Experimental investigation on the influence of silanized graphene coatings on carbon fiber composites as toughening agents at low temperatures

Abstract

Several applications of carbon fiber are being investigated, with the alteration of the carbon fiber surface using graphene based nanoparticles as the primary focus. But, in the present study, carbon fiber was surface modified with 3-aminopropyl trimethoxysilane functionalized graphene nanoparticles using the electrophoretic deposition (EPD) method, and the CFRP composite laminate was fabricated using the VARTM method. The matrix comprises diglycidyl ether of bisphenol A (DGEBA) and triethylenetetramine (TETA) hardener. To assess toughness behaviour, the modified CFRP samples were subjected to charpy impact tests at both room temperature (RT) and cryogenic temperature (CT). The impact strength of CFRP specimens was enhanced by 14.8% and 18.7% at RT and CT, respectively. FTIR analysis was conducted to confirm the presence of flexible silane bonding. SEM analysis was conducted to further examine the fracture surface. At CT, silane functions as a flexible coupler inside CFRP laminates, imparting toughness to CFRP laminates.