Study On Preparation And Properties Of Solid Particle Stabled Multiphase System

Solid particles(one nanometer to ten micrometers in diameter)are widely used in research and many industries,such as food,cosmetics,pharmaceuticals,etal.In addition to the chemical composition,size,shape,and surface charge of solid particles,the wettability of solid particles is one of the most important factors for stabilizing liquid marbles and pickering emulsions.It determines the solid particles adsorption behavior at the gas-liquid interface and the liquid-liquid interface.This thesis mainly uses solid particle silica as raw material.The hydrophobic silica solid particles to prepare stabled liquid marbles,and studied the principle of gas in the gap of the liquid marble shell.The surface modification of hydrophilic silica solid particles was studied,and the effect of silica prepared under different modification conditions on Pickering emulsion was studied.(1)The rolling method was used to prepare a controllable wet liquid marble with a glycerol-water mixture as the core material and a super-hydrophobic micro-silica as the shell.The distribution of silica on the surface of the liquid marbles was observed through a biological microscope and a contact angle measuring instrument,and the hygroscopicity and dehydration of the liquid marbles were detected with an electronic balance.A certain concentration of brine provides sufficient humidity.The performance and mechanism of glycerol liquid marbles are studied from the aspects of liquid marble hygroscopicity,moisture control performance,and wall materials.The results show that the liquid marbles can absorb moisture from the environment when the environmental humidity is high,and can release moisture to the environment when the environmental humidity is low,and have good humidity control performance.Nano-silica-coated liquid marbles have a higher moisture absorption rate than micro-silica-coated liquid marbles,and the droplets have a higher moisture absorption rate and water loss rate than liquid marbles.Coated with multiple layers of super-hydrophobic micro-silica.(2)Based on the moisturizing properties of liquid marbles in Experiment 1,a color-changing liquid marble with copper chloride-glycerol mixture as the core solution and silica as the shell was successfully prepared.The liquid marble was used as the reactor.Induction of ammonia.The distribution of silica on the surface of the liquid marbles was observed through a contact angle measuring instrument and a biological microscope.The results show that when the volume of the core solution of the liquid marble is 8 ?L,the concentration of copper chloride is 0.5 mol/L,the shell wall is micro-silica,and the core solution is obtained by mixing glycerol and copper chloride solution in a 1:1 ratio At the time,the liquid marbles have high stability,obvious color,good moisture retention and long life.The time for the color change reaction between the liquid marble and ammonia gas decreases with the increase of the ammonia concentration,and the lowest ammonia concentration of the liquid marble discoloration is 0.1 mol/L.In different concentrations of ammonia,the number of liquid marbles changing color is different,and the color of the liquid marbles changing color is different.The liquid marbles turn dark blue when absorbing ammonia gas,and turn green when releasing ammonia gas.(3)The Stober method was used to prepare regular morphology silica,and cadmium sulfide was discretely compounded on the surface of silica by uniform precipitation method,and the CdS/SiO2 compound with different hydrophobicity was synthesized by controlling the size of cadmium sulfide by a small number of times Particles,using CdS/SiO2 composite particles as emulsifier to prepare Pickering emulsion.The CdS/SiO2 composite particles were analyzed by SEM and EDS.The results of SEM analysis showed that the size of cadmium sulfide became larger with the increase of the number of recombination.The wettability of CdS/SiO2 composite particles was measured by sedimentation method.The results showed that the hydrophobicity of CdS/SiO2 composite particles prepared under the conditions of cCdSO4=0.01 mol/L and cTAA=0.01 mol/L increased with the number of cadmium sulfide recombination Increased and increased;the hydrophobicity of CdS/SiO2 composite particles prepared under the conditions of cCdSO4=0.0001 mol/L and cTAA=0.001 mol/L did not change.Digital biological microscope was used to observe the size of Pickering emulsion droplets.Pickering emulsions prepared with CdS/SiO2 composite particles with different compounding times were all O/W type.With the increase of compounding times,the number and radius of emulsion droplets increased.,The stabilization time also gradually increased.