Antibacterial Activity of Silver Nanoflake (SNF)-Blended Polysulfone Ultrafiltration Membrane

Abstract

The aim of this research was to study the possibility of using silver nanoflakes (SNFs) as an antibacterial agent in polysulfone (PSF) membranes. SNFs at different concentrations (0.1, 0.2, 0.3 and 0.4 wt.%) were added to a PSF membrane dope solution. To investigate the effect of SNFs on membrane performance and properties, the water contact angle, protein separation, average pore size and molecular weight cutoffs were measured, and water flux and antibacterial tests were conducted. The antimicrobial activities of the SNFs were investigated using Escherichia coli taken from river water. The results showed that PSF membranes blended with 0.1 wt.% SNFs have contact angles of 55°, which is less than that of the pristine PSF membrane (81°), exhibiting the highest pure water flux. Molecular weight cutoff values of the blended membranes indicated that the presence of SNFs does not lead to enlargement of the membrane pore size. The rejection of protein (egg albumin) was improved with the addition of 0.1 wt.% SNFs. The SNFs showed antimicrobial activity against Escherichia coli, where the killing rate was dependent on the SNF concentration in the membranes. The identified bacterial colonies that appeared on the membranes decreased with increasing SNF concentration. PSF membranes blended with SNF, to a great degree, possess quality performance across several indicators, showing great potential to be employed as water filtration membranes.

Design and Manufacturing of Antibacterial Electrospun Polysulfone Membranes Functionalized by Ag Nanocoating via Magnetron Sputtering

“…Such a result is even more interesting when considering the very low content of Ag in our samples, i.e., an Ag/PSU ratio of about 0.1-0.2%wt. in our work vs. typical ratios in the range 0.3-5% employed in other previous works [22,23,25]. After the exponential decay fit of data in Figure 14 (right panel), DOE7-Ag resulted in a slightly faster antibacterial effect, with a bacterial decrease rate that was about 1.5 times higher than that of DOE3-Ag.…”

“…Recently, PSU membranes have been combined with Ag nanoparticles to add antibacterial behavior and control the membrane wettability properties for usages in water filtration and other possible applications [22][23][24][25][26]. However, only in a few of them [25,26] the PSU membranes are fabricated by the electrospinning method, which can present numerous advantages, as described above.…”