An effective approach for the fabrication of reinforced composite hydrogel engineered with SWNTs, polypyrrole and PEGDA hydrogel
High-quality conductive composite hydrogels composed of single-walled carbon nanotubes (SWNTs), polypyrrole (PPy) and poly(ethylene glycol) diacrylate (PEGDA) hydrogel were successfully fabricated through interfacial polymerization (IP). Compared to the conventional sequential interpenetrating polymerization (CI), IP is superior in improving the electrical/electrochemical properties of the incorporated hydrogel due to the higher content of PPy up to 14.1 wt% in its dry weight. The electrical conductivity of PPy/PEGDA hydrogel is nearly more than two orders of magnitude higher than that of the hydrogel prepared via CI. Furthermore, simultaneous incorporation of SWNTs and PPy results in significantly enhanced compressive modulus, from 183 ± 13 kPa to 1823 ± 201 kPa. Electrochemical measurements clearly indicate that the electron-transfer resistance is significantly decreased from 9320 Ω of native PEGDA hydrogel to 247 Ω of SWNT/PPy/PEGDA composite hydrogel.