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Tryptophan photooxidation promoted by new hybrid materials prepared by condensation of naphthalene imides with silicate by the sol-gel process

TRIBONI, Eduardo R.; CAVALHEIRO, Carla C. Schmitt; POLITI, Mario J.; BEMQUERER, Marcelo P.; RODRIGUES, Magali A.
Fonte: ELSEVIER SCIENCE SA Publicador: ELSEVIER SCIENCE SA
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
713.2012%
Three novel hybrid organic/inorganic materials were synthesized from 4-substituted (NO(2), Br, H) 1,8-naphthalene imide-N-propyltriethoxysilane by the sol-gel process. These materials were obtained as a xerogel and partially characterized. The ability to photosensitize the oxidation and degradation of tryptophan indole ring by these materials was studied through photophysical and photochemical techniques. Although the derivatives containing Br and NO(2) as substituent do not cause efficient tryptophan photodamage, the hybrid material obtained from 1,8-naphthalic anhydride is very efficient to promote tryptophan photooxidation. By using laser flash photolysis it was possible to verify the presence of naphthalene imide transient radical species. The presence of oxygen causes an increase of the yield of radical formation. These results suggest that the mechanism of photodegradation of tryptophan occurs by type I, i.e. the transient radical (TrpH(center dot+)) formed by the direct reaction of the triplet state of the naphthalene imide moiety with tryptophan. Thus a inorganic-organic hybrid material that can be used to promote the oxidation of biomolecules was obtained. (C) 2009 Elsevier B.V. All rights reserved.; FAPESP[04/15069-7]; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); CAPES; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); CNPq

Self-supported bacterial cellulose/boehmite organic-inorganic hybrid films

De Salvi, Denise T. B.; Barud, Hernane S.; Caiut, Jose Mauricio A.; Messaddeq, Younes; Ribeiro, Sidney J. L.
Fonte: SPRINGER; DORDRECHT Publicador: SPRINGER; DORDRECHT
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
707.10875%
Self-supported organic-inorganic hybrid transparent films have been prepared from bacterial cellulose and boehmite. SEM results indicate that the BC membranes are covered by Boehmite and XRD patterns suggest structural changes on cellulose due to Boehmite addition. Thermal stability is accessed through TG curves and is dependent on Boehmite content. Transparency, as evaluated by UV-Vis absorption, increases with increasing content of boehmite suggesting application of these materials as transparent substrates for opto-electronic devices.; Brazilian agency FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo); Brazilian agency Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP); Brazilian agency CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico); Brazilian agency CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico); Brazilian Agency: CAPES (Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior); Brazilian agency CAPES (Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior)

Enhanced emission from Eu(III) beta-diketone complex combined with ether-type oxygen atoms of di-ureasil organic-inorganic hybrids

Molina, C.; Dahmouche, K.; Messaddeq, Y.; Ribeiro, SJL; Silva, MAP; Bermudez, V. D.; Carlos, L. D.
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 93-101
ENG
Relevância na Pesquisa
702.54734%
Organic-inorganic hybrids, named di-ureasils and described by polyether-based chains grafted to both ends to a siliceous backbone through urea cross linkages, were used as hosts for incorporation of the well-known coordination complex of trivalent europium (Eu3+) ions described by the formula [Eu(TTA)(3)(H2O)(2)] (where TTA stands for thenoyltrifluoroacetone). By comparing with Eu3+-doped di-ureasil without complex form the new materials prepared here enhanced the quantum efficiency for photoemission of Eu3+ ions. The enhancement can be explained by the coordination ability of the organic counterpart of the host structure which is strong enough to displace water molecules in [Eu(TTA)(3)(H2O)(2)] from the rare earth neighbourhood after the incorporation process. High intensity of Eu3+ emission was observed with a low non-radiative decay rate under ultraviolet excitation. The quantum efficiency calculated from the decay of D-5(0) emission was 74%, which in the same range of values previously obtained for the most efficient Eu3+ coordination compounds reported in literature. Luminescence, X-ray absorption and infrared absorption results considered together leads to a picture where the first coordination shell of Eu3+ is composed of the 6 oxygen atoms of the 3 beta-diketonate ligands and 2 ether-like oxygen atoms of the host. (C) 2003 Elsevier B.V. B.V. All rights reserved.

