Epoxy composite sheets with a large interfacial area from a high surface area-supplying single-walled carbon nanotube scaffold filler

Closed single-walled carbon nanotubes (SWCNTs) with the highest available specific surface area (>1000 m2/g) were used to provide a very large interfacial area with the matrix to fabricate epoxy composite sheets. Through mechanical redirection of the vertically aligned SWCNTs, we created a laterally aligned “scaffold” sheet, into which epoxy resin was impregnated. The SWCNT scaffold was engineered in structure to meet two almost mutually exclusive demands, i.e. to have nanometer mesopores (∼2–50 nm) to facilitate homogeneous impregnation of the epoxy resin and to possess a cohesive mechanical strength to tolerate the compaction forces generated during impregnation. Through this approach, a SWCNT/epoxy composite sheet was realized where long and aligned SWCNTs were loaded at a high weight fraction (33%) with an intertube distance approaching the radius of gyration for polymers. The resultant composite showed a Young’s modulus of 15.0 GPa and a tensile strength of 104 MPa, thus achieving 5.4- and 2.1-fold reinforcement compared to the epoxy resin.