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Registro Completo |
Biblioteca(s): |
Embrapa Recursos Genéticos e Biotecnologia. |
Data corrente: |
05/10/2009 |
Data da última atualização: |
05/10/2009 |
Tipo da produção científica: |
Resumo em Anais de Congresso |
Autoria: |
ANDRADE, L. R. M. D.; WATTEAU, F.; ECHEVARRIA, G.; BARROS, L. M. G.; ANDRADE, S. R. M. D.; RODRIGUES, G. C. |
Afiliação: |
LEIDE ROVENIA MIRANDA DE ANDRADE, CPAC; FRANÇOISE WATTERAU, INRA; GUILLAUME ECHEVARRIA, INRA; LEILA MARIA GOMES BARROS, CENARGEN; SOLANGE ROCHA MONTEIRO DE ANDRADE, CPAC; GUSTAVO COSTA RODRIGUES, CPAC. |
Título: |
Evidência da presença de Al no cloroplasto de folhas de Qualea grandiflora. |
Ano de publicação: |
2009 |
Fonte/Imprenta: |
In: CONGRESSO BRASILEIRO DE FISIOLOGIA VEGETAL, 12., 2009, Fortaleza. Desafios para a produção de alimentos e bioenergia: livro de resumos. Fortaleza: SBFV: UFC: Embrapa Agroindústria Tropical, 2009. Resumo 1212. |
Idioma: |
Português |
Palavras-Chave: |
MET-EDX; Vochysiacea. |
Thesagro: |
Cerrado; Espécie Nativa. |
Categoria do assunto: |
-- |
Marc: |
LEADER 00761nam a2200205 a 4500 001 1513231 005 2009-10-05 008 2009 bl uuuu u01u1 u #d 100 1 $aANDRADE, L. R. M. D. 245 $aEvidência da presença de Al no cloroplasto de folhas de Qualea grandiflora. 260 $aIn: CONGRESSO BRASILEIRO DE FISIOLOGIA VEGETAL, 12., 2009, Fortaleza. Desafios para a produção de alimentos e bioenergia: livro de resumos. Fortaleza: SBFV: UFC: Embrapa Agroindústria Tropical, 2009. Resumo 1212.$c1212 650 $aCerrado 650 $aEspécie Nativa 653 $aMET-EDX 653 $aVochysiacea 700 1 $aWATTEAU, F. 700 1 $aECHEVARRIA, G. 700 1 $aBARROS, L. M. G. 700 1 $aANDRADE, S. R. M. D. 700 1 $aRODRIGUES, G. C.
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Registro original: |
Embrapa Recursos Genéticos e Biotecnologia (CENARGEN) |
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Registro Completo
Biblioteca(s): |
Embrapa Algodão. |
Data corrente: |
14/01/2020 |
Data da última atualização: |
20/01/2020 |
Tipo da produção científica: |
Artigo em Periódico Indexado |
Circulação/Nível: |
A - 1 |
Autoria: |
VASCONCELOS, N. F.; FEITOSA, J. P. A.; ANDRADE, F. K.; MIRANDA, M. A. R.; SASAKI, J. M.; MORAIS, J. P. S.; SILVA, L. M. A. e; CANUTO, K. M.; ROSA, M. de F. |
Afiliação: |
Niédja Fittipaldi Vasconcelos, Universidade Federal do Ceará - UFC/Departamento de Química; Judith Pessoa Andrade Feitosa, Universidade Federal do Ceará - UFC/Departamento de Química; Fábia Karine Andrade, Universidade Federal do Ceará - UFC/Departamento de Engenharia Química; Marcus Aurélio Ribeiro Miranda, Universidade Federal do Ceará - UFC/Departamento de Física; José Marcos Sasaki, Universidade Federal do Ceará - UFC/Departamento de Física; JOAO PAULO SARAIVA MORAIS, CNPA; LORENA MARA ALEXANDRE E SILVA, CNPAT; KIRLEY MARQUES CANUTO, CNPAT; MORSYLEIDE DE FREITAS ROSA, CNPAT. |
Título: |
Chemically modified cellulose nanocrystals as polyanion for preparation of polyelectrolyte complex. |
Ano de publicação: |
2019 |
Fonte/Imprenta: |
Cellulose, v. 26, n. 3, p. 1725-1746, February 2019. |
Idioma: |
Inglês |
Conteúdo: |
Bacterial cellulose nanocrystals (BCNCs) have hydrophilic surfaces due to hydroxyl groups but are water-insoluble. The carboxymethylation improves the solubility of cellulose in polar media through the insertion of carboxymethyl groups. This study aims to evaluate the use of two different alcoholic solvents in the carboxymethylation reaction of BCNCs: ethanol and isopropanol. BCNCs were obtained under two hydrolysis conditions: sulfuric acid (BCNC-S) and combination of sulfuric and hydrochloric acids (BCNC-S/Cl). Two techniques (NMR and titration) were used to determine the degree of substitution (DS) values. Carboxymethylation of BCNC-S/Cl led to high DS compared to BCNC-S and the use of isopropanol promoted an even greater DS. The thermal properties were not affected after the chemical modification. However, functionalization provided an increase in the negative charge density at the surface of nanostructures and a change in the crystal structure (cellulose type Ia for amorphous), making this material a potential polyanion for the synthesis of polyelectrolyte complexes (PECs). The micrographs showed that the nanocrystals became soluble after carboxymethylation. Carboxymethylated