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

Lazaros Tzounis; Markos Petousis; Marco Liebscher; Sotirios Grammatikos; Nectarios Vidakis

doi:10.3390/ma13112668

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

Materials (Basel). 2020 Jun 11;13(11):2668. doi: 10.3390/ma13112668.

Authors

Lazaros Tzounis¹, Markos Petousis², Marco Liebscher³, Sotirios Grammatikos⁴, Nectarios Vidakis²

Affiliations

¹ Department of Materials Science and Engineering, University of Ioannina, 45110 Ioannina, Greece.
² Mechanical Engineering Department, Hellenic Mediterranean University, Estavromenos, 71004 Heraklion, Greece.
³ Institute of Construction Materials, Technische Universität Dresden, DE-01062 Dresden, Germany.
⁴ Group of Sustainable Composites, Department of Manufacturing and Civil Engineering, Norwegian University of Science and Technology, 2815 Gjøvik, Norway.

Abstract

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 (σ) was 81 S/m for the 30 phr composite. Thermoelectric measurements revealed slight differences in the Seebeck coefficient (S), while the highest power factor (PF) was 1.80 × 10^-2 μW/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.

Keywords: conductive polymer composites (CPCs); hierarchical reinforcements; nanostructured interfaces; thermoelectric composites; thermoelectric elastomers; three-dimensional (3D) conductive network.