FABRICATION OF A NEW MESOSTRUCTURED SILICA PREPARED BY DOUBLE REPLICATIONS FROM A MCM-48 SILICA

摘要

Mesoporous carbon frameworks were synthesized by nanocasting of MCM-48 silica molecular sieves as templates and used as molds for second replication to regenerate mesoporous silicas by infiltrating the mesoporous channels of the carbon framework by silica source and performing sol-gel process with HC1 vapor as hydrolysis agent of the silica source, Tetraethylorthosilicate (TOES). The regenerated mesoporous silica, named Hannam University Mesostructure (HUM)-l after removal of the carbon mold is a cubic mesoporous silica that is distinctly different from the original MCM-48 silica and represents a previously unreported new mesoporous silica material. The new HUM-1 silica shows highly periodic nanosturctured order and three-dimensionally interconnected uniform pore arrays as confirmed by XRD, TEM and sorption studies. This new mesoporous silicate was prepared by a cyclic serial replication process and it may not be possible to make this material using the conventional surfactant coassembly methods currently employed for the synthesis of mesoporous silicates.