said gas is selected from the group consisting of air and CO2.

[0401] 56. The population of particles according to any one or any combination of the above paragraphs, wherein said exchange between the entrapped gas and water external to said construct is controlled by at least one parameter selected from the group consisting of material of core, dimension of core, surface area of core, porosity of core, specific gravity of core, surface energy of core, wettability of core, gas permeability of said inorganic composition, water permeability of said inorganic composition, solubility of said inorganic composition, , composition of said inorganic composition; wettability of said inorganic composition, overall wettability of the inorganic composition, type of entrapped gas, amount of entrapped gas, water resistance of the inorganic composition, gas permeability of the inorganic composition, gas resistance of the inorganic composition, outer surface charge, outer surface polarity, outer surface free energy and any combination of same.

[0402] 57. The population of particles according to any one or any combination of the above paragraphs, wherein said controlled exchange between the entrapped gas and water external to said construct is determinable by a settling test whereby at least one of particles' settling rate, % particles settling, amount of particles settling under defined conditions is determined.

[0403] 58. The population of particles according to any one or any combination of the above paragraphs, wherein said water is saltwater or freshwater.

[0404] 59. The population of particles according to any one or any combination of the above paragraphs, wherein said photosynthesizing aquatic organism comprises microalgae.

[0405] 60. The population of particles according to any one or any combination of the above paragraphs, wherein said particles have a size distribution characterized by dimensions between the micrometer range and millimeter range.

[0406] 61. A method of preparing particles, the method comprising: in situ formation of an inorganic composition over an entire surface of a solid core; securing to at least the inorganic composition a scaffold suitable for support growth of photosynthesizing aquatic organism to thereby provide a construct, wherein said construct carries gas entrapped within a plurality of voids of said solid core; wherein the inorganic composition has a water solubility configured to allow controlled exchange between the gas entrapped within said voids and water external to said construct a construct; wherein said gas has a first specific gravity less than that of water and present in an amount sufficient to provide floatation of said particles, once the particles are brought into contact with the water; and wherein said construct having a second specific gravity greater than that of water.

[0407] 62. The method according to paragraph 61, wherein said inorganic composition comprises an inorganic compound and said in situ formation comprises in situ sedimentation of a first component of said inorganic compound, followed by sedimentation of a second component of said inorganic compound, to thereby form said inorganic compound onto said solid core.

[0408] 63. The method according to any one or any combination of the above method-related paragraphs, wherein said inorganic compound is selected from the group consisting of inorganic salt, inorganic hydroxide and inorganic oxide.

[0409] 64. The method according to any one or any combination of the above method-related paragraphs, wherein said inorganic composition comprises amorphous silicate or sodium silicate and said in situ forming comprises sedimentation of said amorphous silicate or sodium silicate.

[0410] 65. The method according to any one or any combination of the above method-related paragraphs, comprising repeating said in situ formation step more than once, prior to said securing of the scaffold.

[0411] 66. A method of preparing particles, the method comprising: providing solid particulates of inorganic composition, the particulates having a plurality of voids distributed therein, and suitable for accommodating a gas; securing onto the solid particulates a scaffold suitable for support growth of photosynthesizing aquatic organism to thereby provide a construct; wherein said construct carries gas entrapped within a plurality of voids of said solid core; wherein the inorganic composition has a water solubility configured to allow controlled exchange between the gas entrapped within said voids and water external to said construct a construct; wherein said gas has a first specific gravity less than that of water and present in an amount sufficient to provide floatation of said particles, once the particles are brought into contact with the water; and wherein said construct having a second specific gravity greater than that of water.

[0412] 67. The method according to paragraph 66, wherein said solid particles are prepared by deposition of inorganic compounds of said inorganic composition while bubbling gas.

[0413] 68. A method for carbon dioxide sequestration, comprising distributing a population of particles according to any one or any combination of the above particle-related paragraphs, over a selected area of body of water comprising at least one photosynthesizing aquatic organism and being open to a source of carbon dioxide to be sequestered.

[0414] 69. The method according to paragraph 68, comprising receiving data relating to said selected area of body of water prior to said distribution, and determining success rate of sequestration based on said data.

[0415] 70. The method according to any one or any combination of the above paragraphs related to carbon dioxide sequestration, comprising actuating said distribution based on said received data.

