Enhancing soundproofing performance of polypropylene nanocomposites for implantable electrodes inside the body through graphene and nanoclay; thermomechanical analysis

Abstract

This study explores the creation and evaluation of nanocomposites formed by integrating polypropylene (PP) with montmorillonite nanoclay and graphene nanosheets (GNs). The nanocomposites were produced via melt blending, utilizing different proportions of clay to GN, ultimately achieving a total loading of 4 wt. %. The objective is to utilize these materials in brain pacemakers to minimize noise and improve the signal-to-noise ratio for brain electrodes. While past studies have mainly focused on enhancing electrode materials within the brain, little attention has been given to the pacemaker material, particularly at the outlet gate. This study bridges this gap by investigating the noise-reducing properties of PP nanocomposites. The primary aim was to determine the optimal clay to GN ratio in the PP matrix. The results indicate that the perforated architecture of the nanocomposite, featuring scattered microspheres within the polypropylene matrix that form an extended channel, facilitates the dissipation of sound waves, rendering it ideal for acoustic insulation in brain pacemakers. In addition, the nanocomposite composed of 2.75% clay and 1.25% graphene nanosheets in the polypropylene matrix demonstrated a markedly improved signal-to-noise ratio in comparison to other examined nanocomposites. Moreover, this study examined the impact of adding PP-g-MA on the sound properties of the nanocomposite, revealing that it was not effective for sound absorption due to its more coherent structure. Various tests were conducted on the nanocomposites to evaluate properties such as tensile strength, elongation percentage, and impact toughness. Dynamic mechanical analysis and thermogravimetric analysis were also carried out to assess dynamic storage modulus and thermal stability. Overall, the study aimed to explore the thermal and mechanical attributes of the nanocomposites for potential use in brain pacemakers, highlighting the significance of choosing nanocomposites based on ductility characteristics for pacemaker applications.