900 results about "Pickering emulsion" patented technology

The invention discloses a method for preparing amphiphilic nano silica powder and is used for preparing nano silica powder with about 90 degrees of a tri-phase contact angle. The method uses ultrasonic preparation, thus having short preparation process; the invention adopts liquid phase modification, thus avoiding processing means such as grinding, calcining and the like which are easy to cause the powder to generate hard particle agglomeration; the invention can prepare better amphiphilic surface (about 90 degrees of tri-phase contact angle) nano silica powder. The invention also discloses a method for preparing Pickering emulsion by using the amphiphilic nano silica powder under the action of ultrasound or cutting, the nano silica powder stably exists in oil-water interface, thus preventing diffused oil (water) droplets to re-agglomerate into big droplets to split phase and stabilizing emulsion. The prepared emulsion can be stored at room temperature without occurrence of demulsification in three months.

The invention relates to a preparation method of an oxidized graphene phase change microcapsule. The preparation method comprises the following steps: dissolving oxidized graphene in water, stirring, performing ultrasound treatment, preparing an oxidized graphene solution; adding a phase change material in the oxidized graphene solution, heating at a temperature higher than a melting point of the phase change material to ensure that the phase change material is melted, stirring to obtain a stable Pickering emulsion of the phase change material wrapped with the oxidized graphene; adding acid in the Pickering emulsion, adjusting the pH value of a system to be 2-3, completing emulsion drops of the phase change material by the oxidized graphene by using an acting force between functional groups to form an oxidized graphene capsule wall; and cooling into a capsule to separate out to obtain the oxidized graphene phase change microcapsule. Compared with the prior art, the oxidized graphene phase change microcapsule has the advantages that the oxidized graphene is used as an emulsifying agent and a heat conducting reinforced wall material, other emulsifying agents need not to be added so that the oxidized graphene phase change microcapsule with better heat conducting material can be obtained. The oxidized graphene phase change microcapsule has the characteristics of high heat conducting coefficient, high heat storage amount, and the like. The preparation method has the advantages of simplicity and convenience in operation, low cost and the like.

The invention relates to magnetic silicon dioxide microspheres with a nuclear shell and surface anisotropic double functional groups and a preparation method thereof. The preparation method comprises the following steps of: preparing superparamagetic microspheres by a solvothermal process; preparing magnetic microspheres which are coated by silicon dioxide by a sol-gel process; preparing the magnetic silicon dioxide microspheres of which the surface has amino group by taking the magnetic silicon dioxide microspheres as seeds and by the copolycondensation of alkyl ester orthosilicate and a silane coupling agent, and drying the magnetic silicon dioxide microspheres to obtain samples; and by a PICKERING emulsion technology, stabilizing a paraffin/aqueous emulsion system with a micrometer scale by using the aminated magnetic microspheres to form single-layer close packing of the magnetic microspheres on the surface of paraffin spheres, then reacting the amino group on the surface of the magnetic microspheres which is exposed in a liquid phase with succinic anhydride to introduce carboxyl into the partial surface of the microspheres, so that the surfaces of the magnetic microspheres have the anisotropic double functional groups. The obtained magnetic microspheres with the double functional groups have the advantages that: magnetic responsiveness is high; grain size can be controlled between 200 and 800 namometers; and the density of the surface functional groups can be adjusted.

Disclosed are Pickering emulsions, related aqueous dispersions, and methods for their preparation, both of which include the use of a water insoluble promoter. Also disclosed are coatings and particle networks formed therefrom.

