Optically Induced Birefringence
Mostrando 1-8 de 8 artigos, teses e dissertações.
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1. Estudo e aplicações do fenômeno de absorção de dois fótons em moléculas azo-aromáticas / Studies and applications of two-photon absorption in azo-aromatic molecules
Here we investigated fundamental and applied aspects of the two-photon absorption process in azoaromatic compounds. Azoaromatic molecules have been studied in the last few years due to their applications in optical storage devices, light modulators and surface relief gratings, processes related to the photo-isomerization mechanism. The main focus of the resu
Publicado em: 2007
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2. "Caracterização estrutural e óptica de elastômeros dopados com ferrofluidos" / Optical and Structural Characterization of Elastomers Dopeds with Ferrofluids
This work aims the structural, mechanical and optical characterization of urethane/urea elastomers (PU/PBDO), based on polypropylene oxide and polybutadiene diol, pure, after swelling in toluene and doped with ferrofluid. The ratios in weight % of PU and PBDO used are 40/60, 50/50, 60/40 and 80/20. The structural analysis were made through of polarized light
Publicado em: 2007
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3. "One and two-photon induced birefringence in Salen dye cast films" / "Estudo da birrefringência fotoinduzida por um e dois fótons em compostos azoaromáticos da família salen".
In this work we present the one- and two-photon optically induced birefringence in cast films of amorphous poly(methyl methacrylate) (PMMA), containing a new series of organometallic azoaromatic compounds, referred to as Salen dyes, which may be used in optical storage applications. For the one-photon optically induced birefringence, longer writing times wer
Publicado em: 2005
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4. Study of photoinduced birefrigence, in layer-by-layer films containing azopolymer and azodye / Estudo de birrefrigência fotoinduzida em filmes automontados de azopolímeros e azocorantes
This work was aimed at investigating the influence of the molecular architecture and film fabrication on the photoinduced birefi-ingence of layer-by-layer (LbL) films containing the azopolymer PS 119® or the azodye Brylliant Yellow (BY) as photoreactive materials. The LbL films were produced with six polications, viz.: poly(allylamine hydrochloride) (PAH),
Publicado em: 2005
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5. Optical storage properties in cast films of an azopolymer
In this paper we discuss the properties of optically induced birefringence in DR19-MDI cast films that may be used in optical storage applications. The selection of DR19-MDI cast films was based on a comparative study of optical storage properties of Langmuir-Blodgett (LB) films from various azopolymers. DR19-MDI possesses a high residual fraction of optical
Materials Research. Publicado em: 2003-06
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6. Estudo das propriedades de armazenamento óptico e grades de relevo em poliuretano derivado de azo-benzeno / Information optically storage and relief gratings study in material derivative of azo-benzene polyrethane
Polymers containing azobenzenic groups have been studied due to their applications on non-linear optics, surface relief gratings (SRG) and photoinduced anisotropy for optical storage. The reversal photoisomerization trans-cis-trans property of the azo group induces a molecular reorientation. In this work, cast films of na azobenzene derivative, the polyureth
Publicado em: 2003
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7. Polymeric nanocomposites containing azodyes, phthalocyanines and luminescent polymers / Compósitos poliméricos nanoestruturados de azocorantes,ftalocianinas e polímeros luminescentes
This thesis describes the fabrication and possible applications of layer-by-Iayer (LBL) nanostructured films for three distinct systems comprising i) azopolymers and azodyes, ii) organometallic molecules (phthalocyanines) and iii) luminescent polymers and azodyes. Optically induced birefringence and surface relief gratings (SRGs) were studied in the azobenze
Publicado em: 2003
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8. Internal structural anisotropy of spherical viruses studied with magnetic birefringence.
Six so called spherical viruses (four plant and two animal) are shown to exhibit magnetically induced birefringence in solution. They must therefore be magnetically and optically anisotropic. This is attributed to static structural anisotropy of the interiors as neither natural shape nor field-induced deformations are likely causes. Thus at least part of the