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A novel superhydrophobic coating prepared from an inverse vulcanized copolymer and SiO2 nanoparticle composite, exhibiting antibacterial properties, photocatalytic behaviour and UV stability.

Superhydrophobic polymer–nanoparticle composite (SPNC) materials are considered to be superior to their molecular equivalents, due to their enhanced functional properties. In this work, we systematically formulate a library of SPNC coatings and demonstrate an interchangeable three component system. Whereby, implementing key formulation principles enables the use of a wide range of polymer and nanoparticulate materials to generate highly water repellent coatings (both solution-based and ‘solvent-free’). Herein, we report how alternating formulation composition can impact overall functionality of the resultant material, and explore the effects this has on; water repellency, ability to self-clean and UV resilience, for various systems. Additionally, confocal fluorescence microscopy was used to shed light on the differences in composite architecture between thermosetting and thermoplastic polymers. When designing coatings for applied self-cleaning technologies, such as; paints, external building materials and industrial processes, these are crucial factors to consider to ensure coatings remain functional throughout their lifecycle.

Self-cleaning superhydrophobic surfaces are a highly sought-after class of materials which have the potential to be hugely beneficial to many commercial industries. A prospective application is within the paints and coatings industry. However, photo-degradation of titanium dioxide-based (TiO2) coatings often limits the practical implementation of applied superhydrophobic coatings. Here, we present a facile process for fabricating pigmented superhydrophobic nanomaterials which display excellent UV durability, owed to the synergistic effect of using cerium oxide (CeO2) nanoparticles and a silicone elastomer, polydimethylsiloxane (PDMS). Composite coatings resisted photo-degradation after 250 hours of intense UV irradiation (over 100 days under ambient conditions) and continued to exhibit promising self-cleaning properties.

The deposition of highly rough surface coatings is applicable to a wide range of scientific and manufacturing fields, particularly with respect to the control of surface morphology and substrate binding. The following article reports a technique (thermally-activated aerosol-assisted chemical vapour deposition – ta-AACVD) that is used to deposit a highly rough thermosetting polydimethylsiloxane (PDMS) elastomer onto unheated substrates. This method facilitates deposition onto temperature-sensitive substrates and demonstrates tremendous potential in applied water repellent technologies.

Superhydrophobic materials have been widely reported throughout the scientific literature. Their properties originate from a highly rough morphology and inherently water repellent surface chemistry. Despite promising an array of functionalities, these materials have seen limited commercial development. This could be attributed to many factors, like material compatibility, low physical resilience, scaling-up complications, etc. In applications where persistent water contact is required, another limitation arises as a major concern, which is the stability of the air layer trapped at the surface when submerged or impacted by water. This review is aimed at examining the diverse array of research focused on monitoring/improving air layer stability, and highlighting the most successful approaches. The reported complexity of monitoring and enhancing air layer stability, in conjunction with the variety of approaches adopted, results in an assortment of suggested routes to achieving success. The review is addressing the challenge of finding a balance between maximising water repulsion and incorporating structures that protect air pockets from removal, along with challenges related to the variant approaches to testing air-layer stability across the research field, and the gap between the achieved progress and the required performance in real-life applications.