The invention discloses a Pickering emulsion with uniform particle size and a preparation method and application thereof. The uniform and stable Pickering emulsion is formed by using a solid particle as a stabilizing agent, dispersing the solid particle in a water (or oil) phase, then subjecting the dispersed solid particle and an oil (or water) phase to emulsification and then allowing a formed pre-emulsion to pass through a membrane emulsification apparatus. Or the uniform and stable Pickering emulsion is formed by allowing a dispersed phase (water phase or oil phase) to pass through membrane holes under pressing and then to enter a continuous phase (oil phase or water phase) with the dispersed solid particle and then enabling an emulsion to fall off from the membrane holes under the action of external force. The preparation method is simple; through adjusting of the proportion of water and oil phases, particle concentration, the size of the particle and a microporous membrane, the properties of the emulsion are regulated and controlled, the prepared emulsion is stable and has a uniform and controllable particle size and enhanced stability, usage of a traditional emulsifier is avoided, and toxicity to human bodies and environmental pollution can be reduced; and the emulsion can be extensively used in fields like biological medicine, cosmetics, food, petroleum and waste water treatment.

Porous carbon monoliths are prepared using emulsions stabilized by carbonaceous particles or aggregates. An illustrative porous carbon monolith comprises carbon black, including any graphitized carbon black particles, carbonized binder and porosity. The porosity includes first pores having a pore size within the range of from about 0.5 μm to about 100 μm and second pores having a pore size within the range of from about 1 nm to about 100 nm. The pore size distribution of the first pores does not overlap with a pore size distribution of the second pores.

The invention relates to a preparation method for an amphiphilic nanometer particle and application of amphiphilic nanometer particle to prepare Pickering emulsion. The novel amphiphilic nanometer particle is formed according to the following preparation method: firstly performing epoxy-group modification on the surface of a nanometer particle by employing a silane coupling agent, then utilizing hexylenediamine to react with epoxy groups, so as to further introduce amino groups, and finally adding proper amount of hydrochloric acid for neutralization. The particle is capable of replacing conventional surfactants for preparing highly-stable Pickering emulsions of silicone oil/water and or toluene/water. The amphiphilic nanometer particle is simple in preparation technology, good in stability and uneasy for being influenced by temperature, pH value, salinity and other factors, and therefore the amphiphilic nanometer particle possesses great application prospect and industrialization capability. The preparation method of the emulsion can be further expanded for preparing different oil/water emulsions, and even has potential application prospect in emulsion polymerization field.

The present invention discloses a preparation method of a stable high internal phase gelatinous wheat gliadin Pickering emulsion. The preparation method comprises the following steps: (1) wheat gliadin is dissolved into an alcohol solution; (2) an chitosan acetic acid solution is prepared; (3) the obtained solution in the step (1) is poured into the chitosan acetic acid solution, homogenization is conducted, and the homogenized solution is subjected to rotary evaporation; (4) a pH value of the obtained solution in the step (3) is adjusted to be 4.0-6.0; and (5) the obtained solution in the step (4) is mixed with oil and the mixture is subjected to shear emulsification to obtain the stable high internal phase gelatinous wheat gliadin emulsion. The obtained wheat gliadin Pickering emulsion by the method is high in stability and good in viscoelasticity, and can be used for embedding a large amount of oil. The stable high internal phase gelatinous wheat gliadin Pickering emulsion is low in requirement for devices, and simple and easy to operate in the method, and has relatively good prospect in the application aspects of novel nutrient delivery carriers and food structure modification base materials.

The invention designs a preparation method and application of a polymer hollow microcapsule. The method comprises the following steps of using nano cellulose as an emulsifier of a Pickering emulsion,adding an initiator, a monomer and a cross-linking agent into a discontinuous phase of the emulsion, afterwards, using the Pickering emulsion as a template, and preparing the polymer hollow microcapsule through the polymerization and cross linking reactions, in a liquid drop of the emulsion, of the monomer. The nano cellulose used in the method has advantages of being good in biocompatibility, wide in source, low in cost, green and environmental friendly, and the like; the range of a polymer to which the method is applicable is wide; hydrophobic and hydrophilic polymer monomers can be selectedand used; an environmental stimuli-responsive polymer or a polymer with a special function, such as a pH (potential of Hydrogen)-response, temperature-response or conducting polymer and the like, canbe selected and used; moreover, the method is simple, convenient and quick; reaction conditions are simple; the polymer hollow microcapsule is adjustable in particle size, low in cost and easy in quantity production and the obtained polymer hollow microcapsule can be used for the entrapment and the controlled release of a medicine and can be widely applied to the fields of medicines, agricultureand the like.

