Publicación:
Monitoring molecular dynamics of bacterial cellulose composites reinforced with graphene oxide by carboxymethyl cellulose addition
Monitoring molecular dynamics of bacterial cellulose composites reinforced with graphene oxide by carboxymethyl cellulose addition
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Fecha
2017
Autores
Sanchis M.J.
Carsí M.
Gómez C.M.
Culebras M.
Gonzales K.N.
Torres F.G.
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Editor
Elsevier Ltd
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Abstracto
Broadband Dielectric Relaxation Spectroscopy was performed to study the molecular dynamics of dried Bacterial Cellulose/Carboxymethyl Cellulose-Graphene Oxide (BC/CMC-GO) composites as a function of the concentration of CMC in the culture media. At low temperature the dielectric spectra are dominated by a dipolar process labelled as a β-relaxation, whereas electrode polarization and the contribution of dc-conductivity dominate the spectra at high temperatures and low frequency. The CMC concentration affects the morphological structure of cellulose and subsequently alters its physical properties. X-ray diffractometry measurements show that increasing the concentration of CMC promotes a decrease of the Iα/Iβ ratio. This structural change in BC, that involves a variation in inter- and intramolecular interactions (hydrogen-bonding interactions), affects steeply their molecular dynamics. So, an increase of CMC concentration produces a significantly decrease of the β-relaxation strength and an increase of the dc-conductivity.
Descripción
This work was supported by the DGCYT [MAT2015-63955-R]; the Vice-Rectorate for Research of the Pontificia Universidad Católica del Perú and the National Council of Science, Technology and Technological Innovation of Peru (CONCYTEC/FONDECYT).
Palabras clave
X ray diffraction analysis,
Cellulose,
Dielectric relaxation,
Graphene,
Hydrogen bonds,
Spectroscopy,
Temperature,
Thermodynamic stability,
Bacterial cellulose,
Broadband dielectric relaxation spectroscopy