[0416] DESCRIPTION OF NON-LIMITING EXAMPLES

[0417] In situ coated Vermiculite with CaCO.

[0418] The following Examples show the efficiency of in-situ CaCOs formation and precipitation on vermiculite particles, and the buoyancy in water of the resulting in situ coated vermiculite particles. Uncoated Vermiculite exhibits a buoyancy of approximately 2-3 days (size dependent), limited by the exchange between water entrance into, and exit of trapped air out of the vermiculite structure.

[0419] The chemical reaction resulting in the in situ precipitation is:

[0420] Three different procedures were employed to coat vermiculite particles, each using a different combination of reagents: NaHCCh with CaCh, Ca(OH)2 with CO2 gas, and Na2COs with CaCh. The in situ coated vermiculite particles were then compared against uncoated vermiculite particles, to show their advantageous floatation in water.

[0421] The following reagent concentrations were used:

[0422] NaHCOs IM in water

[0423] Na2CCh 2.5M in water

[0424] CaCh 2.5M / 1M in water

[0425] Ca(OH)22.5 / 5% in water

[0426] CCh gas 100%

[0427] As shown in the following Examples, coating with CaCCh modified the surface properties of vermiculite, forming a barrier that blocked the entrance of water and release of trapped air, thereby enhancing buoyancy of the particle.

[0428] Example 1- In situ coating with NaHCOs salt and CaCh solution (pH 8 / pH 13) in a coating drum

[0429] The chemical reaction involved in the precipitation of calcium carbonate in this Example is as follows:

[0430] In this Example, 20 g of vermiculite, either 1-2 mm or 2-3 mm in size, were inserted into a coating drum rotating at a speed of 75 RPM. The vermiculite was then subjected to fan heating at temperatures ranging from 90°C to 105°C for a brief duration. 5 g of NaHCCh solid salt were added to the coating drum and mixed thoroughly with the vermiculite. Subsequently, CaCh solution (pH ~8 or pH —13, IM, 40ml) was slowly sprayed into the coating drum to initiate the coating process. Following the coating application, the coated vermiculite was allowed to dry within the coating drum for approximately one hour. For additional layers, 5 g or 10 g of NaHCOs and 40 ml or 80 ml of CaCh were respectively applied.

[0431] The coating procedure in the drum provided a uniform coating evenly dispersed across the particle surfaces.

[0432] Figures 2A-2J are microscope images of uncoated vermiculite and coated vermiculite.

[0433] Specifically, Figures 2A-2B are images of uncoated vermiculite of 2-3 mm dimensions, and l-2mm dimensions, respectively.

[0434] Figure 2C is an image of vermiculite (2-3mm) obtained with a solution of CaCh at pH ~8; Figure 2D is an image of vermiculite (l-2mm) obtained with a solution of CaCh at pH 8; Figure 2E is an image of vermiculite (2-3mm) obtained with a solution of CaCh at pH 13; Figure 2F is an image of vermiculite (l-2mm) obtained with a solution of CaCh at pH 13; Figures 2G-2H are images of vermiculite having two layers of coating, obtained with a solution of CaCh at pH 13; and Figures 2I-2J are images of vermiculite (l-2mm) coated with three layers, obtained with a solution of CaCh at pH 13.

[0435] It is thus shown that it is possible to in situ coat vermiculite using this procedure.

[0436] The chemical reaction involved in the precipitation of calcium carbonate in this Example is as follows:

[0437] In this Example, 5 g of vermiculite (1-2 mm) were added to a beaker containing 100 ml solutions of either 5% or 2.5% Ca(OH)2 saturated solutions for 2 hours (maximum solubility 2%). Following this immersion period, the vermiculite underwent filtration to eliminate any excess Ca(OH)2. Subsequently, the dispersed vermiculite was carefully transferred into a closed vessel and securely covered with paraffin to ensure maximal sealing. Pure CO2 gas, maintained at 100% concentration and a flow rate of 10 1 / hr, was then injected into the vessel for a duration of 2 minutes. The vessel was then sealed to the best extent possible and allowed to stand undisturbed for 24 hours.

[0438] Figures 3A-3D are microscope images of uncoated vermiculite and coated vermiculite obtained in this procedure.