The invention provides a method for preparing Pickering emulsion type alkenyl succinic anhydrides (ASA) papermaking sizing agent. The method comprises the following steps of: intercalating quaternary ammonium salt into nano cation-based modified montmorillonite to prepare nano solid fine grain emulsifier; dispersing the nano solid fine grain emulsifier and magnesium salt into deionized water to form a water phase, mixing the water phase and oil phase ASA, and emulsifying the mixture through high speed shearing to obtain the Pickering emulsion type ASA papermaking sizing agent, wherein the volume ratio of the oil phase to the water phase is (1:1)-(1:6). The Pickering emulsion type ASA papermaking sizing agent is coupled with the emulsion and stabilization characteristics of organic surfaceactive substances and inorganic solid fine grains; compared with the emulsion which is emulsified and stabilized by independently using the surface active substances, the Pickering emulsion type ASA papermaking sizing agent is more stable and higher in sizing efficiency; furthermore, the preparation process is simple, and the ASA can be emulsified into stable emulsion without adding any surfactant and high-molecule polyelectrolyte; and the using amount of the emulsifier is small and the emulsifying cost is low.

The invention provides an amphiphilic Janus nano particle and a preparation method and application thereof. The preparation method comprises the following steps: dispersing silicon dioxide nanoparticles in water to obtain a dispersion liquid, mixing the dispersion liquid and liquid paraffin, heating and stirring in a water bath to form a Pickering emulsion, cooling to obtain small wax balls, adding a silane coupling agent into the small wax balls for modification to obtain modified small wax balls, mixing the modified small wax balls, an amidation catalyst and C12-C18 saturated fatty acid, andcarrying out an amidation reaction process to obtain organic hydrophobic chain grafted oil-water amphiphilic nanoparticles, and removing paraffin in the organic hydrophobic chain grafted oil-water amphiphilic nanoparticles to obtain the amphiphilic Janus nano particles. When the surfactant is used as an oil-displacing agent, oil-water interfacial tension can be effectively reduced at low concentration, rock wettability is changed, oil-displacing efficiency of nanofluid is remarkably improved, economic cost is reduced, and the surfactant has a wide application prospect.

The invention discloses an anion responsive Pickering emulsion. The emulsion is prepared from ionic liquid modified sheet materials which are taken as a particle emulsifier, have different front and back surface properties and are dispersed on an interface of a water phase and an oil phase; one side of the particle emulsifier is a lipophilic group, and the other side is an ionic liquid functional group. According to the emulsion, the ionic liquid functional group has an anion exchangeable characteristic and can adjust the surface wettability while being endowed with functionalization after the anion exchange, and accordingly, the sheet materials have adjustable emulsifying performance; anion control functionalization and phase inversion are performed according to the characteristic that types of the stabilized emulsion are different due to different physicochemical properties of ionic liquid base materials containing different anions in the specific oil-water proportion, and the emulsion has broader application potentiality.

The invention discloses an emulsion type carbon fiber sizing agent and a preparation method and application thereof. The sizing agent comprises main size, an emulsifier, graphene oxide, a diluent and water, wherein the amount of the emulsifier is 0.5-6 weight percent of that of the main size; and the amount of graphene oxide is 0.1-2 weight percent of that of the main size. The preparation method comprises the following steps: mixing the main size, the diluent and the emulsifier, stirring and premixing; and slowly adding an aqueous solution of graphene oxide for performing phase inversion emulsification to form Pickering emulsion in which graphene oxide and the emulsifier are stable, thereby obtaining the sizing agent. The preparation method disclosed by the invention is easy to operate, the stability of the sizing agent is improved by adopting the synergistic effect of graphene oxide and the emulsifier, the amount of the emulsifier is reduced, the environmental pollution is alleviated, the defects that the sizing agent with a single stable emulsifier is low in stability and the amount of the emulsifier is extremely large are overcome, the selection range of the main size is widened, the performances of carbon fibers can be improved after sizing, an interface bonding effect of a carbon fiber composite material is enhanced, and the mechanical strength of the carbon fiber composite material is improved.

