Reproducible synthesis of high quality MCM-48 by extraction and recuperation of the gemini surfactant

摘要: High quality MCM-48 can be repeatedly and reproducibly prepared, as a novel method for the extraction, recuperation re-use of gemini surfactant has been optimized. Gemini surfactants have general formula [CnH2n+1N+(CH3)2(CH2)sN+(CH3)2CmH2m+1]·2Br, shown to produce in very convenient way. In each cycle, more than 95 wt% is extracted under mild conditions. The extracted does not degenerate during this treatment re-used many times. produced by soft narrower mesoporous pore size distribution larger radius materials prepared by normal temperature-programmed calcination. surface still contains sufficient silanol groups, although some groups replaced methoxy groups. number silanols on titrated reaction with hexamethyldisilazane, followed quantification liberated NH3.