Preparation of silver nanoparticles by solid-state redox route from hydroxyethyl cellulose for antibacterial strain sensor hydrogel

•The silver nanoparticles were synthesized by solid-state reduction method.•The effects of the initiators for the polymerization with silver nanoparticles and silver ions.•The mechanical property of the polyacrylamide improved by hydroxyethyl cellulose.•The hydrogel was both antibacterial and conductive for strain sensor.•The Gauge Factor was 4.73 at the range of 125 %–200 % strain. As a smart wearable sensor device, the mildew of the biocompatible hydrogel limits its application. In this paper, silver nanoparticles were prepared by solid-state reduction of hydroxyethyl cellulose and compounded into a chemically cross-linked hydrogel as an antibacterial, flexible strain sensor. Because the high surface energy of silver nanoparticles can quench free radicals, we designed three initiators to synthesize hydrogels: ammonium persulfate (APS), 2,2'-Azobis(2-methylpropionitrile) (AIBN) and 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AIBA). Impressively, silver nanoparticles composite hydrogel could only be successfully fabricated and triggered by the AIBN. The mechanical property of the composite hydrogel (0.12 MPa at 704.33 % strain) was significantly improved because of dynamic crosslinking point by HEC. Finally, the composite hydrogels are applied to the field of antibacterial strain sensor and the highest Gauge Factor (GF) reached 4.07. This article proposes a novel, green and simple strategy for preparing silver nanoparticles and compounding them into a hydrogel system for antibacterial strain sensor.