Effects of heat treatment temperature on microstructure and electromagnetic properties of ordered mesoporous carbon

Ordered mesoporous carbon (OMC) powder was synthesized through template method to investigate its potential as an effective light weight electromagnetic interference (EMI) absorber in the frequency range of 8.2-12.4 GHz (X band). OMCs were heat-treated at 1400 °C, 1600 °C and 1800 °C, respectively, in nitrogen atmosphere for 2 h. The microstructures of the OMCs before and after heat treatment were studied. The dielectric property of the as-received OMC powders was measured. The average loss tangent (tan δ) of samples made from OMC powder heat-treated at 1400 °C was as high as 3.1, much higher than that of the sample made from OMC without heat treatment. Shielding mechanism was studied by resolving the total shielding effectiveness (SE) into absorption and reflection. Samples made from OMC powders heat-treated at 1400 °C and 1600 °C exhibit an EMI shielding behavior dominated by electromagnetic absorption mechanism, implying its promising perspective as electromagnetic wave absorbers.