Study On Preparation And Electro-mechanical Conversion Of Polymer/Graphite Composite Materials

Electroactive polymer?EAP?has excellent motor conversion properties and can be used in flexible actuators,electronic skins,resonant sensors,etc.The electrode material is very important for EAP performance,as shown in the following:polymer electrodes can overcome conventional ionic EAP—Ion exchange polymer metal composites?IPMC?have the disadvantages of water loss,large modulus,and high cost;the adjustable mechanical properties of the polymer can realize the preload-free out-of-plane movement of the electronic EAP-insulating elastomer?DEA?.In this thesis,perfluorosulfonic acid polymer?PFSA?,silicone rubber?PDMS?,and polyvinylidene fluoride?PVDF?are used as the base film.The effect of electrode composition,mechanical and electrical properties on EAP actuation performance is studied.The goal is to obtain an EAP that is commercially available.The results are as follows:1.Using metal Pt nanoparticles as electrodes and sulfonic acid SiO₂ nano-colloid?HSO₃-SiO₂?hybrid PFSA membrane as base film,an IPMC electric actuator with high water content and high ion exchange equivalent was prepared.Compared with conventional IPMC,the new metal nanoelectrodes of IPMC are denser,with higher conductivity and water retention;the water content?WU?and ion exchange equivalent?IEC?of the base film are 1.57 and 2.37 times that of the pure PFSA film;electrical actuation The performance is obviously optimized,the displacement output is increased by 51%,the force output is increased by 233%,and the stable working time is extended by 346%2.PVDF membrane IPMC electroactuators for water and ionic-liquid drives have been prepared using PVDF/graphite?Gr?as electrodes.A new technique for the preparation of hydrophilic polyvinylidene fluoride?PVDF?electrolyte film with polyvinylidene pyrrolidone?PVP?as a pore-forming agent and ionic liquid?IL,[EMIm]·[BF₄]?as a plasticizer was proposed.The porosity of the prepared electrolyte precursor film was as high as 15.8%,and the contents of water and IL reached 44.2%and 38.1%,respectively.Compared with the traditional PVDF/IL material IPMC,the force output of water and IL-driven IPMC prepared in this paper increased by 13.4 times and 3.0 times,and the displacement output increased by 2.2 times and 1.9 times,respectively.The carbon/PVDF composite electrode used has good compatibility with the base film,making the electron transmission between the electrode and the base film more stable and able to withstand the input of a larger voltage,so it can be a large displacement and large drive of the actuator The development of forces provides the conditions.3.Microwave grafting was used to induce a diene addition reaction between the vinyl group of sodium styrenesulfonate?SSS?and the alkenylated PVDF,thereby introducing the SSS group on the PVDF side chain.Infrared spectroscopy traces the effect of alkali concentration and reaction time on alenylation yield.Then,a PVDF-SSS ion exchange membrane with an IEC of 0.65 mmol/L and PVDF/Gr polymer electrodes fixed on both sides was prepared using a phase shift technique to introduce a low voltage electrical signal to obtain a new and inexpensive IPMC electroactuator.The PVDF-SSS membrane IPMC produces a stable electrically driven response at 3V and 0.1Hz AC electric fields.4.Prepared with silicone rubber?PDMS?/Gr as soft electrode,PDMS/Gr/Ag nanoparticles?Ag NPs?as hard electrode,and aminated polydimethylsiloxane?NH₂-PDMS?as dielectric elastomer.A pre-load-free asymmetric electrode DEP electric actuator.The thickness,modulus and surface resistance of the soft and hard electrodes are 54.1?m,9.21MPa,1.02k?/cm² and 166.7?m,87.5MPa,0.13k?/cm²,respectively.Under the excitation of an electric field of 8.8 V/?m,the center of the DEP film produces a deflection angle of 26.3°;increasing the driving voltage or decreasing the frequency,the deflection of the film increases,showing good controllability.