Radially grown carbon nanomaterials on hollow glass microspheres and their application in composite foams with excellent electromagnetic interference shielding

Abstract In the current study, we investigated the effect of processing temperature in chemical vapor deposition (CVD) on the formation of carbon nanomaterials over the hollow glass microsphere. The surface morphology and structural information of the carbon nanomaterials (CNM)‐coated hollow glass microsphere (HGM) were analyzed through scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Then, the 5‐CH [CNF‐coated HGM (Synthesizing temperature in CVD being 500 °C)], 6‐CH [MWCNT‐coated HGM (Synthesizing temperature in CVD being 600 °C)], and 7‐CH [MWCNT‐coated HGM (Synthesizing temperature in CVD being 700 °C)] were individually used as fillers in the epoxy composite foam. Thorough characterization of mechanical and thermo‐mechanical behavior suggests that compression stress, compression modulus, and storage modulus of 6‐CH‐based composite foam are higher than the 5‐CH‐ and 7‐CH‐based composite foam with the contribution of 10%, 15%, and 20%, respectively. The electromagnetic interference (EMI) shielding effectiveness over the frequency of 8–12 GHz increased from 15 dB for without HGM to 21 dB, 25 dB, and 23 dB for 5‐CH, 6‐CH‐, and 7‐CH‐based composite foam, respectively. It is also noticed that, 6‐CH‐based composite foams presented the highest EMI‐SE compared to 5‐CH‐ and 7‐CH‐based composite foams. Enhanced mechanical, thermo‐mechanical, and shielding properties of 6‐CH‐based composite foams are due to improved morphology and quality of CNT grown at 600°C.