The invention discloses a compound emulsifier with a switching property, belonging to the field of colloid and interface chemistry. The emulsifier consists of nano silicon dioxide particles without any modification and a switching-type amphiphilic compound, wherein the original particle size of the nano silicon dioxide particles is 20-200nm, and the use concentration is 0.1-2.0% (based on an aqueous phase); and the switching-type amphiphilic compound is an N'-long chain alkyl-N,N-dimethylacetamidine substance, wherein the total carbon atom number of the long chain alkyl is 8-18, the long chain can be a straight chain or branch chain, the alkyl is a saturated or unsaturated alkyl containing a benzene ring or not, and the use concentration is less than the critical micelle concentration (based on an aqueous phase). A proper oil phase comprises mineral oil (hydrocarbons), animal/vegetable oil (triglycerides) and water-insoluble polar organic matters such as long-chain fatty acid, fatty alcohol and the like. The emulsion prepared by the compound emulsifier belongs to Pickering emulsion, is generally an O/W type and has hyperstability. By introducing nitrogen (N2) or air, the emulsifier can be deactivated to cause demulsification of the emulsion; by introducing carbon dioxide (CO2), the surface activity of the emulsifier can be recovered; and the system becomes stable Pickering emulsion after homogenizing emulsification, namely that the compound emulsifier has a switching property.

The invention belongs to the technical field of materials, and discloses a preparation method of graphite oxide alkene materials with a dissymmetrical structure. The method comprises the steps: using a formwork that oil-in-water Pickering emulsion of paraffine is stabilized by the graphite oxide alkene, performing an epoxy group reaction by using modified agents containing amino and the surface of the graphite oxide alkene to modify a single surface, and then washing to remove the paraffine with solvents to obtain the dissymmetrical modified graphite oxide alkene. The preparation method disclosed by the invention is simple and mild, the raw materials are easy to obtain, the structure of the surface of the graphite oxide alkene can be adjusted, and the amphipathic nature of Janus particles of the graphite oxide alkene can be designed as needed, so that the graphite oxide alkene has better capability for stabilizing the emulsion.

The invention relates to a preparation method of Pickering emulsion and particularly relates to a preparation method of Pickering emulsion with a stable starch nanoparticle emulsifier. The preparation method comprises the following steps: selecting starch with the amylose content of 20%-40%; after gelatinizing, titrating with absolute ethyl alcohol; centrifuging, and freeze-drying sediment to obtain starch nanoparticles; and adding the starch nanoparticles into an oil-water mixed solution to prepare the Pickering emulsion. According to the preparation method of the Pickering emulsion with the stable starch nanoparticle emulsifier, raw materials are natural and preparation conditions are moderate; strong-corrosion reagents including sulfuric acid and the like are not used, so that a preparation process is green and environment-friendly and has no toxin and no emission of harmful substances; the prepared Pickering emulsion has good stability and good sensitive environment stability, and has relatively good heat resistance and salt resistance; and the invention provides an efficient, green and environment-friendly preparation method of starch nanoparticles and the starch nanoparticles can be widely applied the fields of foods and cosmetics, and medicines.

The invention provides aqueous pesticidal concentrates comprising at least one colloidal solid, a dispersed emulsion phase comprising at least one substantially water-insoluble pesticidally active ingredient, which is either itself an oily liquid comprising the oil phase, is a solid but is dissolved in an oily liquid present in the oil phase, is a solid and is dispersed within the oil phase or is present as a colloidal solid adsorbed to the liquid-liquid interface between the continuous aqueous phase and the dispersed oil phase and at least one Ostwald ripening inhibitor.

