title: Amine Enrichment of Thin-Film Composite Membranes via Low Pressure Plasma Polymerization for Antimicrobial Adhesion.
abstract: Thin-film composite membranes, primarily based on poly(amide) (PA) semipermeable materials, are nowadays the dominant technology used in pressure driven water desalination systems. Despite offering superior water permeation and salt selectivity, their surface properties, such as their charge and roughness, cannot be extensively tuned due to the intrinsic fabrication process of the membranes by interfacial polymerization. The alteration of these properties would lead to a better control of the materials surface zeta potential, which is critical to finely tune selectivity and enhance the membrane materials stability when exposed to complex industrial waste streams. Low pressure plasma was employed to introduce amine functionalities onto the PA surface of commercially available thin-film composite (TFC) membranes. Morphological changes after plasma polymerization were analyzed by SEM and AFM, and average surface roughness decreased by 29%. Amine enrichment provided isoelectric point changes from pH 3.7 to 5.2 for 5 to 15 min of plasma polymerization time. Synchrotron FTIR mappings of the amine-modified surface indicated the addition of a discrete 60 nm film to the PA layer. Furthermore, metal affinity was confirmed by the enhanced binding of silver to the modified surface, supported by an increased antimicrobial functionality with demonstrable elimination of E. coli growth. Essential salt rejection was shown minimally compromised for faster polymerization processes. Plasma polymerization is therefore a viable route to producing functional amine enriched thin-film composite PA membrane surfaces.
authors.affiliation: †Institute for Sustainability for Innovation, College of Engineering and Science, Victoria University, Hoppers Lane, Werribee, Victoria 3030, Australia.
authors.forename: Rackel
authors.initials: R
authors.lastname: Reis
authors.affiliation: ‡Institute for Frontier Materials, Deakin University, Pigdons Road, Waurn Ponds,Victoria 3216, Australia.
authors.forename: Ludovic F
authors.initials: LF
authors.lastname: Dumée
authors.affiliation: ‡Institute for Frontier Materials, Deakin University, Pigdons Road, Waurn Ponds,Victoria 3216, Australia.
authors.forename: Li
authors.initials: L
authors.lastname: He
authors.affiliation: ‡Institute for Frontier Materials, Deakin University, Pigdons Road, Waurn Ponds,Victoria 3216, Australia.
authors.forename: Fenghua
authors.initials: F
authors.lastname: She
authors.affiliation: †Institute for Sustainability for Innovation, College of Engineering and Science, Victoria University, Hoppers Lane, Werribee, Victoria 3030, Australia.
authors.forename: John D
authors.initials: JD
authors.lastname: Orbell
authors.affiliation: §Faculty of Engineering, Monash University, Bayview Avenue, Clayton, Victoria 3800, Australia.
authors.forename: Bjorn
authors.initials: B
authors.lastname: Winther-Jensen
authors.affiliation: †Institute for Sustainability for Innovation, College of Engineering and Science, Victoria University, Hoppers Lane, Werribee, Victoria 3030, Australia.
authors.forename: Mikel C
authors.initials: MC
authors.lastname: Duke
mesh_terms: D000327:Adsorption; D000588:Amines / Q000737:chemistry*; D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D001422:Bacterial Adhesion; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D004926:Escherichia coli / Q000187:drug effects* / Q000502:physiology; D008422:Materials Testing; D008567:Membranes, Artificial; D053768:Metal Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry; D058626:Plasma Gases / Q000737:chemistry; D011312:Pressure; D012834:Silver / Q000737:chemistry / Q000494:pharmacology*; D013499:Surface Properties
chemical_list: D000588:Amines; D000890:Anti-Infective Agents; D008567:Membranes, Artificial; D058626:Plasma Gases; D012834:Silver
keywords: amine enrichment; antimicrobial properties; functional thin-film coatings; nanoscale surface engineering; plasma polymerization