[0439] Specifically, Figure 3A is an image of vermiculite (l-2mm) coated with 5% Ca(OH)2; Figure 3B is an image of vermiculite (l-2mm) coated with 2.5% Ca(OH)2; Figure 3C is an image of vermiculite (l-2mm) coated with 5% Ca(OH)2 after being submerged in seawater; and Figure 3D is an image of vermiculite (l-2mm) coated with 2.5% Ca(OH)2 after being submerged in seawater.

[0440] It is thus shown that it is possible to in situ coat vermiculite using this procedure.

[0441] In this Example, the chemical reaction involved in the precipitation of calcium carbonate in this Example is as follows:

[0442] Overall, three different procedures were conducted.

[0443] Procedure A - Two layers coating in drum

[0444] Vermiculite (1-2 mm), 40 g, were inserted into a coating drum, which was set to rotate at 75 RPM. Na2CO3 solution and CaCh solutions were sprayed on the vermiculite together using an air fan at room temperature throughout the process to facilitate drying. Subsequently, Na2CO3 solution and CaCh solutions (concentration of each solution was 2.5 M), were concurrently sprayed into the drum, with 50 ml of each solution dispensed at intervals of 5 ml every 5 minutes. This staggered application allowed for free movement of the vermiculite particles inside the coating drum, ensuring uniform coating. For the application of a second layer, approximately 20 g of the coated vermiculite (coated with a first layer) was taken out of the drum. Subsequently, a second layer comprising 30 ml from each solution was sprayed into the drum simultaneously, with the same time intervals as the first layer.

[0445] Figures 4A-4D are microscope images of inorganic coated vermiculite obtained in this procedure (Fig. 4A and 4C) and inorganic-coated vermiculite after testing stability of coating in seawater (Fig. 4B and 4D).

[0446] Specifically, Figure 4A is an image of vermiculite (l-2mm) coated with one single layer; Figure 4B is an image of vermiculite (l-2mm) coated with one single layer, after being submerged in seawater, Figure 4C is an image of vermiculite (l-2mm) coated with two layers. Figure 4D is an image of vermiculite coated with two layers after being submerged in seawater.

[0447] It is thus shown that it is possible to coat vermiculite using this procedure (Fig. 4A and 4C).

[0448] The inorganic coated vermiculite particles were then submerged in seawater and placed on an orbital shaker (120 RPM) (Fig. 4B and 4D) to evaluate the effectiveness of the coating under simulated environmental conditions.

[0449] It was found that the coating in drum provided an enhanced buoyancy compared to uncoated vermiculite.

[0450] Procedure B - Coatins by submergence

[0451] In this Example, vermiculite is first submerged in CaCh solution, filtered ad then submerged in Na2CCh solution.

[0452] Specifically, 5 g of vermiculite particles (1-2 mm) were submerged in 100 ml of a CaCh solution (2.5 M) in a beaker for 10 minutes. Subsequently, the vermiculite was filtered using a sieve to eliminate any excess CaCk Following this, the vermiculite was immersed in a Na2COs solution (2.5 M) in a beaker, while continuously stirring until a solid white coating was formed on the particles surface. The vermiculite remained in the solution for 45 minutes, after which, the in situ coated vermiculite was transferred onto a sieve and rinsed thoroughly with tap water to remove any excess salts.

[0453] Figures 5A-5B are microscope images of inorganic coated vermiculite obtained in this procedure (Fig. 5A) and inorganic-coated vermiculite after testing stability of coating in seawater (Fig. 5B). Specifically, Figure 5A is an image of vermiculite (l-2mm) coated by first submerging in CaCh solution, followed by submersion in Na2CCh solution and Figure 5B is an image of vermiculite (l-2mm) coated as in Figure 5A, and after being submerged in seawater, showing that the coating remains on the vermiculite particle.

[0454] It is thus shown that it is possible to in situ coat vermiculite using this procedure.

[0455] Procedure C - Coating by Spraying

[0456] In this Example, 2 grams of vermiculite particles (1-2 mm), were dispersed onto a Pyrex tray to create a monolayer. Subsequently, 15 ml of CaCh solution (2.5 M) was sprayed evenly onto the vermiculite layer, followed by an additional 15 ml of Na2COs solution (2.5 M). Following the application of the solutions, the vermiculite was divided into two portions. One half was subjected to air drying, while the other half was dried in an oven at 105°C for a duration of 1 hour as presented by Figures 6A-6B.

