| As an important category of functional fibers,conductive fibers have attracted widespread attention in recent years due to their electrical,thermal,and electromagnetic shielding properties.The applications of conductive fibers in high-performance devices such as thin film transistors,solar cells,energy storage devices,flexible electronic devices,batteries,and wearable devices have increasingly become a research hotspot.Conductive fibers have novel features such as flexibility,stretchability and light weight have particular advantages in application of wearable electronic devices.However,the existing conductive fibers cannot have the above characteristics at the same time,nor can they meet technical requirements for mass production.For this reason,core/shell type conductive fibers were prepared by coating carbon nano-conductive dispersion on flexible polyester fibers to meet the requirements of lightweight,flexible and mass production on the premise of high conductivity.The specific research contents and innovation results are as follows:?1?With water as solvent and ionic liquid as dispersant,three kinds of waterborne resins emulsion?polyurethane,acrylic resin and epoxy resin?were used as interface enhance additive to prepare environmentally friendly carbon nanotubes conductive dispersion.The fluidity and non-Newtonian properties of the conductive dispersions were investigated by rheological behavior.The thermal stability of the conductive dispersions were investigated by thermogravimetric analysis.The strong interaction between carbon nanotubes and waterborne resins was demonstrated by Raman spectroscopy.The dispersibility of carbon nanotubes in conductive dispersions were studied by UV spectroscopy.The results showed that conductive dispersions have good dispersibility and stability.?2?The interaction between conductive dispersions and polyester fibers during the coating process was studied.MWCNTs-acrylic resin conductive dispersion had the highest conductivity and the lowest resistance with carbon nanotube content of 4%.The electrical conductivity of MWCNTs-acrylic resin dispersion was 1.264×10-3 S/cm and the surface resistance of obtained fiber can reach to 732?/cm.After five times coating,resistance of fiber could be kept below 100?/cm.At the same time,wetting process of conductive dispersions on polyester fibers were observed and adhesion works were calculated.The MWCNTs-polyurethane resin conductive dispersion and MWCNTs-acrylic resin conductive dispersion had better wettability and adhesion to polyester fibers.The morphology of conductive layer and distribution of carbon nanotubes and resins on the surface of conductive fiber were observed by scanning electron microscopy.It was proved that this simple coating process could form dense conductive layer on the surface of polyester fibers.Carbon nanotubes and resins in conductive layer were tightly and uniformly distributed.At the same time,mechanical strength of obtained fibers were tested,when the content of carbon nanotubes was 4%,the ultimate tensile stress and elongation at break of the MWCNTs-acrylic resin coated conductive fibers were 261 MPa and 25%,respectively.After heat treatment of conductive fibers,it can be found that conductive layer and polyester fiber was more tightly bonded,and resistance of fiber can be reduced about 20%when conductive fibers were treated at 220°C.?3?The binding energy of-2.78 kal/mol between carbon nanotube molecular and polyester molecular was calculated by quantum chemistry calculation method.This binding energy not only form a strong interaction between carbon nanotubes and polyester substrate but also enhance mechanical properties of conductive fibers.?4?The carbon nanotubes and graphene were combined to obtain a high conductivity composite conductive dispersion with a conductivity of 1.83×10-3 S/cm,and the resistance of coated fiber can reach to468?/cm.In addition,the properties of composite conductive dispersion and its interaction with polyester fibers were studied. |
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