Balancing interface polarization strategy for enhancing electromagnetic wave absorption of carbon materials

摘要

The interface polarization are of great important for electromagnetic wave absorption (EWA). However, the tailored interfacial structure and corresponding effect on EWA remain a huge challenge. Here, a novel strategy of constructing interfacial hierarchical structure is reported to unveil such basic relationship. The melamine carbonized sponge (MCS) composites with interfacial hierarchical structure are successfully synthesized under the assistance of trace amounts of nickel metal catalysis. The as-prepared MCS composites present adjustable microwave absorption performance with carbonization temperature increasing from 600 to 900 degrees C. Experimental and simulation results reveal the excellent EWA benefitting from appropriate interface polarization. Moreover, the model of interface polarization in dielectric behaviors is proposed. As a result, the interface factor, beta, is found to be a key factor to balance interface polarization. Remarkably when the value of beta is optimized to 0.3, MCS8 (carbonized at 800 degrees C) achieves ultralight (5.36 mg cm(-3)) and strong absorption (reflection loss of -76.59 dB). This work also provides a novel and feasible idea for rational design and application of interfacial hierarchical structure toward high-performance carbon absorbing materials with low density.