Thermal Gravimetric Analysis
Mostrando 13-24 de 38 artigos, teses e dissertações.
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13. Synthesis and Characterization of Methylcellulose Produced from Bacterial Cellulose under Heterogeneous Condition
In this work, methylcellulose (MC) was produced from bacterial cellulose (BC), using dimethyl sulfate in a 3 h (MC3h) or 5 h (MC5h) reaction under heterogeneous conditions, with reagent substitution at each hour. MC3h showed a degree of substitution (DS) of 2.26 ± 0.13 and MC5h showed a DS of 2.33 ± 0.05. The two samples were characterized by Fourier trans
J. Braz. Chem. Soc.. Publicado em: 2015-09
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14. MCM-41 for Meloxicam Dissolution Improvement:
in vitro Release and in vivo Bioavailability StudiesIn this study, MCM-41 was prepared as a carrier for poorly water soluble drugs. Meloxicam (MLX) was selected as model compound. Textural and chemical characterizations were carried out by thermal gravimetric analysis (TGA), scanning electron microscope (SEM), nitrogen adsorption/desorption, X-ray diffraction (XRD) and Fourier transform infrared (FTIR). Th
J. Braz. Chem. Soc.. Publicado em: 2015-07
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15. Synthesis and characterization of novel ZrO2-SiO2 mixed oxides
In this study the mixed oxides ZrO2-SiO2, were synthesized by the sol-gel method with a molar ratio of 95:5 (Si/metal) and characterized by X-ray diffraction, absorption-desorption of N2, Fourier transform infrared spectroscopy, thermal gravimetric analysis, temperature-programmed desorption of ammonia, and acidity test by titration. The synthesized material
Mat. Res.. Publicado em: 15/04/2014
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16. Preparation, characterization and gas permeation study of PSf/MgO nanocomposite membrane
Nanocomposite membranes composed of polymer and inorganic nanoparticles are a novel method to enhance gas separation performance. In this study, membranes were fabricated from polysulfone (PSf) containing magnesium oxide (MgO) nanoparticles and gas permeation properties of the resulting membranes were investigated. Membranes were prepared by solution blendin
Braz. J. Chem. Eng.. Publicado em: 2013-09
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17. Preparation and characterization of PbTi0(3) ceramics modified by a natural mixture of rare earth oxides of xenotime
Lead titanate ceramics modified by xenotime (Xm) with nominal composition (Pb, Xm)TiO3, Xm 10 or 15 mol %, were prepared by the conventional oxide mixture technique. Xenotime is a natural mineral consisting of a mixture of rare earth oxides. Thermal, structural and electric properties were investigated through differential and gravimetric thermal analysis, X
Mat. Res.. Publicado em: 23/08/2013
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18. Síntese e caracterização de nanocompósitos poliuretano/dióxido de titânio
Due to the demand of the current market of polymeric materials and materials based on a polymeric structure, as some composites and nanocomposites, the development of new materials is fundamental. Thus, this work aims to study the synthesis and experimental characterization of nanocomposites polyurethane/titanium dioxide, using commercial raw materials. The
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 27/01/2012
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19. Influência do tipo de ácido e tempo de envelhecimento na atividade fotocatalítica de filmes finos de TiO2
TiO2 thin films were prepared by the sol-gel method using different acids (HCl and HAc), with a parallel evaluation of the gel ageing effects on the film properties. After the thermal treatments, the resulting materials were characterized through gravimetric analysis, UV-VIS spectrophotometry (from which optical parameters such as band gap was derived), XRD,
Química Nova. Publicado em: 2011
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20. Síntese da perovsquita do tipo LaNiO3 através do método dos precursores quelantes usando EDTA: otimização do teor de agente quelante
The perovskites are strategic materials due their catalytic, electronic and magnetic properties. These properties are influenced by the calcination and synthesis conditions. In this work was carried out the synthesis of LaNiO3 perovskite-type by chelating precursor method using EDTA and also was studied the optimization of the EDTA content in the synthesis.
Química Nova. Publicado em: 2011
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21. Poliuretanos elastoméricos obtenidos a partir de aceite de ricino y almidón de yuca original y modificado con anhídrido propiónico: síntesis, propiedades fisicoquímicas y fisicomecánicas
Chemical modification of cassava starch was conducted through an acylation reaction by using pyridine and propionic anhydride to replace the functional groups of starch. Polyurethane elastomers were prepared using suspensions of the mixture obtained from castor oil and yucca starch that was modified by a propionic anhydride reaction. The suspensions were cha
Química Nova. Publicado em: 2010
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22. Compositos resina epóxi/nanotubos de carbono de paredes múltiplas: caracterização dos materiais de partida e avaliação das condutividades elétrica e térmica
Investigamos neste trabalho as propriedades elétricas e térmicas de 1)compositos resina epóxi/nanotubos de carbono de paredes múltiplas concêntricas (MWNT) manufaturados com 0,1, 0,5 e 1% em massa de MWNT dispersos aleatoriamente na resina; 2)de compósitos reina/buckpaper; 3) de buckpaper (tecido de MWNT).
Publicado em: 2009
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23. Produção de grês porcelanato a partir de matérias-primas do estado da Bahia
The State Bahia, Brazil, presents different geological sites it with a very expressive variety minerals. It is situated among the very important States which produces minerals for industries, such as pointed aggregate, ornamentals stones and ceramics raw materials. Nowadays only four companies producting ceramics tiles. Porcelainized stoneware tiles is one o
Publicado em: 2009
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24. Preparation of organoclays appropriated and development of plasticized pvc nanocomposites / Preparação de argilas organofílicas para o desenvolvimento de nanocompósitos a partir de compostos de PVC plastificado
Nanocomposites of Plasticized PVC with organoclays have a large potential to improve the thermal resistance of PVC as well as its flame retardancy. However, a great problem in the production of PVC nanocomposites is the decomposition of conventional organic ammonium salts incorporated on the clay which can catalyze PVC degradation and lead to deterioration o
Publicado em: 2009