bacterial cellulose nanocrystals hydrolyzed through the mixture of inorganic acids and modified using isopropanol (CBCNC-S/Cl-IPA) was a suitable polyanion to produce PECs with chitosan. The PECs produced had particle size ranging from 276 to 588 nm and zeta potential ranging from - 24.3 to + 39.0 mV. MenosBacterial cellulose nanocrystals (BCNCs) have hydrophilic surfaces due to hydroxyl groups but are water-insoluble. The carboxymethylation improves the solubility of cellulose in polar media through the insertion of carboxymethyl groups. This study aims to evaluate the use of two different alcoholic solvents in the carboxymethylation reaction of BCNCs: ethanol and isopropanol. BCNCs were obtained under two hydrolysis conditions: sulfuric acid (BCNC-S) and combination of sulfuric and hydrochloric acids (BCNC-S/Cl). Two techniques (NMR and titration) were used to determine the degree of substitution (DS) values. Carboxymethylation of BCNC-S/Cl led to high DS compared to BCNC-S and the use of isopropanol promoted an even greater DS. The thermal properties were not affected after the chemical modification. However, functionalization provided an increase in the negative charge density at the surface of nanostructures and a change in the crystal structure (cellulose type Ia for amorphous), making this material a potential polyanion for the synthesis of polyelectrolyte complexes (PECs). The micrographs showed that the nanocrystals became soluble after carboxymethylation. Carboxymethylated bacterial cellulose nanocrystals hydrolyzed through the mixture of inorganic acids and modified using isopropanol (CBCNC-S/Cl-IPA) was a suitable polyanion to produce PECs with chitosan. The PECs produced had particle size ranging from 276 to 588 nm and zeta potential ranging from - 24.3 to + 39.0 ... Mostrar Tudo |
Palavras-Chave: |
Carboxymethylation; Polyelectrolytic complexes. |
Thesaurus NAL: |
Chitosan; Hydrolysis; Nanocrystals. |
Categoria do assunto: |
-- |
URL: |
https://ainfo.cnptia.embrapa.br/digital/bitstream/item/208702/1/Chemically-modified-cellulose.pdf
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Marc: |
LEADER 02321naa a2200277 a 4500 001 2118682 005 2020-01-20 008 2019 bl uuuu u00u1 u #d 100 1 $aVASCONCELOS, N. F. 245 $aChemically modified cellulose nanocrystals as polyanion for preparation of polyelectrolyte complex.$h[electronic resource] 260 $c2019 520 $aBacterial cellulose nanocrystals (BCNCs) have hydrophilic surfaces due to hydroxyl groups but are water-insoluble. The carboxymethylation improves the solubility of cellulose in polar media through the insertion of carboxymethyl groups. This study aims to evaluate the use of two different alcoholic solvents in the carboxymethylation reaction of BCNCs: ethanol and isopropanol. BCNCs were obtained under two hydrolysis conditions: sulfuric acid (BCNC-S) and combination of sulfuric and hydrochloric acids (BCNC-S/Cl). Two techniques (NMR and titration) were used to determine the degree of substitution (DS) values. Carboxymethylation of BCNC-S/Cl led to high DS compared to BCNC-S and the use of isopropanol promoted an even greater DS. The thermal properties were not affected after the chemical modification. However, functionalization provided an increase in the negative charge density at the surface of nanostructures and a change in the crystal structure (cellulose type Ia for amorphous), making this material a potential polyanion for the synthesis of polyelectrolyte complexes (PECs). The micrographs showed that the nanocrystals became soluble after carboxymethylation. Carboxymethylated bacterial cellulose nanocrystals hydrolyzed through the mixture of inorganic acids and modified using isopropanol (CBCNC-S/Cl-IPA) was a suitable polyanion to produce PECs with chitosan. The PECs produced had particle size ranging from 276 to 588 nm and zeta potential ranging from - 24.3 to + 39.0 mV. 650 $aChitosan 650 $aHydrolysis 650 $aNanocrystals 653 $aCarboxymethylation 653 $aPolyelectrolytic complexes 700 1 $aFEITOSA, J. P. A. 700 1 $aANDRADE, F. K. 700 1 $aMIRANDA, M. A. R. 700 1 $aSASAKI, J. M. 700 1 $aMORAIS, J. P. S. 700 1 $aSILVA, L. M. A. e 700 1 $aCANUTO, K. M. 700 1 $aROSA, M. de F. 773 $tCellulose$gv. 26, n. 3, p. 1725-1746, February 2019.
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