Preparation And Its Application Of Novel Hybrid Capillary Monolithic Column By Pressurized-Capillary Electrochromatography

Organic-silica hybrid monolithic columns,combining obvious merits of both organic and inorganic monoliths,such as easy preparation,high mechanical strength,wide pH tolerance and good solvent resistance,have attracted extensive attentions in recent years.Currently,a novel "one-pot" methed has been developed for the fabrication of organic-inorganic hybrid monolith which was based on sol-gel methed.In this paper,we try to develop a novel organic-silica hybrid monolithic columns for enriching and improving the capillary electrochromatography techniques with the "one-pot" methed.This paper is divided into four chapters and the main contents are as follows:In chapter 1,there is a review,including the principle of CEC,the types of the columns and a brief review about the types and general situations of monolithic columns used in capillary eletrochromatography.The progress and tendency on preparation and application of organic-silica hybrid monoliths have been focused on,and then the topics and experimental profiles for organic-silica hybrid monoliths have been put forward.In chapter 2,a new hexadecenyl-sulfonic acid based organic-inorganic hybrid silica-based monolithic capillary column was prepared by "one-pot" technique,using tetramethoxysilane(TMOS)and vinyltriethoxysilane(VTEO)as silylating agent,the sodium ethylenesulphonate(VS)and hexadecene as the functional monomer.The mechanical stability of the column was discussed.The separation of neutral polar benzene and anilines on hybrid type column were also achieved.In chapter 3,a recognition specificity of boric acid affinity organic-inorganic hybrid silica monolithic column was prepared using 4-vinyl phenylboronic acid(VPB)as organic functional monomer,divinyl benzene(DB)as crosslinking agent,TMOS and VTEO as silane reagent.In this paper,the effect of "one-pot" technique on the preparation of boric acid affinity hybrid monolithic column was investigated.We optimized polymerization conditions on the experiment,and investigated the stability and electroosmotic flow of the prepared hybrid monolithic column,reproducibility.The retention mechanism was investigated using the neutral compounds and aniline compounds.Also,the specificity separation effect of catechol and hydroquinone was investigated in the column.In chapter 4,a novel organic-silica hybrid monolithic was prepared with a modified "one-pot' process of functional monomers and alkoxysilanes.Using the 2,2'-azobis(2-methylpropionamidine)dihydrochloride(AIBA)as initiator,the homogeneous prepolymerization system of this hybrid monolith was successfully obtained by a simple operation.The morphologies of the hybrid-silica monolithic matrixes were observed by scanning electron microscope(SEM),and the performances of the organic-silica hybrid monolithic columns were investigated by pressurized capillary electrochromatography.The mechanical stability and reproducibility of the obtained hybrid monolithic column preformed acceptable.And the separation of neutral molecules,benzoic acid and phenol was also achieved using the obtained hybrid monolithic column.