A silane-phospholipid-isooctyl ester terpolymer, method of preparation, and self-adapting pickering particles and applications made therefrom

Abstract

The application belongs to the field of Pickering emulsifiers and emulsions thereof, and discloses a silane-phospholipid-isooctyl methacrylate terpolymer, a preparation method thereof and self-adaptive Pickering particles prepared by the method. The molecular structure formula of the terpolymer P-3 is shown in the description, wherein m=13-16, n=15-18 and x=14-19; the logP of the extremely hydrophobic isooctyl methacrylate is 3.83, and the logP of the extremely hydrophilic 2-methacryloyloxyethyl phosphorylcholine is-2.95. In an alkaline condition, the hydroxyl groups obtained by hydrolysis of the siloxane groups in the copolymer and the hydroxyl groups on the surface of flaky zinc oxide are condensed to prepare self-adaptive Pickering particles. The Pickering particles can be used as a single emulsifier to stabilize multiple emulsions, and the Pickering particles can be added into white oil No. 26 homogenate to obtain stable Pickering emulsions, which can be applied to the field of cosmetics.

Description

Technical Field

[0001] This invention belongs to the field of Pickering particle technology, and more specifically, relates to a terpolymer of silane-phospholipid-isooctyl ester, its preparation method, the resulting adaptive Pickering particles, and their applications. Background Technology

[0002] Pickering emulsions utilize solid particles to stabilize the oil-water interface. Compared to traditional emulsions, Pickering emulsions do not contain chemical surfactants, making them more human- and environmentally friendly. They also use fewer emulsifier raw materials, saving costs. Because solid particles are anchored at the oil-water interface, they are more stable than traditional emulsions and less affected by external factors. Nano-zinc oxide has excellent potential as a Pickering emulsifier, possessing resistance to infrared and ultraviolet radiation and bactericidal functions. Furthermore, flake zinc oxide has better spreadability and skin adhesion compared to granular zinc oxide, and boasts higher solids content and lower viscosity. logP is the oil-water partition coefficient. The partition coefficient P defines the distribution ratio of a compound in two immiscible solvents; the most commonly used solvent system is n-octanol / water. Generally, the stronger the hydrophilicity, the smaller the negative logP; the stronger the lipophilicity, the larger the logP. 2-Methacryloyloxyethylphosphocholine (MPC) is an organic monomer containing phosphocholine. With a logP value of -2.95, it is extremely hydrophilic and possesses properties similar to the outer layer of human cell membranes. It exhibits excellent characteristics such as high hydrophilicity and non-toxicity. MPC polymers can significantly increase the biocompatibility of materials by modifying their surfaces with a cell membrane-like structure. 3-(isobutenoyloxy)propyltrimethoxysilane (KH-570) is a silane coupling agent commonly used in the surface treatment of inorganic fillers to improve adhesion to inorganic materials and increase water resistance. Isooctyl methacrylate is an extremely hydrophobic branched organic compound with a logP value of 3.83, which can significantly improve the hydrophobicity of zinc oxide surfaces. In recent years, efforts have been made to obtain high-performance inorganic solid particles to stabilize Pickering emulsions. Some patents describe the use of modified Pickering emulsifiers in Pickering emulsions. Patent CN112028112A discloses a preparation process for modified nano-zinc oxide, using a mixture of polymethyl methacrylate (PMMA), polydimethylsiloxane (PDMS), and polyvinyl alcohol (PVA) to further modify the initially modified nano-zinc oxide. This method overcomes the shortcomings of traditional nano-zinc oxide, such as excessive surface energy and easy agglomeration. The resulting nano-zinc oxide has amphiphilic properties and can be well and uniformly dispersed in organic media, greatly increasing its industrial applicability. Patent CN114275805A discloses a method for synthesizing ZnO-coated SiO2 composite nanoparticles. First, ZnO particles are prepared, then a SiO2 shell is coated on the ZnO particles, and finally, a silane coupling agent is used for dispersion to obtain ZnO-coated SiO2 composite nanoparticles. This patent describes a process where nanoparticles are modified on their surface and then coated with inorganic or organic compounds. The resulting composite nanoparticles exhibit uniform morphology, structure, and size, along with excellent dispersibility. Furthermore, by adding the prepared ZnO-coated SiO2 composite nanoparticles to lubricating grease, it was found that the composite particles have a good friction-reducing effect and show broad application prospects in industrial and biological fields.Patent CN109453065A discloses a refreshing, high SPF / PA value oil-in-water sunscreen and its preparation method. It utilizes triethoxyoctylsiloxane to hydrophobically modify zinc oxide and adds sodium acrylate / sodium acryloyldimethyl taurate copolymer / isohexadecane / polysorbate-80 to thicken the solution, resulting in a refreshing zinc oxide emulsion suitable for sunscreen cosmetics. However, the above patents focus on relatively simple surface modification of nano-zinc oxide, often only grafting hydrophilic or hydrophobic groups, resulting in only single hydrophilic or lipophilic properties. Multiple emulsions contain two or more water / oil phases, oil / water interfaces, and two-film three-phase systems spanning an internal aqueous phase / oil phase / external aqueous phase, often requiring two or more different emulsifiers. Therefore, it is essential to develop Pickering emulsifiers that simultaneously possess hydrophilic and lipophilic properties to achieve emulsifier-stabilized multiple emulsions. Summary of the Invention

