Three-Dimensional (3D) Conductive Network of CNT-Modified Short Jute Fiber-Reinforced Natural Rubber: Hierarchical CNT-Enabled Thermoelectric and Electrically Conductive Composite Interfaces

• Main Authors: Lazaros Tzounis, Markos Petousis, Marco Liebscher, Sotirios Grammatikos, Nectarios Vidakis
• Format: Article
• Language: English
• Published: MDPI AG 2020-06-01
• Series: Materials
• Subjects: three-dimensional (3D) conductive network; conductive polymer composites (CPCs); thermoelectric elastomers; thermoelectric composites; hierarchical reinforcements; nanostructured interfaces
• Online Access: https://www.mdpi.com/1996-1944/13/11/2668

Jute fibers (JFs) coated with multiwall carbon nanotubes (MWCNTs) have been introduced in a natural rubber (NR) matrix creating a three-dimensional (3D) electrically conductive percolated network. The JF-CNT endowed electrical conductivity and thermoelectric properties to the final composites. CNT networks fully covered the fiber surfaces as shown by the corresponding scanning electron microscopy (SEM) analysis. NR/JF-CNT composites, at 10, 20 and 30 phr (parts per hundred gram of rubber) have been manufactured using a two-roll mixing process. The highest value of electrical conductivity (<i>σ</i>) was 81 S/m for the 30 phr composite. Thermoelectric measurements revealed slight differences in the Seebeck coefficient (<i>S</i>), while the highest power factor (<i>PF</i>) was 1.80 × 10⁻²<i>μ</i>W/m K⁻² for the 30 phr loading. The micromechanical properties and electrical response of the composite’s conductive interface have been studied in peak force tapping quantitative nanomechanical (PFT QNM) and conductive atomic force microscopy (c-AFM) mode. The JF-CNT create an electrically percolated network at all fiber loadings endowing electrical and thermoelectric properties to the NR matrix, considered thus as promising thermoelectric stretchable materials.