Silica monoliths templated on L-3 liquid crystal

Publication Year
2006

Type

Journal Article
Abstract
Dimensionally stable, optically clear, highly porous (similar to 65% of the apparent volume), and high surface area (up to 1400 m(2)/g) silica monoliths were fabricated as thick disks (0.5 cm) by templating the isotropic liquid crystalline L-3 phase with silica through the hydrolysis and condensation of a silicon alkoxide and then removing the organic constituents by supercritical ethanol extraction. The L3 liquid crystal is a stable phase formed by the cosurfactants cetylpyridinium chloride monohydrate and hexanol in HCl(aq) solvent. Extracted 0.5 cm thick disks exhibited a low ratio of scattered to transmitted visible light (1.5 x 10(-6) at 22 from the surface normal). The degree of silica condensation in the monoliths was high, as determined by Si-29 NMR measurements of Q(3) and Q(4) peak intensities (0.53 and 0.47, respectively). As a result, the extracted and dried monoliths were mechanically robust and did not fracture when infiltrated by organic solvents. Photoactive liquid monomers were infiltrated into extracted silica monoliths and polymerized in situ, demonstrating the possible application of templated silica to optical storage technology.
Journal
Langmuir
Volume
22
Pages
325-331
Date Published
01/2006
Type of Article
Article
ISBN
0743-7463
Accession Number
WOS:000234410300052