Chemo-responsive bilayer actuator film: fabrication, characterization and actuator response
A chemo-responsive bilayer actuator was fabricated by cross-linking a polysaccharide based highly hydrophilic material with the polyamide-6 (PA-6) substrate. The hydrogel material was prepared by grafting the polyacrylamide (PAAm) and poly(acrylic acid) (PAA) copolymer onto carboxymethyl cellulose (CMC) [poly(AA-co-AAm)-g-CMC]. The successful grafting of the copolymer onto CMC was confirmed by Fourier transform infrared spectroscopy and thermogravimetric analysis. The swelling behavior of the poly(AA-co-AAm)-g-CMC hydrogel was examined at a range of pH values and ionic strengths. Fabrication of the bilayer actuator was performed by drop casting a poly(AAm-co-AA)-g-CMC solution onto a PA-6 substrate followed by subsequent cross-linking under ultraviolet radiation. Cross-linking was performed to make the material readily swellable in water but prevent complete dissolution. The actuator response was measured in both water and ethanol.