A self-standing silver/crosslinked-poly(vinyl alcohol) network with microfibers, nanowires and nanoparticles and its linear aggregation

Abstract

Silver/polymer nanocomposites have made inroads into the fields of electronic devices, thermally conductive materials, antimicrobial agents and sensors. Here, we present the hydrothermal synthesis of a novel three-dimensional self-standing silver/crosslinked-poly(vinyl alcohol) (Ag/crosslinked-PVA) hybrid network constructed by linking three different subunits, namely, microfibers, nanowires and nanoparticles. One-dimensional crosslinked-PVA-based microfibers act as the skeleton of the sponge. Ag nanoparticles are uniformly embedded in the interior of the microfibers, and Ag nanowires grow outward from the interior of the microfibers. This Ag/crosslinked-PVA multi-architecture has not be observed or reported in current state-of-the-art studies. We simultaneously carry out two types of reactions, chemical reduction of Ag+ ions and intermolecular crosslinking of PVA chains, in the synthesis under hydrothermal conditions. Ag nanoparticles are formed and dispersed in the crosslinked-PVA microspheres. Then, these Ag/crosslinked-PVA microspheres bridge each other, forming microchains and microfibers. Ultimately, linear aggregation, which has rarely been mentioned in the literature, occurs in some adjacent Ag nanoparticles in the microfibers, and the Ag nanoparticles reorganize into nanowires. The Ag/crosslinked-PVA network is shown to be converted into a Ag/C composite through annealing, which exhibits electrocatalytic activity for glucose oxidation and can be used as a self-supporting electrode in an antibacterial nonenzymatic glucose sensor.