Organic solid-state distributed feedback dye laser with a nonmorphological modification grating

This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in APPLIED PHYSICS LETTERS. 77(17):2641-2643 (2000) and may be found at https://doi.org/10.1063/1.1320034 .ArticleAPPLIED PHYSICS LETTERS. 77(17):2641-2643 (2000)journal articl

<Preliminary>Biomimetic Oxidation of β-O-4 Lignin Model Compound with tert-Butylhydroperoxide and Fe(III)-Octacarboxyphthalocyanine

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました

Fabrication of Helical Mesoporous Silica Nanostructures Using Gelators and the Mixtures with CTAC

Two chiral hydrogelators, L-18ValPyBr and D-18ValPyBr, composed of L- or D-valine, were synthesized. They self-assembled into thin membranes under high concentration and helical nanofibers under low concentration in pure water. Sol-gel transcription reactions were carried out under both acidic and basic conditions using the self-assemblies of these two gelators and the mixtures with CTAC as templates and TEOS as precursor. Under acidic conditions, minimum gel concentrations of L-18ValPyBr and D-18ValPyBr are very low. After sol-gel polymerization, a kind of cotton-like silica constructed by twisted mesoporous silica ribbons was obtained. These ribbons were 60 nm in width and 10 nm in thickness. Under basic conditions, both mesoporous twisted ribbons and nanotubes constructed by tightly coiled ribbons were obtained. Generally, left-handed helical structures were obtained by using L-18ValPyBr, while right-handed helical structures were obtained by using D-18ValPyBr. The morphologies were sensitive to the concentration of NH(3). When the concentration of NH(3) was 2.5 wt%, twisted ribbons were obtained. When the concentration of NH(3) was higher than 5.0 wt%, nanotubes constructed by tightly coiled ribbons were obtained. Mesoporous silica structures in nano- and micro-size were prepared by using the mixtures of L-18ValPyBr and CTAC under both acidic and basic conditions. Under acidic conditions, helical mesoporous fibers were obtained, and their diameter was increased with increasing the ratio of CTAC to gelator. The nanofibers obtained under basic conditions were shorter than those obtained under acidic conditions. The mesoporous channels were parallel each other and running along the axis of nanofibers.ArticleSen'i Gakkaishi. 65(2):80-87 (2009)journal articl