Preparation method of lanolin-derived branched-chain fatty acid nanoemulsion

Abstract

The application provides a preparation method of lanolin source branched fatty acid nanoemulsion, which comprises the following steps: emulsifying lanolin source branched fatty acid, amino-modified nano-silicon dioxide, an organic solvent and water after mixing, to obtain an emulsion; the preparation method of the lanolin source branched fatty acid comprises the following steps: saponification, precipitation, acidification, urea complexation, crystallization and washing of lanolin; the mass ratio of the lanolin source branched fatty acid and the amino-modified nano-silicon dioxide is 10:1-2; the mass-volume ratio of the lanolin source branched fatty acid and the organic solvent is 0.5g-10g:100mL; the mass-volume ratio of the lanolin source branched fatty acid and water is 0.5g-10g:100mL; the amino-modified nano-silicon dioxide comprises the following raw materials: ferroferric oxide, silicate and 3-aminopropyl triethoxysilane; and the nanoemulsion prepared by the preparation method has good stability.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of nanoemulsions, in particular to a preparation method of a lanolin source branched fatty acid nanoemulsion. BACKGROUND

[0002] An emulsion is a system formed by mixing at least two immiscible liquids, one of which (called the dispersed phase) is dispersed in the form of small droplets in the other (the continuous phase). The emulsion is a thermodynamically unstable system, and usually needs an emulsifier to maintain stability. In a Pickering emulsion, the stability of the emulsion is achieved by solid particles adsorbed on the interface. The interfacial wettability and particle size distribution of the particles are key factors for controlling the formation and stability of the Pickering emulsion. The wettability of the amphiphilic particles can enable the particles to be effectively adsorbed on the oil / water interface and reduce the interfacial tension between the water phase and the oil phase. These particles gather on the oil / water interface to form a stable physical barrier, which can effectively prevent droplet coalescence, coalescence and Oswald ripening, thereby better stabilizing the emulsion.

[0003] A microemulsion is usually a transparent or translucent liquid stable dispersion system with thermodynamic stability, which is composed of an appropriate proportion of an oil phase, water, a surfactant and a co-surfactant. The particle size of the microemulsion is in the range of 10 nm to 100 nm, and the surface tension is extremely low. In particular, the oil-in-water microemulsion can be used as a delivery carrier for fat-soluble nutrients, and has broad prospects in the food industry.

[0004] The microemulsion of the related art is stabilized by a surfactant, but the surfactant is usually expensive, and some surfactants can even cause tissue or cell damage and have certain biological toxicity. SUMMARY

[0005] The application is made in view of the above-mentioned problems, and aims to provide a preparation method of a lanolin source branched fatty acid nanoemulsion. The emulsion prepared by the preparation method has good stability.

[0006] Specifically, the application discloses a preparation method of a lanolin source branched fatty acid nanoemulsion, which comprises the following steps:

[0007] The lanolin source branched fatty acid, amino-modified nano-silicon dioxide, an organic solvent and water are mixed and emulsified to prepare an emulsion.

[0008] The preparation method of the lanolin source branched fatty acid comprises the following steps:

[0009] The lanolin is saponified, precipitated, acidified, urea-complexed and washed.

[0010] The mass ratio of the lanolin-derived branched-chain fatty acids to the amino-modified nano-silica is 10:1~2;

[0011] The mass-to-volume ratio of the lanolin-derived branched-chain fatty acids to the organic solvent is 0.5g~10g:100mL;

[0012] The mass-to-volume ratio of the lanolin-derived branched-chain fatty acids to water is 0.5g~10g:100mL;

[0013] The amino-modified nano-silica comprises the following raw materials:

[0014] Iron oxide, silicate esters, and N-aminoethyl-3-aminopropylmethyldimethoxysilane.

[0015] According to one of the technical solutions of the preparation method in this application, at least the following beneficial effects are achieved:

[0016] The nanoemulsions in this application are prepared using lanolin-derived branched-chain fatty acids and amino-modified nano-silica as raw materials. The amino-modified nano-silica consists of hydrophilic particles, while the lanolin-derived branched-chain fatty acids contain lipophilic long carbon chains. The amino-modified nano-silica has amino groups on its surface, which react with the fatty acids to form amphiphilic (hydrophilic and lipophilic) particles. These amphiphilic particles have suitable surface wettability and high interfacial activity, thus effectively adsorbing onto the oil-water interface to form a dense film layer, preventing droplet aggregation and thus forming a stable emulsion.

[0017] The nanoemulsion of this application can also achieve destabilization and demulsification by introducing carbon dioxide. The carbon dioxide increases the hydrogen ion concentration in the system, thereby causing the amphiphilic particles (formed from lanolin-derived branched-chain fatty acids and amino-modified nano-silica) to dissociate, forming lanolin-derived branched-chain fatty acids and protonated amino-modified nano-silica. The protonated amino-modified nano-silica has strong hydrophilicity and therefore desorbs from the oil-water interface and transfers to the aqueous phase; while the lanolin-derived branched-chain fatty acids are insufficient to stabilize the oil-water interface and transfer to the organic solvent phase. When the carbon dioxide is removed from the system, the lanolin-derived branched-chain fatty acids and amino-modified nano-silica form amphiphilic particles again and adsorb onto the oil-water interface, thus the emulsion can be reformed.

