5. Ultrafine Nanofiber Formation by Centrifugal Spinning

Abstract

Large surface-area-to-volume ratio and special morphology of the nano fibers cause them to have remarkable properties such as excellent mechanical properties, heat transfer capacity and electrical features. However, some barriers in nanofiber fabrication techniques such as low production rate, restrictions on materials, process complexity and high production cost limit the mass production of nanofibers. Increasing demand for nanofibers in many applications such as air and water filtering, sensors and protective masks motivates many efforts for eliminating these barriers. Nanofibers produced through the centrifugal spinning (CS) technique have recently been fabricated with much fewer limitations. Nanofiber production through CS, in which a nozzle or orifice rotates at high speed around its axis of symmetry, can produce high volumes of polymeric fibers with average diameters around 300 nm. Although CS is a very practical alternative and promising technique, production of nanofibers by CS technique is facing a number of critical challenges that need to be addressed. Recently invented, CS is still under substantial developments and much research needs to be performed to explain the exact mechanisms responsible for thinning of the fiber through CS. Many physical and geometrical parameters influence the nanofiber production through CS, for example, spinneret angular velocity, orifice radius, polymer solution rheology, surface tension, evaporation rate or temperature. Here, we first introduce the different methods of nanofiber formations and draw a comparison between CS and the other methods based on the literature. Second, we demonstrate our recent attempts to produce and control the nanofiber production through the CS approach, conducted at the Laboratory of Complex Fluids Research in Laval University.