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You searched for subject:(hidrocalumita). Showing records 1 – 2 of 2 total matches.

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Universitat Rovira i Virgili

1. Granados Reyes, Judith Cecilia. Hydrocalumite-based catalysts for glycerol revalorization.

Degree: Departament de Química Física i Inorgànica, 2015, Universitat Rovira i Virgili

During biodiesel production, glycerol is obtained as byproduct in high amounts, becoming a surplus. Therefore, it is necessary to find new outlets to convert glycerol into high-added value products, such as glycerol carbonate or glycidol, which are precursors of polymers. The main objective of this work is to synthesize and characterize layered double hydroxides type hydrocalumite using microwaves radiation and ultrasounds, as well as the materials obtained by calcination at different temperatures, to be tested as catalysts for reactions of great industrial interest, such as the transesterification reaction of glycerol with dimethylcarbonate to obtain glycerol carbonate. Microwaves have been also used as heating method for this reaction. Additionally, several hydrocalumites, hydrotalcites and aluminium hydroxides, these later prepared with microwaves, were tested as catalysts for the decarboxylation of glycerol carbonate to glycidol. The hydrocalumite-type materials calcined at 750 ºC resulted in the best conversion values (88-98 %) and best selectivity to glycerol carbonate values (60-85 %) for the transesterification of glycerol to glycerol carbonate at 90 ºC with conventional heating after 3 h of the reaction. These good results have been explained by the presence of CaO, highly basic, in these catalysts. The use of microwaves during reaction, increased both conversion and selectivity to glycerol carbonate in all cases. For the decarboxylation reaction of glycerol carbonate, the best selectivity to glycidol (72 %) for a 35 % of conversion was achieved with a catalyst composed of an aluminum hydroxide in the presence of Ca species and impregnated with phosphoric acid. Advisors/Committee Members: [email protected] (authoremail), false (authoremailshow), Cesteros, Yolanda (director), Salagre, Pilar (director), true (authorsendemail).

Subjects/Keywords: hidrocalumita; glicerol; carbonat de glicerol; hidrocalumita; glicerol; carbonato de glicerol; hydrocalumite; glycerol; glycerol carbonate; 54; 546; 66

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Granados Reyes, J. C. (2015). Hydrocalumite-based catalysts for glycerol revalorization. (Thesis). Universitat Rovira i Virgili. Retrieved from http://hdl.handle.net/10803/318582

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Granados Reyes, Judith Cecilia. “Hydrocalumite-based catalysts for glycerol revalorization.” 2015. Thesis, Universitat Rovira i Virgili. Accessed February 20, 2020. http://hdl.handle.net/10803/318582.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Granados Reyes, Judith Cecilia. “Hydrocalumite-based catalysts for glycerol revalorization.” 2015. Web. 20 Feb 2020.

Vancouver:

Granados Reyes JC. Hydrocalumite-based catalysts for glycerol revalorization. [Internet] [Thesis]. Universitat Rovira i Virgili; 2015. [cited 2020 Feb 20]. Available from: http://hdl.handle.net/10803/318582.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Granados Reyes JC. Hydrocalumite-based catalysts for glycerol revalorization. [Thesis]. Universitat Rovira i Virgili; 2015. Available from: http://hdl.handle.net/10803/318582

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

2. Fabiana Melo da Silva. SÃntese e caracterizaÃÃo de argilas tipo hidrÃxido duplo lamelar ([Ca2Al(OH)6]NO3.xH2O-Hidrocalumita) para aplicaÃÃes biomÃdicas.