[0003] In order to overcome the deficiencies and disadvantages of the prior art, the primary objective of this invention is to provide a terpolymer of silane-phospholipid-isooctyl ester, wherein the terpolymer simultaneously contains a siloxane group, isooctyl methacrylate (logP = 3.83), a highly hydrophobic group, and 2-methacryloyloxyethyl phosphocholine (logP = -2.95).

[0004] Another objective of this invention is a method for preparing the above-mentioned silane-phospholipid-isooctyl ester terpolymer. This method involves a free radical reaction in which, under the action of a catalyst, the hydroxyl groups of the siloxane groups in the copolymer undergo a dehydration condensation reaction with the hydroxyl groups on the surface of the plate-like zinc oxide, thereby simultaneously grafting segments containing extremely hydrophobic groups with logP equal to 3.83 and extremely hydrophilic groups with logP equal to -2.95 onto the surface of the plate-like zinc oxide.

[0005] Another object of the present invention is to provide adaptive Pickering particles prepared from the above-mentioned terpolymer of silane-phospholipid-isooctyl ester and their application in multiple emulsions.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] A terpolymer of silane-phospholipid-isooctyl ester, abbreviated as P-3, has the following molecular structural formula:

[0008]

[0009] Where m = 13–16, n = 15–18, and x = 14–19; the extremely hydrophobic isooctyl methacrylate has a logP of 3.83, and the extremely hydrophilic 2-methacryloyloxyethyl phosphocholine has a logP of -2.95.

[0010] The method for preparing the terpolymer of silane-phospholipid-isooctyl ester is as follows: the terpolymer is prepared by mixing isooctyl methacrylate, 2-methacryloyloxyethyl phosphocholine and 3-(isobutyryloyloxy)propyltrimethylsilane and dissolving them in an ethanol solution, adding the initiator azobisisobutyronitrile and anhydrous ethanol, mixing the mixture, purging the solution with nitrogen gas, reacting at 70-85°C, and washing and drying the product with deionized water.

[0011] Preferably, the molar ratio of isooctyl methacrylate, 2-methacryloyloxyethyl phosphocholine and 3-(isobutenoyloxy)propyltrimethoxysilane is (3-10):(1-1.5):(20-25).

[0012] An adaptive Pickering particle is prepared by mixing the terpolymer of silane-phospholipid-isooctyl ester, sheet zinc oxide, catalyst, anhydrous ethanol and ammonia solution, stirring the mixture at room temperature, washing the product with deionized water and ethanol, and then drying it under vacuum.

[0013] Preferably, the size of the sheet-like zinc oxide is 30–50 μm.

[0014] Preferably, the ratio of the amount of the sheet-like zinc oxide, anhydrous ethanol, terpolymer of silane-phospholipid-isooctyl ester, ammonia solution, and catalyst is (5-8) g: (80-100) mL: (0.6538-0.7500) g: (7-11) mL: (20-40) μL.

[0015] Preferably, the catalyst is di-n-butyltin dilaurate.

[0016] Preferably, the volume ratio of water to ammonia in the ammonia solution is (3-5):1; and the concentration of ammonia is 25-30 wt%.