[0018] Branched-chain fatty acids (BCFA) refers to the fatty acid with one or more branched alkyl or other functional groups on the alkyl chain of the fatty acid, mostly saturated fatty acids. BCFA can be divided into single branched-chain fatty acids and multi-branched-chain fatty acids according to the number of branched chains on the alkyl chain. The functional secretion lanolin produced by the sebaceous glands of sheep is rich in BCFA, which is an ideal natural raw material for preparing BCFA. The BCFA from lanolin includes fatty acids with carbon chain length of C7-C40. Different lengths of carbon chains have different lipophilicity. By matching different lipophilic fatty acids, the emulsion prepared from the BCFA from lanolin has excellent stability in different environments.

[0019] The raw materials for preparing the amino-modified nano-silicon dioxide include ferroferric oxide, silicate and N-aminoethyl-3-aminopropyl methyl dimethoxy silane (CAS number: 3069-29-2). The silicate is used to form the silicon dioxide material, and the N-aminoethyl-3-aminopropyl methyl dimethoxy silane is used for amino modification to form amino groups on the surface of the silicon dioxide material.

[0020] Optionally, the organic solvent includes at least one of n-hexane, n-heptane, cyclohexane, n-dodecane, n-hexadecane, n-octadecane, toluene and xylene.

[0021] The above organic solvent has small solubility in water, and thus forms two immiscible phases.

[0022] Optionally, the method for preparing the BCFA from lanolin includes the following steps:

[0023] S1, saponification:

[0024] The lanolin, the ethanol aqueous solution with a volume fraction of 75%-85% and sodium hydroxide are mixed, and then reacted at 70-80°C to obtain a first mixture;

[0025] S2, precipitation:

[0026] The first mixture is adjusted in pH, and then a calcium source is added. Solid-liquid separation is performed to collect a first solid phase;

[0027] The first solid phase and the ethanol aqueous solution with a volume fraction of 95%-99.9% are mixed, and then refluxed at 70-80°C. After the refluxing is completed, solid-liquid separation is performed to collect a second solid phase, and a second mixture is obtained;

[0028] S3, acidification:

[0029] The second mixture, an acid, an alkane and water are mixed, and an organic phase is collected to obtain a third mixture;

[0030] S4, urea complexation:

[0031] crystallizing the third mixture, urea and solvent to obtain a urea complex;

[0032] the solvent is composed of 10%~20% of methanol by volume, 70%~75% of ethanol by volume and the rest of water;

[0033] the crystallization temperature is 0℃~4℃;

[0034] S5, washing:

[0035] purifying the urea complex after washing to obtain lanolin-derived branched-chain fatty acids.

[0036] Lanolin is a liposoluble secretion produced by the sebaceous glands of sheep. Generally, the crude lanolin is brown, has a unique odor and is slightly viscous oily paste. After a series of processing steps such as washing, recovery and refining, the refined lanolin is yellow, translucent, viscous oily paste, has a special odor and the melting point is generally 38℃~42℃. Lanolin is insoluble in water, slightly soluble in petroleum ether, chloroform, acetone and other organic reagents with certain toxicity, and has a high solubility in hot ethanol.

[0037] Compared with general animal and plant oils, lanolin almost contains no triglycerides, and the main component is a multi-component ester mixture (about 94%) formed by sterols, fatty alcohols and about the same amount of fatty acids, and also contains free alcohols (about 4%) and a small amount of free fatty acids and hydrocarbon substances.

[0038] In the present application, the lanolin is subjected to saponification treatment to separate the unsaponifiable matter; then the calcium source and the fatty acid are combined to form calcium fatty acid salt, and the calcium fatty acid salt is further acidified to regenerate the fatty acid and remove the fatty alcohol and other impurities; after urea complexation, a urea fatty acid adduct is formed to collect the BCFA.

[0039] Optionally, the calcium source includes calcium chloride;

[0040] The mass ratio of the lanolin to the calcium source is 100:10~20.

[0041] Optionally, the mass ratio of the third mixture to urea is 1:1~2.

[0042] Optionally, the preparation method of the amino-modified nano-silicon dioxide includes the following steps:

[0043] mixing the ferroferric oxide and the silicate solution to obtain ferroferric oxide coated with silicon dioxide;

[0044] The amino-modified nanosilica is prepared by mixing a solution of silica-coated ferroferric oxide and N-aminoethyl-3-aminopropylmethyldimethoxysilane.

[0045] The amino-modified nanosilica is prepared by coating a layer of silica on the surface of ferroferric oxide, and grafting a large number of amino groups on the surface of the silica-coated ferroferric oxide by using an amino compound as a functional reagent.

[0046] Optionally, the amino-modified nanosilica comprises the following raw materials by weight:

[0047] The ferroferric oxide is 1 part, the silicate is 5-10 parts, and the N-aminoethyl-3-aminopropylmethyldimethoxysilane is 0.05-0.2 parts.

[0048] Optionally, the silicate comprises at least one of ethyl silicate and butyl silicate.

