Actuator materials based on graphene oxide/polyacrylamide composite hydrogels prepared by in situ polymerization

Actuator materials based on graphene oxide/polyacrylamide (GO/PAM) hydrogels were prepared by in situ polymerization. Their structure and properties were characterized by scanning electron microscopy, X-ray photoelectron spectrometry, thermogravimetric analysis, Fourier transform infrared spectroscopy and mechanical testing. The results indicate that some PAM macromolecules were grafted onto the GO nanosheets, and this led to good dispersion of the GO nanosheets in the composite hydrogels and consequently a significant improvement of their mechanical properties. The compressive strength of the GO/PAM hydrogel loaded with 1 wt% GO increased 6-fold in comparison to that of pure PAM hydrogel. The GO/PAM based hydrogels were responsive to external stimuli such as pH and electric fields.