Abstract

THURMER, Mônica Beatriz et al. Effect of non-solvents used in the coagulation bath on morphology of PVDF membranes. Mat. Res. [online]. 2012, vol.15, n.6, pp. 884-890.  Epub Sep 13, 2012. ISSN 1516-1439.  http://dx.doi.org/10.1590/S1516-14392012005000115.

The aim of this paper was to prepare a poly (vinylidene fluoride) (PVDF) membrane using different non-solvents in the coagulation bath for the phase inversion method. In order to increase the mechanical strength of membranes, facing the pressure of work, was used a macro-porous polyester support. The morphology and structure of the resulting membranes were evaluated by scanning electron microscopy, porosity measurements, water and 1-octanol uptake, contact angle, pure water flux, hydraulic permeability and hydraulic resistance. The morphology and pure water flux changed significantly using ethanol (symmetric membrane) and/or water (asymmetric membrane) as the non-solvent. The symmetric membrane presented a high hydrophobic surface (water contact angle ~136º) and a higher pure water flux and porosity than the asymmetric membrane, which presented a lower hydrophobicity surface (water contact angle ~90º). The morphologies obtained suggest different applications.

Keywords : contact angle; hydrophobicity; immersion-precipitation; poly (vinylidene fluoride); supported membrane.