Synthesis, Bifunctionalization, and Application of Isocyanurate-Based Periodic Mesoporous Organosilicas

Abstract

Isocyanurate-containing silsesquioxane-bridged periodic mesoporous organosilicas (ICS−PMOs) were synthesized by self-assembly of the nonionic surfactant P123, EO20PO70EO20, and trimethoxysilyl-functionalized isocyanurate (ICS−Si) under acidic conditions in the presence of inorganic additives. The ICS−PMOs have been modified by an alkyl-bridged organosilane (i.e., Et−Si; Et = −CH2CH2−) by substituting ICS−Si with Et−Si in the precursors, at various molar ratios, resulting in bifunctionalized PMOs exhibiting two types of bridged groups (ICS−Et−PMOs). The obtained bifunctionalized ICS−Et−PMOs have been characterized by X-ray diffraction, transmission electron microscopy, nitrogen physical sorption, and solid-state 29Si and 13C magic angle spinning NMR spectroscopy. Experiments show that the ICS−Et−PMOs exhibit hexagonal mesoscopic structures. Increasing the content of the Et−Si functionality in the precursors is found to significantly improve the mesostructural ordering of the product. It is suggested that f...