Bioinspired nanocomposites film with highly-aligned silicon carbide nanowires and polyvinyl alcohol for mechanical and thermal anisotropy.

This work reports a bioinspired anisotropic nanocomposite by polar solution assisted mechanical stretching method, consisting of polyvinyl alcohol (PVA) and silicon carbide nanowires (SiCNWs) with aligned morphology in one direction. Inspired by the structural mimicry of myofibers, in which the uniaxial mechanical property of materials can be improved evidently, highly-aligned SiCNWs and PVA chains that interact using intermolecular force can be obtained. Hysteresis is observed and reversible deformation occurs while tensile-relaxation cycles are applied to the 100% stretched SiCNWs/PVA nanocomposites. The nanocomposites exhibit excellent properties and the tensile strength of 100% stretched SiCNWs/PVA nanocomposites is 188.30 ± 4.2 MPa and elastic modulus is 6.95 GPa, which are increased by 421.90% and 581.37% compared with pure PVA. Finite element simulation of fracture mechanism shows good agreement with the experimental results. An improvement of thermal conductivity is also achieved in well-aligned SiCNWs/PVA. The work imitates the structure of mammal muscle and also has great potential for the macroscopic application of one-dimensional nanomaterials as super flexible heat dissipation materials.