Alignment of Carbon Nanotubes in Poly(methyl methacrylate) Composites Induced by Electric Field

An ideal carbon nanotube (CNT) network structure in poly(methyl methacrylate) (PMMA) can be attained by adjusting simultaneously both evolution of the CNTs alignment in methyl methacrylate (MMA) monomer under alternating current (AC) electric field and polymerization of MMA. Alignment of the CNTs in liquid media is time dependent and can be enhanced by increasing suitably the voltage and frequency of the electric field. There is an optimal time window in which the ideal alignment is achieved after which the alignment degrades and the CNTs start to agglomerate due to the transverse interactions. Viscosity of the MMA increases with its polymerization, and the macro motion of CNTs stops when the viscosity is high enough. Polymerization of the MMA can be accelerated or slowed down by changing polymerization temperature and initiator concentration. If the two courses, the alignment of CNTs and the polymerization of MMA, intersect at a proper point, preferred CNTs alignment will be preserved and the prepared CNT/PMMA composites will be endowed with novel properties.