Organic-inorganic hybrid coatings for corrosion protection of galvanized steel and electroplated ZnFe steel

Souza, M. E. P.; Ariza, E.; Ballester, M.; Yoshida, I. V. P.; Rocha, L. A.; Freire, C. M. A.
Fonte: Associação Brasileira de Metalurgia e Materiais [etc.] Publicador: Associação Brasileira de Metalurgia e Materiais [etc.]
Tipo: Artigo de Revista Científica
Publicado em /05/2005 ENG
Relevância na Pesquisa
715.84%
The development of hybrids materials by the sol-gel process has been extensively investigated in recent years. The combination a wide variety of compositions and production processes had permit the use of these materials in different applications like coatings for corrosion protection of metals and abrasion resistant coatings. In this work organic-inorganic hybrid materials have been prepared from the hydrolysis of tetraethylorthosilicate (TEOS) and silanol-terminated polidymetilmetoxysilane (PDMS) using a sol-gel process. The composition evaluated was 50% TEOS- 50% PDMS. These materials have been applied on galvanized steel and on steel electroplated with a ZnFe alloy. In order to evaluate the degradation behaviour of these coatings, electrochemical techniques were used. They consisting in the monitoring of the open-circuit potential (Ecorr), and in the realization of potentiodynamic polarization measurements of the samples, which was performed in a 3% NaCl aqueous solution. Additionally, electrochemical impedance spectroscopy (EIS) was used as a complementary technique for the evaluation of the corrosion mechanisms of the coating system. The surface of the samples, before and after the electrochemical tests, have been inspected by SEM and EDS. EIS data was fitted to an equivalent circuit from which the electrochemical parameters were obtained. Results show a good protective character of the hybrid films...

Organic-inorganic hybrid coatings for corrosion protection of galvanized steel and electroplated znfe steel

Souza, M. E. P.; Ariza, E.; Ballester, M.; Yoshida, I. V. P.; Rocha, L. A.; Freire, C. M. A.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em //2004 ENG
Relevância na Pesquisa
713.5191%
The development of hybrids materials by the sol-gel process has been extensively investigated in recent years. The combination a wide variety of compositions and production processes had permit the use of these aterials in different applications like coatings for corrosion protection of metals and abrasion resistant coatings. In this work organic-inorganic hybrid materials have been prepared from the hydrolysis of tetraethylorthosilicate (TEOS) and silanol-terminated polidymetilmetoxysilane (PDMS) using a sol-gel process. The composition evaluated was 50% TEOS- 50% PDMS. These materials have been applied on galvanized steel and on steel electroplated with a ZnFe alloy. In order to evaluate the degradation behaviour of these coatings, electrochemical techniques were used. They consisting in the monitoring of the open-circuit potential (Ecorr), and in the realization of potentiodynamic polarization measurements of the samples, which was performed in a 3% NaCl aqueous solution. Additionally, electrochemical impedance spectroscopy (EIS) was used as a complementary technique for the evaluation of the corrosion mechanisms of the coating system. The surface of the samples, before and after the electrochemical tests, have been inspected by SEM and EDS. EIS data was fitted to an equivalent circuit from which the lectrochemical parameters were obtained. Results show a good protective character of the hybrid films...

