Enhanced the properties of carbon‐paste nanocomposite by carboxylation of multi‐walled carbon nanotubes

Abstract

In the present study, attempts were made to manufacture innovative conducting polymer nanocomposites (CPCs) with high performance, low cost, and appropriate electrical, mechanical, and thermal properties. However, one of the main challenges in creating CPCs is the tendency of nanofillers to agglomerate and accumulate, resulting in a decrease in the electrical properties and performance of CPCs. To address this issue, the study developed an efficient and eco‐friendly CPC using carboxymethyl cellulose (CMC) as a binder and carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) as nanofillers. The study employed a chemical functionalization method to modify CNTs and enhance their compatibility and dispersion properties in the CMC matrix. The prepared CPCs were characterized using various techniques, including Fourier‐transform infrared spectroscopy, x‐ray diffraction, and field emission scanning electron microscopy. The results showed an improvement in homogeneity and surface cohesion between CMC and O‐CNTs through chemical surface modification of CNTs via carboxylic acid functional groups. The study observed good dispersion of nanofillers without any aggregation of the CMC/GNP/O‐CNT compared with the nontreated CMC/GNP/CNT composite. While a decrease in the degree of crystallinity was observed, conductivity increased for the CPC containing oxidized CNTs. The study found that the highest conductivity of ~112 S/m was obtained for D‐CMC/GNP/O‐CNT with 25 wt% of O‐CNT, while the maximum conductivity of D‐CMC/GNP/CNT was ~80 S/m with 35 wt% of CNTs. Additionally, the study observed an improvement in electrochemical properties after treatment of CNTs in the form of higher cathodic current in cyclic voltammetry and lower charge transfer resistance in impedance spectroscopy of D‐CMC/GNP/O‐CNT35 compared to untreated one.Highlights Preparation of new conductive nanocomposite consisting of CMC, CNTs, and GNPs. Carboxylation of CNTs to improve O‐CNT and CMC intermolecular interaction CMC/GNP/O‐CNT is 40% more conductive than unmodified CNT nanocomposite. Higher thermal stability and mechanical properties were observed by using O‐CNT. O‐CNT caused higher current density and lower electron transfer resistance for CPCs.