EVALUATION THERMAL AND CRYSTALLOGRAPHIC OF CELLULOSE NANOCRYSTALS BACTERIAL

EVALUATION THERMAL AND CRYSTALLOGRAPHIC OF CELLULOSE NANOCRYSTALS BACTERIAL

Vasconcelos, N. F.; Rodrigues, M. L. L.; Cavalcante, F. L.; Almeida, J. C. V.; Pinheiro, J. A.; Melo, E. F.; Ribeiro, A. C.; Rosa, M. F.

Abstract:

The aim of this work was analyze bacterial cellulose nanocrystals (BCNC) by XRD and TG. BCNC were hydrolysed with two processes: (1) neat H2SO4 (60% w/w) or (2) mixture H2SO4 (60% w/w):HCl (36.5% w/w) 1:1 (v/v), as described by Moreira et al. (2009). The BCNC were analyzed in a Rigaku difffractometer, model DMAXB, Cu X-ray tube, wavelength of 1.54 Å, operating at 40kV and 30mA, 2θ range angle from 10º to 50º. The Crystallinity Index (CI%) was calculated as described by Segal et al., (1959). BCNC from process (1) presented similar CI% (89.3%) to the process (2) (82.6%), and both of them were greater than the CI% (78.6%) from the raw bacterial cellulose (Table 1). Process (2) yield more thermally stable nanocrystals (Tonset 263.3 ºC) than the process (1) (Tonset 224.2 ºC). Although both processes are suitable for production of nanofillers, XRD evidenced differences in the BCNC from the processes. So, if mechanical resistance is more important than thermal stability, process (1) is better than process (2).

The aim of this work was analyze bacterial cellulose nanocrystals (BCNC) by XRD and TG. BCNC were hydrolysed with two processes: (1) neat H2SO4 (60% w/w) or (2) mixture H2SO4 (60% w/w):HCl (36.5% w/w) 1:1 (v/v), as described by Moreira et al. (2009). The BCNC were analyzed in a Rigaku difffractometer, model DMAXB, Cu X-ray tube, wavelength of 1.54 Å, operating at 40kV and 30mA, 2θ range angle from 10º to 50º. The Crystallinity Index (CI%) was calculated as described by Segal et al., (1959). BCNC from process (1) presented similar CI% (89.3%) to the process (2) (82.6%), and both of them were greater than the CI% (78.6%) from the raw bacterial cellulose (Table 1). Process (2) yield more thermally stable nanocrystals (Tonset 263.3 ºC) than the process (1) (Tonset 224.2 ºC). Although both processes are suitable for production of nanofillers, XRD evidenced differences in the BCNC from the processes. So, if mechanical resistance is more important than thermal stability, process (1) is better than process (2).

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DOI: 10.5151/phypro-sic100-086

Como citar:

Vasconcelos, N. F.; Rodrigues, M. L. L.; Cavalcante, F. L.; Almeida, J. C. V.; Pinheiro, J. A.; Melo, E. F.; Ribeiro, A. C.; Rosa, M. F.; "EVALUATION THERMAL AND CRYSTALLOGRAPHIC OF CELLULOSE NANOCRYSTALS BACTERIAL", p-86-86. In: Proceedings of the International Symposium on Crystallography [Blucher Physics Proceedings, v.1, n.3]. São Paulo: Blucher, 2015.
ISSN 23582359, DOI 10.5151/phypro-sic100-086