Photochromic
Mostrando 1-12 de 21 artigos, teses e dissertações.
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1. Effects of the Peripheral Heteroaryl Substituents on the Photochromism of New Pyridine-Containing Diarylethenes
Three new unsymmetrical pyridine-containing diarylethenes with a variable peripheral heteroaryl unit were synthesized and their structures were determined by single-crystal X-ray diffraction analysis. The substituent effects of variable heteroaryl groups on the photochromic and fluorescence properties were systematically discussed. Thienyl and thiazyl could
J. Braz. Chem. Soc.. Publicado em: 2016-11
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2. The Effect of Ormosil Matrix Composition and Alkaline Earth Metal Doping on the Photochromic Response of Ormosil-Phosphotungstate Films
In this study, polyoxometallate based hybrid photochromic materials were prepared by incorporating phosphotungstate anion, PW12O403−, (PW) in hybrid tetraethyl orthosilicate and (3-glycidyloxypropyl)trimethoxysilane TEOS-GPTMS derived organomodified silicates (Ormosil) matrices by sol-gel method and the resulting materials were used to prepare multilayer f
J. Braz. Chem. Soc.. Publicado em: 2015-12
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3. Nanopartículas de dióxido de titânio como aditivos em materiais híbridos orgânico-inogânico fotocrômicos baseados em fosfotungstatos / Titanium dioxide nanoparticles as an additive for photochromic hybrid organic-inorganic materials based on phosphotungstate
Nesse estudo procurou-se avaliar o impacto do aditivo dióxido de titânio, mistura anatase-rutila, no comportamento fotocrômico de nanocompósitos baseados em materiais híbridos do tipo silicatos orgânicos (Ormosis) contendo ácido fosfotúngstico, \ H IND.3\ PW IND.12\ O IND.40\ . O material híbrido foi obtido via processo sol-gel tendo sido caracteriz
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 04/02/2011
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4. Estudo de complexos fotocrômicos de xerogéis de ormosil através de ressonância magnética nuclear em estado sólido / Photochromic Complexes of Ormosil Xerogels Studied by Solid-State Nuclear Magnetic Resonance
Fotocromismo refere-se ao fenômeno reversível no qual um material altera sua coloração quando irradiado com luz. Neste trabalho, é analisada a estrutura de materiais híbridos formada por poliânions de ácido 12-tungstofosfórico (H3PW12O40, HPW) HPW) inseridos em uma matriz de silicatos orgânico-inorgânica (ormosil). Estes materiais apresentam ativi
Publicado em: 2009
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5. SÃntese, caracterizaÃÃo e propriedades fotocrÃmicas da sais derivados do Ãcido N-(3,5-dinitrobenzoil)-α-fenilglicina
The preparation and characterization of salts derived from N-(3,5- dinitrobenzoyl)-α-phenylglycine was carried out by using protonated amines as counter-ion, as follows: NH4 + (DNBAm), (CH3-CH2-)2NH2 + (DNBD), (CH3-CH2-CH2- )NH3 + (DNBP), (CH3-CH2-CH2-CH2-)NH3 + (DNBBu) and (CH3-CH2-)3NH+ (DNBT). These salts showed photocromic effect with ultraviolet (U
Publicado em: 2008
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6. Efeito da matriz no comportamento fotocrômico de ormosils de fosfotungstato / Matriz effect in photochromic behavior of phosphotungstate ormosils
Esta dissertação versa sobre o estudo de filmes híbridos orgânicos-inorgânicos do tipo ormosil com heteropoliânions do tipo Keggin. O heteropoliânion usado nesse trabalho foi: H3PW12O40 enquanto o ormosil foi obtido a partir do processo sol-gel usando tetraetilortossilicato (TEOS) como agente formador da rede 3D de silicatos e organossilanos contendo
Publicado em: 2008
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7. Estudo do comportamento fotocrómico de um naftopirano: uma experiência simples ilustrativa do fotocromismo
An easy experiment on the synthesis of 3,3-diphenyl-3H-naphtho[2,1-b]pyran and characterization of its photochromic behaviour is reported. Upon irradiation of an uncoloured toluene solution of 3,3-diphenyl-3H-naphtho[2,1-b]pyran with near UV light, an intense yellow colouration is produced due to the formation of two coloured open forms. When the irradiation
Química Nova. Publicado em: 2006-06
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8. Fotocromismo em filmes finos de óxidos de tungstênio de diferentes composições
Tungsten oxide thin films with three different compositions were deposited by reactive sputtering in an oxygen-argon plasma. In a system composed of a home made photochemical reactor coupled with an optic fiber spectrophotometer, the photochromic effect was studied in these oxide films as function of UV irradiation time, in ethanol, methanol and formaldehyde
Química Nova. Publicado em: 2003-08
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9. Nonvolatile read-out molecular memory
A versatile molecule is described that performs as a nondestructible read-out optical-storage molecular memory. This molecular memory is composed of two distinct molecules that are chemically bonded to each other to form a single molecule with unique properties. One component is a photochromic fulgimide, and the other is a strongly fluorescing oxazine dy
National Academy of Sciences.
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10. Photoregulation of Biological Activity by Photochromic Reagents, IV. A Model for Diurnal Variation of Enzymic Activity*
Levels of acetylcholinesterase activity can be made to vary in response to the presence or absence of sunlight in a system that can be considered as a model for photoperiodic processes found in nature. The enzyme is rendered photosensitive by the presence of a photochromic inhibitor, N-p-phenylazophenylcarbamyl choline, which changes from a trans to a cis is
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11. PHOTOREGULATION OF BIOLOGICAL ACTIVITY BY PHOTOCROMIC REAGENTS, II. INHIBITORS OF ACETYLCHOLINESTERASE*†
The enzymic activity of acetylcholinesterase can be photoregulated through the mediation of photochromic inhibitors of the enzyme. N-p-phenylazophenyl-N-phenylcarbamyl fluoride, an irreversible inhibitor of acetylcholinesterase, exists as two geometric isomers which are interconvertible through the action of light. The cis isomer, which predominates after ex
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12. PHOTOREGULATION OF BIOLOGICAL ACTIVITY BY PHOTOCHROMIC REAGENTS, III. PHOTOREGULATION OF BIOELECTRICITY BY ACETYLCHOLINE RECEPTOR INHIBITORS*
The photochromic compounds N-p-phenylazophenyl-N-phenylcarbamylcholine chloride and p-phenylazophenyltrimethylammonium chloride inhibit the carbamylcholine-produced depolarization of the excitable membrane of the monocellular electroplax preparation of Electrophorus. The trans isomer of each predominates in the light of a photoflood (420 mμ) lamp; they are