[0049] Optionally, the particle size of the ferroferric oxide is 10-200 nm.

[0050] Optionally, the emulsification process is performed under ultrasonic, and the power of the ultrasonic is 200-300 W. DETAILED DESCRIPTION

[0051] The ranges disclosed herein are defined by the lower and upper limits in the form of a range, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of the particular range. The ranges defined in this way can include or exclude the end values, and can be arbitrarily combined, i.e. any lower limit can be combined with any upper limit to form a range. For example, if the ranges of 60-120 and 80-110 are listed for a particular parameter, it is understood that the ranges of 60-110 and 80-120 are also contemplated. In addition, if the minimum range values of 1 and 2 are listed, and if the maximum range values of 3, 4 and 5 are listed, the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In this application, unless otherwise stated, the numerical range "a-b" represents a shorthand notation for any real combination of integers between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed in this application, and "0-5" is just a shorthand notation for these numerical combinations. In addition, when it is stated that a parameter is ≥2 integers, it is equivalent to disclose that the parameter is, for example, integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0052] If not specifically stated, all embodiments and optional embodiments of the present application can be combined with each other to form new technical solutions.

[0053] All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the application pertains unless clearly indicated otherwise.

[0054] All steps of the application can be performed in any suitable order unless otherwise specified. For example, the method comprises steps (a) and (b) means that the method can comprise steps (a) and (b) performed in sequence, or steps (b) and (a) performed in sequence. For example, the method can further comprise step (c) means that step (c) can be added to the method in any suitable order. For example, the method can comprise steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0055] The terms "comprising" and "including," when used herein, are meant to be interpreted as specifying the presence of who stated features, integers, steps or components but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. For example, the terms "comprising" and "including" can mean "including, but not limited to."

[0056] The term "or," when used herein, is intended to be inclusive, unless otherwise indicated. For example, the phrase "A or B" means "A, B, or both A and B." More specifically, any of the following are satisfied for the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0057] The terms "or less" or "less than about," when used herein, mean that the percentage includes zero percent or a percentage that is not currently detectable.

[0058] The terms "composition" and "mixture" are used interchangeably herein to refer to a combination of two or more materials, substances, parts, etc.

[0059] The term "homogeneous," when used herein, refers to a mixture, composition, especially an emulsion, in which, for example, oil particles are substantially uniformly distributed in a continuous aqueous phase. "Homogeneity" is synonymous with uniformity and can refer to intra-sample homogeneity, batch-to-batch homogeneity, and / or run-to-run homogeneity. For example, intra-sample homogeneity can be determined by analyzing a first portion of an emulsion, mixture, or composition and comparing it to a second portion of the same emulsion, mixture, or composition.

[0060] The emulsions of the present application comprise a continuous aqueous liquid phase and a discontinuous oil phase in immiscible mixture. As used herein, "continuous aqueous liquid phase" refers to the portion of the emulsion in which the discontinuous oil phase is dispersed. Thus, "discontinuous oil phase" refers to the mass of discrete portions of the oil phase of the emulsion dispersed in the continuous aqueous liquid phase and immiscible with the continuous aqueous liquid phase.

[0061] The discontinuous oil phase exists in the form of particles. Generally, as used herein, "particles" refers to the oil phase of the emulsion dispersed within the continuous liquid phase. As used herein, "microparticles" refers to the oil phase of the emulsion comprising a plurality of discrete particles. As used herein, the term "particle size" refers to the diameter of the particle, which is the diameter of the particle based on a volume measurement of the particle on the assumption that the particle is approximately spherical. In addition to spherical particles, the emulsions of the present application can include, but are not limited to, semi-spherical, ellipsoidal, and / or cylindrical particles.

[0062] As used herein, "stability of the emulsion" refers to the ability of the emulsion to resist changes in the physical and chemical properties of the emulsion. Such changes include physical instabilities such as emulsification, flocculation, coalescence, partial coalescence, phase inversion, and Ostwald ripening over time.

[0063] The emulsions of the present application are kinetically stable. That is, the emulsion breaks down slowly and the emulsion is able to maintain its initial state for a period of time beyond the expected use of the product. The initial state can be defined by the parameters used to measure instability.

[0064] Physical instability mechanisms include coalescence, partial coalescence, phase inversion, flocculation, Ostwald ripening, and emulsification. As used herein, "coalescence" refers to the process in which two or more similar particles in the composition come into contact with each other to form a single larger particle. As used herein, "flocculation" refers to the process in which two or more particles associate with each other but preserve their individual integrity and thus accelerate the rate of gravitational separation. As used herein, "Ostwald ripening" refers to the process in which large particles grow at the expense of smaller particles. As used herein, "emulsification" is the process in which particles of lower density than the surrounding liquid in an emulsion move upward in the liquid while the particles remain separate. Emulsified emulsions increase the likelihood of coalescence due to the proximity of the particles in the emulsion. Preferably, the physical instability and oxidation of the emulsion can be controlled by formulation, processing, and storage conditions.

[0065] The emulsions of the present application are stable for long periods of time. In some embodiments, the emulsion is substantially free of coalescence, flocculation, Ostwald ripening, and / or emulsification for a period of about three months, about four months, about five months, about six months, about nine months, or about one year at a temperature of about 4°C.

