Preparation Of Ionic Conductive Hydrogel Fibers And Research On The Performance Of Flexible Electronic Devices

Ionic conductive hydrogel is an elastomer material that obtains high conductivity through the migration of ions in its three-dimensional network.Due to its good signal transmission and mechanical adaptability,it is an excellent candidate for the development of flexible wearable electronic devices.It has been explored for the preparation of energy storage and conversion devices,such as nano-generators,supercapacitors,etc.Elastomer materials developed by various conductive hydrogels have become an important part of the development of flexible wearable electronic devices.However,there are still Ionic conductive hydrogels that are difficult to prepare into fibers through traditional spinning strategies,and they have poor spinnability and ease.Problems such as water loss have greatly restricted the application of Ionic conductive hydrogels in the field of flexible wearable electronic fabrics.Therefore,it is of great research value to prepare ion-conducting hydrogel fibers by spinning and use them to develop flexible wearable electronic devices.Based on these problems,this paper uses acrylamide and N-acryloylglycinamide as monomers,chloride and lithium ions as mobile ions to prepare supramolecular hydrogels with non-covalent multiple hydrogen bonds,and combine dry-wet Ionic conducting hydrogel fibers were developed by the method spinning process,and flexible strain sensors and fabric-type friction nanogenerators were prepared based on this fiber.The main research contents are as follows:1)The ionic conductive supramolecular hydrogel was prepared by copolymerizing N-acryloylglycinamide and acrylamide as monomers and adding lithium chloride.Using the thermoreversible gel-sol transition characteristics of supramolecular hydrogels and the dry-wet spinning strategy,an ionic conductive hydrogel fiber with a core-shell structure was prepared.This hydrogel fiber has high electrical conductivity(0.63 S m^-1),good stretchability（percentage of breaking elongation 919.4%）,and mechanical strength（2.3MPa）.And under the protection of polymethyl acrylate coating,after 15 days of continuous water loss,the quality retention rate of more than 70%can still be maintained.2)The ionic conductive hydrogel fiber is used as a flexible strain sensor to monitor the large deformation caused by the bending of human joints and analyze the body language represented by the output electrical signal.Since this Ionic conductive hydrogel fiber has a good quadratic relationship between resistance change rate and deformation,we can describe the relationship between sensor deformation and resistance change rate by fitting a highly correlated quadratic polynomial function.And this strain sensor has a large strain response range（0-300%）,the short response time（140-160 ms）,and other characteristics,which ensure that this strain sensor can be used to monitor the electrical signal caused by joint angles change.3)The Ionic conductive hydrogel long fibers with core-shell structure obtained by dry-wet spinning strategy have good spinnability.It is woven into a fabric by knitting,and this fabric can be made into a fabric-type single-electrode triboelectric nanogenerator by contacting and separating the fabric with other different materials.This kind of triboelectric nanogenerator can effectively collect the mechanical energy wasted during exercise and convert it into electrical energy to provide energy for commercial light-emitting diodes and electronic watches.Among them,contact and separation with the PTFE film can generate an open circuit voltage of 36 V per cycle,a short circuit current of 0.7μA,and a transfer charge of 10 n C.After more than 1800 cycles,the output still maintains good stability.