Preparation and characterization of novel highly omniphobic cellulose fibers organic-inorganic hybrid materials

Cunha, Ana G.; Freire, Carmen S.R.; Silvestre, Armando J.D.; Neto, Carlos Pascoal Neto; Gandini, Alessandro
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
714.4498%
This paper reports the preparation of class-II organic-inorganic hybrid materials by the heterogeneous chemical modification of cellulose fibers with (3-isocyanatopropyl)triethoxysilane, followed by the acid hydrolysis (and condensation) of the appended siloxane moieties as such, and in the presence of either tetraethoxysilane or 1H,1H,2H,2H-perfluorodecyltriethoxysilane. These modifications produced an inorganic "coating" around the fibers, while preserving their ultrastructure, as confirmed by XRD and SEM. The detailed characterization of these new hybrid materials by FTIR and (29)Si NMR showed that, upon hydrolysis of the ethoxy groups, condensation reactions took place leading mainly to Si-O-Si linear sequences, followed by a smaller contribution of more branched moieties, and that a significant amount of OH groups were also formed, which gave rise to hydrophilic surfaces. The hybrids obtained by hydrolysis in the presence of 1H,1H,2H,2H-perfluorodecyltriethoxysilane displayed a very pronounced hydrophobic and lipophobic character (reaching contact angles with water and diiodomethane as high as 140 degrees and 134 degrees, respectively), due to the presence of the perfluorinated moieties. (C) 2010 Elsevier Ltd. All rights reserved.; FCT - SFRH/BD/31134/2006; FCT - National Program for Scientific re-equipment; Rede/1509/RME/2005; REEQ/515/CTM/2005

Hybrid organic-inorganic materials: application in oxidative catalysis

Rocha, G M S R O
Fonte: Nova Science Publishers Publicador: Nova Science Publishers
Tipo: Parte de Livro
ENG
Relevância na Pesquisa
1019.4095%
Oxidative catalysis has been and will be playing an important role in the production of large quantities of intermediates. This technology has a great potential for improvement and this has led to a series of better processes, including the development of a great diversity of suitable catalysts. Within these compounds, metal phosphates and phosphonates possessing layered and pillared structures were found to constitute a very good alternative as catalysts to be used in oxidative catalysis. Metal phosphates and phosphonates can be considered as strong inorganic solid acids and much of their catalytic activity has been attributed to the Brønsted acidity of the interlayered hydroxyl groups and to the Lewis acidity of the metal center. Metal phosphates and phosphonates can be obtained at low temperatures, in aqueous media, using soft chemical routes and their preparation is quite accessible if the correct phosphonic acids and phophates are available. These heterogeneous materials are very interesting from the economical as well as from the environmental points of view because of the high yields and short reaction times, easy recovery from the reaction mixtures and the possibility to perform reactions in solvent-free conditions. Due to their particular physical and chemical properties and high versatility...

Thin film optimization design of organic-inorganic hybrids for waveguide high-rejection optical filters

Vicente, Carlos M. S.; Venkatachaam, Ramkanna; Ferreira, Bruno M.; Marques, Paulo G.; Marques, Carlos A. F.; Pecoraro, Edison; Carlos, Luis D.; André, Paulo S.; Ferreira, Rute A. S.
Fonte: Universidade de Aveiro Publicador: Universidade de Aveiro
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
706.1168%
We report the fabrication of transparent, low surface roughness (<0.1 nm), and low-loss (1.5 +/- 0.2 dB cm (1), 532 nm) thin films of organic-inorganic hybrids with controlled refractive index values stable under aging. High-rejection optical filters based on first-order Bragg gratings inscribed in channel waveguides were fabricated using UV-laser writing. Their high-rejection figure of merit (similar to 24 dB) is the best value found until now for organic inorganic hybrids reinforcing the potential of sol gel technology in the integration of optoelectronic components based on hybrid materials, namely in the fabrication of cost-effective integrated optics devices. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Synthesis and characterization of organic-inorganic hybrids formed between conducting polymers and crystalline antimonic acid

Beleze,Fábio A.; Zarbin,Aldo J. G.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2001 EN
Relevância na Pesquisa
710.8802%
In this paper we report the synthesis and characterization of novel organic-inorganic hybrid materials between the crystalline antimonic acid (CAA) and two conductive polymers: polypyrrole and polyaniline. The hybrids were obtained by in situ oxidative polymerization of monomers by the Sb(V) present in the pyrochlore-like CAA structure. The materials were characterized by infrared and Raman spectroscopy, X-ray diffraction, cyclic voltammetry, CHN elemental analysis and electronic paramagnetic resonance spectroscopy. The results showed that both polymers were formed in their oxidized form, with the CAA structure acting as a counter anion.

