Nanomaterials 2022, 12, 3986. https://doi.org/10.3390/nano12223986 www.mdpi.com/journal/nanomaterials Article Carbon Fabric Decorated with In-Situ Grown Silver Nanoparticles in Epoxy Composite for Enhanced Performance Meghashree Padhan 1,2 , Umesh Marathe 1,2 and Jayashree Bijwe 1,2, * 1 Centre for Automotive Research and Tribology, Indian Institute of Technology, Delhi 110016, India 2 Industrial Tribology, Machine Dynamics and Maintenance Engineering Centre, Indian Institute of Technology, Delhi 110016, India * Correspondence: jbijwe@gmail.com Abstract: The current study focuses on studying the effect of reinforcement of carbon fabric (CF) decorated with in-situ grown silver (Ag) nanoparticles (NPs) on the performance properties of epoxy composite. The Ag NPs were grown on carbon fabric by reducing silver nitrate. The main objective of developing such an innovative reinforcement was to improve thermal conductivity, in- terlaminar strength, and tribological properties of CF-epoxy composites. The growth of NPs on the surface of CF was confirmed through scanning electron microscopy (SEM), energy dispersive X-Ray spectroscopy (EDAS), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction studies. The development of composites was conducted by the impregnation method, followed by compression molding. It was observed that in-situ growth of Ag NPs enhanced thermal conductivity by 40%, enhanced inter-laminar shear strength by 70%, enhanced wear resistance by 95%, and reduced the friction coefficient by 35% in comparison to untreated CF. Keywords: silver nanoparticles; carbon fabric; epoxy; nano-composites 1. Introduction Carbon fiber reinforced polymer composites have been applied in diverse fields, such as automotive, aviation, aerospace, fuel cell, turbomachinery, antistatic and electro- magnetic shielding, compressed gas storage, transportation, and other related fields, by virtue of their unique properties, including high specific strength, stiffness, thermal sta- bility, self-lubricity, and thermal conductivity. For such polymer composites, the fiber- matrix interface is a critical parameter to performance properties. The surface of carbon fibers, being smooth, chemically inert, and hydrophobic in nature, leads to a weak inter- action with polymeric chains. Hence, surface modification of carbon fibers by various techniques (dry, wet, and multiscale), and treatments with chemicals, plasma, high energy irradiation, electrochemical deposition, etc. (excluding the grafting of carbon nanotubes (CNTs), graphene, or some nanoparticles (NPs) etc.), have been successfully explored in the past few decades [1–22]. An exhaustive literature survey showed that NPs at the in- terface greatly improve properties, and the technique has been increasingly explored for strengthening the interface [17,23]. The treatment with YbF3 was effective at the optimum dose of 0.3 wt.%. A higher dose of NPs led to agglomeration, reducing the benefits. It is quite challenging to either retain or enhance the benefits by increasing the dose of NPs without agglomeration. The present work addresses this issue, and the results are dis- cussed in the subsequent sections. Metallic NPs on the surface offer the additional advantage of imparting higher ther- mal conductivity (TC) and electrical conductivity (EC). Liu and Kumar [24] reviewed the current advancements in carbon-fiber structure, fabrication, and properties in detail, in- cluding incorporating carbon nanotubes (CNTs) in the precursor fiber to improve the me- chanical properties. Thostenson et al. [25] studied CNTs-carbon fiber, hybrid fibers based Citation: Padhan, M.; Marathe, U.; Bijwe, J. Carbon Fabric Decorated with In-Situ Grown Silver Nanoparticles in Epoxy Composite for Enhanced Performance. Nanomaterials 2022, 12, 3986. https://doi.org/10.3390/ nano12223986 Academic Editor: Yongfu Lian Received: 14 October 2022 Accepted: 7 November 2022 Published: 12 November 2022 Publisher’s Note: MDPI stays neu- tral with regard to jurisdictional claims in published maps and institu- tional affiliations. Copyright: © 2022 by the authors. Li- censee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and con- ditions of the Creative Commons At- tribution (CC BY) license (https://cre- ativecommons.org/licenses/by/4.0/).