Effect of organosilane/polymer ratio on adsorption properties of periodic mesoporous ethane-silica

摘要: Abstract Remarkable achievements in the area of pure siliceous mesoporous molecular sieves such as MCM-41, SBA-15, SBA-16 and FDU-1 paved way for discovery periodic organosilicas (PMOs). This work reports effect organosilane/polymer ratio on synthesis PMO with ethane bridging groups inside SBA-15-type framework. ethane-silica was obtained by self-assembly 1,2-bis(triethoxysilyl)ethane (BTESE) precursor poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) triblock copolymer Pluronic P123 (EO20PO70EO20) structure directing agent under low acidic conditions. The amount increased progressively from 0.5 3 g, while mass BTESE gel mixture kept constant. polymeric template removed via extraction acidified ethanolic solution. resulting materials were characterized powder X-ray diffraction, thermogravimetry nitrogen adsorption at −196 °C. latter used to evaluate specific surface area, mesopore width, total pore volume complementary pores. polymer/BTESE weight ratios 0.73 1.46 favoured formation additional amorphous silica channel-like mesopores, which resulted plugged hexagonal templated silicas (PHTS) volume, small size, wide size distribution (PSD), thick walls mesostructural ordering. A further increase (2.2) led a material large diameter, narrow PSD, uniform openings high structural On other hand, (from 2.93 4.39) afforded PMOs very broad PSD non-uniformity entrances well Furthermore, complete removal elevated temperatures air did not lead disappearance ordering OMS studied.