[0066] As used herein, the "D10" or "d(0.1)" value refers to the particle size of the oil phase and is specifically the diameter below which about 10% of all measurable particles in the oil phase have a diameter equal to or less than the D10 value and about 90% of the measurable particles have a diameter greater than the D10 value.

[0067] As used herein, the "D50" or "d(0.5)" value refers to the particle size of the oil phase and is specifically the diameter below which 50% of the measurable particles in the oil phase have an equivalent diameter greater than it and the remaining 50% of the particles have an equivalent diameter less than it. Thus, D50 generally refers to the median particle diameter.

[0068] As used herein, the "D90" or "d(0.9)" value refers to the particle size of the oil phase and is specifically the diameter below which about 90% of all measurable particles in the oil phase have a diameter equal to or less than the D90 value and about 10% of the measurable particles have a diameter greater than the D90 value.

[0069] As used herein, the "D100" or "d(1.000)" value refers to the particle size of the oil phase and is specifically the diameter below which 100% of all measurable particles in the oil phase have a diameter equal to or less than the D100 value and 0% of the measurable particles have a diameter greater than the D100 value.

[0070] In some embodiments, the emulsions of the present application are stored at about 4°C for 6 months or more without a substantial change in particle size. Preferably, the emulsions of the present application do not have a substantial change in particle size when stored at about 4°C or colder (but not frozen). As used herein, a "substantial change in particle size" means an increase of about 10% or more, such as about 20% or more, about 25% or more, about 30% or more, or about 40% or more in any of D10, D50, and / or D90. In some embodiments, the emulsions of the present application can be stored for 9 months or more, or 1 year or more without a substantial change in particle size.

[0071] The present application discloses a preparation method of lanolin-derived branched fatty acid nanoemulsion, comprising the following steps:

[0072] The lanolin-derived branched fatty acid, the amino-modified nanosilica, the organic solvent and water are mixed and emulsified to obtain the emulsion.

[0073] The preparation method of the lanolin-derived branched fatty acid comprises the following steps:

[0074] The lanolin is saponified, precipitated, acidified, urea-complexed and washed.

[0075] The mass ratio of the lanolin-derived branched-chain fatty acid and the amino-modified nanosilica is 10:1-2;

[0076] The mass-volume ratio of the lanolin-derived branched-chain fatty acid and the organic solvent is 0.5g-10g:100mL;

[0077] The mass-volume ratio of the lanolin-derived branched-chain fatty acid and water is 0.5g-10g:100mL;

[0078] The amino-modified nanosilica comprises the following raw materials:

[0079] Ferrosoferric oxide, silicate and N-aminoethyl-3-aminopropyl methyl dimethoxy silane.

[0080] According to one of the technical solutions of the preparation method of the application, at least the following beneficial effects are achieved:

[0081] In the application, the raw materials for preparing the nanoemulsion are the lanolin-derived branched-chain fatty acid and the amino-modified nanosilica; the amino-modified nanosilica is a hydrophilic particle, while the lanolin-derived branched-chain fatty acid contains a long carbon chain that is oleophilic; the surface of the amino-modified nanosilica contains an amino group, which reacts with the fatty acid to form an amphiphilic (hydrophilic and oleophilic) particle; the amphiphilic particle has suitable surface wettability and high interfacial activity, thereby effectively adsorbing on the oil-water interface to form a dense film layer that prevents coalescence between droplets, thereby forming a stable emulsion.

[0082] The nanoemulsion of the application can also be destabilized and broken by introducing carbon dioxide; the carbon dioxide increases the concentration of hydrogen ions in the system, thereby causing the amphiphilic particles (formed by the lanolin-derived branched-chain fatty acid and the amino-modified nanosilica) to dissociate to form the lanolin-derived branched-chain fatty acid and protonated amino-modified nanosilica; the protonated amino-modified nanosilica is highly hydrophilic and thus desorbs from the oil-water interface and transfers to the aqueous phase; the lanolin-derived branched-chain fatty acid is not sufficient to stabilize the oil-water interface and thus transfers to the organic solvent phase; when the carbon dioxide is removed from the system, the lanolin-derived branched-chain fatty acid and the amino-modified nanosilica form the amphiphilic particles again and adsorb on the oil-water interface, so that the emulsion can be reformed.

[0083] Branched-chain fatty acids (BCFA) refers to the fatty acid with one or more branched alkyl or other functional groups on the alkyl chain of the fatty acid, mostly saturated fatty acids. BCFA can be divided into single branched-chain fatty acids and multi-branched-chain fatty acids according to the number of branched chains on the alkyl chain. The functional secretion lanolin produced by the sebaceous glands of sheep is rich in BCFA, which is an ideal natural raw material for preparing BCFA. The BCFA from lanolin includes fatty acids with carbon chain length of C7-C40. Different lengths of carbon chains have different lipophilicity. By matching different lipophilic fatty acids, the emulsion prepared from the BCFA from lanolin has excellent stability in different environments.

