Electrospun Butyl Rubber for Stretchable Superhydrophobic Coatings

Electrospinning has been recognized as one effective method to fabricate sub- to nano-scale fibers, and subsequent films, mats and membranes. Compared to films made by other conventional methods like melt or solution casting, spray coating, and melt blowing, electrospun films provide much higher porosity, high surface area, and 3-dimentional fibrous structure, all of which enhance the potential in different applications. One of the potential novel applications is for superhydrophobic surfaces. Superhydrophobic surfaces have been receiving much attention due to their non-adhesive and non-wetting features for various applications such as self-cleaning, anti-corrosion, anti-icing, low friction, and anti-biofouling. In this paper, novel method to fabricate electrospun nonwoven superhydrophobic butyl rubber mats is introduced. A pre-compounded butyl rubber was dissolved in tetrahydrofuran (THF) solvent for 24 hours. Then dispersed hydrophobic silica NPs in THF were added to the solution and allowed mixing for 15 minutes. The solution was electrospun on aluminum substrate and cured under heat. Different ratio between the silica NPs and butyl rubber were studied to optimize the roughness needed for superhydrophobicity. Scanning Electron Spectroscopy (SEM) was used to study the final morphology while contact angle was carried to confirm the superhydrophobic properties of the coated mats.