Study On The Preparation And Chromatographic Properties Of Hollow And Porous SiO₂

Chromatographic separation and analysis technology has become an important and wildly used analysis,technology in the field of organic chemistry,biochemistry and medical.The chromatographic column is the key to realize the effective and fast separation,and for the packing column,the property of the packing material is directly related to the separation performance of the chromatographic column.Due to chemical and mechanical stability,tunable controlled pores,high specific surface area and large Si-OH on the surface,SiO₂ is considered to be an ideal alternative packing material for liquid chromatography.In this paper,we try to research a kind of packing material,which has high column efficiency and low column pressure,based on porous SiO₂.The main research content is as follows:?1?The preparation of polystyrene microsphere.The polystyrene microspheres obtained respectively by dispersion polymerization are of monodispersity and uniform diameter.The paper also investigated the effect of the kinds of initial on the surface charge of the PS mircospheres.?2?The preparation of PS@SiO₂ by sol-gel and layer-by-layer self assembly technique.The PS@SiO₂ microspheres are fabricated by applying positive charged PS as template,tetraethoxysilane?TEOS?as precursor,cetyltrimethylammonium Bromide?CTAB?as surface active argent,ammonia solution?NH3·H2O?as catalyst and using sol-gel and layer-by-layer technique.The effect of the ratio of PS and TEOS and the quantity of the CTAB and catalyst is investigated in the paper.And the PS@SiO₂ mircospheres are characterized by Zeta Potential Meter,Fourier transform infrared?FTIR?,scanning electron microscope?SEM?,transmission electron microscope?TEM?.?3?The preparation of the hollow SiO₂.The hollow SiO₂ mircospheres can be obtained by calcining the PS@SiO₂ at high temperature.The effect of the sintered temperature on the mechanical stability of the SiO₂ is studied by Fourier transform infrared?FTIR?and Thermo gravimetric analysis?TGA?.?4?The surface alkylation of the hollow silica.The surface chemical modification of hollow silica is obtained by using octadecyltrichlorosilane as silane reagents at the condition of schlenk,and the structure and morphology of the target product is characterized by Fourier transform infrared?FTIR?and transmission electron microscope?TEM?.?5?The chromatographic application of the hollow silica.The hollow silica is pumped into a 5cm*4.6mm chromatographic column,and then it is used to separate materials on the liquid chromatography to test its column efficiency.The property of the C18-SiO₂ is tested in the same way.