[0017] Preferably, the stirring reaction time is 24–48 h; the vacuum drying temperature is 40–50 °C; and the vacuum drying time is 8–10 h.

[0018] The application of the aforementioned adaptive Pickering particles in the cosmetics field.

[0019] This invention first synthesizes a terpolymer of silane-phospholipid-isooctyl ester. The hydroxyl groups of the siloxane groups in this copolymer undergo a dehydration condensation reaction with the hydroxyl groups on the surface of plate-like zinc oxide under the action of a catalyst. This simultaneously grafts a highly hydrophobic isooctyl methacrylate group (logP = 3.83) and a highly hydrophilic 2-methacryloyloxyethyl phosphocholine group (logP = -2.95) onto the surface of the plate-like zinc oxide, yielding amphiphilic plate-like zinc oxide. The siloxane segments of the terpolymer serve as anchor points for surface modification of the two-dimensional plate-like zinc oxide. Pickering particles (modified zinc oxide) are dispersed in an oil phase or an aqueous phase. Between the oil and water phases, on the oil phase side, the Pickering particles adaptively expand the grafted lipophilic groups and contract the grafted hydrophilic groups; on the aqueous phase side, the Pickering particles adaptively expand the grafted hydrophilic groups and contract the grafted lipophilic groups, thus anchoring the Pickering particles at the oil-water interface. This results in the formation of several submicron-sized oil droplets in the aqueous phase, or several submicron-sized water droplets in the oil phase. Modified zinc oxide is added to deionized water and ethanol, thoroughly dissolved by ultrasonication, and then homogenized with white oil No. 26. The resulting Pickering emulsion is exceptionally stable and less affected by changes in external temperature and pH, achieving the effect of simultaneously stabilizing oil-in-water and water-in-oil emulsions using an emulsifier. Furthermore, it can stabilize multiple emulsions using an emulsifier. Therefore, adaptive Pickering particles can be used as a single emulsifier to stabilize multiple emulsions, and can be widely applied in the cosmetics industry.

[0020] A stable Pickering emulsion, in addition to ensuring the stable adsorption of solid particles at the oil-water interface, must also prevent aggregation when the two dispersed phase droplets approach each other. The main factor preventing aggregation, namely the pressure that the liquid film formed by the continuous phase can withstand, is called the maximum capillary force. The adaptive Pickering particles prepared in this invention, due to the grafting of hydrophilic and hydrophobic groups to form a structure similar to surfactants, allow molecules containing hydrophobic and hydrophilic chains to adsorb at the gas / water interface and form a monomolecular film, improving the foaming properties and foam stability of water, and reducing the interfacial tension between the two phases. When grafting hydrophobic groups with logp greater than 5 and hydrophilic groups with logp less than -3.5, the resulting Pickering particles cannot be well dispersed in the aqueous or oil phase due to excessive hydrophobicity and hydrophilicity. They cannot adaptively shrink the hydrophilic / lipophilic groups, making it impossible to stabilize a two-film, three-phase multi-emulsion using a single Pickering particle. However, when grafting simultaneously a highly hydrophobic isooctyl methacrylate with logp = 3.83 and a highly hydrophilic 2-methacryloyloxyethyl phosphocholine with logp = -2.95, the total logp value of the Pickering particles is between 0 and 2. In this state, the maximum capillary force of the adaptive Pickering particles is close to the three-phase water contact angles of 70° and 110°, which are most effective in stabilizing the emulsion.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. This invention synthesizes a terpolymer containing siloxane groups via a free radical reaction. The hydroxyl groups of the siloxane groups in the copolymer undergo a dehydration condensation reaction with the hydroxyl groups on the surface of plate-like zinc oxide under the action of a catalyst, thereby simultaneously grafting a highly hydrophobic group with a logP of 3.83 and a highly hydrophilic group with a logP of -2.95 onto the surface of the plate-like zinc oxide. The preparation method is simple, the raw materials are readily available, and it has great application potential.

[0023] 2. Typically, multiple emulsions require two or more different emulsifiers. Generally, surface modification of zinc oxide is a single modification, making it hydrophilic or oleophilic. However, this invention utilizes the terpolymer p-3 to simultaneously graft a hydrophobic group with a logP value of 3.83, a hydrophilic group with a logP value of -2.95, and a siloxane as an anchor onto the surface of plate-like zinc oxide, achieving the effect of stabilizing multiple emulsions with a single emulsifier.

