# Effects of Carbon Fillers on Electrical and Mechanical Properties of Water-Based Polymer Nanocomposites

## TL;DR

This study explores how adding carbon fillers to a water-based polymer affects both electrical conductivity and mechanical properties, showing that the right mix can create flexible and conductive materials for electronics.

## Contribution

A novel water-based method for creating rGO-MWCNT/polymer composites with tunable electrical and mechanical properties is introduced.

## Key findings

- MWCNT-rich fillers achieved the highest conductivity (up to 8.2 × 10−3 Sm−1) due to a segregated filler network.
- Mechanical properties like elongation at break increased significantly with specific filler ratios and loadings.
- The study highlights the need for careful optimization of filler content and ratios for flexible electronics applications.

## Abstract

Both the electrical conductivity and tailored mechanical characteristics—showing flexibility and structural integrity—are key properties of polymer composites. In this work, a novel, simple, and water-based strategy for synthesizing rGO-MWCNT/polymer composites was developed. Namely, carbon nanofillers in a mixture of reduced graphene oxide (rGO) and multi-walled carbon nanotubes (MWCNTs) were incorporated in a waterborne methacrylic polymer matrix at loadings of 0.25, 0.5, and 1.0 wt.% nanofiller, and with rGO-to-MWCNT ratios of 10:1, 1:1, and 1:10 (w/w) at room temperature. Electrically conductive composites were obtained with all tested filler rates showing the highest conductivity (up to 8.2 × 10−3 Sm−1) for the MWCNT-rich filler due to the formation of a segregated network of the filler in the matrix. The mechanical properties of the composites—characterized by their Young’s modulus and elongation at break—strongly depended on both the filler incorporation rate and the rGO:MWCNT ratio. For instance, soft and flexible composites were obtained by incorporating 0.25 wt.% of the MWCNT-rich filler, which increased the elongation at break from 154.2% (neat polymer) to 252.4%. Overall, this study emphasizes the sensitive interplay between carbon filler introduction incorporating conductivity and the fillers’ impact on the mechanical properties of a polymer composite, both necessitating careful optimization for applications, e.g., in flexible electronics.