Enhanced electro-responsive behaviors of agar/xanthan gum interpenetrating compound hydrogel

The agar/xanthan gum compound hydrogels were synthesized with/without a direct current (DC) electric field, and their behaviors and structure were investigated by dynamic mechanical analyzer (DMA), scanning electron microscope (SEM), infrared spectroscopy (IR), and thermo gravimetry and differential scanning calorimetry (TG-DSC). The results demonstrate that GA (the storage modulus of the agar/xanthan gum compound hydrogel gelled with an electric field) is greater than GB (that gelled without an electric field). The maximum of modulus increment (ΔG = GA-GB) and modulus increment sensitivity (ΔG/GB) appear when the xanthan gum weight fraction is at 0.8 wt%, which is the best electro-response of the compound hydrogels. The agar/xanthan gum compound hydrogel also exhibits a positive electro-response effect by increasing with the increasing field strength. All the response behaviors point to the conclusion that the DC electric field induces a more ordered and denser network structure of agar/xanthan gum compound hydrogel.