Surface modification of the polyethersulfone membrane using acrylic acid plasma and its effect on water viral removal

MERCEDES L. MÉNDEZ; VERÓNICA B. RAJAL; ELZA CASTRO VIDAURRE; LAURA PALACIO; JOSÉ I. CALVO; PEDRO PRÁDANOS

Mar del Plata

Workshop; 14th Latin American Workshop on Plasma Physics, LAWPP 2011; 2011

Currently the plasma treatment is a tool widely used in surface modification of different materials to optimize their properties against a particular application. In this study were carried out modification of ultrafiltration (UF) membranes by low temperature plasma treatment in an inductive reactor. The aim was enhancing hydrophilicity and uniforming surface pores of the UF membranes in order to reduce the fouling and enhance the flux.UF membranes were modified by two consecutive treatments: first with argon plasma (Ar) followed by polymerization with acrylic acid (AA). The pre-treatment with Ar plasma was performed for 2, 5, 10 and 15 minutes at a pressure of 200 mTorr, with the goals of cleaning the surface and improve adhesion between the substrate and plasma polymerised acrylic acid coatings. In the plasma polymerization was used a mixture of AA with Ar at a pressure of 300 mTorr by 30 minutes. The radio frequency power source (8- 13.56 kHz) was 10,2W for all case. UF membranes were prepared by phase inversion method based on Polyethersulfone with polyethylene glycol of molecular weight 10.000 as additive.The characterization of the membranes before and after the surface modification was done using contact angle to determine its effect on the surface hydrophilicity. Also SEM images have been obtained in order to follow morphological changes produced by the plasma modification. A homogeneous coating was observed as a thin film that would cover part of the membrane pores. Attenuated total reflectance spectrums, ATR-FTIR, were analyzed to understand the changes on the chemical composition of the surface of the modified membrane. The pure water permeability and tests of retention of viral model, bacteriophage PP7 using the host Pseudomonas aeruginosa, were measured showing a proper performance.The plasma polymerization of AA is of great interest in surface modification of UF membranes with the aim of adjust membrane performance by simultaneously controlling the surface hydrophilicity, permeability and retention.