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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Crystallite Width Determines Monolayer Hydration across a Wide Spectrum of Celluloses Isolated from Plants

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Autor(es):
Driemeier, Carlos [1] ; Bragatto, Juliano [1]
Número total de Autores: 2
Afiliação do(s) autor(es):
[1] CTBE CNPEM, Lab Nacl Ciencia & Tecnol Bioetanol, BR-13083970 Campinas, SP - Brazil
Número total de Afiliações: 1
Tipo de documento: Artigo Científico
Fonte: Journal of Physical Chemistry B; v. 117, n. 1, p. 415-421, JAN 10 2013.
Citações Web of Science: 19
Resumo

Relating cellulose structure to its water uptake is a classical problem with many investigations done through measurements of cellulose ``crystallinity{''}. However, there is presently a growing consensus that crystallinity measurements are appreciably uncertain, leading to ambiguous interpretations of underlying cellulose organization. In this scenario, this article revisits the relations between cellulose structure and water uptake, moving the emphasis away from degree of crystallinity and directing it toward crystallite width, which is inferred with less ambiguity from the broadening of 200 X-ray diffraction peaks. With this approach, analysis of a wide spectrum of celluloses isolated from plants (preserving cellulose I phase and having variable contents of residual hemicelluloses) reveals a simple linear relation (R-2 = 0.98) between reciprocal crystallite width and rnonolayer hydration (determined from vapor sorption). The primary role of crystallite width supports that most water-accessible polysaccharides are laterally associated with the crystallites, with a minor fraction in disordered domains along the fibrils. Furthermore, the secondary role left to hemicellulosic contents indicates cellulose being partly decrystallized to complement the disordered amount required to interface the crystallites. Finally, a substantial part of hydration is attributed to polysaccharides in voids left by the imperfect packing of aggregated crystallites. (AU)

Processo FAPESP: 10/05523-3 - Alterações nanomorfológicas da matéria lignocelulósica de cana-de-açúcar
Beneficiário:Carlos Eduardo Driemeier
Linha de fomento: Auxílio à Pesquisa - Apoio a Jovens Pesquisadores