Abstract

<i>n</i>-Octadecyltriethoxysilane (C₁₈-TEOS) and tetraethoxysilane (TEOS) were used as the precursors to fabricate an organic-inorganic hybrid composite by sol-gel processing. The hydrolysis and initial condensation reactions of TEOS and C₁₈-TEOS/TEOS mixtures were studied by ²⁹Si-NMR spectroscopy. The rate of disappearance of the silane precursors and the evolution of the various silicon species during the reaction indicate that TEOS hydrolyzes and condenses faster than C₁₈-TEOS. The rate of hydrolysis for C₁₈-TEOS, however, increases when reacting in the C₁₈-TEOS/TEOS hybrid mixture, indicating that the condensation reactions involving TEOS species drive the reaction of C₁₈-TEOS. The formation of cross-condensed products leads to the composite with octadecyl groups incorporated into the final glass material. The maximum degree of condensation in the C₁₈-TEOS/TEOS mixture was observed after 2 h of reaction. Fused-silica capillary columns were coated with the C₁₈-TEOS/TEOS mixture while in its liquid-like stage. After drying, the columns were tested for open tubular capillary electrochromatography (OT-CEC). Coating of the columns was performed after the maximum degree of condensation was achieved, which has been shown to correlate with maximum chromatographic retention.

Photo-patternable GeO₂-contained organic-inorganic hybrid sol-gel films for photonic applications

Wenxiu Que, C. Y. Jia, M. Sun, Z. Sun, L. L. Wang, and Z. J. Zhang
Opt. Express 16(6) 3490-3495 (2008)

Sol-gel co-assembly of hollow cylindrical inverse opals and inverse opal columns

Ni Haibin, Wang Ming, and Chen Wei
Opt. Express 19(27) 25900-25910 (2011)

Single-step fabrication of continuous surface relief micro-optical elements in hybrid sol-gel glass by laser direct writing

W. X. Yu, X. -C. Yuan, N. Q. Ngo, W. X. Que, W. C. Cheong, and V. Koudriachov
Opt. Express 10(10) 443-448 (2002)

Synthesis of titania- and silica-polymer hybrid materials and their application as refractive index-matched layers in touch screens

A-Ra Cho and Soo-Young Park
Opt. Mater. Express 5(4) 690-703 (2015)

Characterization of thermo-optic coefficient and material loss of high refractive index silica sol-gel films in the visible and near-IR

Brian A. Rose, Ashley J. Maker, and Andrea M. Armani
Opt. Mater. Express 2(5) 671-681 (2012)