Plasma deposition of silver nanoparticles on ultrafiltration membranes: antibacterial and antibiofouling properties

MERCEDES C. CRUZ; M. WOLF; R. SCHMITTGENS; ELZA CASTRO VIDAURRE; VERÓNICA B. RAJAL

Aachen

Conferencia; 6th IWA Specialist Conference on Membrane Technology for water and wastewater treatment; 2011

The use of membranes for water purification is increasing, yet the microbiological contamination (biofouling) of polymeric membranes and associated decrease in membrane flux reduce the efficacy of the process. To improve the efficiency of the disinfection process and develop membrane systems less susceptible to biofouling considering the bactericidal activity of Ag nanoparticles (Ag-NP), commercial membranes were modified. They were activated with low temperature plasma of different gases (Ar and O2), then a thin polymer film of Poly(methyl metacrylate) was deposited by plasma-enhanced chemical vapour deposition and finally subjected to Ag-NP deposition by gas flow sputtering. Several characterizations of the virgin and modified membranes were made, including contact angle, superficial energy, compaction, hydraulic permeability, scanning electron microscopy, Energy Dispersive X-ray Spectroscopy observations, bactericidal properties, and disinfection by ultrafiltration. The results allow to establish antibacterial properties and substantial resistance to biofouling of modified membranes that enhance membranes lifetime.