In spite of worldwide research, carbon nanotubes (CNTs) still have not fully realized their
original promise as ideal reinforcements for composite materials due to a number of
challenging issues such as weak interface, poor dispersion, misalignment and lack of optimized
design. Here we propose a bio-inspired structure of CNT bundles with controllable
crosslink density and staggered pattern of organization that mimic the architecture of
natural collagen fiber. Molecular mechanics (MM) simulations show that, under tensile
loading, the bio-inspired CNT bundles undergo a transition in failure mode from CNT
pull-out to CNT break as the crosslink density increases, with strength an order of magnitude
higher than that of the existing strongest conventional carbon fibers. Based on the MM
simulations, a generalized tension-shear chain model with four dimensionless parameters
is developed to guide the design of CNT bundles for optimized mechanical properties.
The paper is available online in CARBON, http://authors.elsevier.com/a/1PPDo1zU9zgIT