[0024] 3. The amphiphilic Pickering particles prepared by this invention, due to the grafting of extremely hydrophobic groups, greatly enhance the dispersibility of zinc oxide in water and oil, reduce the aggregation of zinc oxide in emulsions, and enhance the biocompatibility of plate-like zinc oxide. Since phosphorylcholine has similar properties to the phospholipid bilayer of human skin, its biocompatibility is further enhanced. Attached Figure Description

[0025] Figure 1 This is a flowchart illustrating the preparation process of the adaptive Pickering particles of this invention.

[0026] Figure 2 This is a schematic diagram of the chemical formula for the synthesis of the ternary copolymer of the present invention;

[0027] Figure 3 The infrared spectra of the modified sheet zinc oxide prepared in Example 1, the synthesized ternary polymer P-3, the siloxane used, and the unmodified zinc oxide are shown.

[0028] Figure 4 The NMR spectrum of the terpolymer P-3 obtained in Example 1;

[0029] Figure 5 Digital camera images of the water-in-oil Pickering emulsions prepared in Examples 1-12 after standing at room temperature for 24 hours, and corresponding industrial microscope photographs of the emulsions.

[0030] Figure 6 The images shown are digital camera images of the oil-in-water Pickering emulsions prepared in Examples 13-24 after standing at room temperature for 24 hours, and corresponding photographs of the emulsions under an industrial microscope.

[0031] Figure 7An industrial microscope photograph of the water-in-oil-in-water pickerling emulsion prepared in Application Example 26;

[0032] Figure 8 The images show digital camera images and industrial microscope photographs of the Pickering emulsion prepared in Application Example 3 and the Pickering emulsion prepared in Comparative Example 1 after standing at room temperature for 24 hours.

[0033] Figure 9 This is a schematic diagram of the oil-water interface of the adaptive Pickering particles of the present invention in the oil-in-water Pickering emulsion a, the water-in-oil emulsion b, and the multiple emulsion c formed therefrom. Detailed Implementation

[0034] The present invention will be further described below with reference to specific embodiments, but these should not be construed as limiting the invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field.

[0035] Example 1

[0036] 1. Weigh 0.006 mmol (0.0177 g) of 2-methacryloyloxyethyl phosphocholine, 0.2 mmol (0.03966 g) of isooctyl methacrylate, and 1.5 mmol (0.3725 g) of 3-(isobutyryloxy)propyltrimethoxysilane into a thumb flask. Add 2 mL of ethanol and purge the solution with nitrogen for 10 min. Then transfer the thumb flask to an oil bath at 80 °C, add 1 mL of anhydrous ethanol and 0.0001 g of azobisisobutyronitrile from the thumb flask, and stir for 3 h to obtain a terpolymer of silane-phospholipid-isooctyl ester, abbreviated as p-3, with the structure shown below. Figure 2 As shown;

[0037] 2. Weigh 5g of sheet-like zinc oxide (30-50μm) and 100mL of anhydrous ethanol into a round-bottom flask, then add a mixture of terpolymer p-3, 6mL of water, and 2mL of ammonia (25wt%). Sonicate the mixture for 30min to ensure thorough dispersion. Add the catalyst di-n-butyltin dilaurate, and magnetically stir the mixture at 500rpm for 24h at room temperature. Filter and wash the resulting product multiple times with anhydrous ethanol and deionized water. Place the filter paper loaded with the product in a vacuum drying oven and dry overnight at 40℃. After drying, grind it into powder to obtain adaptive Pickering particles, as described in the preparation process. Figure 1 As shown.

[0038] Figure 3 The images show the infrared spectra of the terpolymer obtained in Example 1, the adaptive Pickering particles, the siloxane used, and the unmodified zinc oxide. Figure 3It can be seen that terpolymers and adaptive Pickering particles at 2900 cm⁻¹ -1 The characteristic peaks of the tertiary amine N(CH3) of 2-methacryloyloxyethyl phosphocholine were observed in all three polymers, including the ternary polymer P-3, adaptive Pickering particles, and 3-(isobutenoyloxy)propyltrimethoxysilane at 800 cm⁻¹. -1 The characteristic Si-O peaks of 3-(isobutyryloxy)propyltrimethoxysilane were observed in all samples, indicating that the terpolymer of silane-phospholipid-isooctyl ester was successfully prepared. Figure 4 The NMR spectrum of the terpolymer P-3 obtained in Example 1 is shown below. Figure 4 As shown, δ H 0, 0.75~1 equals the ppm peak value corresponding to -CH2Si-, δ H 4–4.25 ppm corresponds to the peak value of -N(CH3), δ H The peak value of 7-7.5 ppm corresponds to -POCH2, indicating that the terpolymer of silane-phospholipid-isooctyl ester was successfully prepared.

