Preparation And Application Of Flexible Polyaniline-based Electroconductive Hydrogels

Conducting polymer is a kind of polymer material with the function of delocalized p-πconjugated electron system.Polyaniline is the most widely and easily studied among all conductive polymers because the raw materials for making polyaniline are cheap and the synthesis process is simple.Polyaniline is also the most promising large-scale commercialized conductive polymer material due to its high stability and unique properties.Hydrogel is a flexible and three-dimensional(3D)material with excellent mechanical properties.Polyaniline conductive hydrogel combines the advantages of hydrogel and polyaniline,so it is widely used in supercapacitors and sensors.Therefore,polyaniline/polyacrylamide(PANI/PAAm)conductive hydrogel and polyaniline-gelatin/polyvinyl alcohol(PANI-Gel/PVA)conductive double-network hydrogel were synthesized,and their capacitance and pressure sensitivity were investigated.Thus,a flexible polyaniline-based conductive hydrogel with great research prospects in the field of supercapacitors and pressure sensors is presented.(1)Polyaniline electrode can be combined with hydrogels to form capacitors,was prepared by electrochemical method.This paper mainly changes the concentration of aniline and doped acid to synthesize different electrode sheets.After that,the electrochemical workstation was used to carry out cyclic voltammetry test,constant current charge discharge test and impedance test.Finally,it was found that the experimental parameters of electrode synthesis with the best electrochemical performance were 200 ml 1 mol/L hydrochloric acid solution containing 5 g aniline and200 ml 0.8 mol/L p-toluenesulfonic acid solution containing 2.6 g aniline,respectively.(2)In this paper,PANI/PAAm conductive hydrogels were studied.The influence of the concentration ratio of doped acid to aniline monomer on the performance of the synthesized polyaniline was investigated.The experimental data show that polyaniline with nanofiber structure can only be obtained stably at a specific concentration ratio.The electrochemical properties and pressure sensitivity of PANI/PAAm conductive hydrogels are best at this specific concentration ratio.When the concentration ratio of hydrochloric acid to aniline is 20:3 and the concentration ratio of p-toluene sulfonic acid to aniline is7:10,the performance of the capacitor assembled by hydrogel and polyaniline electrodes is the best,and its specific capacitance can reach 635 m F/cm~2 and 1022 m F/cm~2.Furthermore,the PANI/PAAm conductive hydrogel was connected with the electrochemical workstation and assembled into a sensor,which showed that the hydrogel could sense subtle changes in body movement.The results show that the capacitance and piezoelectric sensitivity of PANI/PAAm conductive hydrogel are closely related to the performance of polyaniline.(3)PANI-Gel/PVA conductive double-network hydrogel is a multifunctional conductive hydrogel.Compared with single-network hydrogels,the mechanical properties of double-network hydrogels can be enhanced by the presence of multiple cross-linked three-dimensional network structures.When a hydrogel is subjected to external forces,energy is dissipated when the structure of its internal multiple gel network is damaged,which further improves the strength of the hydrogel.In addition,the porous structure inside the hydrogel can provide space for the growth of polyaniline molecules in the hydrogel.Fibrous polyaniline has capacitance and electrochemical sensing functions,so the addition of polyaniline can give the hydrogel excellent electrochemical properties.The polyaniline hydrogel was prepared by using the concentration ratio of hydrochloric acid to aniline 20:3 and the concentration ratio of p-toluene sulfonic acid to aniline 7:10.Under these two experimental parameters,even if the hydrogel does not contain polyaniline electrodes,it can also have excellent electrochemical performance,and its specific capacitance can reach 311 m F/cm~2 and 485 m F/cm~2.Furthermore,when PANI-Gel/PVA conductive dual-network hydrogel is connected with the electrochemical workstation to assemble the sensor,it is found that the pressure sensitivity of the sensor composed of polyaniline doped with p-toluene sulfonic acid and hydrogel is the best.The results show that organic acid doped polyaniline has the best capacitance and electrochemical properties.Figure[33]Table[5]Reference[119]...