[0084] The raw materials for preparing the amino-modified nano-silicon dioxide include ferroferric oxide, silicate and N-aminoethyl-3-aminopropyl methyl dimethoxy silane (CAS number: 3069-29-2). The silicate is used to form the silicon dioxide material, and the N-aminoethyl-3-aminopropyl methyl dimethoxy silane is used for amino modification to form amino groups on the surface of the silicon dioxide material.

[0085] Optionally, the organic solvent includes at least one of n-hexane, n-heptane, cyclohexane, n-dodecane, n-hexadecane, n-octadecane, toluene and xylene.

[0086] The organic solvent has small solubility in water, and thus forms two immiscible phases.

[0087] Optionally, the organic solvent is n-dodecane.

[0088] Optionally, the D50 of the emulsion is 100 nm-600 nm.

[0089] Optionally, the method for preparing the BCFA from lanolin includes the following steps:

[0090] S1, saponification:

[0091] The lanolin, the ethanol aqueous solution with a volume fraction of 75%-85% and sodium hydroxide are mixed, and then reacted at 70-80°C to obtain a first mixture;

[0092] S2, precipitation:

[0093] The first mixture is adjusted in pH, and then a calcium source is added. Solid-liquid separation is performed to collect a first solid phase.

[0094] The first solid phase and the ethanol aqueous solution with a volume fraction of 95%-99.9% are mixed, and then refluxed at 70-80°C. After the refluxing is completed, solid-liquid separation is performed to collect a second solid phase, and a second mixture is obtained.

[0095] S3, acidification:

[0096] mixing the second mixture, acid, alkane and water, collecting the organic phase to obtain a third mixture;

[0097] S4, urea complexation:

[0098] crystallizing the third mixture, urea and solvent to obtain a urea complex;

[0099] the solvent is composed of 10% to 20% methanol by volume, 70% to 75% ethanol by volume and the rest water;

[0100] the crystallization temperature is 0°C to 4°C;

[0101] S5, washing:

[0102] purifying the urea complex after washing to obtain lanolin-derived branched chain fatty acids.

[0103] Lanolin is a liposoluble secretion produced by the sebaceous glands of sheep. Generally, the crude lanolin is brown, has a unique odor and is slightly viscous and oily paste. The refined lanolin is yellow, translucent, viscous and oily paste, has a special odor and the melting point is generally 38°C to 42°C. Lanolin is insoluble in water, slightly soluble in petroleum ether, chloroform, acetone and other organic reagents with certain toxicity, and has a relatively high solubility in hot ethanol.

[0104] Compared with general animal and plant oils, lanolin almost does not contain triglycerides, and the main component is a multi-component ester mixture (about 94%) formed by sterols, fatty alcohols and about equal amount of fatty acids, and also contains free alcohols (about 4%) and a small amount of free fatty acids and hydrocarbon substances.

[0105] In the present application, the lanolin is subjected to saponification treatment to separate the unsaponifiable matter; the calcium source is reacted with the fatty acid to form calcium fatty acid salt, and the calcium fatty acid salt is further acidified to regenerate the fatty acid and remove the fatty alcohol and other impurities; and the urea fatty acid adduct is formed by urea complexation to collect the BCFA.

[0106] Optionally, the pH after adjusting in step S2 is 8 to 9.

[0107] Optionally, the calcium source includes calcium chloride.

[0108] Optionally, the mass ratio of the lanolin to the calcium source is 100:10 to 20.

[0109] Optionally, the alkane is hexane.

[0110] Optionally, the pH of the mixture in step S3 is 2.5-3.5.

[0111] Optionally, the mass ratio of the third mixture to urea is 1:1-2.

[0112] Optionally, the temperature of the mixture in step S4 is 55-65°C.

[0113] Optionally, the time of the mixture in step S4 is 0.5-2h.

[0114] Optionally, the time of the crystallization in step S4 is 4-24h.

[0115] Optionally, the method for preparing the amino-modified nanosilica comprises the following steps:

[0116] mixing the ferroferric oxide and the silicate solution to obtain the silica-coated ferroferric oxide;

[0117] mixing the silica-coated ferroferric oxide and the N-aminoethyl-3-aminopropyl methyl dimethoxy silane solution to obtain the amino-modified nanosilica.

[0118] The method wraps a layer of silica on the surface of the ferroferric oxide, and uses an amino compound as a functional reagent to graft a large number of amino groups on the surface of the silica-coated ferroferric oxide, thereby obtaining the amino-modified nanosilica.

[0119] Optionally, the amino-modified nanosilica comprises the following preparation raw materials by weight:

[0120] 1 part of ferroferric oxide, 5-10 parts of silicate, and 0.05-0.2 parts of N-aminoethyl-3-aminopropyl methyl dimethoxy silane.

[0121] Optionally, the silicate comprises at least one of ethyl orthosilicate and butyl orthosilicate.

[0122] Optionally, the particle size of the ferroferric oxide is 10-200nm.

[0123] Optionally, the ultrasonic power in the emulsification process is 200-300W.

[0124] Optionally, the ultrasonic time is 1-6min.