Degree: Master, 2015, Universidade Federal do Ceará

Os hidrÃxidos duplos lamelares (HDLs) sÃo materiais argilosos, que possuem ocorrÃncia natural e tambÃm podem ser sintetizados em laboratÃrio por rotas simples e de baixo custo. Apresentando grande variabilidade de aplicaÃÃes, os HDLs podem ser utilizados como catalisadores, trocadores iÃnicos, antiÃcidos e adsorventes. O objetivo geral do presente trabalho à de sintetizar e caracterizar uma argila do tipo HDL e verificar sua bioatividade. O HDL sintetizado foi a hidrocalumita (Ca-Al-NO3-HDL). Para a sÃntese utilizou-se o mÃtodo de coprecipitaÃÃo a pH 7, 10 e 13. O material foi caracterizado por meio de difraÃÃo de raios X (DRX), espectroscopia no infravermelho (IV), microscopia eletrÃnica de varredura (MEV), espectroscopia de energia dispersiva (EDS), microscopia de forÃa atÃmica (AMF), anÃlise termogravimÃtrica (ATG), calorimetria exploratÃria diferencial (DSC) e testes in vitro (SBF). Para os resultados obtidos atravÃs da realizaÃÃo da DRX foi encontrada a fase da hidrocalumita nas amostras. O resultado do espectro do infravermelho revelou todos os possÃveis grupos funcionais esperados na sÃntese para a confirmaÃÃo da formaÃÃo da Ca-Al-NO3-HDL. A anÃlise morfolÃgica (MEV) da amostra revelou a presenÃa de cristais em forma de placas sobrepostas. Pelos resultados obtidos, a rota de sÃntese do material em estudo mostrou-se eficaz, porÃm com a necessidade de ajustes para que a hidrocalumita seja a Ãnica fase obtida. Os experimentos revelaram tambÃm a bioatividade do material.

Layered double hydroxides (LDH) can be synthesized in laboratories by simple routes at low cost. Introducing great variety of applications, LDH can be used as catalysts, ion exchangers, adsorbents and antacids. The objective of this work was to synthesize and characterize a LDH type clay and check bioactivity. LDH was synthesized to hidrocalumite (Ca-Al-NO3-LDH). The synthesis was carried out using the coprecipitation method at pH 7, 10 and 13 and characterization performed by X-ray diffraction (XRD), infrared spectroscopy, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), atomic force microscopy (AMF), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and in vitro tests. X-ray diffraction detected the hidrocalumite phase in the samples. The infrared spectrum shows all functional groups expected in the synthesis attesting the formation of the Ca-Al-NO3-LDH. Morphological analysis (SEM) showed the presence of crystals in the form of overlapping plates. Based on the results obtained, the synthesis route of the material under study was effective, but with the need for further adjustments for the hidrocalumite be, the only phase obtained. The experiments also revealed the bioactivity of the material.

Advisors/Committee Members: Igor Frota de Vasconcelos, CecÃlia AmÃlia de Carvalho Zavaglia, Ricardo EmÃlio Ferreira Quevedo Nogueira.

Subjects/Keywords: BIOMATERIAIS E MATERIAIS BIOCOMPATIVEIS; Bioatividade; Hidrocalumita; Argila; Layered Double Hydroxide; Hidrocalumite; Bioactivity; CiÃncia dos materiais

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Silva, F. M. d. (2015). SÃntese e caracterizaÃÃo de argilas tipo hidrÃxido duplo lamelar ([Ca2Al(OH)6]NO3.xH2O-Hidrocalumita) para aplicaÃÃes biomÃdicas. (Masters Thesis). Universidade Federal do Ceará. Retrieved from http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=13756 ;

Chicago Manual of Style (16th Edition):

Silva, Fabiana Melo da. “SÃntese e caracterizaÃÃo de argilas tipo hidrÃxido duplo lamelar ([Ca2Al(OH)6]NO3.xH2O-Hidrocalumita) para aplicaÃÃes biomÃdicas.” 2015. Masters Thesis, Universidade Federal do Ceará. Accessed February 20, 2020. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=13756 ;.

MLA Handbook (7th Edition):

Silva, Fabiana Melo da. “SÃntese e caracterizaÃÃo de argilas tipo hidrÃxido duplo lamelar ([Ca2Al(OH)6]NO3.xH2O-Hidrocalumita) para aplicaÃÃes biomÃdicas.” 2015. Web. 20 Feb 2020.

Vancouver:

Silva FMd. SÃntese e caracterizaÃÃo de argilas tipo hidrÃxido duplo lamelar ([Ca2Al(OH)6]NO3.xH2O-Hidrocalumita) para aplicaÃÃes biomÃdicas. [Internet] [Masters thesis]. Universidade Federal do Ceará 2015. [cited 2020 Feb 20]. Available from: http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=13756 ;.

Council of Science Editors:

Silva FMd. SÃntese e caracterizaÃÃo de argilas tipo hidrÃxido duplo lamelar ([Ca2Al(OH)6]NO3.xH2O-Hidrocalumita) para aplicaÃÃes biomÃdicas. [Masters Thesis]. Universidade Federal do Ceará 2015. Available from: http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=13756 ;

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