Dimensionally stable, optically clear, highly porous (∼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 L 3 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 × 10 -6 at 22° from the surface normal). The degree of silica condensation in the monoliths was high, as determined by 29Si 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.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Surfaces and Interfaces