[0125] Optionally, the method for preparing the amino-modified nanosilica comprises the following steps:

[0126] mixing the ferroferric oxide, the silicate solution, and the acid, and then reacting at 70-80°C and pH 5-6 for 2-3h to obtain the silica-coated ferroferric oxide;

[0127] The amino-modified nanosilica is prepared by mixing the silica-coated ferroferric oxide and the N-aminoethyl-3-aminopropylmethyldimethoxysilane solution and then reacting at 40-60℃ for 20-50h.

[0128] Optionally, the method for preparing the ferroferric oxide comprises:

[0129] The iron salt, the ferrous salt, the polyacrylic acid and the sodium hydroxide solution are reacted at 80-90℃ for 4-6h.

[0130] Optionally, the molecular weight of the polyacrylic acid is 5000-10000.

[0131] In the present application, lanolin is purchased from National Medicine Group Chemical Reagent Co., Ltd.

[0132] Embodiment 1

[0133] The present embodiment is a method for preparing a lanolin-derived branched-chain fatty acid nanoemulsion, comprising the following steps:

[0134] The lanolin-derived branched-chain fatty acid, the amino-modified nanosilica, the organic solvent (n-dodecane) and water are mixed and emulsified (ultrasonic for 3min at 250W) to prepare an emulsion;

[0135] The mass ratio of the lanolin-derived branched-chain fatty acid to the amino-modified nanosilica is 10:1.8.

[0136] The mass-volume ratio of the lanolin-derived branched-chain fatty acid to the organic solvent is 2g:100mL.

[0137] The mass-volume ratio of the lanolin-derived branched-chain fatty acid to water is 2g:100mL.

[0138] The method for preparing the lanolin-derived branched-chain fatty acid in the present embodiment comprises the following steps:

[0139] S1, saponification:

[0140] The lanolin, the 80% ethanol aqueous solution and the sodium hydroxide are mixed and refluxed at 70℃ for 4h to prepare a first mixture;

[0141] The mass-volume ratio of the lanolin to the 80% ethanol aqueous solution is 1g:4mL.

[0142] The mass ratio of the lanolin to the sodium hydroxide is 100:14.

[0143] S2, precipitation:

[0144] After adjusting the pH of the first mixture (pH is 9 under the condition of 1 mol / L hydrochloric acid), a calcium source (7% calcium chloride aqueous solution by mass fraction) is added, and reflux is carried out at 50°C for 2h, and then solid-liquid separation is carried out, and the first solid phase is collected;

[0145] The mass ratio of lanolin to calcium chloride is 100:14;

[0146] After the first solid phase is mixed with 99% ethanol aqueous solution by volume fraction and then refluxed at 70°C for 2h, solid-liquid separation is carried out after the reflux is completed, and the second solid phase is collected, and a second mixture is obtained;

[0147] The mass-volume ratio of lanolin to 99% ethanol aqueous solution by volume fraction is 1g:1mL;

[0148] S3, acidification:

[0149] The second mixture, an acid (3 mol / L hydrochloric acid), an alkane (hexane), and water are mixed to adjust the pH to 3, and then the organic phase is collected, washed with 5% sodium chloride aqueous solution by mass fraction, and dried to obtain a third mixture;

[0150] The volume ratio of the alkane to water in this step is 1:2;

[0151] The mass-volume ratio of lanolin to the alkane is 1g:1mL;

[0152] S4, urea complexation:

[0153] The third mixture, urea, and a solvent are mixed to crystallize (crystallization is carried out at 4°C for 10h), and then solid-liquid separation is carried out, and the solid phase is collected to prepare a urea complex;

[0154] The mass ratio of the third mixture to urea is 1:1.5;

[0155] The mass-volume ratio of urea to the solvent is 1g:6mL;

[0156] The solvent is composed of 10% methanol by volume fraction, 75% ethanol by volume fraction, and the rest is water;

[0157] S5, washing:

[0158] After the urea complex is washed (with an equal volume of 5% sodium chloride aqueous solution by mass fraction), purification is carried out (after the urea complex is dissolved in an equal volume of petroleum ether, the upper organic phase is collected, dried with anhydrous sodium sulfate, and rotary evaporation is carried out at 65°C), and then lanolin-derived branched fatty acids are prepared.

[0159] The amino-modified nano-silicon dioxide comprises the following preparation raw materials by weight fraction:

[0160] The preparation raw materials are as follows: 1 part of ferroferric oxide, 8 parts of silicate (butyl silicate), and 0.1 part of N-aminoethyl-3-aminopropyl methyl dimethoxy silane.

[0161] The preparation method of the amino-modified nanosilica in the embodiment comprises the following steps:

[0162] After mixing the ferroferric oxide, the silicate solution (silicate ethanol solution), the acid (1 mol / L hydrochloric acid) and water, reflux reaction is carried out at a temperature of 80℃ and a pH of 6 for 3h, solid-liquid separation is carried out, and the solid phase is collected and washed to obtain the silica-coated ferroferric oxide;

[0163] After mixing the silica-coated ferroferric oxide and the N-aminoethyl-3-aminopropylmethyldimethoxysilane solution (N-aminoethyl-3-aminopropylmethyldimethoxysilane aqueous ethanol solution, the volume ratio of ethanol to water is 1:1), reflux reaction is carried out at 40℃ under nitrogen protection for 48h, solid-liquid separation is carried out, the solid phase is collected and washed and dried to obtain the amino-modified nanosilica.

