Preparation Of Porous Carbons And Its Performance On Adsorption

Several methods were used to synthesis mesoporous carbon and the influences of the technological condition on the pore structure and the adsorption properties were studied. Mesoporous carbon with high mesopore volume and narrow pore size distribution was synthesized and the adsorption behavior of organic molecules on the mesoporous carbon was studied.We used sucrose as carbon source and sodium silicate as silica source, to form a nanoscale sucrose copolymer/silica gel networks and by the process of heat treatment. After carbonization and etching the silica template, mesoporous carbons with pore size of about 8~25nm were obtained. When the sucrose/ silica mol ratio is 0.32, pH of the sol solution is 3, gelling temperature is 80℃and carbonization temperature is 850℃, the porous carbon prepared has BET surface area of 597.63 m2/g, good pore volume, high mesoporosity and food adsorption properties to rhamnolipid, whose adsorbed amount is 4~5 times of common activated carbon.A carbon/silica nanocomposite was prepared by the sol-gel process using tetraethoxy silane (TEOS) and sucrose as the precursors. After carbonization the silica framework was removed by HF treatment. The residue carbon was porous. When the sucrose/TEOS mol ratio is lower (0.13, 0.25, 0.5), the porous carbon has more mesopores. When the sucrose/TEOS mol ratio is higher (1.0, 2.0), there are more micropores. When gelling temperature is 80℃and carbonization temperature is 850℃, HCl/TEOS mol ratio is 0.01 and sucrose/TEOS is 0.25, the porous carbon prepared has BET surface area of 1744 m~2/g, pore volume of 1.24cm~3/g, and mesoporosity is 48.5% with pore size about 2~4nm.During preparing mesoporous carbons, the self-arranging micelle of non-ionic surface active agent tween-60 was used as the template. The sol-gel reaction of TEOS and the carbon sucrose (such as epoxy, starch, sucrose) occured at the interfaces of micelles to form a network, then carbonization and silica etching were carried on. The experimental results show that epoxy is the best one to improve the yield and the pore volume. The mesoporous carbon prepared has BET surface area of 1192m~2/g and pore volume of 0.982cm~3/g, with mesopore size about 4nm. The SEM and TEM images show that the mesoporous carbon has the hollow ball like structure.Waste tires were used to prepare mesoporous carbon by charring and activation with KOH, the mesoporous carbon had mesopores size of about 50nm in diameter.