Pressure-controlled growth of piezoelectric low-dimensional structures in ternary fullerene C60/carbon nanotube/poly (vinylidene fluoride) based hybrid composites

Hybrid composites, consisting of polymers and nanostructured carbon allotropes, can exhibit different properties than their constituent components. In this work, the synergistic action of fullerene C60 and carbon nanotube (CNT) on poly (vinylidene fluoride) (PVDF) was evaluated, in terms of the dispersion of the carbonaceous fillers in the polymer matrix during the composite preparation, and the control of crystalline morphology of the polymer at high pressure. The synergistic effect of the zero-dimensional and one-dimensional carbon materials resulted in a well dispersed ternary C60/CNT/PVDF based composite, which was simply fabricated by a physical and mechanical route. Furthermore, the pressure-controlled growth of piezoelectric low-dimensional crystalline structures of PVDF, including hollow nanowires and extended-chain lamellae, was achieved by the simultaneous introduction of C60 and CNT. Especially, PVDF nanowires with folded- and extended-chain lamellae as their substructures were obtained respectively by controlling the crystallization conditions of the ternary composite at high pressure. Under specific conditions, composite samples, which crystalline structures were totally with extended-chain β- or γ-form lamellae, further self-reinforced with extended-chain β-form nanowires, were successfully crystallized. The present study provides a facile and effective approach for the fabrication and the multi-level control of polar crystalline structures of a polymer based hybrid composite, with an overall good dispersion of zero- and one-dimensional nanostructured carbonaceous materials.