Influence of the Chemical Modification of Carbon Nanotube Fibers on Electrical properties and Electromechanical Response

The electromechanical response (EMR) of carbon nanotube (CNT) fibers is related to the densification process of the CNT network driven by electromagnetic force. The study of the interaction between the electrical properties and the electromechanical response of carbon nanotubes is of great theoretical significance for exploring the microstructure of carbon nanotube fibers and developing the related flexible electronic devices. This study investigated the relationship between the conductive pathway network and EMR, by analyzing the internal structural characteristics of the CNT fibers after undergoing hydrogen peroxide oxidation and iodine modification. The results show that impurities such as amorphous carbon impeded electron transport and deformation of CNT networks. After hydrogen peroxide oxidation treatment, he carbon nanotube surface impurities inside the fibres were reduced, the van der Waals forces between carbon nanotubes were increased, the deformation of the carbon nanotube network was enhanced, and the negative effect of the decrease in the elastic modulus of the fibres caused by the increase in temperature was weakened. In the case of iodine-decorated CNT fibers, carbon-iodine bonds effectively strengthened the interaction between CNTs, but hinders the contraction of the carbon nanotube network, resulting in a weaker electromechanical response. Hydrogen peroxide oxidation treatment is more beneficial than iodine modification to improve the shrinkage and deformation ability of carbon nanotube fibres in the electromechanical response.