Novel monolithic columns with templated porosity

A new type of monolithic stationary phase was prepared within the confines of fused-silica tubing by in situ polymerization of divinylbenzene or ethylene dimethacrylate either with styrene or butyl methacrylate. The porosity of the monolith was dictated by silica beads packed in the capillary prior to flushing the column with the monomeric solution. Subsequent washing of the polymeric rod with sodium hydroxide rendered a porous monolith that was used for both micro-LC and capillary electrochromatography. The novelty of the approach presented herein lies in preparing the polymer within the confines of a fused-silica capillary. The challenges posed in this new context and their resolution are presented in detail. In addition, this study proposes that in addition to tailoring the pore size, the silica beads, through their surface chemistry, can influence the surface characteristics of the finished polymer monolith. For example, the data suggests that octadecyl modified silica particles interacted with hydrophobic moieties of monomers before initiation of polymerization, thus dictating their orientation in the resulting polymer. (C) 2001 Elsevier Science B.V. All rights reserved.