Single-walled carbon nanotube nucleated solution-crystallization of polyethylene

Solution crystallization of polyethylene (PE) with single-walled carbon nanotubes (SWNTs) was investigated by morphological observations and thermal analyses of the resultant films. In this study, long chains of ultrahigh-molecular-weight (UHMW) PE were chosen for a possible interaction with SWNTs. The solvent used was dichlorobenzene, which can disperse both SWNTs and UHMW-PE chains in a hot solution. Electron microscopy observation revealed that a unique network morphology composed of PE single-crystalline lamellae connected by SWNT backbones is developed after cooling to room temperature. A comparison of the obtained morphologies for different SWNT concentrations suggested that SWNT surfaces function as nuclei for solution-crystallization of UHMW-PE. The melting behavior of the films prepared from the aggregates of UHMW-PE/SWNT composites indicated that SWNTs prevent the thickness doubling of solution-crystallized PE lamellae during heating, which is usually observed for the stacked single crystals of pure PE.