title: Enhanced wetting behavior at electrospun polyamide nanofiber surfaces.
abstract: Nanofibers of polyamide have been synthesized using electrospinning processes and their wetting properties determined directly from a nanoscale Wilhelmy balance approach. Individual electrospun polyamide nanofibers were attached to atomic force microscope (AFM) tips and immersed in a range of organic liquids with varying polar and dispersive surface tension components. AFM was used to measure nanofiber-liquid wetting forces and derive contact angles using Wilhelmy balance theory. Owens-Wendt plots were used to show a considerable increase in the polar component of the surface free energy of the polyamide nanofibers compared with bulk film of the same polymer. Chemical surface analysis of the polyamide nanofibers and films using X-ray photoelectron spectroscopy provided evidence for enhanced availability of polar oxygen groups at the electrospun nanofiber surface relative to the film. Our results therefore confirm chemical group orientation at the electrospun polyamide nanofiber surface that promotes availability of polar groups for enhanced wetting behavior.
authors.affiliation: Nanoforce Technology Ltd. and ‡Department of Materials, School of Engineering and Materials Science, Queen Mary University of London , Mile End Road, London E1 4NS, United Kingdom.
authors.forename: Urszula
authors.initials: U
authors.lastname: Stachewicz
authors.forename: Asa H
authors.initials: AH
authors.lastname: Barber
mesh_terms: D018625:Microscopy, Atomic Force; D057139:Nanofibers / Q000737:chemistry*; D009757:Nylons / Q000737:chemistry*; D010316:Particle Size; D056951:Photoelectron Spectroscopy; D013499:Surface Properties; D017155:Wettability
chemical_list: D009757:Nylons