Thermochimica Acta, Vol.583, 8-14, 2014
Thermal behavior and properties of chitosan fibers enhanced polysaccharide hydrogels
Composite hydrogel based on chitosan fibers (CSFs), high- and low-acyl gellan gum (HLG) was fabricated. The strong interactions between CSFs and HLG were confirmed by Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD) and thermogravimetric (TG) analysis. Differential scanning calorimetry (DSC) study shows that the dehydration activation energy decreases as the content of CSFs increases. The rheological measurement showed that the storage modulus of 2.0CSF-HLG (where 2.0 represents the mass ratio between CSF and HLG) hydrogels is 48 kPa at regular frequency of 1 rad/s, which is 1.8 times higher than that of HLG hydrogel. In addition, the SEM images demonstrated that 2.0CSF-HLG hydrogel exhibits three dimensional architectures with HLG attaching to CSFs. A weak swelling capacity of CSF-HLG hydrogels was observed, indicating fibroid CSFs would hinder the movement of HLG chain segments in solution. (C) 2014 Elsevier B.V. All rights reserved.