Cage-like octa(trimethylsiloxy)silsesquioxane [(Me3SiO)SiO1.5]8 has been synthesized via the trimethylsilylation of cubic tetramethylammonium silicate octamer [(Me4NO)-SiO1.5]8 with chlorotrimethylsilane. The silicate...Cage-like octa(trimethylsiloxy)silsesquioxane [(Me3SiO)SiO1.5]8 has been synthesized via the trimethylsilylation of cubic tetramethylammonium silicate octamer [(Me4NO)-SiO1.5]8 with chlorotrimethylsilane. The silicate octamer can be selectively formed by the reaction of tetraethoxysilane Si(OEt)4 with aqueous tetramethylammonium hydroxide in equal展开更多
Polydimethylsiloxane-ladder like phenylsilsesquioxane copolymer as a novel membrane material has good film-forming ability, high mechanical properties and low swelling capacity. The copolymer membrane displays the per...Polydimethylsiloxane-ladder like phenylsilsesquioxane copolymer as a novel membrane material has good film-forming ability, high mechanical properties and low swelling capacity. The copolymer membrane displays the permselectivity of organic liquid for the pervaporation of organic liquid/water mixtures. The pervaporation of aqueous solution of ethanol through the membrane has been investigated. High separation factor can be obtained in the range of low ethanol concentration. The flux of ethanol increases and the flux of water keeps constant as the concentration of ethanol in feed increases. The membrane shows good stability of separation at room temperature to 70℃. The comparison of the pervaporation behavior of the aqueous solutions of methanol, ethanol, 2-propanol, acetone, THF reveals that the magnitude of the separation factors and the fluxes increases in the following order: methanol<ethanol<2-propanol<acetone<THF, in spite of the size of the permeating molecules.展开更多
文摘Cage-like octa(trimethylsiloxy)silsesquioxane [(Me3SiO)SiO1.5]8 has been synthesized via the trimethylsilylation of cubic tetramethylammonium silicate octamer [(Me4NO)-SiO1.5]8 with chlorotrimethylsilane. The silicate octamer can be selectively formed by the reaction of tetraethoxysilane Si(OEt)4 with aqueous tetramethylammonium hydroxide in equal
文摘Polydimethylsiloxane-ladder like phenylsilsesquioxane copolymer as a novel membrane material has good film-forming ability, high mechanical properties and low swelling capacity. The copolymer membrane displays the permselectivity of organic liquid for the pervaporation of organic liquid/water mixtures. The pervaporation of aqueous solution of ethanol through the membrane has been investigated. High separation factor can be obtained in the range of low ethanol concentration. The flux of ethanol increases and the flux of water keeps constant as the concentration of ethanol in feed increases. The membrane shows good stability of separation at room temperature to 70℃. The comparison of the pervaporation behavior of the aqueous solutions of methanol, ethanol, 2-propanol, acetone, THF reveals that the magnitude of the separation factors and the fluxes increases in the following order: methanol<ethanol<2-propanol<acetone<THF, in spite of the size of the permeating molecules.