[0457] Example 4: Coating with Sulfate, Phosphate or Silicate minerals

[0458] Additional materials for inorganic coating of a solid core are applied as described in Examples 1 and 3. The following reaction schemes are used:

[0459] CaSO 4-based minerals

[0460] Na2SO4+ CaCl2-> CaSO4f (Anhydrite) + 2NaCl

[0461] Na2SO4+ CaCl2+ 2H2O -> CaSO4■ 2H2O f (Gypsum) + 2NaCl Na2SO4+ CaCl2+ 0.SH2O -> CaSO4■ 0.SH2O f (Bassnite) + 2NaCl

[0462] In addition, further reactions leading to gypsum precipitation are utilized as described in Reiss, A. G. et al. 2021, “Gypsum Precipitation under Saline Conditions: Thermodynamics, Kinetics, Morphology, and Size Distribution” Minerals, 11(2), 141, the entire contents thereof are hereby incorporated by reference.

[0463] Calcium phosphate (Cax(PO4)y)-based minerals

[0464] 2Na3PO4+ 3CaCl2-> Ca3(PO4)24 (Tuite) + 6NaCl yNa3PO4+ xCaCl2+ nH20 -> Cax(PO4)y■ nH20

[0465] 4 (Amorphous calcium phosphate) These reactions occur rapidly under saturation indices (SI, see Equation 5) of >0 and high pH values (>8), which are adjusted using alkaline solutions such as concentrated KOH or NaOH

[0466] IAP

[0467] Equation 5: SI = log — sp where IAP represents ion activity product; and Ksp denotes minerals solubility coefficient.

[0468] Silicate minerals

[0469] In contrast to CaSO4 and Cax(PO4)y-based minerals, amorphous silicate (SiO2-nH2O) precipitation primarily occurs under low pH conditions. Adjusting the pH with an acid such as HC1, enhances precipitation and allows controlled deposition of the precipitates on the solid core when SI values are above zero (>0).

[0470] Reactions leading to precipitation of silicate minerals are utilized as described in Milne, Nicholas A., et al. "Chemistry of silica scale mitigation for RO desalination with particular reference to remote operations." Water research 65 (2014): 107-133, the entire contents thereof are hereby incorporated by reference.

[0471] The sulfate, phosphate and silicate coatings described herein result in a coating that is stable under environmental conditions and provides enhanced buoyancy compared to uncoated vermiculite.

[0472] Example 5: Applying fibers onto inorganic coated core

[0473] Fibers are attached to CaCOs-coated vermiculite by following the procedure set forth in procedure A of Example 3.

[0474] Specifically, viscose fibers having a length of approximately 0.5 mm are introduced into the coating drum while the inorganic-coated vermiculite is still wet, i.e., prior to the drying step. Water is added by spraying into the drum to promote the adhesion of the fibers within the CaCCh precipitate. The resulting solid product is then subjected to a drying process under hot air.

[0475] Example 6: Applying fibers using a cross-linkable natural polymer

[0476] The viscose fibers are spread uniformly on a sheet, sprayed by a 2% alginate solution in water. While the polymer is still wet (i.e. not yet self- or cross-linked), the CaCCh-coated vermiculite particles are spread on the fibers, the Ca is partially dissolved in the alginate solution and cross-links the alginate, forming a hydrogel that glues the fibers to the vermiculite. This procedure is followed by placing the layer of fibers and vermiculite particles on top of another layer of fibers sprayed with alginate. This forms a sheet of a layered structure (fibers- alginate coated-> salt coated-vermiculite), which is then cut into smaller size particles.

Claims

CLAIMS:

1. A population of particles, each particle comprising: a construct comprising: at least one solid core having an outer surface comprising an inorganic composition, a scaffold secured in place with respect to said solid core, the scaffold being suitable for support growth of photosynthesizing aquatic organism; gas entrapped within plurality of voids in said at least one solid core, wherein said inorganic composition has a water solubility configured to allow controlled exchange between the entrapped gas and water external to said construct; wherein said gas has a first specific gravity less than that of water and present in an amount sufficient to provide floatation of said particle, once the particle is brought into contact with the water; and wherein said construct having a second specific gravity greater than that of water.