[0039] Application Example 1

[0040] 0.0595 g of adaptive Pickering particles (1% of white oil by mass) from Example 1 and 7 mL of white oil No. 26 were added to a beaker. The mixture was stirred at 800 rpm / min for 20 min at room temperature, then sonicated for 5 min. 3 mL of deionized water was added, and the mixture was homogenized at 230,000 rpm / min for 5 min in a homogenizer to obtain a Pickering water-in-oil emulsion. Figure 5 Emulsion A is shown.

[0041] Application Example 2

[0042] The mass of the adaptive Pickering particles in Application Example 1 is 3% of the white oil mass fraction, 0.1785 g. Other steps are the same as in Application Example 1. Figure 5 Emulsion B is shown.

[0043] Application Example 3

[0044] The mass of the adaptive Pickering particles in Application Example 1 is 5% of the white oil mass fraction, which is 0.2975 g. Other steps are the same as in Application Example 1. Figure 5 Emulsion C is shown.

[0045] Application Example 4

[0046] In this application example, the adaptive Pickering particles account for 7% of the white oil mass fraction, or 0.4165 g. Other steps are the same as in Application Example 1. Figure 5 Emulsion D is shown.

[0047] Application Example 5

[0048] In this application example, isooctyl methacrylate is replaced with 0.0655 g and 0.3 mmol. Other steps are the same as in Application Example 1. Figure 5 Emulsion E is shown.

[0049] Application Example 6

[0050] In this application example, isooctyl methacrylate is changed to 0.0655 g, 0.3 mmol. The mass of adaptive Pickering particles is changed to 3% of the white oil mass fraction, 0.1785 g. Other steps are the same as in Application Example 1. Figure 5 Emulsion F is shown.

[0051] Application Example 7

[0052] In this application example, isooctyl methacrylate is replaced with 0.0655 g (0.3 mmol). The mass of adaptive Pickering particles accounts for 5% of the white oil mass fraction, 0.2975 g. Other steps are the same as in Application Example 1. Figure 5 Emulsion G is shown.

[0053] Application Example 8

[0054] In this application example, isooctyl methacrylate is replaced with 0.0655 g (0.3 mmol). The mass of adaptive Pickering particles accounts for 7% of the oil mass fraction, 0.4165 g. Other steps are the same as in Application Example 1. Figure 5 The intermediate emulsion H is shown.

[0055] Application Example 9

[0056] In this application example, isooctyl methylcyclohexanoate is 0.09 g, 0.45 mmol. Other steps are the same as in Application Example 1. Figure 4 As shown in Emulsion I.

[0057] Application Example 10

[0058] In this application example, isooctyl methacrylate is 0.09 g, 0.45 mmol. The adaptive Pickering particles account for 3% of the white oil mass fraction, 0.0595 g. Other steps are the same as in Application Example 1. Figure 5 As shown in the middle emulsion J.

[0059] Application Example 11

[0060] In this application example, isooctyl methacrylate is 0.09 g, 0.45 mmol. The mass of adaptive Pickering particles accounts for 5% of the white oil mass fraction, 0.1785 g. Other steps are the same as in Application Example 1. Figure 5 As shown in the middle emulsion K.

[0061] Application Example 12

[0062] In this application example, isooctyl methacrylate is 0.09 g, 0.45 mmol. The mass of adaptive Pickering particles accounts for 7% of the white oil mass fraction, 0.4165 g. Other steps are the same as in Application Example 1. Figure 5 As shown in the middle emulsion L.

