Insight into profiled CNT/polymer interphase: A molecular dynamic simulation study of load transfer and shock response

In this paper, by utilising molecular dynamic simulations, profiled carbon nanotubes (CNT), represented by CNT containing bead and spiral structure, were built from warping graphene layers with carefully introduced defects. The tensile behaviour of profiled CNTs, pulling and shock response of profiled CNTs within the polyamide matrix were investigated and compared to the corresponding conventional CNT. The result indicates that as mechanically interlocked with the matrix, profiled CNT could effectively relieve the stress concentration during load transfer by distributing the stress into a larger part of the matrix. In this case, a more efficient load transfer could be achieved, thus contributing to the mechanical performance of the composite without modification of the chemical structure. However, the profiling geometry, which is shaped by defects, will introduce stress concentration within the profile CNTs when subject to a tensile load. The stress concentration may not only deteriorate the tensile performance of CNTs, such as ultimate load at break and modulus but also result in an earlier deformation. In this case, care should be taken during the design phase of the profiled CNT. For shocking responses, profiled CNTs were capable of constraining the local chain move thus contributing to the integrity of the composite system during shockwave propagation.