Production, characterization and testing of antibacterial PVA membranes loaded with HA‐Ag 3 PO 4 nanoparticles, produced by SC‐CO 2 phase inversion

BACKGROUND Silver‐loaded hydroxyapatite nanoparticles were incorporated into poly(vinyl alcohol) (PVA) membranes obtained by supercritical CO 2 (SC‐CO 2 ) assisted phase inversion. Ag 3 PO 4 crystals of 2.2 ± 0.6 nm were dispersed in synthesized needle‐like hydroxyapatite nanoparticles (20 × 65 nm) and were uniformly deposited on the internal surfaces of the PVA membranes. Operative conditions to produce membranes by SC‐CO 2 , PVA concentration and the effect on membrane porosity and morphology were studied. RESULTS Solutions at 20% w/w PVA produced membranes with cellular morphology and nanoporous walls, whereas 30% and 50% w/w solutions produced nanostructured membranes. Silver ions were released from PVA membranes mainly by diffusion according to the Peppas–Sahlin model. Membranes obtained at 20% w/w PVA showed a significant E. coli inhibition at an Ag concentration of 9 ppm, reaching the minimal inhibitory concentration (MIC) and improving the bactericidal activity of the nanoparticles. CONCLUSION A concentration of Ag 3 PO 4 crystals of about 22 ppm was calculated as being capable of completely destroying these bacteria, reaching the minimum bactericidal concentration (MBC). © 2018 Society of Chemical Industry