Membranas na forma de fibra oca de polietersulfona e polisulfona com atapulgita modificadas com a polivinilpirrolidona.

Abstract

The membrane separation process has been growing due to its easy production and adaptation in several industrial sectors. Thus, the objective of this research was to produce polyethersulfone (PES) and polysulfone (PSf) hollow fiber membranes, using two types of attapulgite and two types of PVP (polyvinylpyrrolidone) (K30 and K90). Initially, the two types of attapulgite clay (UBM and Basf) were characterized. Basf clay had a greater range of particle size distribution, as well as a higher purity degree when compared to UBM clay. The hollow fiber membranes produced with PVP K30 and PVP K90 were characterized by dispersion viscosity, X-ray diffraction (XRD), contact angle and scanning electron microscopy (SEM). From the viscosity, it was seen that the PSf solution had a higher viscosity, since it has a higher molar mass than PES. Dispersions with PVP K90 had a higher viscosity than with PVP K30. By XRD it was seen that the membranes with 10% clay obtained a possible intercalation with the polymer. As for membranes with 20%, there was the appearance of peaks characteristic of attapulgite, indicating the formation of a microcomposite. For the PVP K90 this behavior was more pronounced. Contact angle measurements indicated that the presence of clay and the type of PVP considerably increased the hydrophilicity of PES and PSf. By SEM it was observed that the addition of clay modified the morphology of hollow fiber membranes. Dispersions with PVP K90, which are more viscous, generated membranes with more uniform morphology in relation to pore size and uniformity. Flux tests indicated that membrane permeability increases with the incorporation of attapulgite and/or the two types of PVP in both investigated matrices. All membranes produced from the composites were selective in the oil/water separation, presenting a rejection of up to 99.0%, as obtained in permeate turbidity tests.