Preparation Of Superamphiphobic Coatings And Separation Filter Membranes By Hydrolysis Of Tetraethylorthosilicate

The hydrolysis of organic silicon sources can prepare silica nanomaterials with different morphologies and properties under different conditions,which makes silica nanomaterials have greater application value in the fields of biomedicine,national defense and military industry.Although the reaction conditions of organosilicon hydrolysis are easy to reach and control,it is important to precisely control the reaction conditions of organosilicon hydrolysis to prepare silica materials/composites materials with different characteristics and application potentials,thereby expanding the scope of its application value.In this paper,silica materials/composites materials were prepared by hydrolyzing tetraethylorthosilicate（TEOS）under different conditions,and explored its applications in the field of superamphiphobic with microfluidic performance and filtration separation.The main research contents are as follows:（1）Based on the St?ber method,in the presence of（Heptadecafluoro-1,1,2,2-tetradecyl）trimethoxysilane（AC-FAS）and magnetic ferroferric oxide nanoparticles（Fe₃O₄ NPs）,TEOS was hydrolyzed to prepare Fe₃O₄@Si O₂/F NPs with a core-shell structure under alkaline conditions.The prepared Fe₃O₄@Si O₂/F NPs have high surface roughness and low surface energy,therefore the coating has excellent superamphiphobic property:the water contact angle（WCA）is about 170°,and the oil contact angle（OCA）is about 160°.In addition,Fe₃O₄@Si O₂/F NPs are magnetic,and their saturation magnetization value is 12.0 emu/g.The coating based on Fe₃O₄@Si O₂/F NPs has superamphiphobic property and magnetic property,combined it with polydimethylsiloxane and dimethicone mixture（PDMS@SO）membrane which can produce the elastic deformation,it can achieve the purpose of using magnetism to drive the movement of water droplets or oil droplets,which will have potential application potential in the field of microfluidics.（2）By changing the hydrolysis conditions of TEOS,we unexpectedly obtained silica nanosheets with uniform mesoporous structure.Further research on the synthesis,performance and application potential of mesoporous silica nanosheets.In this paper,in the mixed solution of water and n-hexane,the micelles formed by the surfactant cetyl trimethyl ammonium bromide（CTAB）were used as templates to prepare unsupported mesoporous silica nanosheets at the water-n-hexane interface.During the preparation process,impurities can be removed only through ethanol washing and freeze-drying steps to obtain pure mesoporous silica nanosheets.The electron microscope measurement and Brunner-Emmet-Teller（BET）measurement results shown that the prepared mesoporous silica nanosheets have a complete lamellar structure,uniform pore structure,thin thickness and large surface area.By depositing mesoporous silica nanosheets on a cellulose acetate（CA）membrane,the resulting separation filter membrane can pass 93.46%of cyt c molecules and intercept 52.73%of OVA molecules,which prove mesoporous silica nanosheets’potential application in molecular filtration and separation based on nanometer size.