Microporous PVDF membranes were prepared by isothermal immersion precipitation of PVDF/DMSO and PVDF/TEP casting dopes in different alcohol baths. The formed membranes exhibited the so-called particulate morphology, being packed by interconnected crystalline particles of a similar size. For the alcohol/TEP/PVDF system, the particles appeared as sheaf-like spherulites consisting of curled lamellae with thickness of similar to 15 nm. In contrast, for the alcohol/DMSO/PVDF system, the formed membranes comprise relatively compact globules whose surface was covered with granular objects of ca. 30 nm dia. Wide angle X-ray diffraction patterns of the membranes indicate that the sheaf-like crystals were of the a-type structure, while the compact globules the g-type structure, as were confirmed by FTIR-ATR analyses. F-19 NMR spectroscopy indicated that PVDF chains exhibited TG(+)TG(-) conformation in TEP and T(3)G(+)T(3)G(-) conformation in DMSO. These conformations remained unchanged during immersion-precipitation to yield the a-and g-type crystal structures. The crystallinity of the membranes, as determined by X-ray diffraction and differential scanning calorimetry, was found to be similar to 68%. Furthermore, desalination by membrane-distillation of 3.5% NaCl(aq) feed at 50 degrees C were carried to see the desalination capability of the membranes. High fluxes (10-13 LMH) and rejections (similar to 99.8%) were obtained for both types of membranes. (C) 2017 Elsevier Ltd. All rights reserved.