Poly(vinyl alcohol)/borax/modified silver nanowire composite hydrogel with self-healing, high conductivity, and electromagnetic interference shielding properties

Abstract

The increasing prevalence of electronic devices has led to a notable rise in the severity of electromagnetic interference (EMI). Nanofillers in conventional EMI shielding materials aggregate in the matrix, affecting their usability. Hence, with the aim of optimizing the dispersion of silver nanowires (AgNWs) within the matrix and augmenting its conductivity, we herein report a method for modifying silver nanowires and conduct an exhaustive investigation into its practical implementation and performance. An ultra-long aspect ratio AgNWs with an average length of 150.23 μm, an average diameter of 129.82 nm, and an aspect ratio of about 1157 was prepared. Surface hydroxylated silver nanowires (M-AgNWs) were obtained by bis(2-hydroxyethyl) disulfide modification. Polyvinyl alcohol (PVA) and borax hydrogel systems were prepared by the addition of M-AgNWs, resulting in the formation of PVA/Borax/M-AgNWs hydrogels (PB/M-AgNWs). The tensile strength of the self-healing PB/M-AgNWs (0.1 %) hydrogel was able to reach 78 % of the original value. The PB/M-AgNWs (0.2 %) hydrogel, with a conductivity of 3.59 S/m, exhibited a conductivity of 3.09 S/m following self-healing at room temperature, with an estimated self-healing efficiency of 86 %. The hydrogel EMI shielding effectiveness of 2 mm PB/M-AgNWs (0.1 %) is 32.03 dB. 8 mm PB/M-AgNWs (0.1 %) hydrogel has an EMI shielding effectiveness of 65.10 dB, which is 99.9999 % attenuation of the incident electromagnetic waves (EMW).