Yazar "Kasapgil, Esra" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim
    Öğe
    Multi-liquid repellent, fluorine-free, heat stable SLIPS via layer-by-layer assembly
    (Elsevier, 2022) Kasapgil, Esra; Erbil, H. Yıldırım; Şakir, İlke Anaç
    Slippery liquid-infused porous surfaces (SLIPS) are an emerging class of bio-inspired materials attracting re-searchers due to their good anti-fouling, anti-icing, and self-cleaning performance. The fluorinated lubricants which are used in the preparation of multi-liquid repellent SLIPS are not suitable for practical applications because of the lubricant losses by evaporation and water drop cloaking and also they cause environmental and health problems. In this study, layer-by-layer (LbL) assembly technique via a capping approach is used to obtain PDMS-based SLIPSs. Amino terminated PDMS was used as a homofunctional polymer layer and three different co-polymers of anhydride [poly(ethylene-alt-maleic anhydride) PEMA, poly(isobutylene-alt-maleic anhydride) PIMA and poly(maleic anhydride-alt-1-octadecene) PMAO] were used as the capping layers to give LbL layers having advancing contact angles between 115 and 120? with the change of the type of anhydride copolymer used and the constituent concentration. Silicone oil was used as the lubricant giving a fluorine-free LbL-SLIPS having a contact angle hysteresis as low as 5-6 repelling water and various other liquids such as glycerol, ketchup and soy sauce by preserving the low contact angle hysteresis for long durations. Moreover, LbL-SLIPS samples also had good heat resistance (to 80 ?C for 8 days) and chemical stability against acids and bases and were durable under the flow of continuous water droplets for a period of 4 h without any damage to SLIPS properties. The best performing LbL-SLIPS sample was prepared using the PEMA capping layer where the decrease in silicone oil thickness and in-crease in contact angle hystresis were found to be lowest under continuous water droplet flow after 4 h.
  • Küçük Resim Yok
    Öğe
    Producing Fluorine- and Lubricant-Free Flexible Pathogen- and Blood-Repellent Surfaces Using Polysiloxane-Based Hierarchical Structures
    (Amer Chemical Soc, 2022) Ladouceur, Liane; Shakeri, Amid; Khan, Shadman; Rincon, Alejandra Rey; Kasapgil, Esra; Weitz, Jeffrey I.; Soleymani, Leyla
    High-touch surfaces are known to be a major route for the spread of pathogens in healthcare and public settings. Antimicrobial coatings have, therefore, garnered significant attention to help mitigate the transmission of infectious diseases via the surface route. Among antimicrobial coatings, pathogen-repellent surfaces provide unique advantages in terms of safety in public settings such as instant repellency, affordability, biocompatibility, and long-term stability. While there have been many advances in the fabrication of biorepellent surfaces in the past two decades, this area of research continues to suffer challenges in scalability, cost, compatibility with high-touch applications, and performance for pathogen repellency. These features are critical for high-touch surfaces to be used in public settings. Additionally, the environmental impact of manufacturing repellent surfaces remains a challenge, mainly due to the use of fluorinated coatings. Here, we present a flexible hierarchical coating with straightforward and cost-effective manufacturing without the use of fluorine or a lubricant. Hierarchical surfaces were prepared through the growth of polysiloxane nanostructures using n-propyltrichlorosilane (n-PTCS) on activated polyolefin (PO), followed by heat shrinking to induce microscale wrinkles. The developed coatings demonstrated repellency, with contact angles over 153 degrees and sliding angles <1 degrees. In assays mimicking touch, these hierarchical surfaces demonstrated a 97.5% reduction in transmission of Escherichia coli (E.coli), demonstrating their potential as antimicrobial coatings to mitigate the spread of infectious diseases. Additionally, the developed surfaces displayed a 93% reduction in blood staining after incubation with human whole blood, confirming repellent properties that reduce bacterial deposition.