GRAPHENE MODIFIED E-TEXTILE : AN INDUSTRY RELEVANT APPROACH OF DOPING AND VISUALISING A FULLY TEXTILE P-N JUNCTION DIODES

Abstract: As a wonder material, graphene has been studied in various applications due to its exceptional properties. Recently it has been used in textile to obtain functionalised garments as E-textile. From an industry-relevant perspective, it is essential to introduce a process that could be scaled-up. GO dispersion has been used in this project as the main component to functionalize the textile. Polyester and viscose woven fabrics were treated in alkali and chitosan solution to get better attraction and coating with the GO. A dip coating has been performed and a reduction of the GO-coated samples has been done subsequently. This study includes the investigation of reduction parameters such as concentration and time of the process, using tannic acid as bio-sourced agent and dithionite sodium. Samples were characterized by water contact angle showing a better uptake of the GO dispersion and better coating performance when treated. Zeta potential measurement has been displayed, showing the surface charge change from negative to positive after the treatment. The sheet resistance has been obtained and results shows that the treatment and the choice of the reducing agent the reduction parameters (concentration and time) have a big effect on the conductivity. The lowest mean resistance that has been measured for both viscose and polyester are around 2.61 kO/? and 4.45 kO/? respectively. These resistances have been achieved by reducing the GO-coated samples using 100 mM of sodium dithionite solution as reducing agent for 60 minutes. Afterward, these E-textiles are both p-type and n-type doped, using nitrogen plasma treatment to prepare nitrogen-doped graphene as a p-type E-textile and electrochemical deposition of titanium on graphene as n-type doped E-textiles. Doping of rGO-modified textiles open a visualization of the p-n junction fully-textile diodes and its further applications.