Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1211438 | Journal of Chromatography A | 2006 | 11 Pages |
Abstract
Highly ordered morphological features were characterized for molecular dynamics simulated alkyl-modified silica models that represent chromatographic materials with enhanced shape recognition capability. Deep cavities (8-10Â Ã
wide) within the alkyl chains were identified for C18 polymeric models corresponding to shape-selective RPLC stationary phases. The all-trans conformational distal-end segments of these isolated cavities averaged over a 100Â ps simulation time interval were observed to increase (up to 15Â Ã
) in models with an increase in both surface coverage and corresponding shape selectivity. Similar-structure cavities with significant alkyl chain ordered regions (>11Â Ã
) were isolated from two independent C18 models (differing in bonding chemistry, density and temperature) that represent highly shape-selective materials. The size and depth of these ordered regions increased (up to 28Â Ã
) for the extended-length C30 alkyl phase models. These initial results offer a physical representation of alkyl-modified surfaces that may facilitate the identification of potential molecular features that may be involved in the shape-selective retentive processes, as well as illustrating the potential for such computational techniques to predict the molecular recognition capabilities of novel analyte-specific sorbents.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Katrice A. Lippa, Lane C. Sander,