Fabrication And Analysis On Electromechanical Properties Of The Carbon Nanotube/Polyvinyl Alcohol Composite Yarn

With the development of the society, the fabric plays a more and more important role in our everyday life. And the function of the fabric is not just for warming. There are more and more multifunctional fabrics, for example waterproof and breathable fabrics to improve the comfort, flame retardant fabrics to be used in the firefighting, UV resistant fabrics, and electromagnetic shielding fabrics. Among so many kinds of fabric, the smart fabric are getting more and more attention.Smart fabrics can be grouped to two categories. One is called fabric-based smart fabric, and the sensing elements or electrical circuits are directly attached on the fabric. The comfort of this smart fabrics is very poor; the other is called yarn-based smart fabric, and the conductive fibers, optical fibers, piezoresistive materials are directly attached on the fabric. The comfort of this smart fabrics is good, but the sensing properties is poor.In1991, doctor lijima of Japanese found a multilayer tubular carbon of nano-size structure, which is called carbon nanotube. Carbon nanotubes have lots of good properties, for example excellent modulus of1TPa, good stress of100GPa, and piezoresistive performance. But because of the nano-size, the application of the carbon nanotube is limited until the fabrication of the carbon nanotube yarns.The excellent piezoresistive performance of the carbon nanotube yarn can be used in the smart fabric, but the abrasion resistance of the carbon nanotube yarn is poor, the cost of the good mechanical properties carbon nanotube yarn is high, and the mechanical properties of the carbon nanotube yarns in low cost is poor. So the carbon nanotube yarn in low cost would be fabricated into the CNT/PVA composite yarn in the paper, and the research content is shown as the follow text:1. Three kinds of CNT yarns would be analyzed and one of them would be chosen to fabricate the composite yarn. One of the CNT yarn is prepared by the CNT Array, which is called the ACNT yam; and the other two is fabricate by the chemical vapor deposition, but the process parameters and diameter is different, and one is called FCNT14yarn and the other is called FCNT60yarn. At last, the FCNT60was chosen to prepare the composite yarn. 2. As for the compositing method, the Wind-dipping composite method was chosen from three kinds of the method (the Dunking method, the Dropping method and the Wind-dipping method). As for the polymer, the PVA was chosen and the different concentration of the PVA solution brought about different CNT/PVA composite yarns.3. Tensile properties and abrasion resistance of the five kinds of the composite yam and the FCNT60yam have been studied. When the concentration of the PVA solution was5%, the properties of the composite yarn was the best. And compared with the FCNT60yarn, the stress increased by22%, modulus increased by86%, and abrasion resistance time increased by110%. Besides, after compositing, the mechanical reversible properties and mechanical fatigue has been improved.4. Sending properties of the five kinds of the composite yarn and the FCNT60yarn have been studied. When the concentration of the PVA solution was5%, the sensing properties of the composite yarn was the best. And compared with the FCNT60yam, the gage factor increased by47.8%. Besides, after compositing, the electrical fatigue has been improved.