Preparation And Applications Of Flexible Electronic Materials Based On Natural Polymers

Natural biological materials provide economical and abundant raw materials for the research of the next-generation of wearable flexible electronic devices,which have the advantages of wide sources,low pollution to environment and low price,etc.Therefore,taking these natural substances as raw materials for chemical research is conducive to promoting the development process of green chemistry.There are a lot of phenol compounds(TP)from green tea and can be used as to modify various substrate surfaces.It usually takes a long time to reach the ideal polymer layer,and the introduction of poly(ethyleneimine)(PEI)can significantly shorten the time of the polyphenols'oxidative polymerization grafting to the substrate surface,they are cross-linked to various substrate surfaces by Schiff base chemistries and Michael addition reactions,which formed a hydrophilic TP/PEI layer on the surface via some supramolecular interactions,secondly,the introduction of PEI can increase the sites for seizing catalyst ions so that the obtained metal layer has good conductivity and flexibility.Herein,a universal strategy of nature-inspired and amine-promoted metallization(NIAPM)is presented to make high quality metal layer for various kinds of flexible electronics with good performance.The specific content of our study is as follows:(1)Universal nature-inspired and amine-promoted metalization for flexible electronics and supercapacitorsThe natural phenolic compounds from green tea are cross-linked with PEI in a weakly alkaline buffer solution(pH=8.5)by Michael addition and Schiff based chemistries to form polymer layer and graft to various substrates,then the surface of substrate contains a large number of amine groups,and the catalyst is immobilized by ion exchange,finally,the electroless plating of metal films on various substrates were carried out in the corresponding plating baths.The as-made thin metal films of Cu and Ni feature high conductivity(~1.0?/?),excellent mechanical stability and flexibility even at the bending radius of~1 mm,this indicates that the mechanical properties of the metal layer are very strong.In terms of application,firstly,the typical lithography technique is used to fabricate metallic patterns on the flexible substrates,and the flexible circuit diagrams that can control the lighting of different LED lights are prepared.Secondly,two devices based on melamine-templated Cu sponges are prepared for detecting the change of external pressure with a resistance sensitivity of 18.1kpa~-11 and it is also used to separate high viscosity crude oil from water,respectively.Finally,the used tea leaves are collected and carbonized as electrode materials,a cloth deposited with nickel is used as a collecting fluid and conductive substrate,and then the electrode material is dipping-coated on the nickel cloth to assemble a high performance flexible solid supercapacitor.This method can be widely used in the preparation of flexible supercapacitors from biomass carbonized materials.(2)Preparation of conductive fiber materials from waste bamboo fibersBamboo is a kind of natural material with excellent flexibility and mechanical durability,the waste bamboos are processed by hydrothermal method to make bamboo fiber materials,the surface of bamboo fiber materials are modified with pyrogallic aicd(PG)and PEI,the metal is deposited on the surface of the substrates by electroless deposition.Finally,it is made into fiber materials with good conductivity.We mainly explore the conductivity and stability of the material and its application in the field of sensor.