Research On The Electroresponsive Behavior Of Polyvinyl Chloride Gel

Electroresponsive smart polymer gels are sensitive to electro-stimulation,and they have been widely applied in smart devices,such as actuators,sensors,artificial muscles and so on.In the gels,polyelectrolyte gels are most studied,which are composed of the ionic groups.Polyelectrolyte gels need aqueous conditions to respond;they are subject to low voltage or current,and it is difficult to avoid liquid leakage.Polyvinyl chloride(PVC)gel belongs to the electroresponsive smart polymer.gel that does not require water and deforms under electro-stimulation in the air.Therefore,PVC gel has great market potential.However,the existing PVC gel products have not well used,due to the limitation of the electrode structures and the faultiness of deformation mechanism.In the paper,the research progress of PVC gels at home and abroad was reviewed,and the existing bottleneck problems of PVC gels were analyzed.The fundamental laws and simulation model of the electroresponsive behavior of PVC gel were studied.Based on unilateral contact,a PVC gel bridge type actuator was proposed and expanded to some other actuators;the electroresponsive behavior of the PVC gel bridge type actuator was studied.Based on the bridge type structure,a varifocal microlens made of PVC gel was also proposed and analyzed.The electroresponsive mechanism of PVC gel on the bridge type electrodes was deeply investigated finally.The main work is as follows.Using environmentally friendly plasticizer dioctyl terephthalate(DOTP)and different types of PVC resins,different PVC/DOTP gels were prepared by the solution casting method.The optimal PVC resin and the corresponding process were determined.And the visible light transmittance of PVC gels with different plasticizer contents was measured.An experimental setup of recording the bending deformation process of PVC gels under electro-stimulation was established to obtain the evolution law and the theoretical model of bending angles of PVC gel samples under different voltages.The finite element software(ANSYS 15.0)was used to establish the circular PVC gel simulation model,and the relationship of creep deformation and charge density of PVC gels was gotten.The deformation conditions of PVC gel through incomplete contact and complete contact with the two electrodes were investigated.A bridge type actuator that PVC gel was assemblied on one side of both electrodes was put forward,and the coupling effect of soft materials and rigid electrodes and self-deformation of PVC gels could be realized.Based on the actuator structure,an experimental setup of measuring the deformation of the PVC gel bridge type actuator was established,the creeping and bending deformation process of the actuator under a certain voltage or continuous variable voltages could be obtained,and the theoretical model of the deformation of the actuator was built.The influence of plasticizer contents and electrode structures on the deformation was studied.Based on the bridge structure,a new PVC gel varifocal concave microlens was put forward,which breaks the limit of the sandwich structure reported in the previous literatures.Experimental setup for recording the focus and image changes of the PVC gel microlens at different time were established,respectively.The zoom phenomenon and the formation were illuminated.The influences of conduction time on the zoom and applied voltage on stable focal length were studied.Changing the voltage from 100 V to 1000 V,the focal length could be realized in the range from-148.3 mm to-21.3 mm.The bridge structure was also expanded to PVC gel varifocal convex microlens.A small thickness and a large range of zoom became a unique advantage of the PVC gel microlens.The strong interaction between PVC and DOTP molecular chains were found by dielectric measurements.Using Fourier transform infrared spectroscopy(FTIR),the ratio of spectral peak areas that reflects the DOTP contents in PVC gels was found.The plasticizer transfer behavior between the positive and negative electrodes of PVC gel under electro-stimulation was verified.The pure PVC,DOTP and PVC gel were tested by in situ Raman spectroscopy,respectively.The influence of the interaction between PVC and DOTP molecular chains on deformation rate of gels was inferred.The special equipment was used to test the PVC gel under electro-stimulation by in situ Raman spectroscopy,and the process of plasticizer migration and the relationship between the deformation and the plasticizer migration were studied.The memory effect of PVC gels under electro-stimulation was explained.In summary,the bending behaviors and characteristics of PVC gels under electro-stimulation were studied.A simulation model of PVC gel with a creep behavior was established.A new PVC gel bridge type actuator was put forward,and its deformation characteristic,theoretical model and expanded structures were also investigated.A PVC gel varifocal microlens based on the bridge structure was developed.The interaction between PVC and plasticizer was revealed.The plasticizer migration process in PVC gels and its corresponding relations with the deformation were found.The methods of improving the practicability and performance of PVC gels were expounded from the aspects of exploring the electroresponsive behavior,new structures and function and mechanism of PVC gels under electro-stimulation,which provided new ideas and directions for solving the related scientific problems in the PVC gel field.