EFEITO DA UTRA-ESTABILIZAÇÃO DA ZEOLITA Y NO HIDRO-CRAQUEAMENTO DE ÓLEO DE SOJA BRUTO

Como alternativa ao consumo de combustíveis fósseis, há a possibilidade de se produzir combustíveis renováveis a partir de biomassa, como do óleo de soja. Pelo processo de hidrocraqueamento catalítico se obtém combustíveis e insumos petroquímicos a partir de triglicerídeos. Neste trabalho foram utilizados os catalisadores NaY e USY, com diferentes quantidades de Si e Al em suas estruturas e diferentes cátions de compensação, o que levou uma diferença da acidez dos seus sítios ativos, observadas por ressonância magnética nuclear de 29Si e dessorção à temperatura programada (DTP), respectivamente. A reação de hidrocraqueamento foi realizado em reator de leito fixo e o produto foi analisado após trinta minutos de reação por cromatografia a gás com espectrometria de massas. Obteve-se elevada seletividade a hidrocarbonetos, principalmente gasosos, e uma grande diferença entre os produtos líquidos dos dois catalisadores utilizados. Foi observada uma pequena quantidade de ácidos orgânicos no produto final

Fotodegradação de corante textil azul RB 250 e produção Fotocatalítica de H2 utilizando TiO2 Nano suportado em Zeolita ZSM-5 / RB 250 blue dye photodegradation and H2 Photocatalytic production using TiO2 Nano supported on Zeolite ZSM-5

Os processos oxidativos avançados (POAs) são uma alternativa promissora para o tratamento de efluente têxteis, principalmente se combinado a produção fotocatalítica de hidrogênio. O objetivo deste trabalho foi a  aplicação da fotocatálise heterogênea no tratamento do efluente têxtil sintético e posterior produção fotocatalítica de hidrogênio utilizando radiação artificial UV, utilizando como catalisador TiO2 nano particulado, suportados na zeólita ZSM-5 com 5 e 10% de fase ativa. Os catalisadores suportados foram caracterizados para identificação das propriedades texturais, estruturais e morfológicas, esses foram utilizados na degradação fotocatalítica do corante azul reativo RB250 no reator em batelada com reciclo e para produção de hidrogênio no reator em batelada. Os fotocatalisadores que apresentaram apresentaram descoloração do corante em 100% nos primeiros minutos de reação. A mineralização do efluente foi avaliada  e como todos os catalisadores foi obtido mineralização superior a 80%. Na produção de H2 o catalisador puro comercial se mostrou ser mais eficiente ques os catalisadores suportados na zeólita, obetendo uma produção de 11.05 µmol H2.gcat-1 sendo 50% mais eficiente que os catalisadores com 5 e 10% de fase ativa, os quais apresentaram um perfil de produção bastante próximos

Preparation and characterization of cotton fabrics with antimicrobial properties through the application of chitosan/silver-zeolite film

The development of antimicrobial cotton fabrics using chitosan/silver-zeolite film has been investigated in the present work. The film was applied to 100% cotton fabric using a common pad-dry-cure technique and citric acid was used as crosslinking agent. The resulting fabrics were characterized through infrared spectroscopy (FTIR), contact angle and scanning electron microscopy with X-ray microanalysis (SEM/EDS). The antimicrobial activity of the fabrics was assessed through the viable-cell counting method and the materials showed activity against S. aureus and T. rubrum. The textile performance of the fabrics was analysed regarding their characteristics of hydrophilicity and breathability. The finishing did not change the hydrophilic behaviour of the material. Although the permeability to air has reduced 20%, the permeability to water vapour remained practically unchanged. Therefore, the results suggested that the process approach of applying chitosan/silver-zeolite film is recommended to produce textiles with antibacterial properties.CNPq-Brazil (Conselho Nacional de Desenvolvimento Científico e Tecnológico – Brazil/National Council of Scientific and Technological Development – Brazil) for the doctoral scholarship (233550/2014-3). This work is also financed by FEDER funds through the Competitivity Factors Operational Programme – COMPETE and by national funds through FCT – Foundation for Science and Technology within the scope of the project POCI-01-0145-FEDER-007136. This research was partially supported by the Strategic Funding UID/Multi/04423/2013 through national funds provided by FCT - Foundation for Science and Technology and European Regional Development Fund (ERDF), in the framework of the program PT2020.info:eu-repo/semantics/publishedVersio

