Preparation of large-pore silica microspheres using templating method and their applications to protein separation with high performance liquid chromatography

Abstract

Large-pore silica microspheres were synthesized by utilizing weak cation exchange polymer beads as templates, -trimethoxysilylpropyl--trimethylammonium chloride (TMSPTMA) as a structure-directing agent, tetraethoxysilane (TEOS) as a silica precursor, and triethanolamine as a weak base catalyst. The hydrolysis and condensation of the silica precursors occurred inside the templating polymer beads yielded polymer/silica composite microspheres. After the organic polymer templates were removed in the calcination step, large-pore silica microspheres were produced. The effects of different reaction conditions on the morphology, structure and dispersibility of the formed silica microspheres were investigated. It has been shown that when the volume ratio of TMSPTMA, TEOS and triethanolamine was 1:2:2, silica microspheres with pore size range of 50-150 nm and particle size around 2 μm were obtained. The as-prepared silica microspheres were then bonded with chlorodimethyloctadecylsilane (C18), packed into a 50 mm×4.6 mm column, and evaluated for the separations of some common standard proteins and soybean isolation proteins. The results showed that the large-pore silica spheres from this work have potentials for protein separation in HPLC.

Preparation of silica microspheres with a broad pore size distribution and their use as the support for a coated cellulose derivative chiral stationary phase

“…Nevertheless, when noncrosslinked or slightly crosslinked macroporous polymeric beads were used as the templates in above studies, the formed silica spheres had the similar size to the templates, these methods were still limited in the creation of silica microspheres with ultra‐large pore size. In our recent study , we found that highly crosslinked polymeric beads could be used as the templates to synthesize ultra‐large pore silica microspheres that showed promising protein separations in HPLC after C18 silane bonding on the silica surface. In this study, we prepared the silica microspheres with a broad pore size distribution using the newly developed templating technique, and evaluated the as‐prepared silica microspheres as the supports for the coating of cellulose tris(3,5‐dimethylphenyl carbamate) to prepare chiral stationary phases for enantiomer separations in HPLC.…”