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Surface modification by plasma treatment is widely used for textiles and polymeric materials. Plasma processes are environmentally friendly and reduce chemicals and energy consumption. This study reports the effect of cold, low-pressure oxygen plasma on the wettability properties of polypropylene (PP) nonwoven mats. The wetting properties were examined using contact angle, surface energy, and diameters of the drop after 20 s of treatment. It was found that plasma treatment had a significant effect on the wettability of PP fibers. The ageing for 90 days had no significant effect on the wettability. It was also shown that the morphology of the fibers was not affected by the plasma treatment.

Novel nanofibers from blends of polylactic-co-glycolic acid (PLGA) and chitosan have been produced through an emulsion electrospinning process. The spinning solution employed polyvinyl alcohol (PVA) as the emulsifier. PVA was extracted from the electrospun nanofibers, resulting in a final scaffold consisting of a blend of PLGA and chitosan. The fraction of chitosan in the final electrospun mat was adjusted from 0 to 33%. Analyses by scanning and transmission electron microscopy show uniform nanofibers with homogenous distribution of PLGA and chitosan in their cross section. Infrared spectroscopy verifies that electrospun mats contain both PLGA and chitosan. Moreover, contact angle measurements show that the electrospun PLGA/chitosan mats are more hydrophilic than electrospun mats of pure PLGA. Tensile strengths of 4.94 MPa and 4.21 MPa for PLGA/chitosan in dry and wet conditions, respectively, illustrate that the polyblend mats of PLGA/chitosan are strong enough for many biomedical applications. Cell culture studies suggest that PLGA/chitosan nanofibers promote fibroblast attachment and proliferation compared to PLGA membranes. It can be assumed that the nanofibrous composite scaffold of PLGA/chitosan could be potentially used for skin tissue reconstruction.

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The effects of fiber diameter and activation temperature on the pore characteristics of polyacrylonitrile based activated carbon nanofibers are investigated. It was found that lower fiber diameters as well as higher activation temperatures lead to a higher weight loss, specific surface area and total pore volume. The nitrogen adsorption capacity of activated carbon nanofibers is almost three times that of activated carbon fiber with a diameter of 10 µm. As far as the size of pores in activated carbon nanofibers is concerned, it is basically the micropores that dominate the scene. Moreover, tailoring the pore characteristics by adjusting the activation temperature and fiber diameter is plausible.