Length scale effects on percolation of geometrically complex nanocomposites

POSTER

Abstract

With growing interest in materials that include nanostructures the focus on nanocomposites (a polymer-based matrix that is enhanced by a nanometer sized particle) has grown. Electrospun nanocomposites contain a complex geometry including fiber sizes of $\approx $ 200 nm arranged in a random mat with a porosity of $\ge $ 70{\%}. Composites utilize connected paths of particles throughout the sample to enhance the mechanical and electrical properties of the matrix. Previous literature has shown, in the case of continuous films, that this percolation phenomenon is affected by the sample size. This work aims to investigate these length scale effects within a complex morphology, such as a nanofiber mat. For a clear understanding of the change in percolation vs. length scale we fabricated interdigitated electrodes (IDEs) with a finger spacing of 10 to 100 $\mu $m, electrospun mats onto the IDEs, and performed electrical conductance measurements. In addition, computation simulations of the experimental systems were undertaken. I will discuss our results and the role sample size/shape plays on 1) the percolation threshold and 2) the conductivity vs. doping fraction curve.

Authors

  • T.J. Hoffman

    Department of Physics, N.C. State University

  • D.R. Stevens

    Department of Physics, N.C. State University

  • Jaetae Seo

    NC A\&T State University, Penn State University, The Ohio State University, Wright State University, AFRL/RYHC Hanscom AFB MA 01731, Harvard University, The College of William \& Mary, NCSU Near-field Optics Lab, University of North Carolina at Chapel Hill, Weizmann, PTB, Braunschweig, UMass, TUNL/Duke, UConn, UConn/TUNL, University of North Carolina, Chapel Hill, North Carolina State University, Brimrose Corporation of America, Hampton University, Elizabeth City State University, Department of Physics, Florida A\&M University, Tallahassee, Florida-32307, Department of Physics, University of Rajshahi, Rajshahi-6205, Bangladesh, Department of Physics, University of Rajshahi, Rajshah-6205, Bangladesh, Department of Physics, University of Rajshahi, Rajshahi-6250, Bangladesh, Department of Physics, University of Rajshahi-6205, Bangladesh, Alabama A\&M University, Fachbereich C-Mathematik und Naturwissen-Schaften, Bergische Universitat Wuppertal, D-42097, Wuppertal, Germany, NC State University, College of William and Mary, Department of Physics, N.C. State Univeristy, Research Triangle Institute, NCSU Physics, Pennsylvania State University, Tsinghua University, Lawrence Berkeley National Laboratory, Vanderbilt University, LSU, UNIRIB, U. Tenn., ORNL, Miss. St., University of North Carolina at Chapel Hill and Triangle Universities Nuclear Laboratory, NCA\&T, Duke, NCCU, UNC-Chapel Hill, Department of Physics, North Carolina State University, Department of Chemistry, North Carolina State University, Department of Physics and Astronomy, University of North Carolina, Chapel Hill, Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hil, North Carolina School of Science and Mathematics, Department of Physics, Elon University, Dept. of Physics - UNC - Chapel Hill, Nanyang Technological University, School of Materials Sciences and Engineering, Singapore, Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3255, USA, Argonne National Laboratory, Department of Physics, Hampton University, Hampton, VA 23668, Korea Research Institute of Standards and Science, Daejeon, 305-600, South Korea, Department of Chemistry, Gyeongsang National University, Jinju 660-701, South Korea, Electronics and Telecommunications Research Institute, Daejeon, 305-700, South Korea, Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, MA 01609

  • R.E. Gorga

    Department of Textile Engineering, N.C. State University

  • L.I. Clarke

    Deparment of Physics, N.C. State University