Poperties of polyethersulphone ultrafiltration membranes modified with polyethylene glycols

MENDEZ MERCEDES L.; ROMERO ANALIA I.; RAJAL VERÓNICA B.; CASTRO VIDAURRE ELZA F.; CALVO JOSE IGNACIO; PALACIO LAURA; HERNÁNDEZ ANTONIO

POLYMER ENGINEERING AND SCIENCE

JOHN WILEY & SONS INC

Lugar: New York; Año: 2013 p. 1 - 15

0032-3888

Polyethersulfone ultrafiltration membranes have been prepared by using PEGs, of: 400; 1,000 and 10,000 g/mol, as additive with dimethylacetamide as solvent. IR analysis proves that PEG leaves almost 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 measured for the membranes.Results show that the addition of PEG increases slightly hydrophilicity and decreases pore size and narrows the corresponding pore size distribution while thickening the skin layer, in spite of the fast disappearance of the added PEG form the membrane surface. The resulting flux and pure water permeability are higher when middle size PEGs are added but decrease again when very high molecular weight PEGs are added. Retention decreases initially for increasing molecular weights of PEG although for very long PEG chains (MW of 10,000 g/mol) retention increases again. After filtration, the membranes with PEG added showed a lower relative flux reduction that decreases for increasing molecular weight of the added PEGs.