Theoretical and experimental developments for accurate determination of crystallinity of cellulose I materials

Autor(es)

Driemeier, Carlos ; Calligaris, Guilherme A.

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF APPLIED CRYSTALLOGRAPHY; v. 44, p. 9-pg., 2011-02-01.

Resumo

This work defines the crystallinity of cellulose I materials on a dry-weight basis. Theoretical and experimental developments in X-ray diffraction lead to a crystallinity determination method that is estimated to reach 1 Sigma accuracies of better than 0.05 (crystallinity defined between 0 and 1). The method is based on Rietveld modelling, to resolve cellulose I Bragg peaks, and a standard truncated invariant integral. Corrections are derived to account for incoherent scattering, moisture content and other compositional deviations from pure cellulose. The experimental development uses X-ray diffraction in transmission fibre geometry with two-dimensional pattern Rietveld modelling, including a crystal-orientation distribution function. The crystallinities of a few commercial cellulose I materials were determined with the aim of illustrating the applicability of the method. (AU)

• Processo FAPESP: 10/05523-3 - Alterações nanomorfológicas da matéria lignocelulósica de cana-de-açúcar
• Beneficiário: Carlos Eduardo Driemeier
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores