Adsorção de íons dicromato nos compósitos celulose/ZrO2.nH2O preparados pelos métodos da precipitação convencional e em solução homogênea

Mulinari, Daniella Regina; Silva, Gilberto Luís J. P. da; Silva, Maria Lúcia Caetano P. da

doi:10.1590/s0100-40422006000300017

Cited by 21 publications

(4 citation statements)

References 9 publications

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“…1 mostra os difratogramas de raios X dos óxidos de zircônio hidratados obtidos pelo método PC e PSH. Observa-se que o ZrO 2 .nH 2 O obtido pelos 2 métodos, apresenta-se amorfo com um ombro característico em torno de 2θ=30 [30][31][32]. Comparou-se os difratogramas obtidos com o padrão JCPDS.…”

Section: Resultsunclassified

Adsorção de íons sulfato em ZrO2.nH2O preparado pelo método da precipitação convencional e da precipitação em solução homogênea

2009

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ResumoEste trabalho visa a preparação, caracterização e estudo da adsorção de íons sulfato em óxido de zircônio hidratado preparado pelos métodos da precipitação convencional e da precipitação em solução homogênea. Os materiais obtidos foram caracterizados por difração de raios X, análise termogravimétrica, microscopia eletrônica de varredura e análise de área superficial específica pelo método BET. Através da constante Q 0 , relacionada com a capacidade de adsorção máxima, observou-se que o ZrO 2 .nH 2 O/PSH possui maior capacidade de adsorção para íons sulfato que o ZrO 2 .nH 2 O/PC. Pelos resultados de ∆G, observou-se que os íons sulfato foram adsorvidos através de reações energeticamente favoráveis para toda a faixa de concentração estudada. Palavras-chave: óxido de zircônio hidratado, adsorção, isoterma de Langmuir. Abstract This work reports the preparation, characterization and adsorption study of sulfate on hydrous zirconium oxides prepared by conventional and homogeneous solution precipitation methods. The materials prepared were characterized by X-ray diffraction

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Section: Resultsunclassified

Adsorção de íons sulfato em ZrO2.nH2O preparado pelo método da precipitação convencional e da precipitação em solução homogênea

2009

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“…This technique was used to remove residual lignin. Furthermore the bleached cellulose fibers dried at 50 ºC for 12 h (Mulinari et al 2006).…”

Section: Materials Preparation Preparation Of the Bleached Cellulosementioning

confidence: 99%

Sugarcane bagasse pulping and bleaching: Thermal and chemical characterization

Pereira

Voorwald

Cioffi

et al. 2011

BioRes

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Cellulose fibers were isolated from sugarcane bagasse in three stages. Initially sugarcane bagasse was subjected to a pre-treatment process with hydrolyzed acid to eliminate hemicellulose. Whole cellulosic fibers thus obtained were then subjected to a two-stage delignification process and finally to a bleaching process. The chemical structure of the resulting cellulose fibers was studied by Fourier Transform Infrared (FTIR) spectroscopy. Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD) were used to analyze the effects of hydrolysis, delignification, and bleaching on the structure of the fibers. Two different thermal analysis techniques were used to study the bleaching cellulose fibers. These techniques confirmed that cellulose fibers were isolated from sugarcane bagasse. A future goal is to use these fibers as reinforcement elements in composites, organic-inorganic hybrid, and membranes for nanofiltration.

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“…This type modification made in the cellulose fibers have also been used for specific applications such as: TiO 2 for bactericidal activities and reinforcement in polymers matrixes, ZrO 2 for retention and analysis of Cr(VI) and for adsorption of sulfate ions. [23][24][25][26]…”

Section: Introductionmentioning

confidence: 99%

Cellulose fiber-reinforced high-density polyethylene composites—Mechanical and thermal properties

Mulinari

Voorwald

Cioffi

et al. 2016

Journal of Composite Materials

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In this investigation, the thermal and mechanical properties of cellulose fibers from sugarcane bagasse reinforced with high density polyethylene composites were evaluated. Cellulose fibers were modified with hydrous Zr oxide to clean the fiber surface and improve the fibers-matrix adhesion. Composites were manufactured using a thermokinetic mixer process and the fiber content was responsible for 5, 10, 20, 30, and 40wt% in the composition. The chemical modification of the cellulose fibers with zirconium oxide was verified by FTIR analysis and the fibers' morphological aspects by SEM. After the chemical modification, the FTIR results showed reduction of OH bonds. SEM characterization showed that the modification changed the morphology of fibers. The results show that composites reinforced with modified cellulose fibers have an improvement in the thermal and mechanical properties, when compared to the non-cellulose fibers. In addition, an enhancement on the mechanical properties of composites was found, i.e. a gain of 122.4% compared to neat polymer at 40wt.% fiber loading in Young's modulus. The thermal properties show a slight decrease with increase of modified cellulose.

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Adsorção de íons dicromato nos compósitos celulose/ZrO2.nH2O preparados pelos métodos da precipitação convencional e em solução homogênea

Cited by 21 publications

References 9 publications

Adsorção de íons sulfato em ZrO2.nH2O preparado pelo método da precipitação convencional e da precipitação em solução homogênea

Adsorção de íons sulfato em ZrO2.nH2O preparado pelo método da precipitação convencional e da precipitação em solução homogênea

Sugarcane bagasse pulping and bleaching: Thermal and chemical characterization

Cellulose fiber-reinforced high-density polyethylene composites—Mechanical and thermal properties

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