Preparation And Performance Simulation Of Electrospun Polyvinylidene Fluoride Piezoelectric Nanofilms

Polyvinylidene fluoride(PVDF)has high piezoelectric output,is lightweight,convenient,and flexible,and is an important material for making flexible sensor devices.In this paper,electrospinning technology was used to optimize the preparation parameters,and pure polyvinylidene fluoride nano-piezoelectric fiber films with high voltage electrical properties were prepared.Using the first-principles calculation method,the process of PVDF molecular structure transformation under electric field polarization was simulated.This paper systematically explores the preparation,theoretical calculation and testing of polyvinylidene fluoride(PVDF)piezoelectric fiber film.The main research contents are as follows:1)The PVDF nano-piezoelectric fiber films was prepared by optimizing the spinning voltage.XRD and SEM were used to measure the crystal composition,fiber morphology,and fiber diameter distribution of the PVDF fiber film.The degree of fiber orientation and ?-phase content increased with the increase of spinning voltage.Large,but the situation becomes worse after the spinning voltage exceeds 24KV;The preparation of fiber filaments is nano-sized,with a single diameter between 300 and 1200 nm.The main crystalline component is the ? phase with a content between 72% and 79%.2)The first-principles calculation method is used to simulate the structural transformation and properties of PVDF molecules under electric field polarization.Two types of PVDF molecular models were established,and calculated and analyzed from the energy band structure and density of states of the electronic structure,and the complex dielectric function,absorption spectrum,reflection spectrum,dipole moment,and average molecular polarizability of optical angle.It was found that the ? phase has better properties than the ? phase in various aspects such as electron transition and photon absorption.The ??? phase transition process under different electric field strengths was simulated,and the electrical property strength of PVDF under different structures was calculated.The electric field can directly affect PVDF undergoes a phase transition.The more ?-phase content,the better thepiezoelectricity of PVDF.3)The quasi-static piezoelectric constant and dynamic piezoelectric response performance of PVDF nano-piezoelectric fiber film.Use D33 piezoelectric constant between about 15 p C/N?35p C/N.The PVDF nano-piezoelectric fiber film was prepared and assembled into a sensor,and its dynamic piezoelectric response was tested using a cantilever method.The output voltage value of each sample was obtained at a frequency of 10 Hz.The output voltage decreases when the spinning voltage exceeds 24 KV.The minimum output voltage of the sample is 100 m V,and the maximum output voltage is 4V.