Photocatalytic water splitting with noble-metal free cocatalysts for a comprehensive study of two nonidentical photoreactors designs

Here, the authors (i) discuss the most prominent co-catalyst for H2 generation struc tured in the form of Me-TiO2/MCM-41 (Me: Ag, Co, Cu, Ni) based on structural, electronic, textural, morphological and optical characterization techniques, such as XRD, wide and small angle, XPS, Fourier-transform infrared spectroscopy, scanning electron microscopy, B.E.T., textural analysis, photoacoustic spectroscopy and photo luminescence spectroscopy; and (ii) evaluate the difference in hydrogen production in two distinct geometric reactors based on a theoretical study of light distribution inside the reactors supported by the experimental quantum yield calculation. As a result, copper-doped photocatalyst generated higher hydrogen amount compared to the others. The high photocatalyst performance was due to the greater lamp spec trum absorption, marked by the low bandgap value, and high photoactivity justified by the low rate of electronic recombination. The hydrogen generation in the quartz reactor was seven times higher than the annular one, and when at maximum light power, it is comparable to the most sophisticated reaction systems found in litera ture. The larger light exposure area per unit volume of the quartz reactor compared to the annular one is the reason why it obtained better results due to the lower emit ted photon blockade, with a 1.81% apparent quantum yield

Desenvolvimento e caracterização de filmes compósitos de quitosana e zeólitas com prata

Resumo Zeólitas foram submetidas à troca iônica ou impregnação com prata e posteriormente adicionadas em filmes de quitosana para a confecção de curativos para queimaduras. As zeólitas foram avaliadas por Ressonância magnética nuclear (RMN), Fluorescência de raios X por reflexão total (TXRF), Microscopia eletrônica de varredura (MEV). Os filmes poliméricos foram analisados com relação às suas propriedades mecânicas, permeabilidade ao vapor d’água (PVA) e liberação de prata. Observou-se que o procedimento de troca iônica não alterou a morfologia das zeólitas de partida. Grumos de zeólita foram observados nas micrografias dos filmes e estes influenciaram nas propriedades mecânicas devido à desorganizaçao local no empacotamento das cadeiras poliméricas da quitosana. A metodologia de troca iônica ou impregnação influenciou diretamente na quantidade de prata presente superficialmente na zeólita e consequentemente alterou o perfil de liberação de prata em uma solução simulada de exudato de ferida. Os modelos cinéticos sugeriram que a liberação da prata não foi essencialmente regulada pela lei de difusão de Fick

Natural polysaccharides in wound dressing applications

This chapter discusses one innovative pharmaceutical form: the so-called two-dimensional system or flat system. They can be subdivided into films (or membranes), or even fabrics. The main applications of these systems are in the development of controlled release formulations, wound dressings, and in tissue engineering. This chapter focuses on the wound dressings for healing. A brief conceptualization and introduction on the main characteristics of these systems are presented, as well as an overview of the products available in the world market and the methods of preparation of the dressings. The materials used to produce these systems may be of synthetic or of natural sources, such as natural polysaccharides or semisynthetic polysaccharides. Two of the main properties of dressings are fluid-handling capacity and wound healing. An overview of publications on natural polysaccharidesbased dressings is presented. Finally, the leading mathematical models for the release of active compounds from flat systems are introduced.(undefined)info:eu-repo/semantics/publishedVersio

Development of chitosan/silver sulfadiazine/zeolite composite films for wound dressing