Characterization of organic-inorganic hybrid coatings for corrosion protection of galvanized steel and electroplated ZnFe steel

Souza,Maria Eliziane Pires de; Ariza,Edith; Ballester,Margarita; Yoshida,Inez Valéria Pagotto; Rocha,Luis Augusto; Freire,Célia Marina de Alvarenga
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2006 EN
Relevância na Pesquisa
713.2012%
The development of hybrids materials has been extensively investigated in recent years. The combination of a wide variety of compositions and production processes had permitted the use of these materials in different applications like coatings for corrosion protection of metals. In this work organic-inorganic hybrid materials have been prepared from the hydrolysis of tetraethylorthosilicate and silanol-terminated polidymetilmetoxysilane using a sol-gel process. These materials have been applied on galvanized steel and on steel electroplated with a ZnFe. In order to evaluate the degradation behavior of these coatings, electrochemical techniques (Electrochemical Impedance Spectroscopy and Potentiodynamic Polarization) were used. EIS data was fitted to an equivalent circuit from which the electrochemical parameters were obtained. Results show a good protective character of the hybrid films, when compared with uncovered specimens. The overall performance of the coating systems appears to be highly dependent on the kind of metallic coating applied to the steel.

Preparation of sol-gel hybrid materials from gamma-methacryloxypropyltrimethoxysilane and tetramethyl orthosilicate: study of the hydrolysis and condensation reactions

El Hadad, Amir; Carbonell, Diógenes; Barranco, V.; Jiménez Morales, Antonia; Casal, Blanca; Galván Sierra, Juan Carlos
Fonte: Springer Publicador: Springer
Tipo: info:eu-repo/semantics/submittedVersion; info:eu-repo/semantics/article Formato: application/pdf
Publicado em 01/12/2011 ENG
Relevância na Pesquisa
700.7917%
Organic-inorganic hybrid materials suitable for the development of sol&-gel coatings for metallic surfaces were prepared by hydrolysis and condensation of gamma-methacryloxypropyltrimethoxysilane (MAPTMS) and tetramethyl orthosilicate (TMOS). The hydrolysis of MAPTMS/TMOS was carried out in an ethanol/water solution. The prehydrolysis stage of MAPTMS/TMOS system was monitored by Fourier transform infrared spectroscopy (FTIR) and liquid-state 29Si and 13C nuclear magnetic resonance (29Si and 13C NMR). FTIR analysis indicated that the hydrolysis of MAPTMS/TMOS was accomplished as far as the (SiOMe) band corresponding to unhydrolyzed silane disappeared. The concentration of the alkoxy groups and the extent of self-condensation of mono-, di-, and trisubstituted siloxanes (T species) in the sol were estimated by using liquid-state 29Si NMR spectroscopy. The hydrolysis of the prepared sol was also evaluated by liquid-state 13C NMR spectroscopy. The results indicated that under the adopted synthesis strategy conditions, the hydrolysis process requires 4 h to be completed.; This work has been supported by the Ministry of Science and Innovation of Spain (Projects MAT2006-04486 and MAT2009-13530) and the Regional Community of Madrid (Project 2009/MAT-1585). AA El hadad acknowledges a predoctoral contract JAE financed by CSIC...

