Electro-response characteristic of starch hydrogel crosslinked with Glutaraldehyde.

The facile synthesis of the starch hydrogel with anisotropic microstructure and dynamic behaviors was developed in the presence (A-gel) and absence of DC electric field (B-gel). The microstructures of hydrogels were characterized by environmental scanning electron microscope. Their electro-responsive property of hydrogels was investigated with their storage modulus (G'). The result demonstrates that the G' of A-gel is greater than that of B-gel, and the modulus of A-gel increases along with the external field, which signifies positive electroresponse. In addition, the G' of A-gel and B-gel ((G'(A) and G'(B)) also continuously increases with increasing starch concentration, whereas both the maximum of modulus increment (ΔG' = G'(A)−G'(B) ) and that of modulus increment sensitivity (ΔG'/G'(B)) occur with the starch weight fraction at around 36.5%. To enhance the electro-responsive effects of the hydrogels, dielectric particles were dispersed in the hydrogel. It is found that BaTiO3/chitosan core-shell composite particles significantly enhance the electroresponse of the hydrogel. The mechanism of the electro-response mode is proposed.