Biopolymeric films with silver sulfadiazine (AgSD) are proposed as an alternative to the occlusive AgSD-containing creams and gauzes, which are commonly used in the treatment of conventional burns. While the recognized cytotoxicity of AgSD has been reported to compromise its use as an antimicrobial drug in pharmaceuticals, this limitation can be overcome by developing sustained-release formulations. Microporous materials as zeolites can be used as drug delivery systems for sustained release of AgSD. The purpose of this work was the development and characterization of chitosan/zeolite composite films to be used as wound dressings. Zeolite was impregnated with AgSD before the production of the composite films. The physicochemical properties of zeolites and the films were evaluated, as well as the antimicrobial activity of the polymeric films and the cytotoxicity of the films in fibroblasts Balb 3T3/c. Impregnated zeolite exhibited changes in FTIR spectra and XRD diffraction patterns, in comparison to non-impregnated composites, which corroborate the results obtained with EDX-SEM. The pure chitosan film was compact and without noticeable defects and macropores, while the film with zeolite was opaquer, more rigid, and efficient against Candida albicans and some gram-negative bacteria. The safety evaluation showed that although the AgSD films present cytotoxicity, they could be used in a concentration-dependent fashion.The authors wish to thank CAPES (Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior) for the scholarship granted to the first author. EBS acknowledges the financial support received from the Portuguese Science and Technology Foundation (FCT/MCT) and European Funds (PRODER/COMPETE) under the project reference M-ERA-NET/0004/2015-PAIRED, co-financed by FEDER, under the Partnership Agreement PT2020. MCG and ESL wish to acknowledge the Institute of Nanoscience and Nanotechnology for the project ART(2018) and the Generalitat of Catalonia for the project 2017SGR-1477

Photocatalytic water splitting with noble‐metal free cocatalysts for a comprehensive study of two nonidentical photoreactors designs

Here, the authors (i) discuss the most prominent co-catalyst for H2 generation struc tured in the form of Me-TiO2/MCM-41 (Me: Ag, Co, Cu, Ni) based on structural, electronic, textural, morphological and optical characterization techniques, such as XRD, wide and small angle, XPS, Fourier-transform infrared spectroscopy, scanning electron microscopy, B.E.T., textural analysis, photoacoustic spectroscopy and photo luminescence spectroscopy; and (ii) evaluate the difference in hydrogen production in two distinct geometric reactors based on a theoretical study of light distribution inside the reactors supported by the experimental quantum yield calculation. As a result, copper-doped photocatalyst generated higher hydrogen amount compared to the others. The high photocatalyst performance was due to the greater lamp spec trum absorption, marked by the low bandgap value, and high photoactivity justified by the low rate of electronic recombination. The hydrogen generation in the quartz reactor was seven times higher than the annular one, and when at maximum light power, it is comparable to the most sophisticated reaction systems found in litera ture. The larger light exposure area per unit volume of the quartz reactor compared to the annular one is the reason why it obtained better results due to the lower emit ted photon blockade, with a 1.81% apparent quantum yield

Thermal and antimicrobial evaluation of cotton functionalized with a chitosan-zeolite composite and microcapsules of phase-change materials

Antimicrobial cotton was developed using silver zeolites (SZ). Three different application approaches are followed for cotton surface functionalisation: (1) SZ alone, (2) SZ combined with chitosan film, and (3) chitosan-zeolite (CS-SZ) composite, previously synthesized by gelation process with sodium tripolyphosphate (TPP). All finishes were applied into the textile materials through conventional pad-dry-cure processes and the obtained results were then compared. The resulting materials were characterized using Fourier Transform infrared spectroscopy (FTIR), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS), differential scanning calorimetry (DSC), infrared thermography and contact angle measurement, and the antimicrobial activity was evaluated. The results suggest that the application of CS-SZ should be recommended to produce textiles with antibacterial properties, showing activity against E. coli, S. aureus, C. albicans and T. rubrum. In addition, the finish can be combined with the application of microcapsules of phase change materials (mPCM) to obtain textiles with thermoregulation properties.CNPq-Brazil (Conselho Nacional de Desenvolvimento Científico e Tecnológico – Brasil/National Council of Scientific and Technological Development – Brazil) for the doctoral scholarship (233550/2014-3). This work was supported through national funds provided by FCT/MCTES - Foundation for Science and Technology from the Minister of Science, Technology and Higher Education (PIDDAC) and European Regional Development Fund (ERDF) through the COMPETE – Programa Operacional Factores de Competitividade (POFC) programme, under the Strategic Funding UID/Multi/04423/2013, in the framework of the programme PT2020. This work is also financed by FEDER funds through the Competitivity Factors Operational Programme - COMPETE and by national funds through FCT – Foundation for Science and Technology within the scope of the project POCI-01-0145-FEDER-007136.info:eu-repo/semantics/publishedVersio