Designing high-performance ultrathin composites with spread carbon fiber and carbon dots modified epoxy resin

Abstract

Combining spread carbon fiber (CF₂₄) with an epoxy matrix modified by carbon dots (CDs), this study develops ultrathin composites exhibiting superior mechanical, thermal, electrical, and electromagnetic interference (EMI) shielding performance. The fiber spreading process enhances fiber alignment, contributing to the high-performance characteristics of the composites. The incorporated CDs demonstrate excellent compatibility and dispersion within the epoxy resin, and participate in the curing reaction, leading to a notable improvement in matrix properties. Optimal performance is achieved at a CDs loading of 0.15 wt%, with the resulting composite showing increases of 54.79 % in transverse fiber bundle strength, 37.02 % in interlaminar shear strength, and 24.83 % in compressive strength relative to the baseline CF₂₄ composite. Moreover, the 0.15 wt% CDs composite exhibits the highest thermal diffusivity, the lowest electrical resistivity, and an exceptional EMI shielding effectiveness of 41.84 dB. This work broadens the application scope of CDs in epoxy resin systems and demonstrates a viable strategy for fabricating functionalized ultrathin carbon fiber reinforced polymer composites with integrated multifunctional properties.