1 PVDF membrane morphology - influence of polymer 2 molecular weight and preparation temperature . 3

1 Departament d’ enginyeria química, Universitat Rovira i Virgili, Av. dels Països Catalans 26, 43007 6 Tarragona, Spain; A. Mickiewicz University, Faculty of Chemistry, Umultowska 89b, 61-614 Poznan, 7 Poland [email protected] 8 2 Departament d’ enginyeria química, Universitat Rovira i Virgili, Av. dels Països Catalans 26, 43007 9 Tarragona, Spain; A. Mickiewicz University, Faculty of Chemistry, Umultowska 89b, 61-614 Poznan, 10 Poland; [email protected] 11 3 Departament d’ enginyeria química, Universitat Rovira i Virgili, Av. dels Països Catalans 26, 43007 12 Tarragona, Spain; A. Mickiewicz University, Faculty of Chemistry, Umultowska 89b, 61-614 Poznan, 13 Poland; [email protected] 14 4 A. Mickiewicz University, Faculty of Chemistry, Umultowska 89b, 61-614 Poznan, Poland; 15 [email protected] 16 5 Departament d’ enginyeria química, Universitat Rovira i Virgili, Av. dels Països Catalans 26, 43007 17 Tarragona, Spain; [email protected] 18 6 Centre Tecnològic de la Química de Catalunya, Carrer de Marcel·lí Domingo, 43007 Tarragona, Spain 19 * Correspondence: [email protected]; Tel.: +34-977-297-086 20 21 Abstract: The global polyvinyldene flouride market is estimated to reach $937,278.5 thousand by 22 2019, therefore to develop new membranes and gain pioneering ideas, which could create innovative 23 business opportunities, a fundamental knowledge about membrane properties fabricated from recent 24 commercially available PVDF polymers is highly mandatory. In this study, we successfully prepared 25 nine non-woven supported PVDF membranes using a phase inversion precipitation method starting 26 from a 15 wt% PVDF solution in N-methyl-2-pyrrolidone. Various membrane morphologies were 27 obtained by using (1) PVDF polymers with diverse molecular weight in a range from 300.000 Da to 28 700.000 Da and (2) different temperatures of the coagulation bath (20, 40, and 60 ±2°C) used for the 29 films precipitation. Environmental Scanning Electron Microscope (ESEM) was used for surface and 30 cross-section morphologies characterization. Atomic Force Microscope (AFM) was employed to 31 investigate surface roughness, while Contact Angle (CA) instrument was used for membranes 32 wettability studies. Fourier Transform Infrared Spectroscopy (FTIR) results show that the fabricated 33 membranes are formed by a mixture of TGTG’ chains in α phase crystalline domains and all-TTTT 34 trans planar zigzag chains characteristic to β phase. Moreover, generated results indicate that the 35 phases content and membrane morphologies depend on the polymer molecular weight and 36 conditions used for the membranes preparation. The diversity of fabricated membranes could be 37 applied by the End User Industries for different applications. 38