Triblock Copolymer Syntheses of Mesoporous Silica with Periodic 50 to 300 Angstrom Pores

Abstract

Use of amphiphilic triblock copolymers to direct the organization of polymerizing silica species has resulted in the preparation of well-ordered hexagonal mesoporous silica structures (SBA-15) with uniform pore sizes up to approximately 300 angstroms. The SBA-15 materials are synthesized in acidic media to produce highly ordered, two-dimensional hexagonal (space group p6mm) silica-block copolymer mesophases. Calcination at 500 degrees C gives porous structures with unusually large interlattice d spacings of 74.5 to 320 angstroms between the (100) planes, pore sizes from 46 to 300 angstroms, pore volume fractions up to 0.85, and silica wall thicknesses of 31 to 64 angstroms. SBA-15 can be readily prepared over a wide range of uniform pore sizes and pore wall thicknesses at low temperature (35 degrees to 80 degrees C), using a variety of poly(alkylene oxide) triblock copolymers and by the addition of cosolvent organic molecules. The block copolymer species can be recovered for reuse by solvent extraction with ethanol or removed by heating at 140 degrees C for 3 hours, in both cases, yielding a product that is thermally stable in boiling water.

A Highly Stable Anode, Carbon‐Free, Catalyst Support Based on Tungsten Trioxide Nanoclusters for Proton‐Exchange Membrane Fuel Cells

“…The 2-4 nm pores may arise from the removal of the silica wall, and those at 9-13 nm are likely to be related to the structure of the hard template, SBA-15. [26] The Brunauer-Emmett-Teller (BET) surface area of the WO 3 support synthesized in this study is calculated to be 47 m 2 g À1 with a total pore volume of 0.124 cm 3 g À1 .…”

Ligand-assisted preparation of highly active and stable nanometric Pd confined catalysts for deep catalytic oxidation of toluene

“…Mesoporous SBA-15 was synthesized following the literature procedure [26]. Typically, 4 g of P123, 135 g of H 2 O, 24 g of HCl and 9.1 ml of TEOS were mixed under stirring at 35 • C for 20 h, and then aged at 100 • C for 48 h. The recovered solid was washed and dried to obtain the as-SBA-15 sample.…”

Analysis of the human urine endogenous peptides by nanoparticle extraction and mass spectrometry identification

“…Nanoporous materials have shown great promise for sample pretreatment of body fluid in recent years [17,34,35]. The silica materials with highly ordered mesoporous structure such as M41s [36] and SBA-15 [37] have unique properties of high surface areas, extremely narrow pore size distribution and perfectly adjustable pore size. Another obvious advantage of these materials is their significantly higher in-pore surface area than the external surface area.…”