Triethylphosphite as a network forming agent enhances in-vitro biocompatibility and corrosion protection of hybrid organic-inorganic sol-gel coatings for Ti6Al4V alloys

El Hadad, Amir; Barranco, V.; Jiménez Morales, Antonia; Hickman, G. J.; Galván, J. C.; Perry, C. C.
Fonte: Royal Society of Chemistry Publicador: Royal Society of Chemistry
Tipo: info:eu-repo/semantics/acceptedVersion; info:eu-repo/semantics/article
Publicado em /10/2014 ENG
Relevância na Pesquisa
707.10875%
The biocompatibility and life of metallic implants can be enhanced through improving the biocompatibility and corrosion protection characteristics of the coatings used with these materials. In this study, triethylphosphite (TEP) was used to introduce phosphorus into organic-inorganic hybrid silica based sol-gel coatings prepared using gamma-methacryloxypropyltrimethoxysilane and tetramethylorthosilicate. Addition of TEP dramatically increased the rate of intermolecular condensation and resulted in materials showing greater cross-linking. Protein (fibrinogen) uptake, osteoblast in vitro biocompatibility and corrosion resistance was enhanced in coatings containing TEP. Although higher concentrations of phosphorus supported the greatest improvement in biocompatibility, a compromise in the phosphorus concentration used would be required if corrosion resistance was most desirable parameter for optimisation. Films prepared by dip coating on Ti6Al4V alloys from these sols offer a promising alternative to wholly metallic prostheses.; This work was supported by the Ministerio de Economía y Competitividad (Project MAT2012-30854).; In Press, Accepted Manuscript

Organic-inorganic hybrid materials towards passive and active architectures for the next generation of optical networks

Ferreira, Maria R.; Andre, Paulo; Carlos, Luís
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
707.10875%
The advances in optoelectronics over the last three decades have been quite dramatic, namely the mass manufacturing of low cost integrated circuits, revolutionizing the speed and the capability of computing and communication. However, today's ever-increasing demand for high-bandwidth data is outgrowing the performance of electronics in many applications, such as in telecommunications where the traffic demand has been increasing steadily and, therefore, the transmission technology requires bandwidth that exceeds the one provided by actual copper based networks. In this context, the fabrication of low-cost integrated optics (IO) devices using sol-gel derived organic-inorganic hybrid (OIH) materials has received increasing attention in the last years. This review will focus on examples of OIHs that can be used in IO devices for the next generation of optical networks. Emphasis will be given to passive (planar and channel waveguides, couplers and multimode interference splitters) and active (lasers and optical amplifiers) optical architectures for long haul/metro and access/indoor networks. (c) 2010 Elsevier B.V. All rights reserved.; FEDER; PTDC/CTM/72093/2006; PTDC/EEA-TEL/72025/2006; PTDC/CTM/101324/2008

Hybrid improper ferroelectricity in a Multiferroic and Magnetoelectric hybrid organic-inorganic perosvkite

Stroppa, Alessandro; Barone, Paolo; Jain, Prashant; Perez-Mato, Jean Manuel; Picozzi, Silvia
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 26/03/2014
Relevância na Pesquisa
720.1672%
There is great interest in hybrid organic-inorganic materials such as metal-organic frameworks (MOFs). The compounds [C(NH$_{2}$)$_{3}$]M(HCOO)$_{3}$, where M=Cu$^{2+}$ or Cr$^{2+}$ are Jahn-Teller (JT) active ions, are MOF with perovskite topology which crystallizes in polar space group Pna2$_{1}$. In inorganic compounds, octahedral tilting and Jahn-Teller structural distortions are usually non-polar distortions. However, in this MOF cooperative interactions between the antiferro-distortive distortions of the framework and the C(NH2)$_{3}$ organic cation via hydrogen bonding breaks the inversion symmetry and induces a ferroelectric polarization.[Angew. Chem. Int. Ed. 50, 5847, 2011] Our ab-initio study supports the picture of an orbital-order-induced ferroelectricity, a rare example of dipolar ordering caused by electronic degrees of freedom. The switching of polarization direction implies the reversal of the weak ferromagnetic component. The microscopic mechanism in this JT-based MOF with ABX$_{3}$ perovskite structure displays a Hybrid Improper Ferroelectric (HIF) state, arising from a trilinear coupling between different structural deformations that comprise tilting, rotations and Jahn-Teller distortions of both the BX$_{3}$ framework and the organic cation at the A sites. Since these distortion modes in perovskite-inorganic compounds usually freeze-in at elevated temperatures...

