Slippery lubricant-infused silica nanoparticulate film processing for anti-biofouling applications

Abstract

Microbial biofilm build-up in water distribution systems can pose a risk to human health and pipe material integrity. The impact is more devastating in space stations and to astronauts due to the isolation from necessary replacement parts and medical resources. As a result, there is a need for coatings to be implemented onto the inner region of the pipe to minimize the adherence and growth of biofilms. Lubricant-infused surfaces has been one such interesting material for anti-biofouling applications in which their slippery property promotes repellence to many liquids and thus prevents bacterial adherence. Textured and porous films are suitable substrate candidates to infuse and contain the lubricant. However, there is little investigation in utilizing a nanoparticulate thin film as the substrate material for lubricant infusion. A nanoparticulate film has high porosity within the structure which can promote greater lubricant infusion and retention. The implementation as a thin film structure aids to reduce material consumption and cost. In our study, we utilized a well-studied nanoporous thin film fabricated via layer-by-layer assembly of polycations and colloid silica and then calcination for greater stability. The film was further functionalized to promote fluorinated groups and improve affinity with a fluorinated lubricant. The pristine nanoporous film was characterized to determine its morphology, thickness, wettability, and porosity. The lubricant-infused film was then tested for its lubricant layer stability upon various washing conditions and its performance against bacterial biofilm adherence as a result of its slippery property. Overall, the modified silica nanoparticulate thin film demonstrated potential as a base substrate for lubricant-infused surface fabrication that repelled against ambient aqueous solvents and as an anti-biofouling coating that demonstrated low biofilm coverage and colony forming unit values. Further optimization to improve lubricant retention or incorporation of a secondary function can aid in developing better coatings for biofilm mitigation.

Sustainable Biofilm Inhibition Using Chitosan-Mesoporous Nanoparticle-Based Hybrid Slippery Composites

“…We investigated and compared the antibiofilm performance of other biofilm inhibition methods developed using environmentally friendly and/or nontoxic approaches. As shown in Table S1, the majority of antibiofilm approaches based on environmentally friendly or nontoxic approaches demonstrated only short-term inhibition performance within 24 h with reductions of 80–99.6%, while some demonstrated long-term performance of approximately 5–7 days with reductions of 75–97.2%. − In comparison, our hybrid approach demonstrated a reduction of 97.7% over 7 days of incubation, validating the long-term biofilm resistance of the slippery composites based on the hybrid approaches. Additionally, the PDMS-CTS-MSN-SO composite also showed excellent long-term antibiofilm efficacy against the Gram-positive bacteria of S. aureus with overall similar trends for Gram-negative bacteria of E. coli (Figure S6).…”