[0063] Figure 5 Digital camera images of the water-in-oil Pickering emulsions prepared in Application Examples 1-12 after standing at room temperature for 24 hours, and corresponding industrial microscope photographs of the emulsions (from left to right corresponding to Application Examples 1-12; the bottle cap shows the mass fraction of adaptive Pickering particles in the dispersed phase, and the lower left corner shows the water contact angle of the adaptive Pickering particles); Figure 5 It can be seen that, from left to right, the modified zinc oxide contents of 1–7% with a water contact angle of 60°, 90°, and 105°, respectively, were prepared under the experimental conditions in Application 1. As the content of adaptive Pickering particles increased, the particle size of the resulting water-in-oil Pickering emulsion decreased, and the layering height reduced. The emulsion became more stable and less prone to layering. Among them, the water-in-oil emulsion prepared with adaptive Pickering particles at a water contact angle of 60° exhibited the best stability. This indicates that the water-in-oil emulsion with a water contact angle of 60° and a content of 7% adaptive Pickering particles showed the best stability.

[0064] Example 2

[0065] 1. Weigh 2-methacryloyloxyethyl phosphocholine (0.06 mmol, 0.0177 g), isooctyl methacrylate (0.2 mmol, 0.03966 g), and 3-(isobutyryloxypropyltrimethoxysilane) (1.5 mmol, 0.3725 g) into a thumb flask, add 2 mL of ethanol, and purge the solution with nitrogen for 10 min. Then transfer the thumb flask to an oil bath at 80 °C, add 0.0001 g of azobisisobutyronitrile to 1 mL of anhydrous ethanol, and then add it to the thumb flask. Stir the reaction for 3 h to obtain a terpolymer of silane-phospholipid-isoctyl ester, abbreviated as p-3;

[0066] 2. Weigh 5g of zinc oxide flakes and 100mL of anhydrous ethanol into a round-bottom flask. Add a terpolymer of silane-phospholipid-isooctyl ester, 6mL of water, and 2mL of ammonia (25wt%). Sonicate the mixture for 30min to ensure thorough dispersion. Add the catalyst di-n-butyltin dilaurate and magnetically stir the mixture at 500rpm for 24h at room temperature. Filter and wash the product multiple times with anhydrous ethanol and deionized water. Place the filter paper loaded with the product in a vacuum drying oven and dry overnight at 40℃. Grind the dried product into powder using a mortar and pestle to obtain adaptive Pickering particles.

[0067] Application Example 13

[0068] 0.066 g of adaptive Pickering particles (1% of the total mass fraction of deionized water and ethanol) prepared in Example 2 were added to a beaker along with 5 mL of deionized water and 2 mL of ethanol. The mixture was stirred at 800 rpm for 20 min at room temperature, then sonicated for 5 min. 3 mL of white oil No. 26 was added, and the mixture was homogenized at 23000 rpm for 5 min using a homogenizer to obtain a Pickering oil-in-water emulsion. Figure 6 The intermediate emulsion M is shown.

[0069] Application Example 14

[0070] In this application example, the mass of the adaptive Pickering particles accounts for 3% of the total mass fraction of deionized water and ethanol, which is 0.198 g. Other steps are the same as in Application Example 13, such as... Figure 6 The intermediate emulsion N is shown.

[0071] Application Example 15

[0072] In this application example, the adaptive Pickering particles account for 5% of the total mass fraction of deionized water and ethanol, amounting to 0.33 g. Other steps are the same as in Application Example 13, such as... Figure 6 As shown in the middle emulsion O.

[0073] Application Example 16

[0074] In this application example, the mass of the adaptive Pickering particles accounts for 7% of the total mass fraction of deionized water and ethanol, which is 0.462 g. Other steps are the same as in Application Example 13, such as... Figure 6 The intermediate emulsion P is shown.

[0075] Application Example 17

[0076] In this application example, isooctyl methacrylate is replaced with 0.0655 g and 0.3 mmol. Other steps are the same as in application example 13, such as... Figure 6 The intermediate emulsion Q is shown.

[0077] Application Example 18

[0078] In this application example, isooctyl methacrylate is replaced with 0.0655 g, 0.3 mmol. The mass of the adaptive Pickering particles accounts for 3% of the total mass fraction of deionized water and ethanol, 0.198 g. Other steps are the same as in application example 13, such as... Figure 6 The intermediate emulsion R is shown.

