Effect of Nano Silica Fillers on Dynamic Mechanical Performance and Accelerated Ageing Behavior of Carbon/Epoxy Composites

Abstract

The impact of nano-silica (NS) fillers on the mechanical and aging characteristics of carbon fiber epoxy composites (CFECs) is examined in this work. Composite samples with 0–6 weight percent NS were exposed to UV light and moisture to hasten aging. According to Dynamic Mechanical Analysis (DMA), the glass transition temperature (Tg) improved by 6.6%, reaching a peak of 48.57 °C, while the storage modulus (E′) increased by up to 27.5%, from 184 GPa in NS0-U to 234.5 GPa in NS4-U. At 2–4% filler loading, interlaminar shear strength (ILSS) decreased by 45% as a result of nanosilica addition. The NS4-U sample's Charpy impact strength was 60 kJ/m2, yet there was a noticeable overall drop in impact resistance as the filler content increased. Upon ageing, all properties showed degradation; however, NS4-A composites retained higher mechanical properties than the aged unfilled baseline, confirming the filler’s role in enhancing environmental resistance. These results highlight that optimal NS loading (4 wt%) can significantly reinforce CFECs while offering improved ageing durability.