Surface Modification of Polypropylene Non-woven Substrates by Padding with Antistatic Agents for Deposition of Polyvinyl Alcohol Nanofiber Webs by Electrospinning

Abstract

In recent years, the electrospinning process has become one of the most interesting processes to obtain nanofiber webs with interesting properties for uses in a wide variety of industrial sectors such as filtration, chemical barriers, medical devices, etc., as a consequence of the relatively high surface-to-volume ratio. Among the wide variety of polymers, polyvinyl alcohol (PVA) offers good advantages since it is water-soluble and this fact enables easy processing by electrospinning. There are many variables and parameters to be considered in order to optimize PVA nanofiber webs: some of them are related to the polymer solution, some others are related to the process, and some of them are related to the collector substrate. In this work a study on the effects of two different surface pre-treatments on a non-woven polypropylene substrate as a collector of PVA nanofiber webs has been carried out. In particular, a chemical treatment with anionic antistatics and a physical treatment with low-pressure plasma have been investigated. The effects of these pre-treatments on morphology of PVA nanofiber webs have been evaluated by scanning electron microscopy. Results show that surface resistivity is one of the main parameters influencing the web formation as well as the nature of the electric charge achieved by the pre-treatment. The plasma treatment promotes changes in surface resistivity but it is not enough for good web deposition. Chemical pre-treatment (padding) with anionic antistatic leads to a decrease in surface resistivity up to values in the 1 × 10 ⁹— 1 × 10¹¹ Ω which is enough for good nanofiber deposition.