Dual-stimuli sensitive composites based on multi-walled carbon nanotubes and poly(N,N-diethylacrylamide-co-acrylic acid) hydrogels

A strategy to prepare dual-stimuli sensitive poly(N,N-diethylacrylamide-co-acrylic acid) composite hydrogels has been demonstrated. Multi-walled carbon nanotubes (MWCNTs) functionalized with vinyl groups were copolymerized with N,N-diethylacrylamide (DEA), acrylic acid (AA) and N,N′-methylenebisacrylamide (NNMBA) to obtain the composites (NCG). As expected, the compression properties of the NCG were greatly improved without noticeably reducing the response rates to temperature changes. Field emission scanning electron microscopy showed that the surface of the NCG was denser, which affords the NCG better compression properties, while there was obvious MWCNTs aggregation on the surface of the hybrid gel sample by physical mixing of the MWCNTs (HYG).