2. The population of particles of claim 1, wherein said solid core comprises or is expanded or porous particulate.

3. The population of particles of claim 1 or 2, wherein said core comprises expanded particulate mineral.

4. The population of particles of claim 2 or 3, wherein said particulate mineral is selected from the group consisting of vermiculite, montmorillonite, bentonite, hectorite, saponite, kaolinite, halloysite, illite, palygorskite, sepiolite, nontronite, and any combinations of same.

5. The population of particles of claim 4, wherein said expanded particulate mineral is expanded vermiculite.

6. The population of particles of claim 2, wherein said solid core is or comprises an expanded particulate volcanic glass.

7. The population of particles of claim 6, wherein said expanded particulate volcanic glass is or comprises expanded perlite.

8. The population of particles of claim 7, wherein said particulate volcanic glass is or comprises expanded pumice.

9. The population of particles of claim 1 or 2, wherein said solid core is a porous core comprising a second inorganic composition which may be the same or different from the inorganic composition forming the at least one outer surface.

10. The population of particles of claim 1 or 2, wherein said solid core is a particulate organic core.

11. The population of particles of claim 10, wherein said particulate organic core is selected from the group consisting of carbon-based sponge, carbon-based foam, carbonbased fibrous material.

12. The population of particles of any one of claims 1 to 11, wherein the particles comprise a single solid core embedded withing said inorganic composition.

13. The population of particles of any one of claims 1 to 12, wherein the particles comprise two or more solid cores embedded within said inorganic composition.

14. The population of particles of claim 1 or 2, wherein said solid core comprises a particulate hydrocolloid.

15. The population of particles of claim 14, wherein said particulate hydrocolloid comprises a polysaccharide.

16. The population of particles of claim 15, wherein said particulate hydrocolloid comprises a polysaccharide selected from the group consisting of alginate, agar-agar, agarose, carrageenan, pectin, methylcellulose, hydroxypropyl methylcellulose (HPMC), ethylcellulose, carboxymethyl cellulose (CMC), microcrystalline cellulose, hydroxy ethyl cellulose (HEC), hydroxypropyl cellulose (HPC), carboxymethyl hydroxyethylcellulose (CMHEC), carboxymethyl hydroxypropylcellulose (CMHPC), chitosan, carboxymethyl chitosan, xanthan gum, guar gum, locust bean gum, galactomannan, konjac gum,glucomannan, tara gum, gellan gum, acacia gum (Gum Arabic), curdlan, fucoidan, pullulan, hyaluronic acid and any combination of same.

17. The population of particles of claim 15 or 16, wherein said particulate hydrocolloid comprises a self-linked or cross-linked polysaccharide.

18. The population of particles of any one of claims 1 to 17, wherein said solid core has a size distribution characterized by dimensions between the micrometer range and millimeter range.

19. The population of particles of any one of claims 1 to 18, wherein said inorganic composition is in a form of a continuous layer coating over the at least one solid core.

20. The population of particles of any one of claims 1 to 19, wherein the inorganic composition has a solubility in water, at 25°C, of up to 5gr / L.

21. The population of particles of any one of claims 1 to 20, wherein said at least one layer of the inorganic composition is an in situ layer.

22. The population of particles of any one of claims 1 to 21, wherein the inorganic composition comprises at least one inorganic compound selected from the group consisting of inorganic salt, inorganic oxide, inorganic hydroxide, and amorphous silicate and combination of same.

23. The population of particles of any one of claims 1 to 22, wherein the inorganic composition comprises at least one inorganic salt or hydroxide selected from the group consisting of calcium carbonate (CaCCh), calcium sulphate (CaSCh), calcium hydroxide (Ca(OH)2), barium hydroxide (BaO), calcium phosphate (Cax(PO4)y), magnesium carbonate (MgCCh), magnesium phosphate (Mg3(PO4)2), magnesium hydroxide (Mg(OH)2), and any combination of same.

24. The population of particles of any one of claims 1 to 23, wherein the inorganic composition comprises at least one inorganic oxide selected from the group consisting of calcium oxide (CaO), magnesium oxide (MgO), manganese oxide (MnCh), ferric oxide (Fe2O3), magnetite (FesC ), ferrous oxide (FeO), copper oxide (CuO), and any combination of same.

