Mots-clés:

Nanocomposites, Antifouling surfaces, ZnO Nanowire arrays, capillary rise infiltration, liquid repellency

Abstract

Liquid-repellent surfaces provide useful functionality for various coating applications. However, maintaining the stability of such liquid repellency over a long time remains an unresolved challenge. Moreover, despite remarkable progress, conventional methods for fabricating these surfaces require multiple steps and are only suitable for lab-scale fabrication. This thesis focuses on the fabrication of anti-fouling nanocomposite surfaces that maintain their stability under challenging conditions. Specifically, we fabricate these nanocomposite surfaces by inducing the infiltration of polymers into the interstices of surface-grown ZnO nanowires. Two capillary-based techniques are developed: 1) leaching-enabled capillary rise infiltration of uncross-linked and mobile oligomer chains from a poly(dimethylsiloxane) (PDMS) elastomer and 2) wicking of silicone oil into the space between ZnO nanowires. Our methods enable a cost-effective and large-scale fabrication of ZnO nanowires -based liquid-repellent surfaces. By changing the infiltrated species (PDMS or silicone oil), two types of liquid repellency- superhydrophobic or slippery - can be achieved. Our liquid-repellent surfaces present several useful features: self-cleaning, anti-icing, solvent and chemical resistance, high transparency, self-healing, and anti-biofouling properties. Key findings of this thesis are: 1) a straightforward and scalable approach for fabricating liquid-repellent nanocomposite surfaces that precisely retain the original morphology of ZnO nanowires; 2) retaining lubricant within the nanostructures, which is a key for producing stable slippery liquid infused surfaces. The approaches developed in this study are straightforward, efficient, and potentially scalable. The fundamental understanding from this work can enable others to design long-lasting liquid-repellent surfaces. In addition, we also describe the applicability of these ZnO nanowires -based liquid-repellent surfaces to preventing bacterial biofilms formation, in which we have found some encouraging preliminary results. Furthermore, we show the ability to grow ZnO nanowires on commercial membranes (glass fiber and stainless-steel mesh) to extend the applicability of our materials for separation applications.