بررسي خواص الكترواكتيو لايه نانو الياف پلي وينيل الكل ﴿حاوي نانو ذرات تيتانيوم دي اكسيد﴾ پوشش داده شده با پلي آنيلين و بررسي تغيير شكل ابعادي آن با استفاده از پردازش تصوير

چكيده انگليسي :

An Investigation on the Electroactive Properties of PVA TiO2 Nanofibers Webs Coated With Polyaniline and the Study of Their Dimensional Change Through Image Analysis Fateme Fereydonian f fereydonian@tx iut ac ir Date of Submission 2011 9 22 Departmant of Textile Engineering Isfahan University of Technology Isfahan84156 83111 Iran Degree M Sc Language Persian Supervisors Mohammad Morshed morshed@cc iut ac ir Dariush Semnani d semnani@cc iut ac ir Advisor Behzad Rezaei rezaei@cc iut ac irAbstractActuators are working by using materials that response to applied electrical voltage For converting electricalenergy to mechanical energy actuators have been named artificial muscle Among many materials such asshape memory alloys and electroactive ceramics conductive polymers have received attention proposedadecad ago because their high actuation strain at low voltage High swelling strain and excellent mechanicalstrength of hydrogels such as chitosan and PVA make them attractive for using in actuators Furthermore many researchers have reported about using PVA nanofiber webs as electroactive materials defect ofelectrical conductivity is one of the limitation of hydrogels for their application as actuators This limitationis recompense with using of blend of hydrogel with conductive polymers A high surface area of nanofibersimproved mechanical properties of conducting Polymer based actuatoras Also high porocity in nanofibers issuitable for the diffiution of ions new material which proposed for blending with polymers are metal oxides Many optical electrical biological properties of TiO2 such as acting as a charge carrier nontoxicty andphotostability are suitable for blending to obtain nano composites with better mechanical thermal andelectrical properties Furthermore nanofillers act as reinforcing materials which delaying the completeshred of the composite hydrogels Therefore in this thesis PVA nanofiber webs with and withoutnanoparticles were prepared by electrospinning to made a flexible conductive polymer actuators usinghydrogel nanofibers as template Nanofiber system provids large surface area and high porocity for diffusingof ions influencing ions transport The Effect of TiO2 nanoparticles on the morphology electrical mechanical properties and electrochemical actuation of polyaniline coated webs of pva nanofiber wasinvestigated Also with using of image processing the actuation strain of fiber in nanofiber webs have beenestimated Results show that viscosity of polymer soulation and mean fiber diameter enhance with increasedpercentage of nanoparticles in constant concentration of polymer In this work electrical resistance ofpolyaniline coated webs of nanofiber is depend on the applied pressure on the surface of nanofiber webs andpercentage of TiO2 nanoparticles Electrical resistance reduced considerably as applied pressure on thesurface of nanofiber webs Moreover electrical resistance reduced with increase percentage of TiO2nanoparticles Cyclic voltammogram of polyaniline coated nanofiber webs shows that TiO2 nanoparticlesincreased the peak of electrochemical redox reaction Furthermore current from nanofiber webs with 15wt of nanoparticles was 2times higher than polyaniline coated webs of PVA nanofiber without nanoparticles opproximately It is also observed that TiO2 nanoparticles increas actuation strain of polyaniline coatednanofiber webs In this work strain actuation of fibers was estimated by using image processing on the SEMof nanofiber webs The Results show that actuation strain of fibers which estimated by image processing isconsiderably more than of actuation strain of nanofiber webs that was produced by experiments Resultsshow that increase of orientation between nanofiber causes increase actuation strain of nanofiber webs Overall considering the presence of TiO2 nanoparticles in polyaniline coated nanofiber webs depictedexcellent electrical and electrochemical effectiveness Keywords Nanofiber TiO2 Polyaniline Electroactive Ele

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