The invention belongs to the technical field of materials, and particularly relates to a method for preparing a through-hole polymer porous aquagel by using graphene oxide (GO). The method mainly comprises the following steps: carrying out surface modification on hydrophilic GO by using an oleophylic modifier, wherein the modified GO is used as a stabilizer of a Pickering emulsion; and adding a monomer, a crosslinking agent, an initiator and a pore-forming agent, emulsifying to obtain an oil-in-water high-inner-phase emulsion, and carrying out continuous phase polymerization on the high-inner-phase emulsion to obtain the through-hole-structure polymer porous aquagel. The method has the advantages of simple preparation process and lower cost. The prepared through-hole polymer porous aquagel has the advantages of controllable pore structure, large pore size (5-200 mu m), large interconnection size (2-70 mu m), favorable permeability, favorable swelling capacity and favorable adsorbability.

The invention relates to a preparation method of monodisperse quantum dot micro spheres with the optical gain property. Through the processes of dispersion, emulsification, polymerization curing and surface coating and the like, the stable monodisperse large-particle-diameter micro sphere carriers are prepared from pickering emulsion; the carriers are compounded into micro spheres by using a dense accumulation mode of quantum dots in the micro sphere; quantum dot micro spheres with the optical gain characteristics are prepared. The quantum dot micro sphere with the optical gain property is prepared. The obtained quantum dot micro sphere product has the advantages that the sphericity degree is high; the particle diameter distribution is uniform (the standard difference is smaller than 15 percent), the particle diameter is controllable in a range being 5 to 50 mum; the corresponding defects of the existing method for preparing the large-particle diaemter micro sphere carriers are overcome; relevant problems of quantum dot micro sphere preparation are solved. The stable quantum dot micro sphere with the optical gain property has the potential application in the fields of biological tags, molecular detection and lasers.

The invention discloses a method for preparing Pickering emulsion by utilizing modified nano-crystalline cellulose. The method comprises the following steps: 1) taking the nano-crystalline cellulose modified with an amphiphilic segmented copolymer and grinding into powder, thereby acquiring the amphiphilic segmented copolymer modified nano-crystalline cellulose powder; 2) dispersing the amphiphilic segmented copolymer modified nano-crystalline cellulose powder acquired in the step 1) into deionized water, thereby forming modified nano-crystalline cellulose dispersion liquid; and 3) weighting an oily solvent, adding into the modified nano-crystalline cellulose dispersion liquid acquired in the step 2), and mixing and emulsifying, thereby forming stable Pickering emulsion. The method for preparing the Pickering emulsion by utilizing the modified nano-crystalline cellulose has the characteristics of less CNC dosage and low application cost.

The invention belongs to the technical field of emulsion polymerization preparation, and discloses a stable methylacryloyl cage type silsesquioxane emulsion with a Pickering effect and a preparation method thereof. The preparation method comprises the steps: making methylacryloyl cage type silsesquioxane and a polymerization monomer carry out an emulsion reaction in a water system under the action of an emulsifying agent to prepare a pre-emulsion, and then by adopting a seed emulsion polymerization method, performing a polymerization reaction under the action of an initiating agent to obtain the emulsion with the Pickering effect. According to the preparation method, an MA-POSS (methyl methacrylate polyhedral oligomeric silsesquioxane) is polymerized with St (styrene), MMA (Methyl Methacrylate) or BA (butyl acrylate) instead of a conventional emulsifying agent to obtain the emulsion with the Pickering effect, because the MA-POSS has an organic-inorganic nano hybridization structure, and is larger in molecular weight, favorable heat performance, mechanical performance and the like of the MA-POSS are introduced into the polymer emulsion, the performances such as heat resistance and stretching of the polymer can be effectively improved, and the application range of the Pickering emulsion is greatly enlarged.

Described herein are nanoparticle silica Pickering emulsions comprising an aqueous suspension of colloidal silica mixed with a quaternary ammonium biocide. Additionally, the composition may include a small amount of organic solvent; such as methanol, ethanol, isopropanol, and mixtures thereof; wetting agents, such as a silicone-based wetting agent; and organic bases which act as solvent buffers, if it is desirable to raise the pH of the composition, such as monoethanolamine (MEA). The combination of nanoparticle silica and quaternary ammonium biocide provides food contact sanitization at less than 200 ppm of quaternary ammonium active.