Preparation And Piezoelectric Properties Of Polyaniline Composite Fiber Membranes

There are very abundant small mechanical energy and vibration energy in life.How to convert these small mechanical energy into usable energy,and the development of mechanical energy-to-electricity conversion devices have aroused great research interest.Most of the existing mechanical energy-electric energy conversion devices produce alternating current output and cannot be used directly.Polyaniline(PANI)is a polymer with good electrical conductivity.After forming an energy device with Al electrode and Au electrode,it produces DC output under compression cycle.In this paper,by optimizing the process conditions,a device with good electromechanical conversion performance is prepared,and its DC output mechanism is analyzed.Firstly,PANI is loaded on pure polyester fabric and pure cotton fabric by in-situ polymerization to prepare PANI composite fabric.The effects of different doping acid,doping acid concentration,aniline concentration,oxidant type,initial molar ratio of oxidant to aniline,oxidation time and oxidation temperature on the electromechanical conversion performance of PANI composite fabrics were discussed.The results show that PANI is the doping acid is hydrochloric acid,the doping acid concentration is 0.5mol/L,the aniline concentration is 0.3 mol/L,the oxidant is ammonium persulfate,the initial molar ratio of the oxidant to aniline is 1,and the oxidation temperature is room temperature(26 ?)the best oxidation degree and load state,the best electromechanical conversion performance.The best oxidation time on polyester fabric is 120 min,and the best oxidation time on pure cotton fabric is 90 min.Through scanning electron microscopy(SEM),infrared spectroscopy(FTIR),X-ray diffraction analysis(XRD),thermogravimetric analysis(Tg)and fabric mechanical property testing,the interaction between the fabric and PANI was analyzed.The results show that different preparation conditions affect the degree of oxidation of PANI and the surface state of the fabric loaded on the fabric,thereby affecting the electromechanical conversion performance of the PANI composite fabric.The PANI wafer was prepared using the optimal process conditions of the previous study.The electromechanical conversion performance of the PANI wafer,PANI polyester composite fabric,and PANI pure cotton composite fabric was compared.The result showed that the PANI polyester composite fabric was 3.75 of the output voltage of the PANI wafer.Times,57 times the output current.Tests have proved that the surface roughness of the device affects its frictional contact area,thereby affecting the amount of surface charge and causing differences in electromechanical conversion performance.In order to further study the mechanism of DC output,compare the effects of compression conditions on electrical output,change the charging method,prepare different electroplating electrode combinations,and test the I-V curve under different electrode combinations.The results prove that the DC output comes from the Schottky contact between PANI and Al electrode,and the electrical output of the device mainly comes from the friction charge generated by PANI and Al during the compression cycle.