Viscoelastic, ductile and repairable carbon nanotube films formed with CNT/PEI double networks containing branched polyethylenimine

Manipulating nanostructure assemblies is important in using them as structural and functional materials. Carbon nanotubes (CNTs) lack the ability to reconstruct their entangled network. In this work, we report a strategy with which to realize efficient manipulation of CNT networks by forming double networks with branched polyethylenimine (PEI). The double network was highly viscoelastic and ductile and enabled efficient film stretching or creeping for CNT alignment, which dramatically improved the mechanical strength of the CNT films. Due to the viscous drag from the polymer network, the CNTs showed enhanced movability in reconstructing new networks, which made the film repairable. The repairability resulted from the branched polymeric structure. This double-networking strategy provides a new way to manipulate CNT assemblies for high-performance applications. In this work, we report a strategy with which to realize efficient manipulation of CNT networks by forming double networks with branched polyethylenimine (PEI). The double network was highly viscoelastic and ductile and enabled efficient film stretching or creeping for CNT alignment, which dramatically improved the mechanical strengths of the CNT films. Due to viscous drag from the polymer network, the CNTs showed enhanced movability in reconstructing new networks, which made the film repairable. The repairability resulted from the branched polymeric structure. This double-networking strategy provides a new way to manipulate CNT assemblies for high-performance applications.