[0079] Application Example 19

[0080] In this application example, isooctyl methacrylate is replaced with 0.0655 g and 0.3 mmol. The adaptive Pickering particles account for 5% of the total mass fraction of deionized water and ethanol, and are 0.33 g. Other steps are the same as in application example 13, such as... Figure 6The intermediate emulsion S is shown.

[0081] Application Example 20

[0082] In this application example, isooctyl methacrylate is replaced with 0.0655 g, 0.3 mmol. The mass of the adaptive Pickering particles accounts for 7% of the total mass fraction of deionized water and ethanol, 0.462 g. Other steps are the same as in application example 13, such as... Figure 6 As shown in the intermediate emulsion T.

[0083] Application Example 21

[0084] In this application example, isooctyl methacrylate is replaced with 0.09 g and 0.45 mmol. Other steps are the same as in application example 13, such as... Figure 6 The intermediate emulsion U is shown.

[0085] Application Example 22

[0086] In this application example, isooctyl methacrylate is changed to 0.09 g, 0.45 mmol. The mass of the adaptive Pickering particles accounts for 3% of the total mass fraction of deionized water and ethanol, 0.198 g. Other steps are the same as in application example 13, such as... Figure 6 As shown in Emulsion V.

[0087] Application Example 23

[0088] In this application example, isooctyl methacrylate is replaced with 0.09 g, 0.45 mmol. The adaptive Pickering particles account for 5% of the total mass fraction of deionized water and ethanol, 0.33 g. Other steps are the same as in application example 13, such as... Figure 6 The intermediate emulsion W is shown.

[0089] Application Example 24

[0090] In this application example, isooctyl methacrylate is replaced with 0.09 g, 0.45 mmol. The adaptive Pickering particles account for 7% of the total mass fraction of deionized water and ethanol, 0.462 g. Other steps are the same as in application example 13, such as... Figure 6 Emulsion X is shown.

[0091] Figure 6 The images show digital camera views of the oil-in-water Pickering emulsions prepared in Application Examples 13-24 after standing at room temperature for 24 hours, and their corresponding industrial microscope photographs. (From left to right, they correspond to Application Examples 13-24; the bottle cap shows the mass fraction of adaptive Pickering particles in the dispersed phase, and the lower left corner shows the water contact angle of the adaptive Pickering particles). Figure 6It can be seen that, from left to right, the modified oil-in-water Pickering emulsions prepared under the experimental conditions in Application Example 13 were prepared using zinc oxide with a modified water contact angle of 60° (1-7%), a water contact angle of 90° (1-7%), and a water contact angle of 105° (1-7%). With the increase of the amount of adaptive Pickering particles, the particle size of the prepared oil-in-water Pickering emulsion decreased, and the separation height decreased. The emulsion became more stable and less prone to separation. Among them, the oil-in-water Pickering emulsion prepared with adaptive Pickering particles with a water contact angle of 60° exhibited the best stability. This indicates that the oil-in-water emulsion with a water contact angle of 60° and a content of 7% adaptive Pickering particles showed the best stability.

[0092] Application Example 25

[0093] Adaptive Pickering particles (7% of white oil mass, modified water with a contact angle of 60°) and 7 mL of white oil No. 26 were added to a beaker. The mixture was stirred at 800 rpm / min for 20 min at room temperature, then sonicated for 5 min. 3 mL of deionized water was added, and the mixture was homogenized at 23000 rpm / min for 5 min in a homogenizer to obtain Pickering water-in-oil emulsion x (water-in-oil means oil containing water droplets).

[0094] Application Example 26

[0095] Adaptive Pickering particles (7% of the total mass fraction of deionized water and ethanol) were added to a beaker along with 16.7 mL of deionized water and 6.7 mL of ethanol. The mixture was stirred at 800 rpm for 20 min at room temperature, then sonicated at room temperature for 5 min. Finally, 10 mL of the prepared Pickering oil-in-water emulsion x was added dropwise to the homogenizer at 5000 rpm for 5 min to obtain water-in-oil-in-water Pickering emulsion y (water-in-oil-in-water emulsion has multiple structures, where water contains oil droplets and the oil droplets contain water droplets).

[0096] Figure 7 An industrial microscope photograph of the water-in-oil-in-water Pickering emulsion y prepared in Example 26; by Figure 7 It can be clearly seen that the multi-phase emulsion structure of two films and three phases can be formed, indicating that the prepared adaptive Pickering particles can achieve multi-phase emulsion stabilization with a single emulsifier.

