Enhanced mechanical and electrical properties of carbon nanotube buckypaper by in situ cross-linking

Inter-tube cross-linking of carbon nanotubes (CNTs) is an effective approach to improve the inter-tube stress and current transfer abilities. Results of the microstructure characterization indicated that the cross-linking of CNTs in the solution induced severe tube aggregations, which had a negative impact on the mechanical and electrical properties of the buckypaper. To avoid the tube aggregations, an in situ cross-linking technique was developed by filtering the 1,4-benzoquinone solution through the as-prepared buckypaper. Micro-tensile and electrical conductivity testing results indicated that the bulk mechanical and electrical properties of the in situ cross-linked buckypaper were improved significantly. Interestingly, the in situ cross-linking process changed the Poisson’s ratio of the buckypaper from positive to negative. An overall evaluation and application perspectives of the buckypaper were also noted.