Preparation and characterization of highly hydrophobic poly(vinylidene fluoride) - Clay nanocomposite nanofiber membranes (PVDF-clay NNMs) for desalination using direct contact membrane distillation

Electrospun nanofiber membranes consisting of poly(vinylidene fluoride) (PVDF) blended with clay nanocomposites were prepared and tested in this paper for direct contact membrane distillation (DCMD) applications. Various compositions of PVDF-clay nanocomposite nanofiber membranes (NNMs) were prepared and characterized by water contact angle, Fourier transform infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy and investigated for DCMD. The incorporation of clay nanocomposites increase the hydrophobicity of the membranes, which increase as the concentration of clay nanocomposite increases in the mixture. The highest water contact angle achieved was 154.20 +/- 3.04 degrees. The melting point of the PVDF-clay electrospun nanofiber membrane increases with the increasing concentration of clay indicating that the clay particles influence the crystallization process of the nanocomposite membrane. The PVDF-clay NNMs showed improved performance in DCMD applications and provide a way to prevent pore wetting in DCMD process. (C) 2012 Elsevier B.V. All rights reserved.