[0097] Comparative Example 1

[0098] The modified flake zinc oxide used in this comparative example is triethoxyoctylsilane-modified flake zinc oxide with a water contact angle of 130°, produced by Changzhou Nao. 0.2975 g of modified flake zinc oxide (7% by mass of white oil) and 7 mL of No. 26 white oil were added to a beaker and stirred at 800 rpm for 20 min at room temperature. Then, the mixture was sonicated for 5 min at room temperature. Finally, 3 mL of deionized water was added, and the mixture was homogenized at 23000 rpm for 5 min using a homogenizer to obtain the Pickering emulsion.

[0099] Figure 8 Digital camera images and industrial microscope photographs of the Pickering emulsions prepared in Application Example 3 and Comparative Example 1 after standing at room temperature for 24 hours. Figure 8 It is evident that the Pickering emulsion prepared using the adaptive Pickering particles obtained in this invention is more stable. The stability of the emulsion prepared with terpolymer-modified platelet zinc oxide is significantly stronger than that prepared with ordinary triethoxyoctylsilane monosilane, and the emulsion particle size is smaller and more uniform under an industrial microscope. This is because the modified platelet zinc oxide in the adaptive Pickering particles is simultaneously grafted with segments containing extremely hydrophobic groups (logP = 3.83) and extremely hydrophilic groups (logP = -2.95). The resulting Pickering emulsion exhibits better stability than modified zinc oxide prepared using only hydrophobic groups or surface-coated surfactants.

[0100] Figure 9 This is a schematic diagram of the oil-water interface of the adaptive Pickering particles of the present invention in the oil-in-water Pickering emulsion a, the water-in-oil emulsion b, and the resulting multiple emulsion c. Figure 9 As shown, adaptive Pickering particles are first prepared by modifying sheet-like zinc oxide with an amphiphilic ternary copolymer. If the adaptive Pickering particles are first added to oil, dispersed, and then water is added and homogenized, it becomes a water-in-oil emulsion; if the adaptive Pickering particles are first added to water, and then oil is added and homogenized, it becomes an oil-in-water emulsion. If an oil-in-water emulsion (b) is first prepared, and then the oil-in-water emulsion is used as the oil phase of the oil-in-water Pickering emulsion (a), homogenization forms a multiple emulsion (c).

[0101] The above application examples are preferred application modes of the present invention, but the application modes of the present invention are not limited to the above application examples. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. An adaptive Pickering particle, characterized in that, The adaptive Pickering particles are prepared by mixing a terpolymer of silane-phospholipid-isooctyl ester, sheet-like zinc oxide, a catalyst di-n-butyltin dilaurate, anhydrous ethanol, and ammonia solution, stirring the mixture at room temperature, washing the product with deionized water and ethanol, and then vacuum drying. The ratio of the sheet-like zinc oxide, anhydrous ethanol, terpolymer of silane-phospholipid-isooctyl ester, ammonia solution, and catalyst is (5~8) g : (80~100) mL : (0.6538~0.7500) g : (7~11) mL : (20~40) g. The terpolymer is prepared by mixing isooctyl methacrylate, 2-methacryloyloxyethyl phosphocholine and 3-(isobutenoyloxy)propyltrimethylsilane and dissolving them in an ethanol solution, adding the initiator azobisisobutyronitrile and anhydrous ethanol, then purging the solution with nitrogen gas and reacting at 70~85℃. The product is washed and dried with deionized water. The molar ratio of isooctyl methacrylate, 2-methacryloyloxyethyl phosphocholine and 3-(isobutenoyloxy)propyltrimethoxysilane is (3~10):(1~1.5):(20~25).

2. The adaptive Pickering particle according to claim 1, characterized in that, The size of the zinc oxide flakes is 30~50μm.

3. The adaptive Pickering particle according to claim 1, characterized in that, The volume ratio of water to ammonia in the ammonia solution is (3~5):1; the concentration of ammonia is 25~30 wt%.

4. The adaptive Pickering particle according to claim 1, characterized in that, The stirring reaction time is 24-48 hours; the vacuum drying temperature is 40-50°C, and the vacuum drying time is 8-10 hours.

5. The application of the adaptive Pickering particles according to any one of claims 1-4 in the cosmetics field.

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