Polyethylene/carbon nanotube nano hybrid shish-kebab obtained by solvent evaporation and thin-film crystallization

Crystallization of polymers on carbon nanotubes (CNTs) has resulted in a novel nano hybrid shish kebab (NHSK) structure, within which CNTs serve as the nucleation sites (shish) and polymer lamellar crystals form the kebabs. Previously reported NHSK structures were obtained by solution crystallization, bulk crystallization and physical vapor deposition methods. Herein we report a simple, rapid, yet effective approach to produce NHSK materials using solvent evaporation and thin film crystallization. Polyethylene (PE) was used as the model polymer. PE solution was drop cast on CNT-coated carbon films, and upon solvent evaporation, PE crystallized onto/near CNTs, following the template of the latter and NHSK structure was then formed. The final morphology was found to result from the competition between heterogeneous nucleation and homogeneous nucleation of PE. The formation of NHSK also strongly depends on the structure of CNTs as well as the molecular weight of PE. This work shows a facile method to form NHSK and to study CNT-induced crystallization under nonequilibrium conditions.