25. The population of particles of any one of claims 1 to 21, wherein said at least one inorganic composition comprises amorphous silicate or sodium silicate.

26. The population of particles of claim 25, wherein said amorphous silicate is fumed silica.

27. The population of particles of any one of claims 1 to 26, wherein said scaffold comprises any one or combination of fibers and water-insoluble porous particulate material.

28. The population of particles of any one of claims 1 to 27, wherein said scaffold comprises a nutrient composition suitable for supporting growth of photosynthesizing aquatic organism.

29. The population of particles of claim 28, wherein said nutrient composition comprises at least one nutrient selected from the group consisting of iron (Fe), Zinc (Zn), Copper (Cu), Manganese (Mn), Molybdenum (Mo), Selenium (Se), Chromium (Cr), Cobalt (Co), Iodine (I), Fluorine (F), Magnesium (Mg), Silicon (Si), Nitrogen (N), Phosphorus (P), Sulfur (S), Strontium (Sr), Nikel (Ni), Vanadium (V) and any combination of same.

30. The population of particles of claim 28 or 29, wherein said at least one nutrient comprises at least iron.

31. The population of particles of any one of claims 28 to 30, wherein said at least one nutrient comprises at least Manganese.

32. The population of particles of any one of claims 28 to 31, wherein said scaffold comprises said fibers and said fibers are organic fibers.

33. The population of particles of claim 32, wherein said organic fibers are nonsynthetic organic fibers.

34. The population of particles of claim 32 or 33, wherein said organic fibers are selected from the group consisting of abaca fibers, banana fibers, bamboo fibers, broom fibers, coir fibers, cotton fibers, cannabus fibers, elephant fibers, flax fibers, hemp fibers, jute fibers, kenaf fibers, linseed fibers, oil palm fruit fibers, ramie fibers, rice husk fibers, roselle fibers, sisal fibers, sun hemp fibers, wheat fibers, wood fibers and any combination of same.

35. The population of particles of claim 34, wherein said organic fibers comprise cotton fibers.

36. The population of particles of claim 32, wherein said fibers comprise synthetic fibers.

37. The population of particles of claim 36, wherein said synthetic fibers comprise polyester fibers.

38. The population of particles of claim 36, wherein said synthetic fibers comprise recycled fibers.

39. The population of particles of any one of claims 27 to 38, wherein said scaffold comprises the water insoluble porous particulate material.

40. The population of particles of any one of claims 1 to 39, comprising a binder.

41. The population of particles of claim 40, wherein said binder is a bio-based binder and / or biodegradable binder.

42. The population of particles of claim 40, wherein said binder is a synthetic binder.

43. The population of particles of any one of claims 40 to 42, wherein said binder binds between any one or combination of (i) the fibers and / or the water insoluble porous particulate matter the of the scaffold and the outer surface of the inorganic composition (ii) fibers of the scaffold; (iii) fibers of the scaffold and the water insoluble porous particulate material of the scaffold.

44. The population of particles of any one of claims 1 to 43, when dependent directly or indirectly on claim 39, wherein said water-insoluble porous particulate material comprises minerals and / or particulate rock.

45. The population of particles of claim 44, wherein said water-insoluble porous particulate material comprises a clay mineral, aluminosilicate mineral and / or a carbonate mineral.

46. The population of particles of claim 45, wherein said water-insoluble porous particulate material is a mineral selected from the group consisting of zeolites, bentonite, montmorillonite, halloysite, sepiolite, attapulgite and dolomite.

47. The population of particles of claim 46, wherein said water insoluble porous particulate matter comprises bentonite and / or montmorillonite.

48. The population of particles of claim 44, wherein said water insoluble porous particulate material comprises particulate rock.

49. The population of particles of claim 48, wherein said particulate rock is selected from the group consisting of tuff, sandstone, diatomaceous earth, shale, marl and vesicular basalt.

50. The population of particles of claim 49, wherein said water-insoluble porous particulate material is tuff.

51. The population of particles of any one of claims 1 to 50, when dependent directly or indirectly on any one of claims 39, and 45 to 48, and directly or indirectly on any one of claims 28 to 31, wherein said water-insoluble porous particulate material holds said nutrient composition.

