Closed-loop recycling and fabrication of hydrophilic CNT films with high performance

Carbon nanotube (CNT) film has attracted tremendous attention in functional material research for its unique structure and excellent properties. However, pristine CNT (PCNT) film is hydrophobic, and mechanical strength and conductivity are poor than reported individual CNT. These challenges impede its wide application. Highly efficient closed-loop recycling of both monomer and CNT film is a major challenge. Herein, hydrophilic CNT film with high mechanical strength and conductivity was prepared under the synergistic effects of nitrogen doping and thiol-ene click reaction. The tensile strength, Young’s modulus, and electrical conductivity both in perpendicular and in longitudinal directions are 1,362, 1,658, 222, and 218% higher than those of PCNT film. Closed-loop recycling of CNT film and monomer with high recyclability (100 and 86.72%) has been achieved in a gentle acid environment. The CNT films are 100% recovered and reused to fabricate thiol-functionalized CNT film without deterioration of performance after three cycles, which provides a novel strategy for the preparation of high-performance CNT film and a pathway for high-efficiency closed-loop recycling of CNT film and monomer.