Chemical polymerization of polyaniline and polypyrrole by phosphomolybdic acid : In situ formation of hybrid organic-inorganic materials

Gómez-Romero, P.; Casañ Pastor, Nieves; Lira-Cantú, Monica
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 579917 bytes; image/jpeg
ENG
Relevância na Pesquisa
702.8206%
International Symposium on the Reactivity of Solids. - Texto completo disponible en la web del autor: http://www.cienciateca.com/PAni_PPy_PMo12_Chem_SSI_97_101_875.pdf; The oxidative polymerization of aniline or pyrrole by phosphomolybdic acid (H3PMo12O40) is described. These reactions take place in the absence of other anions and result in the incorporation of the photoactive and electroactive PMo12O403− anion into the lattice of the polymer. The resulting hybrid materials present the good conductivity and polymeric nature of the matrix plus the added electroactivity of the inorganic cluster, which is anchored in the polymer and not exchanged upon reduction. The hybrids can work as electrodes harnessing the electrochemical properties of the polyoxometalic clusters; This work was financed by DGICYT (Spain) (PB93-0122). We also thank the Ministry of Education and Science for a predoctoral fellowship (MECAECI) awarded to M.L.C. Partial support by the Generalitat de Catalunya is also acknowledged.; Peer reviewed

Hybrid organic–inorganic nanocomposite materials for application in solid state electrochemical supercapacitors

Gómez-Romero, P.; Chojak, Malgorzata; Cuentas Gallegos, A. K.; Asensio, Juan Antonio; Kulesza, Pawel J.; Casañ Pastor, Nieves; Lira-Cantú, Monica
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 579917 bytes; image/jpeg
ENG
Relevância na Pesquisa
707.10875%
Full-text version available Open Access at: http://www.cienciateca.com/SupercapPaniPmo12_Electrochem%20Comm_5_2003_149.pdf; Integration into a conducting polymer matrix to form a hybrid material is an effective way to harness the electrochemical activity of nanosized oxide clusters. By anchoring them into polyaniline, the reversible redox chemistry of the otherwise soluble polyoxometalate clusters can be combined with that of the conducting polymer and be put to work in energy storage applications. We present here preliminary results that show how the resulting hybrid polymer displays the combined activity of its organic and inorganic components to store and release charge in a solid state electrochemical capacitor device.; Partial financial support from the Ministry of Science and Technology (Spain) (Grants MAT2001-1709-C04-01 and MAT2002-04529-C03), and from the Domingo Martínez Foundation, as well as fellowships from the European Marie Curie Program (to M.C.), from the ministry of Education (Spain) (to J.A.A.) and from CONACYT (Mexico) (to K.C.G.) are gratefully acknowledged. P.J.K. and M.C. appreciate partial support from State Committee for Scientific Research (KBN), Poland (Grant 7 T09A 03120).; Peer reviewed

Obtención de nuevos materiales híbridos orgánico-inorgánicos fotosensibles utilizables como láseres de colorante en estado sólido; Synthesis of new photosensitive organic-inorganic hybrid materials used as solid state dye laser

García Ballesteros, Olga; Sastre Muñoz, Roberto; Costela González, Ángel; García-Moreno, Inmaculada; Gómez Hernández, M. Clara
Fonte: Sociedad Española de Cerámica y Vidrio Publicador: Sociedad Española de Cerámica y Vidrio
Tipo: Artículo Formato: 587125 bytes; application/pdf
SPA
Relevância na Pesquisa
729.3897%
[ES] La síntesis de nuevos materiales de carácter híbrido (orgánico-inorgánico) dopados con colorantes resultan altamente atractivos como medio activo en láseres de estado sólido ya que permiten combinar las excelentes propiedades térmicas que presentan los vidrios inorgánicos con las excelentes propiedades ópticas que presentan los materiales polímeros. Mediante un proceso simultaneo de policondensación sol-gel y de polimerización de la parte orgánica (monómero vinílico ó acrílico con grupos OH), de forma que los grupos –OH del monómero orgánico participen también en el proceso de policondensación, hemos conseguido obtener monolitos válidos para su aplicación como láseres de colorante en estado sólido. Se ha llevado a cabo la síntesis y caracterización de nuevas matrices híbridas incorporando pirrometeno 567 como colorante láser (PM567); combinando polímeros de metacrilato de 2-hidroxietilo (HEMA) y copolímeros de HEMA y metacrilato de metilo (MMA) con diferentes proporciones en peso respecto al componente inorgánico (TEOS). Los primeros resultados obtenidos con estos nuevos materiales demuestran que la presencia de pequeñas proporciones de TEOS en copolímeros de p(HEMA/MMA 1/1) aumentan la estabilidad térmica del colorante mejorando significativamente su acción láser. De hecho...

