A simple and versatile method has been invented to fabricate conducting polymer hydrogels via supramolecular self-assembly between polymers and multivalent cations. As-prepared hydrogels composed of poly(3,4-ethylenedioxythiophene) and poly(styrenesulfonate) (PEDOT-PSS) exhibit expanded-coil conformation in polymer chains, phase-separate at nanometer scale, possess controllable microstructure, and is responsive to external stimulus. The conducting PEDOT-PSS hydrogels have then been introduced into multiple-network hydrogels to obtain composite hydrogels combining enhanced mechanical strength and excellent electrical activity. Triple-network (TN) and special double-network (sDN) hydrogels, containing poly(acrylic acid) (PAA) and poly(acrylamide) (PAAm) as the matrix respectively, are successfully prepared. Finally, PEDOT-PSS hydrogels with self-strengthening function are directly fabricated via a one-step process under optimized conditions. The strengthening mechanisms for each kind of hydrogels are proposed, and the applicability in electrosensors, supercapacitors and electromechanical actuators are briefly demonstrated.
Synthesis of new conducting materials on the basis of polymer hydrogels
