Materials for capillary electrochromatography: Study of fluoropolymer particles and silica-based sol-gel glass composites.

摘要

Capillary electrochromatography (CEC) is a microseparation technique that involves the use of electroosmosis rather than pressure to transport the mobile phase across the capillary column. Stationary phases used in this technique involve mainly reverse-phase silica-based materials. As an alternative for certain chromatographic applications, we have explored the use of a fluoropolymer as the stationary phase. In order to impart a different selectivity to the fluoropolymer particles, we modified their surface using radio frequency glow discharge (rfgd) plasma, followed by silanization. These particles were characterized using Electron Spectroscopy for Chemical Analysis (ESCA).; Another type of stationary phases that has been used for CEC include silica-based sol-gel glass composites. We performed surface analysis of sol-gel glass films which were prepared by sol-gel processing, using tetraethoxysilane (TEOS), n-octyltriethoxysilane (C₈-TEOS), and n-octadecyltriethoxysilane (C₁₈-TEOS) as precursors. The films studied include pure TEOS, and hybrids of this one with the other precursors. The surface analysis techniques used for this study were ESCA and Scanning Electron Microscopy (SEM).