Open Journal of Composite Materials, 2019, 9, 230-248 http://www.scirp.org/journal/ojcm ISSN Online: 2164-5655 ISSN Print: 2164-5612 DOI: 10.4236/ojcm.2019.92013 Apr. 29, 2019 230 Open Journal of Composite Materials Enhancing the Mechanical Strength for a Microwave Absorption Composite Based on Graphene Nanoplatelet/Epoxy with Carbon Fibers Maryam Jahan, Richard Osuemeshi Inakpenu, Kuo Li, Guanglin Zhao * Physics Department, Nano Catalysts Laboratory, Southern University and A&M College, Baton Rouge, LA, USA Abstract Microwave absorption (MWA) materials such as graphene nanoplatelet (GNP)/epoxy are mostly used as coatings on existing structures without con- sidering mechanical properties. In this work, we aim to enhance the mechan- ical strength of the composite for multifunctional potentials. We used carbon fiber (four layers) to reinforce GNP/epoxy composite (2 mm thick) and in- vestigated their multifunctional properties with GNP loading from 3 to 7 wt%. We measured the tensile strength, hardness, and MW absorption (26.5 - 40 GHz) of composite samples. Our results showed an increase in tensile strength to 109.1 ± 7.9 MPa with 7 wt% GNP in the composite from 15.3 MPa for pure epoxy. The hardness of the composites was also substantially en- hanced with GNP loading up to 7 wt%. A MW absorption ratio of 72% was attained for the sample with 7 wt% GNP loading near 40 GHz. The homo- genous dispersion of GNPs in the matrix reduces the stress concentration and minimizes the influence of the defects. The high MW absorption and large transmission loss together with enhanced mechanical strength provides a novel multifunctional material for potential applications. Keywords Microwave Absorption, Mechanical Strength, Graphene Nanoplatelet/Epoxy/Carbon Fiber Composite, Multifunctional Composite 1. Introduction Electromagnetic-wave absorbing (EMA) materials are designed to provide elec- How to cite this paper: Jahan, M., Inak- penu, R.O., Li, K. and Zhao, G.L. (2019) Enhancing the Mechanical Strength for a Microwave Absorption Composite Based on Graphene Nanoplatelet/Epoxy with Carbon Fibers. Open Journal of Composite Materials, 9, 230-248. https://doi.org/10.4236/ojcm.2019.92013 Received: March 29, 2019s Accepted: April 26, 2019 Published: April 29, 2019 Copyright © 2019 by author(s) and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/ Open Access