Experimental Research On Mechanical Properties Of Polythiophene Nanofibers

Conductive polymers(CPs)are regarded as an attractive materials on solar cells,thermoelectric energy conversion,CP actuators,and rechargeable batteries,etc.,due to their high thermal conductivity,good flexible film formation and electrical conductivity.Polythiophene(Pth)is easy to be modified,and holds others unique properties,including that,the degree of polymerization can be controlled,and the nanofibers prepared under special conditions are stronger than aluminum.As a new type of polymer material,polythiophene is the main material for organic semiconductors,electrode materials and sensors.But the mechanical failure of polythiophene materials may lead to the malfunction or even failure of the entire device.However,related researches on the mechanical properties of Pth are mainly concentrated on bulks or films.None of these research has been done on the mechanical properties of single Pth nanofibers.In this thesis,the mechanical properties of Pth nanofibers were experimentally studied and analyzed.For example,the Young's modulus and adhesion properties of Pth nanofibers were studied and analyzed.The main research work of this thesis is as follows.1.Highly ordered Pth nanofibers array were prepared from thiophene monomer using electrochemical three-electrode template method,by porous anodic aluminum oxide(AAO)template.The Pth nanofibers prepared in the experiment were characterized by Raman spectroscopy,scanning electron microscopy(SEM),and transmission electron microscopy(TEM).In addition,polyvinylidene fluoride(PVDF)nanofibers were prepared from PVDF particles by electrospinning.2.Based on the three-point bending method,the Young's modulus of the single Pth nanofibers was systematically tested by atomic force microscopy(AFM).The test results showed that the Young's modulus of single Pth nanofibers with an average diameter of 90.51 nm was 64.4±8.33 GPa,and the average Young's modulus of single polythiophene nanofibers with different diameters was 113.76 GPa.In the diameter range of 75-180 nm,the diameter ofPth nanofibers has no size effect on their Young's modulus,and the change of aspect ratio has no significant effect on the Young's modulus of Pth nanofibers.3.The adhesion between the same probe and Pth nanofibers in the diameter range of85-180 nm was systematically tested by atomic force microscopy.The test results demonstrated that the average adhesion between the Pth nanofibers with the length range of8-23?m and the AFM probe was 107.02±7.06 nN.After comparing the adhesion test results between the same AFM probes and different nanofibers such as Pth nanofibers,PVDF nanofibers and silver nanowires,it was found that the adhesion between Pth nanofibers and the AFM probe was stronger than that of the others.In this thesis,the mechanical properties of Pth nanofibers were experimentally studied and analyzed,which provided theoretical analysis and reference value for the engineering application of polymers.