Electrospinning involves the uniaxial stretching of a viscoelastic jet derived from a polymer solution or melt. The stretching is because of a very high voltage applied to the polymer solution (or melt) relative to a collector. The jets, when dry, form nanofibers with diameters in the submicron range. This arrangement typically produces a single jet and consequently a single fiber. The mass rate of fiber deposition from a single jet is relatively slow (hundredths or tenths of grams per hour). To increase the production rate multiple jets are required.
A novel method for the electrospinning of polymer solution into nanofibers is now proposed. The objective of this work is to demonstrate the production of suitable multiple jets on a porous surface for electrospinning, without a multi-needle arrangement. In this experiment, a cylindrical nozzle made from porous polypropylene with pore sizes ranging between 10-20 microns served as the porous matrix through which a 20.0 wt% Nylon 6 solution flowed at 5 psig.
Several stable jets that formed on the surface spun fibers of nanoscale as seen in Figures 1(A-D). Multiple jets, some that lasted for many minutes and some intermittent jets that lasted for much shorter periods, formed all over the surface of the nozzle. The fiber formation is very simple and fast. The fibers formed were collected on a cylindrical wire mesh surrounding the nozzle. The production was 250 times the rate of production from a single spinneret, on a mass basis. The Nylon 6 fibers collected were analyzed and fitted to the log-normal distribution ( nanometers and ). Consequently, we have presented a method for the mass production nanofibers that has many advantages over other known methods.
Journal: TechConnect Briefs
Volume: 2, Technical Proceedings of the 2006 NSTI Nanotechnology Conference and Trade Show, Volume 2
Published: May 7, 2006
Pages: 812 - 815
Industry sectors: Advanced Materials & Manufacturing | Personal & Home Care, Food & Agriculture
Topics: Advanced Materials for Engineering Applications, Composite Materials