Preparation Of Multifunctional Piezoelectric Polyacrylonitrile Electrospun Fiber Membrane And Its Application In Flexible Sensors

PVDF and PAN are both piezoelectric polymers,which have received more and more attention.In this study,polyacrylonitrile with low dielectric loss and large dipole moment（3.5 Debye）was selected,and PAN nanofiber membrane with high content of planar zigzag conformation was successfully prepared by electrospinning technology.There are two structures in the PAN molecule.,when the planar zigzag conformation content is greater than 3¹helical conformation（that is,the planar zigzag conformation is dominant）,the prepared PAN nanofiber membrane will produce higher piezoelectric output,and the piezoelectricity is also better,thus obtaining a high-voltage output The polyacrylonitrile film,in addition,a simple pressure sensor device was fabricated,and this technique demonstrated the commercialization prospects of polyacrylonitrile film.In this paper,by adding inorganic fillers（Ba Ti O₃,Ionic Liquid（IL）,Fe Cl₃·6H₂O,Eu（NO₃）₃·6H₂O）to PAN,the PAN after adding inorganic fillers was tested by SEM,FTIR,XRD,LCR and other testing methods.The structure and properties were characterized,and the research contents included:（1）Influence of inorganic filler content on the morphology,piezoelectric properties,dielectric properties,and sensitivity of sensor devices of PAN composite fiber membranes;（2）Adding different inorganic fillers,The effect of PAN composite fiber membrane on the properties;（3）The effects of single filler and two-component filler on the performance of PAN composite fiber membrane were studied,and then the mechanism of the two-component filler system was explored.Research indicates:（1）.Adding an appropriate amount of KH550 modified Ba Ti O₃,the dielectric properties of the composite fiber film are greatly improved.The loss is greatly increased（up to 0.50）,and the increase in dielectric loss is very unfavorable for its application.At the same time,the addition of Ba Ti O₃also endows the composite fiber film with ferroelectric properties,and the polarization strength of the PAN/Ba Ti O₃composite fiber film(P_sat)is 0.46μC/cm²,which is nearly twice that of pure PAN fiber membrane（0.24μC/cm²）,and breakdown electric field（E_b）of 1450 k V/cm is much higher than that of pure PAN fiber membrane（780 k V/cm）;（2）.When the PAN concentration remains unchanged,by adding an appropriate amount of IL,the dielectric constant of the composite fiber membrane can reach 6.14.While increasing the dielectric constant of the PAN composite fiber,its dielectric loss remains basically unchanged（only 0.03～0.05）.Better than PAN/Ba Ti O₃system.When a small amount of IL is added,the PAN fibers will have certain orientation characteristics,the fibers are neatly distributed on the receiver,and due to the influence of the electrostatic field,the content of the plane zigzag conformation in the PAN molecule is increased（>90%）,and the highest possible Up to93.08%,it can improve its piezoelectric properties,and due to the orientation of the fibers,the mechanical properties of the composite fiber film are also greatly improved,its Young’s modulus is 3.88 MPa,the strain is 110%,and the sensitivity of the prepared sensor device can be Up to 0.56 k P^-1higher than PAN/Ba Ti O₃system(0.47 k P^-1);（3）.After adding Fe Cl₃·6H₂O and IL,the size of PAN fibers will decrease due to the increase of the conductivity of the solution.In most cases,the fiber diameter increases with the increase of the additive content,but when the charged particles in the solution When increasing,the fiber diameter decreases instead,and the addition of dual fillers can greatly improve the dielectric properties of PAN fibers（<0.05）;（4）.The addition of Eu（NO₃）₃·6H₂O not only imparts fluorescence properties to the PAN composite film,but also greatly improves the sensitivity of the sensor device(0.69 k Pa^-1),which is higher than that of the PAN/IL system(0.56 k P^-1)and PAN@Fe/IL system(0.51k P^-1).