Preparation Of Carbon Nanotube Fibers And Their Application As Electrothermal Materials

With the development of science and technology,nanomaterials are getting into people's life in various ways,meanwhile the requirements for used nanomaterials gets more and more stringent and diversify,people hope that the material could be more portable,secure and multifunctional so that it can play a role in life.Carbon nanotubes(CNTs),as a member of nanomaterials,with the deepening of scientific research personnel,it has made great progress in many ways in recent years.the paper mainly studies the preparation method of macro CNTs fiber,and then explore the application of the CNTs fibers which was used as electrode material in the arc;and with the traditional electric materials(nickel-chromium wire)heating comparative experiments to explore the feasibility of new electric CNTs fiber materials,the main results are as follows:(1)By fixing the two ends of CNTs cylinder to the electric motor shaft,setting the twisting speed of the motor can prepare longer CNTs fibers,and then strong,flexibility,lower density CNTs fibers can be prepared after pass through the hole of the wire-drawing die,the CNTs fiber can withstand bending without damage.Through the Raman detection,the values of IG/ID is 6.9,the result indicates that the CNTs fiber has high degree of graphitization.(2)At a lower voltage of 30 V,CNTs fiber and metal wire were respectively connected to the positive and negative,they can generate electrical arc in the contact area,and the voltage of produced arc which is much lower than that of a metallic material in contact with each other solely,and generates sufficiently large intensity arc which emit a lot of heat can melt the metal electrode.After the arc reaction,the crystallinity of CNTs had a little change.Experiments show that,CNTs fibers may be used repeatedly in an arc experiments.Produce such a high intensity arc showed that as electrode materials,CNTs fiber have great potential application in welding,melting metal or other relevant areas.(3)Under the voltage of 20 V or even more lower voltage,CNTs fiber as a heating wire will emit more intense infrared light while the voltage increases,and the temperature of the heating wire is also increasing,indicating that as heating material its unique microstructure has a great advantage;and because CNTs fiber has excellent thermal conductivity,while disconnect the power supply at the moment,CNTs fibers from the red-hot state immediately turned back to the original black,and shine effects is hardly change after repeated use,indicating that as a heating material it has very stable cycling performance.(4)At the same voltage,5 cm long CNTs fiber and 50 cm long nickel-chromium alloy wire has substantially the same heating effect at the same voltage of 9 V,mainly because the larger resistance value of per unit length of the CNTs fiber,although the size difference between the larger and the nickel chromium wire,but it does not affect its heating effect,taking into account that light quality,better flexibility of CNTs fiber,it has better heating effect than conventional nickel-chromium heating wire,indicating there are great prospects in electric-thermal materials.(5)The heating effect of CNTs fibers mainly influenced by its resistance,since the CNTs itself are composed of porous network structure in micro,unlike metallic dense,so its density is also an important factor in apply to electric-thermal materials.Experiment that CNTs fibers with different densities were heated 100 ml distilled water,CNTs fiber with lager density has better heating effect,mainly due to CNTs with larger density comprising more CNTs bundle inside the fiber,such that electrons have more channels circulation,reducing resistance,at the same voltage,higher heating power to heat faster.So as electric-thermal materials the CNTs fiber with larger density will have better heating effect.