Investigation of Biocidal Effect of Microfiltration Membranes Impregnated with Silver Nanoparticles by Sputtering Technique

Abstract

Silver nanoparticles were loaded in microfiltration membranes by sputtering technique for the development of biocidal properties and biofouling resistance. This technology allows good adhesion between silver nanoparticles and the membranes, and fast deposition rate. The microfiltration membranes (15 wt.% polyethersulfone and 7.5 wt.% polyvinylpyrrolidone in N,N-dimethylacetamide) were prepared by phase inversion method, and silver nanoparticles were deposited on their surface by the physical technique of vapor deposition in a sputtering chamber. The membranes were characterized by Field Emission Scanning Electron Microscopy, and the presence of silver was investigated by Energy-Dispersive Spectroscopy and X-ray Diffraction. Experiments of silver leaching were carried out through immersion and filtration tests. After 10 months of immersion in water, the membranes still presented ~90% of the initial silver, which confirms the efficiency of the sputtering technique. Moreover, convective experiments indicated that 98.8% of silver remained in the membrane after 24 h of operation. Biocidal analyses (disc diffusion method and biofouling resistance) were performed against Pseudomonas aeruginosa and confirmed the antibacterial activity of these membranes with 0.6 and 0.7 log reduction of viable planktonic and sessile cells, respectively. These results indicate the great potential of these new membranes to reduce biofouling effects.

Fabrication and Characterization of Sulfonated Graphene Oxide-Doped Polymeric Membranes with Improved Anti-Biofouling Behavior

“…Pure water flux of membrane was checked using a cross-filtration apparatus and mechanical properties like tensile strength of fabricated membrane were evaluated using Instron tensile testing machine. Particularly, for each type of membrane the specimens were stretched in unidirection at the rate of 5 mm/min [ 29 ]. The pure water flux of SGO membranes was determined using dead end stirred filtration system having membrane active area of ~18.5 cm 2 .…”

“…Permeated water was then collected and weighed out using digital balance. The following formula was employed for the calculation of pure water flux Jw (L m −2 h −1 ) [ 29 ]: where V is the permeate volume (L), A is the effective area of membrane (m 2 ) and Δt is the time of filtration (h).…”

“…Permeated water was then collected and weighed out using digital balance. The following formula was employed for the calculation of pure water flux Jw (L m −2 h −1 ) [29]:…”

Current Trends and Perspectives in the Application of Polymeric Materials to Wastewater Treatment

“…Eleven research works [1][2][3][4][5][6][7][8][9][10][11] by distinguished international authors were published within this SI on "Current Trends and Perspectives in the Application of Polymeric Materials for Wastewater Treatment", which covered a wide range of issues related to this topic.…”

“…These authors demonstrated that NMO incorporation not only improved the membranes' antifouling properties and permeation performance but also allowed for an enhanced color separation from palm oil mill effluent, which was related to the synergism between surface deprotonation and pore size screening. For their part, Linhares et al [6] loaded silver nanoparticles (AgNPs) in microfiltration polymeric membranes (15 wt.% polyethersulfone and 7.5 wt.% polyvinylpyrrolidone in N,N-dimethylacetamide) by the sputtering technique. They demonstrated the efficiency of this technique to load AgNPs, which provided membranes with biocidal properties resistant to biofouling and made them proficient for water disinfection treatments.…”