Hybrid materials. Functional properties. From Maya Blue to 21st century materials

Gómez-Romero, P.; Sánchez, Clément
Fonte: Royal Society of Chemistry (Great Britain) Publicador: Royal Society of Chemistry (Great Britain)
Tipo: Artículo Formato: 808619 bytes; application/pdf
ENG
Relevância na Pesquisa
707.3509%
The field of hybrid organic-inorganic materials has reached a stage of ripeness that is beginning to make possible extraordinary new developments. On the one hand the field has witnessed a trend towards the design of functionality in hybrids materials, while broadening spectacularly the variety of hybrid combinations explored. On the other hand, improved understanding and control of the chemistry, processing and microstructure of these versatile nanocomposite systems announce a new landscape of opportunities in dealing with increasingly complex chemistries and materials.; Peer reviewed

Hybrid Nanocomposite Materials

Gómez-Romero, P.; Lira-Cantú, Monica
Fonte: John Wiley & Sons Publicador: John Wiley & Sons
Tipo: Capítulo de libro Formato: 579917 bytes; image/jpeg
ENG
Relevância na Pesquisa
733.1951%
In: Kirk-Othmer Encyclopedia of Chemical Technology; Hybrid organic–inorganic materials constitute a fast-growing field that has already led to a very large variety of materials and applications. These nanocomposite materials abound both with organic or inorganic matrices and represent oportunities to design eclectic materials by taking advantage of the best properties of their components. But the hybrid concept can even go beyond this approach by creating materials with novel structures or supramolecular architectures, with synergic properties, or even with activities impossible for the isolated components. This article is a general review of the field, discussing the different categories of materials according to their chemical nature and their applications as structural or functional materials. A variety of hybrids with organic matrics (most commonly polymers) are distinguished from these in which the dominating phase is inorganic (polymeric or extended in nature). To the category of silicon-based hybrids that predominated in the early literature a larger variety of hybrids has followed which includes, among many others, inorganic molecular species intergrated in organic polymers, perovskites built with organic and inorganic building blocks or polymer-inserted inorganic phases. All of them are categorized and discussed with emphasis on their many different applications and commercial developments.; Peer reviewed

Hybrid Organic-Inorganic Materials - In Search of Synergic Activity

Gómez-Romero, P.
Fonte: John Wiley & Sons Publicador: John Wiley & Sons
Tipo: Artículo Formato: 579917 bytes; image/jpeg
ENG
Relevância na Pesquisa
723.39984%
Full-text available Open Access at: http://www.cienciateca.com/PGR_Review_Hybrids_AdvMat2001.pdf; This review surveys the work developed in the field of functional hybrid materials, especially those containing conducting organic polymers (COPs), in combination with a variety of inorganic species, from molecular to extended phases, including clusters and nano-sized inorganic particles. Depending on the dominating structural matrix, we distinguish and analyze organic-inorganic (OI) hybrids, nanocomposite materials, and inorganic-organic (IO) phases. These materials have been used in a wide variety of applications, including energy-storage applications, electrocatalysis, the harnessing of electrochromic and photoelectrochromic properties, application in display devices, photovoltaics, and novel energy-conversion systems, proton-pump electrodes, sensors, or chemiresistive detectors, which work as artificial noses.; Peer reviewed