材料期刊网

Electrical and thermal conductivities of carbon nanotube (CNT)/polymer composites are greatly hindered by polymer-wrapping around CNTs due to high surface energy of CNTs. The graphitized multi-walled CNTs filled poly(methyl methacrylate) (PMMA) were investigated on the basis of surface physical chemistry and wetting thermodynamics. The electrical and thermal conductivities of the graphitized CNT/PMMA composites were measured to evaluate enhancing affects of the graphitized CNTs. The graphitized CNT/PMMA composites exhibit high electrical conductivity and a low percolation threshold of is 0.8% (mass fraction), and the thermal conductivity of the composites with 3% (mass fraction) increases by 193% in comparison with that of the neat PMMA, which is due to the integrated microstructures of the graphitized CNTs, weak CNT-PMMA interactions, low contact resistance between CNTs, and efficient conducting CNT-networks. We suggest that high-performance composites can be designed and fabricated by fully considering the surface energy of components and the filler-polymer interactions.