Purified Preparation And Thermoluminescence Properties Of Single-walled Carbon Nanotube Fibers

Carbon nanotube fibers have the potential for multi-functional applications,such as ultrastrong composites,actuators,supercapacitors,lithium ion batteries,nanogenerators,sensors and so on,duing to their excellent electrical and mechanical properties,macroscopic maneuverability.At present,carbon nanotube fiber has been prepared continuously,but there are a large number of impurities in carbon nanotubes when quantity production,including catalyst particles and amorphous carbon.These impurities seriously restricts its performance and thus limit its application,so it is necessary to remove the impurities in practical applications.In this paper,a purification method combining current injection and acid treatment is proposed.The method can directly improve the purity of carbon nanotube fiber,accordingly,improve the electrical conductivity and tensile strength of the fibers.The carbon nanotube fibers purified by above-mentioned method are prepared into a helical fiber,which shows properties of stretchable and bendable.Then we used the helical fiber as a filament,which can be applied to a hot light source of stretchable and moldable.The main work content and conclusions are as follows:Single-walled carbon nanotubes(SWNTs)were prepared by chemical vapor deposition(CVD),and the single-walled carbon nanotubes straight fibers and helical fibers were prepared by dry spinning.Carbon nanotube straight fiber presents a standard flexional cylinder,and the structure of carbon nanotube helical fiber is extremely uniform.A method for the purification of carbon nanotube fibers by current injection and acid treatment was proposed.The instantaneous large current generated joule heat to oxidize carbonaceous impurities,exposing carbon-coated carbon nanotubes and iron catalyst particles while oxidizing iron to form ferric oxide.Ferric oxide is more likely to react with acids to achieve efficient purification.The purity of the purified fibers were increased to 94%.The conductivity of the purified fibers was increased to 4 times and the tensile strength was increased to 2 times.It is find that the component of Single-walled carbon nanotube helical fibers without purifying is very unstable during current injecting,because that the presence of impurities lead to the filament fiber undergoes serious structural deformation at high temperatures.In order to improve the stability of the thermoluminescence material,the carbon nanotube straight fiber was purified by the above purification method,and then the purified straight fiber was prepared as a helical fiber.The results show that the structural deformation of the helical fiber is effectively suppressed and the stability of the purified SWNT helical fiber is greatly improved...