PROPERTIES OF POLYETHERSULPHONE ULTRAFILTRATION MEMBRANES MODIFIED WITH POLYETHYLENE GLYCOLS

9. MERCEDES L. MÉNDEZ, ANALÍA I. ROMERO, VERÓNICA B. RAJAL, ELZA F. CASTRO VIDAURRE, LAURA PALACIO, JOSÉ I. CALVO, ANTONIO HERNÁNDEZ.

Polymer Engineering and Science

John Wiley & Sons

Lugar: Londres; Año: 2013 vol. 54 p. 1211 - 1221

Polyethersulfone ultrafiltration membranes have been prepared by using PEGs, of: 400; 1,000and 10,000 g/mol, as additive with dimethylacetamide as solvent. IR analysis proves that PEG leavesalmost completely the surface of the membranes after 24 hours of water immersion. SEM, contact angle,and liquid-liquid displacement porometry have been used to characterize the membrane morphology,surface hydrophilicity and porous structure. The relative flux reduction factor, flux, retention ? of PEG(20,000 and 35,000 g/mol) and BSA (67,000 g/mol) ?and pure water permeability have been measuredfor the membranes.Results show that the addition of PEG increases slightly hydrophilicity and decreases pore sizeand narrows the corresponding pore size distribution while thickening the skin layer, in spite of the fastdisappearance of the added PEG form the membrane surface. The resulting flux and pure waterpermeability are higher when middle size PEGs are added but decrease again when very high molecularweight PEGs are added. Retention decreases initially for increasing molecular weights of PEG althoughfor very long PEG chains (MW of 10,000 g/mol) retention increases again. After filtration, themembranes with PEG added showed a lower relative flux reduction that decreases for increasingmolecular weight of the added PEGs.