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Titolo:
Patterned block-copolymer-silica mesostructures as host media for the laser dye rhodamine 6G
Autore:
Wirnsberger, G; Yang, PD; Huang, HC; Scott, B; Deng, T; Whitesides, GM; Chmelka, BF; Stucky, GD;
Indirizzi:
Univ Calif Santa Barbara, Dept Chem, Santa Barbara, CA 93106 USA Univ Calif Santa Barbara Santa Barbara CA USA 93106 Barbara, CA 93106 USA Univ Calif Santa Barbara, Dept Chem Engn, Santa Barbara, CA 93106 USA UnivCalif Santa Barbara Santa Barbara CA USA 93106 Barbara, CA 93106 USA Harvard Univ, Dept Chem & Chem Biol, Cambridge, MA 02138 USA Harvard UnivCambridge MA USA 02138 & Chem Biol, Cambridge, MA 02138 USA
Titolo Testata:
JOURNAL OF PHYSICAL CHEMISTRY B
fascicolo: 27, volume: 105, anno: 2001,
pagine: 6307 - 6313
SICI:
1520-6106(20010712)105:27<6307:PBMAHM>2.0.ZU;2-8
Fonte:
ISI
Lingua:
ENG
Soggetto:
MESOPOROUS MOLECULAR-SIEVES; AMPLIFIED SPONTANEOUS EMISSION; SOL-GEL GLASSES; THIN-FILMS; ORGANIC-MOLECULES; SOFT LITHOGRAPHY; METAL-OXIDES; SURFACTANT; POLYMER; FIBERS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
57
Recensione:
Indirizzi per estratti:
Indirizzo: Stucky, GD Univ Calif Santa Barbara, Dept Chem, Santa Barbara, CA 93106 USA Univ Calif Santa Barbara Santa Barbara CA USA 93106 93106 USA
Citazione:
G. Wirnsberger et al., "Patterned block-copolymer-silica mesostructures as host media for the laser dye rhodamine 6G", J PHYS CH B, 105(27), 2001, pp. 6307-6313

Abstract

Rhodamine 6G-doped mesostructured silica is prepared by an acidic sol-gel route using poly-b-poly(propylene oxide)-b-poly(ethylene oxide) (EOx-POy-EOx) block copolymer surfactants. Using low-refractive-index (n similar to 1.2) mesoporous SiO2 as a support, the synthesis is combined with soft lithography to produce high-quality waveguides. This enables efficient waveguiding in the line-patterned rhodamine 6G-doped mesostructured domains, which have a higher refractive index than both the mesoporous support and cladding. For the structure-directing block copolymer surfactants used, (EO)(20)(PO)(70)(EO)(20) (P123) and (EO)(106)(PO)(70)(EO)(106)(F127), X-ray diffractionpatterns and transmission electron microscopy reveal hexagonal mesophases,whose longitudinal cylinder axes are aligned predominantly parallel to thesubstrate plane. For samples made by micromolding-in-capillaries (MIMIC), the longitudinal axes are also aligned along the longitudinal waveguide axes. Samples made by micromolding also possess a high mesostructural order, though in the absence of an aligning flow field, their long-range order (ca.several hundred nanometers) is lower than for samples processed using the MIMIC technique. When optically pumped, the rhodamine 6G-doped waveguides exhibit amplified spontaneous emission with thresholds as low as similar to6kW cm(-2), substantially lower than rhodamine 6G-doped sol-gel glasses. This is attributed to the ability of the polymeric surfactant to coassemble with the dye molecules, thereby leading to high dye dispersions and reduced dye dimerization. Additionally, rhodamine 6G shows good photostability in the mesostructured waveguides, similar to that of rhodamine 6G in organically modified silicates.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 28/03/20 alle ore 22:44:43