Preparation of Core–Shell Silica Microspheres with Controllable Shell Thickness for Fast High Performance Liquid Chromatography Separation of Alkyl Benzenes and Intact Proteins

As it is difficult to prevent secondary nucleation and agglomeration during the preparation of core–shell silica microspheres, these issues have been successfully resolved in this study using template-dissolution-induced redeposition. The non-porous particles are transformed into core–shell silica microspheres (CSSMs) in the presence of cetyltrimethylammonium bromide and octyltrimethylammonium bromide under basic conditions. The shell thickness and pore sizes of the CSSMs are controlled by adjusting the etching time and molar ratio of the template, respectively. The CSSMs are modified using octadecyltrimethylammonium chloride to separate the mixture of alkyl benzenes, and a high column separation efficiency is achieved within two minutes. The CSSMs are used for the separation and analysis of proteins and the digests of bovine serum albumin. The chromatographic column packed with core–shell particles affords a significantly higher separation efficiency than the commercial column. Therefore, as a chromatographic stationary phase, these core–shell particles can potentially be used for the fast separation of proteins, small solutes, and complex samples.