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Synthesis And Characterization Of The Mesoporous Carbon/Silica Hybrid Materials And Carbons With Ordered And Uniform Pore Structure

Posted on:2007-11-29Degree:DoctorType:Dissertation
Country:ChinaCandidate:X B LiuFull Text:PDF
GTID:1101360185461399Subject:Physical chemistry
Abstract/Summary:PDF Full Text Request
Mesoporous carbons have many unique properties, such as 3D interconnected channels, chemical inertness and large pore volume, which exhibit numerous potential applications in adsorption of large hydrophobic molecules, chromatographic separations, electrochemical double-layer capacitors and lithium batteries.The thesis focuses on the two main subjects. The effect of adding various counterions, absolute alcohol and sucrose on mesoporous structure was studied in process of hydrothermal synthesis; on the other hand, a series of hybrid mesoporous carbon/silica composites with tailored pore size are prepared by the pretreatment of impregnation with concentrated sulfuric acid, then the mesoporous carbons are obtained by removed the silica wall or resulted from the mesopores filling with carbon.The mesoporous carbon/silica composites can be prepared by directly carbonized the surfactant locked in mesopores or impregnated with concentrated sulfuric acid then carbonized under nitrogen atmosphere. The structural properties of mesoporous carbon/silica composites can be tuned by changed the amount of concentrated sulfuric acid in pretreatment process and calcined conditions. The pore size distribution of resultant carbon/silica composites are tailored between 6.4 and 11.0 nm, and the mesoporous structure is preserved perfectly after impregnation and carbonization treatment.Nanoporous carbons are prepared by removed the silica wall of above-mentioned carbon/silica composites, which possess two pore systems with sizes centred at approximately 0.9 nm and 4.3 nm, respectively. Because our method can tailor the silica wall thickness to some extent, the mesoporous carbons with tailored pore size can be synthesized by filled mesopores with carbon precursors and then removed silica wall, and the pore diameters of resultant products can be modulated rationally within the range of 3.5~4.5 nm.
Keywords/Search Tags:characterization, mesoporous carbon/silica composites, mesoporous carbons, uniform and ordered pore size, tailor pore sizes
PDF Full Text Request
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