Surface modification to control the water wettability of electrospun mats

Electrospun mats have many possible applications in which it is important to control their interaction with water: when used as separation membranes, superhydrophobic mats can remove oil from water, whereas when used as scaffolds for tissue engineering, hydrophilic mats present better cell affinity. Frequently, however, the surface properties of the polymer fibers that compose the mat need to be modified and tuned. This review covers the main surface modification techniques used to change the water wettability of mats produced by electrospinning. Some basic aspects of the electrospinning process and wetting theories are presented as a starting point for the discussion, highlighting the common wetting switching mechanism found in highly porous structures like electrospun mats. The surface modification techniques are then classified as post-treatments or one-step modification during electrospinning. The fundamental aspects of each technique are followed by a discussion emphasizing their technical advantages and drawbacks.