Various asymmetric microporous poly(vinylidene fluoride) (PVDF) hollow fiber membranes with different pore sizes and effective porosities were prepared by the phase inversion method using dimethylacetamide (DMAc) as solvent and LiCl and water as additives. The membranes were characterized using scanning electron microscopy (SEM) and field emission scanning electron microscopy (FESEM) for its microstructure and surface pore size. A gas permeation method was also applied for determining and comparing the effective surface porosity and mean pore size of the different membranes. Moreover, the contact angle with water, critical entry pressure (CEP) of water and collapsing pressure of the PVDF hollow fibers were also determined. Five membrane modules were prepared using the spun hollow fibers and applied in removing 1,1,1-trichloroethane (TCA) from its aqueous solution by vacuum membrane distillation (VMD) process. The effects of dope composition and spinning conditions on hollow fiber morphology and TCA separation by VMD process are examined. Post-treating of the spun fibers by solvent exchange using ethanol produced membranes exhibiting higher porosity and higher permeability. A highly porous hollow fiber membrane with a smaller mean pore size can achieve both high TCA permeation flux and high separation factor. (C) 2007 Wiley Periodicals, Inc.