Abstract: The present disclosure provides catheters comprising polytetrafluoroethylene (PTFE) tubes with advantageous combinations of strength, flexibility, and size. Such tubes can exhibit features including an average wall thickness of 0.001? or less, a tensile stress at break of greater than 5000 psi, and a storage modulus of less than 100,000 psi at 37° C. These tubes can be also be provided independently (i.e., not within a catheter) and can be employed in various applications.

Abstract: An improved process for forming a polymer mat is described. The process of electrospinning polymer fibers includes providing an apparatus having a charge source, a target a distance from the charged source and a slot die having a spinning edge with a slit. The spinning edge has a radius of curvature between 5 cm and 100 cm. The method further includes providing a polymeric preparation (solution, dispersion, suspension, or melt) to the slot die and applying an electric field to a part or the whole apparatus or polymeric preparation. When the electric field is applied, a plurality of Taylor cones are produced with jets that stretch the polymeric preparation into a fibrous structure that can be collected on a target surface.