Triblock Copolymer Synthesis of Highly Ordered Large-Pore Periodic Mesoporous Organosilicas with the Aid of Inorganic Salts

Abstract

This communication describes the first preparation of highly ordered large-pore hexagonal periodic mesoporous organosilicas (PMOs) using triblock copolymer P123 as the template and inorganic salts as the auxiliary agents under strongly acidic conditions. The long-range structural order of the PMOs results from the enhanced self-assembly interaction imparted by inorganic salts.

Highly ordered periodic mesoporous ethanesilica synthesized under neutral conditions

“…39 This will benefit the interaction between the PEO corona and the hydrophobic organosilica oligomer. 17 Also, this competition for water with the ethylene oxide will lower the solubility of the Brij-76 surfactant and thus reduce the critical micelle concentration (CMC). The decrease in CMC favors the micelle-micelle interaction, and enhances the assembly ability of the micelles to help the formation of the ordered phase.…”

“…Highly ordered PMOs with 2D, 3D hexagonal and cubic Pm3n, Im3m, Fm3m mesophases can be synthesized under strongly basic or acidic conditions based on the electrostatic interaction between the organosilica and the template aggregates. 1,6,[14][15][16][17][18][19][20][21] However, because many organic groups are sensitive to acid or base and the breakage of Si-C bonds will possibly occur under such conditions, 22 …”

Highly Ordered Mesoporous Organosilica Hybrid Materials

“…Guo et al found that the addition of a salt such as NaCl improves the degree of ordering of the materials. 37 More recently, they also reported that the addition of a large amount of K 2 SO 4 to a synthesis mixture containing BTME and pluronic F127 (EO 106 PO 70 EO 106 ) under acidic conditions affords a high quality cubic (Im 3 3m) ethane-silica mesophase with large cavities 9.8 nm in diameter. 38 Therefore, the most commonly studied typical organic linker group is the ethane group (-CH 2 -CH 2 -) because 1,2-bis(trialkoxysilyl)ethane is a widely available bridged organosilane precursor.…”

Acid catalyzed synthesis of ordered bifunctionalized mesoporous organosilicas with large pore

“…KCl was added for the synthesis of ordered P123-SH n because the inorganic salt plays an important role for getting wellordered mesoporous ethane-silica using P123 as surfactant [16]. The sulfur contents increase irregularly as the concentration of MPTMS in the initial mixture increases (Table 1).…”