Developing strong and tough carbon nanotube films by a proper dispersing strategy and enhanced interfacial interactions

A new approach for making carbon nanotube (CNT) films that are both strong and tough is detailed in this paper. Aqueous dispersions of long CNTs were first obtained by dispersing CNT arrays with heights of about 200 mm in deionized water with the help of polyvinylpyrrolidones (PVPs) and polydopamines (PDAs). CNT films were then obtained by vacuum-assisted filtration of CNT dispersions. The tensile strength and toughness of the composite films can be as high as 143.5 MPa and 5.0 MJ/m(3), respectively, which was 330.7% and 213.8% higher than CNT films made without using PVPs and PDAs. The underlying mechanism of PVPs and PDAs induced CNT film strengthening and toughening was revealed through preliminary molecular dynamics simulations, which indicated that the hydrogen bonds between the PVPs and PDAs enhanced the strength of the film, and these bonds can cyclically break and reform, making CNT films tougher. The strategy proposed here can also be applied to making other nano-materials based strong and tough macro-assemblies. (C) 2019 Published by Elsevier Ltd.