New processing method to fabricate high-performance carbon-nanotube/polyvinyl alcohol composite films

Bad dispersion, low volume fraction, and poor alignment of long carbon nanotubes (CNTs) in a polymer matrix are the main reasons for the disappointing performance of CNT reinforced polymer composites. Here, we report a novel technique for the preparation of high performance CNT/Polyvinyl alcohol (PVA) composite films, involving continuous production of a hollow cylindrical CNT assembly from a tubular reactor and its in-situ deposition on a paper substrate wrapped on a winding drum under the spray of a PVA solution. The distribution, alignment and loading of CNTs in the composite film are easily tailored by changing the winding rate and the PVA concentration in the spray solution. It is found that the properties of the prepared film are strongly dependent upon the CNT loading in the film. At the optimal high CNT loading of 56.8 wt%, the tensile strength has reached 3.16 GPa, and electrical conductivity 1322 S cm−1. This combination of mechanical and electrical properties is superior to any other CNT/polymer composites developed to date. In terms of its versatility and simplicity, the reported process paves a new way for continuous production of high-performance CNT reinforced composites.

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