Effect of multi-walled carbon nanotube additive on the microstructure and properties of pitch-derived carbon foams

The multi-wall carbon nanotube-reinforced carbon foams were prepared via foaming, carbonization, and graphitization process using pretreatment pitches as matrix precursor and modified multi-wall carbon nanotube as additive. The effects of modified multi-wall carbon nanotube additive amount on the microstructure, mechanical strength, thermal conductivity, and electrical conductivity of carbon foams were investigated by X-ray diffraction, scanning electronic microscopy, universal testing machine, laser thermal conductivity tester, and four-probe resistance meter, respectively. It was found that the introduction of modified multi-wall carbon nanotube had a significant effect on the microstructure of carbon foams. The compressive strength and electrical conductivity of carbon foams increased with the increase of modified multi-wall carbon nanotube additive amount, the maximum were 11.72 MPa and 28.89 × 10³ S/m, respectively. However, the thermal conductivity of carbon foams increased firstly with increasing modified multi-wall carbon nanotube additive amount up to 2 wt%, and then decreased.