【摘要】 从理论上计算了碳纳米管(CNT)与聚甲基丙烯酸甲酯(PMMA)的相互作用及浸润性,并测试了CNT/PMMA复合材料的电学、热学和光学性能.发现石墨化CNT/PMMA复合材料具有较好的导热和导电性能,其渗流阈值在0.8%左右,当CNT质量分数为3%时,复合材料的导热系数提高193%.这种电学及热学性能的提高一方面与石墨化CNTs的规整结构有关,另一方面与石墨化CNT-PMMA体系的弱相互作用、CNT间的有效接触以及高效的CNT网络输运性能有密切关系.研究结果表明,通过调控CNT与聚合物基体的表面性质、相互作用及浸润性,可以有效地构建优化的CNT输运网络,获得性能优异的功能复合材料.更多还原

【Abstract】 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 compo-sites were measured to evaluate enhancing effects 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.更多还原