[0164] The preparation method of the ferroferric oxide in the embodiment comprises the following steps:

[0165] After mixing the PAA (molecular weight is 8000) and the sodium hydroxide solution (1.5 mol / L) (mixing at 80℃ for 30min), a first solution is prepared;

[0166] The mass-volume ratio of the PAA and the sodium hydroxide solution is 1g:500mL;

[0167] After dissolving FeCl3·6H2O and FeSO4·7H2O in dilute hydrochloric acid (0.5 mol / L) and stirring, a second solution is prepared;

[0168] The mass ratio of FeCl3·6H2O and FeSO4·7H2O is 10.9:4;

[0169] The mass-volume ratio of FeSO4·7H2O and dilute hydrochloric acid is 4g:50mL;

[0170] The volume ratio of dilute hydrochloric acid and sodium hydroxide solution is 1:5.

[0171] Embodiment 2

[0172] The preparation method of the lanolin-derived branched-chain fatty acid nanoemulsion in the embodiment comprises the following steps:

[0173] After mixing the lanolin-derived branched-chain fatty acid, the amino-modified nanosilica, the organic solvent (n-dodecane) and water, emulsification is carried out (ultrasonic for 3min at 250W) to prepare an emulsion;

[0174] The mass ratio of the lanolin-derived branched-chain fatty acid and the amino-modified nanosilica is 10:2;

[0175] The mass-volume ratio of lanolin-derived branched-chain fatty acid and organic solvent is 0.5g:100mL;

[0176] The mass-volume ratio of lanolin-derived branched-chain fatty acid and water is 0.5g:100mL.

[0177] The amino-modified nanosilica comprises the following raw materials by weight:

[0178] The amino-modified nanosilica comprises the following raw materials by weight:

[0179] The preparation method of the amino-modified nanosilica, lanolin-derived branched-chain fatty acid and ferroferric oxide in this embodiment is carried out according to the method in Embodiment 1.

[0180] Embodiment 3

[0181] The embodiment is a preparation method of a lanolin-derived branched-chain fatty acid nanoemulsion, comprising the following steps:

[0182] The lanolin-derived branched-chain fatty acid, amino-modified nanosilica, organic solvent (n-dodecane) and water are mixed and emulsified (ultrasonic for 3min under 250W) to obtain the emulsion.

[0183] The mass ratio of lanolin-derived branched-chain fatty acid and amino-modified nanosilica is 10:1.

[0184] The mass-volume ratio of lanolin-derived branched-chain fatty acid and organic solvent is 5g:100mL.

[0185] The mass-volume ratio of lanolin-derived branched-chain fatty acid and water is 5g:100mL.

[0186] The amino-modified nanosilica comprises the following raw materials by weight:

[0187] The amino-modified nanosilica comprises the following raw materials by weight:

[0188] The preparation method of the amino-modified nanosilica, lanolin-derived branched-chain fatty acid and ferroferric oxide in this embodiment is carried out according to the method in Embodiment 1.

[0189] Embodiment 4

[0190] The embodiment is a preparation method of a lanolin-derived branched-chain fatty acid nanoemulsion, comprising the following steps:

[0191] The lanolin-derived branched-chain fatty acid, amino-modified nanosilica, organic solvent (n-dodecane) and water are mixed and emulsified (ultrasonic for 3min under 250W) to obtain the emulsion.

[0192] The mass ratio of lanolin-derived branched fatty acid and amino-modified nanosilica is 10:1.5;

[0193] The mass-volume ratio of lanolin-derived branched fatty acid and organic solvent is 8g:100mL;

[0194] The mass-volume ratio of lanolin-derived branched fatty acid and water is 8g:100mL.

[0195] The amino-modified nanosilica comprises the following raw materials by weight:

[0196] Three ferroferric oxide 1 part, silicate (butyl silicate) 6 parts and N-aminoethyl-3- aminopropyl methyl dimethoxy silane 0.1 part.

[0197] The preparation method of amino-modified nanosilica, lanolin-derived branched fatty acid and ferroferric oxide in this example is carried out according to Example 1.

[0198] Example 5

[0199] The example is a preparation method of a lanolin-derived branched fatty acid nanoemulsion, comprising the following steps:

[0200] After mixing lanolin-derived branched fatty acid, amino-modified nanosilica, organic solvent (n-dodecane) and water, emulsification (ultrasonic 3min under 250W) is carried out to obtain an emulsion;

[0201] The mass ratio of lanolin-derived branched fatty acid and amino-modified nanosilica is 10:1.2;

[0202] The mass-volume ratio of lanolin-derived branched fatty acid and organic solvent is 10g:100mL;

[0203] The mass-volume ratio of lanolin-derived branched fatty acid and water is 10g:100mL.

[0204] The amino-modified nanosilica comprises the following raw materials by weight:

[0205] Three ferroferric oxide 1 part, silicate (butyl silicate) 6 parts and N-aminoethyl-3- aminopropyl methyl dimethoxy silane 0.1 part.

[0206] The preparation method of amino-modified nanosilica, lanolin-derived branched fatty acid and ferroferric oxide in this example is carried out according to Example 1.

