Plasma-modified polytetrafluoroethylene (PTFE) membranes for use in membrane distillation were prepared with composite PTFE membranes. The composite membrane consisted of a porous woven support and a dense PTFE layer. The membranes were characterized using different technologies such as SEM, AFM, and contact angle measurement. Finally, the plasma-modified membranes were tested for their performance in the process of desalination by means of the direct contact membrane distillation (DCMD). It was found that the plasma treatment strongly affects the surface hydrophilicity of the membranes and thus enhanced their desalination performance. It was also found that prolonging the plasma treatment time and increasing the plasma power significantly decreased the water contact angle and significantly changed the surface morphology of the modified membranes. Furthermore, the plasma treatment only slightly changed the roughness and surface porosity. Such changes in the surface's morphology and polarity enhanced the hydrophilicity of the modified membranes and then significantly improved the permeation flux but expectedly decreased the salt rejection.
