| As a novel structural material, monoliths have attracted intensive attention for several years. It has been widely used in separation and purification, catalysis, synthesis etc. Generally monolith can be classified into two categories: organic polymer-based monolith and silica-based monolith. The former is easy to prepare while it usually suffers from deforming, swelling etc., which severely limited their applications. The latter, which possesses high mechanical strength and can be easily derived with various moieties, seems to be more popular. However, the preparation of the latter is relatively difficult. Until now only a few groups reported the preparation method of them. Based on these observations, the present author intends in this dissertation to systematically investigate the synthesis of silica monolith and expand its applications including template casting (or template synthesis), preparation of carbon monolith, and capillary monolith for CEC separation.(1) In Chapter 1, the preparation and application of monoliths are reviewed. Emphasis is laid on various technologies for the monoliths' preparation. Their usage in separation, catalysis and template synthesis are also included.(2) In Chapter 2, preparation conditions of silica monoliths were systematically studied. The mechanism of its novel structure formation was expounded. Parameters affecting mesopore structures, such as CTAB additive, ammonium hydroxide treatment, was also studied in details.(3) In Chapter 3, a novel method was proposed to fabricate the silica monolith with ordered mesopores in the presence of F127. F127 has been shown to act as a phase separation inducing agent and a structure-directing agent. The former resulted in the interconnected skeletons and continuous through pores; while the latter leaded to the formation of ordered mesopores.(4) In Chapter 4, a novel method was proposed for the preparation of a carbon-silica composite monolith with high carbon content. A silica monolith with bicontinuous structures and bimodal pores was impregnated with styrene and divinylbenzene. After polymerization and carbonization, a carbon-coated silica monolith was formed. Tedious procedures of spinning and drying were eliminated, and the carbon content in the final product was as high as 21% (w/w).(5) In Chapter 5, trimodal porous carbon monolith, for the first time, was reported. A silica monolith was used as a template for its preparation. The resultant carbon monolith is characterized by high surface area, micropores, uniform mesopores and through pores, which facilitate its usage in adsorption, separation and purification etc..By selecting silica templates, we accomplished morphology controlling and pore size tailoring of carbon monoliths. Cylindrical, triangular, square, orbicular, and pentagonal carbons were synthesized, with their skeleton pore size varying from 6.5 to 7.6 nm and through pores ranging from one micrometer to several micrometers.(6) The preparative conditions for capillary silica monolith were systematically studied in Chapter 6. Octadecyl group was grafted to the monolithic matrix to afford separation media for amino- derivatives of aromatic hydrocarbons and alkylbenzenes. Column efficiency as high as 159,000 plates per meter was obtained for benzene.For the first time a zirconia membrane was covalently bonded to the monolithic surface. Owing to the amphoteric character of the surface zirconia, the monolithic column took on switchable EOF, which facilitates the separation of basic compounds. After being modified with octadecylphosphonic acid, the zirconia-coated silica monolith demonstrated its suitability for separation in a reversed phase mode CEC. Alkaloids and PAHs were easily separated on the column.
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