[0207] Comparative Example 1

[0208] The comparative example is a preparation method of an emulsion, which is different from Example 1 in that:

[0209] N-aminoethyl-3-aminopropylmethyldimethoxysilane is replaced by 3-aminopropyltriethoxysilane.

[0210] Comparative Example 2

[0211] The present comparative example is a method for preparing an emulsion, which differs from Example 1 in that:

[0212] Sheep tallow-derived branched fatty acid is replaced by oleic acid (CAS No: 112-80-1).

[0213] Comparative Example 3

[0214] The present comparative example is a method for preparing an emulsion, which differs from Example 1 in that:

[0215] The mass ratio of sheep tallow-derived branched fatty acid and amino-modified nanosilica is 10:0.5.

[0216] Comparative Example 4

[0217] The present comparative example is a method for preparing a composition, which consists of the following steps:

[0218] The organic solvent and water (volume ratio 1:1) are mixed (ultrasonic for 3 min at 250 W) to prepare the composition.

[0219] The performance test results of the examples and comparative examples of the present application are shown in Table 1.

[0220] Table 1 Performance test results of Examples 1-5 and Comparative Examples 1-4 of the present application

[0221]

[0222] From the data in Table 1, when the amino-modified nanosilica in Examples 1-5 is selected, the dodecane-water interfacial tension is reduced to below 25.9 mN / m, while the dodecane-water interfacial tension is 53.2 mN / m; therefore, the solution in Example 1 of the present application has higher interfacial activity, thereby having better stability.

[0223] It should be noted that the present application is not limited to the above-described embodiments. The above-described embodiments are only examples, and embodiments having the same technical idea and playing the same role and effect within the scope of the technical solutions of the present application are all included in the technical scope of the present application. In addition, within the scope of the main idea of the present application, various modifications that can be thought of by those skilled in the art, and other ways constructed by combining part of the components of the embodiments are also included in the scope of the present application.

Claims

1. A method for preparing a lanolin-derived branched-chain fatty acid nanoemulsion, characterized in that, Includes the following steps: An emulsion is prepared by mixing and emulsifying lanolin-derived branched-chain fatty acids, amino-modified nano-silica, an organic solvent, and water; the organic solvent includes at least one selected from n-hexane, n-heptane, cyclohexane, n-dodecane, n-hexadecane, n-octadecane, toluene, and xylene. The method for preparing the lanolin-derived branched-chain fatty acids includes the following steps: S1. Saponification: Lanolin, an aqueous ethanol solution with a volume fraction of 75%-85% and sodium hydroxide are mixed and reacted at 70℃-80℃ to obtain the first mixture. S2, Precipitation: After adjusting the pH of the first mixture, a calcium source is added, and solid-liquid separation is performed to collect the first solid phase; the first solid phase is mixed with an ethanol aqueous solution with a volume fraction of 95%-99.9% and refluxed at 70℃-80℃. After reflux, solid-liquid separation is performed to collect the second solid phase to obtain the second mixture; S3, Acidification: Mix the second mixture, acid, alkane and water, collect the organic phase to obtain the third mixture; S4, Urea Complexation: A urea complex is prepared by mixing the third mixture, urea, and solvent and then crystallizing the mixture; the solvent consists of 10%-20% methanol, 70%-75% ethanol, and the balance being water; the crystallization temperature is 0℃-4℃. S5. Washing: After washing the urea complex, purify it to obtain lanolin-derived branched-chain fatty acids; The mass ratio of the lanolin-derived branched-chain fatty acids to the amino-modified nano-silica is 10:1-2; The mass-to-volume ratio of the lanolin-derived branched-chain fatty acids to the organic solvent is 0.5g-10g:100mL; The mass-to-volume ratio of the lanolin-derived branched-chain fatty acids to water is 0.5g-10g:100mL; The amino-modified nano-silica comprises the following raw materials: Iron oxide, silicates and N-aminoethyl-3-aminopropylmethyldimethoxysilane; The preparation method of the amino-modified nano-silica includes the following steps: Ferric oxide and silicate ester solution were mixed to prepare silica-coated ferric oxide. Amino-modified nano-silica was prepared by mixing silica coated with iron oxide and N-aminoethyl-3-aminopropylmethyldimethoxysilane solution.

2. The preparation method according to claim 1, characterized in that, The calcium source includes calcium chloride; The mass ratio of lanolin to calcium source is 100:10-20.

3. The preparation method according to claim 1, characterized in that, The mass ratio of the third mixture to urea is 1:1-2.

4. The preparation method according to claim 1, characterized in that, The amino-modified nano-silica comprises the following raw materials in parts by weight: 1 part of iron(III) oxide, 5-10 parts of silicate ester and 0.05-0.2 parts of N-aminoethyl-3-aminopropylmethyldimethoxysilane.

5. The preparation method according to claim 1, characterized in that, The silicate ester includes at least one of tetraethyl orthosilicate and tetrabutyl orthosilicate.

6. The preparation method according to claim 1, characterized in that, The particle size of the iron oxide is 10nm-200nm.

7. The preparation method according to any one of claims 1 to 5, characterized in that, The emulsification process involves ultrasound, with a power of 200W-300W.

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