View Item 
      •   Home
      • 7. Theses and Dissertations
      • Theses and Dissertations
      • View Item
      •   Home
      • 7. Theses and Dissertations
      • Theses and Dissertations
      • View Item
      JavaScript is disabled for your browser. Some features of this site may not work without it.
      Subject Lookup

      Browse

      All of DR-NTUCommunities & CollectionsTitlesAuthorsBy DateSubjectsThis CollectionTitlesAuthorsBy DateSubjects

      My Account

      Login

      Statistics

      Most Popular ItemsStatistics by CountryMost Popular Authors

      About DR-NTU

      Morphologies, structures and properties of electrospun poly(vinylidene difluoride)-based materials.

      Thumbnail
      View/Open
      TmseG0603313D.pdf (5.439Mb)
      Author
      Yee, Wu-Aik.
      Date of Issue
      2012
      School
      School of Materials Science and Engineering
      Abstract
      Electrospinning is a technique that can be used to produce nanofibers, and it is discovered that it is able to enhance the β-phase of poly(vinylidene difluoride), PVDF. Owing to its highest polarization per unit cell, the β-phase of PVDF exhibits the maximum electroactive properties, i.e., ferro-, pyro- and piezo-electric properties, in comparison with other phases of PVDF. Although researches have shown that the β-phase of PVDF can be improved by (1) alteration of the chemical structure, (2) usage of additives, (3) application of a stretching force and (4) the use of high temperature and pressure treatments, the synergistic effects among (2), (3) and (4) on polymorphism behaviors and electro-active of PVDF have not been studied. Thus, this work was undertaken to study polymorphism behaviors, morphologies and electro-active properties of electrospun poly(vinylidene fluoride-co-hexafluoropropene) (P(VDF-HFP)) nanofibers and P(VDF-HFP)/carbon nanotube (CNT) composite nanofibers, which experienced high extensional forces in the electrospinning and collection processes, as well as high temperature and pressure treatments in supercritical carbon dioxide (SCCO2). Firstly, a modified rotating disk collector is used in electrospinning to provide stronger stretching force to the electrospun P(VDF-HFP) nanofibers. By attaching seperate, parallel electrodes onto a rotating disk collector, well aligned nanofibers of P(VDF-HFP)) and P(VDF-HFP)/CNT nanocomposites can be directly deposited onto flat substrates forming uniform and compact nanofibrous mats. The attachment alters the electric-field distribution on the rotating disk while providing an additional stretching force during the fanning of the fibers. This additional stretching force exerted by the modified rotating disk prevents the relaxation of the polymer chains during solvent evaporation, and hence results in the formation of extended-chain β-chain crystallites with a slightly reduced inter-chain distance, as evidenced by wide angle X-ray diffraction (WAXD) patterns and Fourier transform infrared (FTIR) spectra of the samples.
      Subject
      DRNTU::Engineering::Materials::Nanostructured materials
      DRNTU::Engineering::Materials::Functional materials
      Type
      Thesis
      Collections
      • Theses and Dissertations

      Show full item record

      Related items

      Showing items related by title, author, creator and subject.

      • Synthesis and electrochemical performance of aluminum antimonide alloy anode prepared by melt spinning 

        Kharistal, Daniel Julian (2014)
        In this work we have successfully synthesized melt spun Al-Sb alloy and studied the electrochemical performance of these Al-Sb alloy as anodes for lithium ion batteries. The melt spun Al-Sb alloy has unique morphological ...
      • Polymer assisted synthesis of functional nano-materials. 

        Liang, Yen Nan. (2013)
        Polymer assisted solution synthesis is a common and versatile strategy for preparation of colloidal inorganic nano-materials with novel morphological and functional properties. Although block copolymers are usually employed, ...
      • Solution-processible carbon nanotubes-based thin films as counter electrodes in dye sensitized solar cells. 

        Zhang, Liling. (2013)
        Platinum (Pt) and fluorine-doped tin oxide (FTO) are commonly used as counter electrodes (CEs) in dye sensitized solar cells (DSSC), but the high processing temperature of Pt and brittle behavior of FTO makes them unsuitable ...

      NTU Library, Nanyang Avenue, Singapore 639798 © 2011 Nanyang Technological University. All rights reserved.
      DSpace software copyright © 2002-2015  DuraSpace
      Contact Us | Send Feedback
      Share |    
      Theme by 
      Atmire NV
       

       


      NTU Library, Nanyang Avenue, Singapore 639798 © 2011 Nanyang Technological University. All rights reserved.
      DSpace software copyright © 2002-2015  DuraSpace
      Contact Us | Send Feedback
      Share |    
      Theme by 
      Atmire NV
       

       

      DCSIMG