Effect of filler content on morphology and physical–chemical characteristics of poly(vinylidene fluoride)/NaY zeolite-filled membranes

Poly(vinylidene fluoride) electrospun membranes have been prepared with different NaY zeolite contents up to 32 wt%. Inclusion of zeolites induces an increase of average fiber size from ~200 nm in the pure polymer up to ~500 nm in the composite with 16 wt% zeolite content. For higher filler contents, a wider distribution of fibers occurs leading to a broader size distribution between the previous fiber size values. Hydrophobicity of the membranes increases from ~115o water contact angle to ~128o with the addition of the filler and is independent on filler content, indicating a wrapping of the zeolite by the polymer. The water contact angle further increases with fiber alignment up to ~137°. Electrospun membranes are formed with ~80 % of the polymer crystalline phase in the electroactive β phase, independently on the electrospinning processing conditions or filler content. Viability of MC3T3-E1 cells on the composite membranes after 72 h of cell culture indicates the suitability of the membranes for tissue engineering applications.