Superhydrophobic behavior of electrospun nanofibers with variable additives
This report presents the hydrophobic (90<Ѳ<150) and superhydrophobic (150<Ѳ<180) behaviors of electrospun fibers in the presence and absence of various inclusions. The research on superhydrohobicity has accelerated around the globe and many researchers have been taking keen interests in fabrication of superhydrophobic materials, using several methods, such as sol-gel, vapor deposition, plasma treatment, surface etching and layer by layer assembly. In the present research, polystyrene (PS) and polyvinyl chloride (PVC) fibers with diameters between 200 nm and 7.60 µm were fabricated by electrospinning technique, and then surface morphology and superhydrohobicity of these electrospun nanofibers were investigated. The results indicate that the water contact angle of the nanofiber surfaces goes up to 165° based on the fiber diameter, type of materials and surface porosity/roughness. Additives such as graphene, surfactant and titanium dioxide (2TiO) nanoparticles (nano powders) ranging from 10-25 nm were added into the same polymers (PVC, PS) and investigated to determine their performances. Both heat treatment and surface treatment were also applied to the fabricated fibers. The results with the additives indicate that the water contact angle is even further increased up to 178°. This may be because of the nanoscale voids (entrapped air) in the pores and surface energy of the nanofiber surface. These higher contact angle nanomaterials can have various industrial applications, such as non-wettable fabric, antibacterial surface, low friction devices, MEMS, NEMS, microfluidics and nanofluidics.
Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Mechanical Engineering