Three-dimensional polymer nanofibrous mats with tunable wettability have been fabricated using a single step non-conductive template assisted electrospinning process. Cellulose acetate nanofibers are electrospun over a nylon mesh, which acts as the template. The as-deposited fiber mat is removed from this template to produce a free standing three-dimensional micropatterned nanofibrous mat. By simply varying the template mesh dimensions, the fraction of the air-liquid interface can be changed which allows control of the wetting mechanics. It is shown that the water contact angle can be varied from about 30 degrees for a planar network to about 140 degrees for a patterned mat implying a complete transition from hydrophilic to hydrophobic behavior. Furthermore, upon stretching the fiber mat loses its pattern irreversibly and reducing the contact angle from 140 degrees to 110 degrees with increasing stretching. (C) 2017 Wiley Periodicals, Inc.