Superhydrophobic behavior of polyimide–siloxane mats produced by electrospinning

In this study, a series of novel superhydrophobic polyimide–siloxane electrospun mats was prepared using an electrospinning process. Segmented polyimide–siloxane copolymers were prepared using 4,4′-oxydianiline (ODA) and 3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA) as hard segments and aminopropyl terminated polydimethylsiloxane (APPS) and BTDA as soft segment. The polyimide–siloxane copolymers were synthesized by varying the APPS loading (10 and 20 mol%) and also the molecular weight of APPS (1000 and 2500 g/mol), respectively. Electrospinning of the polyamic acids was followed by thermal imidization to construct the electrospun polyimide–siloxane mats. The electrospun mats were characterized by FTIR, scanning electron microcopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimeter (DSC) and contact angle measurement. According to SEM results, the polyimide–siloxane electrospun mats have nano-roughness morphology. Bead on string type surface morphology that has been generated by electrospinning yields stable superhydrophobicity with a contact angle of 167°.