52. The population of particles of any one of claims 1 to 51, wherein said scaffold is physically anchored into said inorganic composition, at one or more locations.

53. The population of particles of any one of claims 1 to 52, wherein said scaffold has free movement with respect to said solid core.

54. The population of particles of any one of claims 1 to 53, wherein said scaffold surrounds said solid core.

55. The population of particles of any one of claims 1 to 54, wherein said gas is selected from the group consisting of air and CO2.

56. The population of particles of any one of claims 1 to 55, wherein said exchange between the entrapped gas and water external to said construct is controlled by at least one parameter selected from the group consisting of material of core, dimension of core, surface area of core, porosity of core, specific gravity of core, surface energy of core, wettability of core, gas permeability of said inorganic composition, water permeability of said inorganic composition, solubility of said inorganic composition, , composition of said inorganic composition; wettability of said inorganic composition, overall wettability of the inorganic composition, type of entrapped gas, amount of entrapped gas, water resistance of the inorganic composition, gas permeability of the inorganic composition, gas resistance of the inorganic composition, outer surface charge, outer surface polarity, outer surface free energy and any combination of same.

57. The population of particles of any one of claims 1 to 56, wherein said controlled exchange between the entrapped gas and water external to said construct is determinable by a settling test whereby at least one of particles' settling rate, % particles settling, amount of particles settling under defined conditions is determined.

58. The population of particles of any one of claims 1 to 57, wherein said water is saltwater or freshwater.

59. The population of particles of any one of claims 1 to 58, wherein said photosynthesizing aquatic organism comprises microalgae.

60. The population of particles of any one of claims 1 to 59, wherein said particles have a size distribution characterized by dimensions between the micrometer range and millimeter range.

61. A method of preparing particles, the method comprising: in situ formation of an inorganic composition over an entire surface of a solid core; securing to at least the inorganic composition a scaffold suitable for support growth of photosynthesizing aquatic organism to thereby provide a construct, wherein said construct carries gas entrapped within a plurality of voids of said solid core; wherein the inorganic composition has a water solubility configured to allow controlled exchange between the gas entrapped within said voids and water external to said construct a construct; wherein said gas has a first specific gravity less than that of water and present in an amount sufficient to provide floatation of said particles, once the particles are brought into contact with the water; and wherein said construct having a second specific gravity greater than that of water.

62. The method of claim 61, wherein said inorganic composition comprises an inorganic compound and said in situ formation comprises in situ sedimentation of a first component of said inorganic compound, followed by sedimentation of a secondcomponent of said inorganic compound, to thereby form said inorganic compound onto said solid core.

63. The method of claim 62, wherein said inorganic compound is selected from the group consisting of inorganic salt, inorganic hydroxide and inorganic oxide.

64. The method of claim 62, wherein said inorganic composition comprises amorphous silicate or sodium silicate and said in situ forming comprises sedimentation of said amorphous silicate or sodium silicate.

65. The method of any one of claims 62 to 64, comprising repeating said in situ formation step more than once, prior to said securing of the scaffold.

66. A method of preparing particles, the method comprising: providing solid particulates of inorganic composition, the particulates having a plurality of voids distributed therein, and suitable for accommodating a gas; securing onto the solid particulates a scaffold suitable for support growth of photosynthesizing aquatic organism to thereby provide a construct; wherein said construct carries gas entrapped within a plurality of voids of said solid core; wherein the inorganic composition has a water solubility configured to allow controlled exchange between the gas entrapped within said voids and water external to said construct a construct; wherein said gas has a first specific gravity less than that of water and present in an amount sufficient to provide floatation of said particles, once the particles are brought into contact with the water; and wherein said construct having a second specific gravity greater than that of water.

67. The method of claim 66, wherein said solid particles are prepared by deposition of inorganic compounds of said inorganic composition while bubbling gas.

68. A method for carbon dioxide sequestration, comprising distributing a population of particles of any one of claims 1 to 60, over a selected area of body of water comprisingat least one photosynthesizing aquatic organism and being open to a source of carbon dioxide to be sequestered.

69. The method of claim 68, comprising receiving data relating to said selected area of body of water prior to said distribution, and determining success rate of sequestration based on said data.

70. The method of claim 68 or 69, comprising actuating said distribution based on said received data.

Images