High Strength AgNWs/PAm Composite Hydrogels: Synthesis and Conductivity Study

Conductive hydrogels, as a kind of functional polymeric soft material, have been demonstrated a wide application prospect in the field of flexible electronics devices in recent years. Therefore, it is of great value to develop a synthesis method for conductive hydrogels with high strength in both fundamental and applied research. In this work, we present a facile method for preparing high-strength hydrogels, in which one-dimensional silver nanowires (AgNWs) are effectively composited with sulfur-containing organic polymers via Ag-S coordination, significantly improving the strength of hydrogel, and also imposing high conductivity. The details for this hydrogel are as follows: First, linear polythioether (P1) with side vinyl groups is obtained by ring-opening polymerization of 1-allyloxy-2,3-sulfopropane, and subsequently a sufficient amount of carboxyl groups are introduced through thiol-ene click reaction to endow its solubility in water. The modified linear polythioether (P2) interacts with AgNWs to afford composited cross-linking agent (AgNWs@P2) through Ag-S coordination. The cross-linking agent and acrylamide (Am) monomer were polymerized in water using potassium persulfate (KPS) as the free radical initiator to prepare silver nanowire/polyacrylamide composite hydrogels (AgNWs/PAms, AC gels). The images of high-resolution field emission scanning electron microscope confirm the effective composition of AgNWs and P2 in nanoscale. The introduction of rigid AgNWs provides hydrogel with excellent mechanical strength and the largest elongation and maximum fracture stress strength can reach similar to 4500% and similar to 2.2 MPa, respectively. In addition, this hydrogel has high conductivity of 0.44 S/m. During the stretching process, the change of electrical resistance is linearly related to the deformation of the hydrogel, and especially this process has good cyclic stability. The stable resistance response capability of AC gel provides a promising application in the field of flexible electronics devices. [GRAPHICS] .