Assessment of anti-bacterial adhesion and anti-biofouling potential of plasma-mediated poly(sulfobetaine methacrylate) coatings of feed spacer

In this work, an easy to up-scale method combining atmospheric plasma treatment and wet chemical coating with zwitterionic poly(sulfobetaine methacrylate) (pSBMA) was employed to modify the feed spacer surface aiming at reducing its susceptibility to biofouling. The goals of the study were: 1) to verify whether the proposed modification method is suitable for preparation of homogenous feed spacer coatings and 2) to compare the biofouling propensity of pSBMA modified and unmodified spacers. The effect of the plasma intensity and monomer concentration on the feed spacer surface composition, morphology and roughness were studied. The most favorable modification was compared with the reference material in a batch experiment and a continuously operated fouling simulator. The zwitterionic coating showed reduced adhesion of Pseudomonas fluorescens by 70% and postponed the EPS production in the short-term batch testing. However, the long-term studies performed under continuous flow conditions with nutrient dosage did not demonstrate any significant biofouling mitigation of the surface-conditioned spacers.