Functional Silver‐Silicone‐Nanofilament‐Composite Material for Water Disinfection

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2017-01, Vol.13 (4), p.np-n/a
• Main Authors: Meier, Margrith, Suppiger, Angela, Eberl, Leo, Seeger, Stefan
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - pharmacology; antibacterial surfaces; Bacteria; Beads; Coating; Disinfection - methods; Escherichia coli - drug effects; Expansion; Glass; Glass - chemistry; high surface area; Metal Nanoparticles - chemistry; Microbial Sensitivity Tests; Microspheres; Nanoparticles; Nanostructure; silicone nanostructures; Silicones - chemistry; Silver; Silver - chemistry; silver nanoparticles; Water - chemistry; water disinfection; Wettability
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.201601072

The roughness of superhydrophobic silicone nanofilaments (SNFs) is exploited to enlarge the contact area of conventional filter material. As an efficient wetting of the filter material is crucial for water treatment, the wettability of SNFs is readily modified from superhydrophobic to hydrophilic during the functionalization process. SNFs are coated on glass beads and subsequently modified with biocidal silver nanoparticles (AgNPs). The enlarged surface area of SNFs allows a 30 times higher loading of AgNPs in comparison to glass beads without SNF coating. Thus, in column experiments, the AgNP‐SNF‐nanocomposite‐modified glass beads exert superior antibacterial activity towards suspensions of E. coli K12 compared to AgNP functionalized glass beads without SNFs. Additionally, reusing the AgNP‐SNF‐nanocomposite‐coated glass beads with fresh bacteria contaminated medium increases their efficacy and reduces the colony forming units by ≈6 log units. Thereby, the silver loss during percolation is below 0.1 μg mL−1. These results highlight, first, the potential of AgNP‐SNF‐nanocomposite‐modified glass beads as an effective filter substrate for water disinfection, and second, the efficiency of SNF coating in increasing the contact area of conventional filter material. Silicone nanofilaments (SNFs) are coated on glass beads and used as support material for silver nanoparticles (AgNPs) in water disinfection. The high surface area of SNFs significantly enhances the AgNP loading. Thus, the AgNP‐SNF‐nanocomposite‐coated glass beads show superior antibacterial activity against E. coli compared to AgNP‐coated glass beads without SNF.