Stability of mesoporous silica under acidic conditions

Control of amine functionality distribution in polyvinylamine/SBA-15 hybrid catalysts for Knoevenagel condensation

“…4.2), caused changes in the textural and structural parameters of SBA-15. A slight decrease in the value of a parameter can be attributed to densification of silica walls [14], whereas the deposition of polymer inside mesopores results additionally in a drop in S BET , V total and D [15]. It should therefore be assumed that the formed PNVF chains interact with the inner and outer surfaces of SBA-15 support, probably by hydrogen bonding and/or electrostatic attraction between silanol groups and formamide groups [16,17].…”

Influence of Porous Texture and Surface Chemistry on the CO2 Adsorption Capacity of Porous Carbons: Acidic and Basic Site Interactions

“…60 El Mourabit et al 60 demonstrated that H 3 PO 4 has a great effect on both SBA-15 structure and porosity. SBA-15 silica is especially sensitive to this acid since it is partially solved, resulting in a gel; in a first stage, the microporosity of the SBA-15 template is blocked by the gel, leading to a decrease in the micropore volume; finally, the mesopore walls are also affected by the same process.…”

Differences in Catalytic Activity of Poly(vinylamine) Introduced on Surface of Mesoporous SBA-15 by Grafting from and Grafting onto Methods in Knoevenagel Condensation

“…It is noteworthy that the calculated unit cell parameter does not change significantly with increasing amount of introduced polymer species. This result suggests that the stepwise modification of silica may cause somewhat densification of silica walls65All TEM pictures clearly show the p6mm hexagonal morphology with well-ordered 1D arrays, typically representing the SBA-15 materials. The preservation of the cylindrical shape of the pores and their hexagonal mesostructure indicates that the channel structure of parent SBA-15 is not destroyed during the polymer grafting.…”