Synthesis of superhydrophobic polymer/tungsten (VI) oxide nanocomposite thin films

Abstract

A method is presented to enable the preparation of superhydrophobic polymer/tungsten (VI) oxide (WO3) nanocomposite coatings on glass substrates. WO3 nanoparticles were incorporated via the swell-encapsulation-shrink method into superhydrophobic silicone polymer films deposited on glass via aerosol-assisted chemical vapour deposition (AACVD) to produce the novel nanocomposite films. The technique overcomes the limitations of previous methods for nanoparticle incorporation to provide a synthetic route to previously unattainable materials. The nanocomposite films retain the properties of the superhydrophobic polymer while the presence of the nanoparticles is clearly evident. As such, the films have a range of potential applications including high surface area photocatalysis and self-cleaning photochromic or electrochromic coatings. The two-stage synthesis is shown to be flexible and suggests great scope for producing any number of future novel materials. The thin films were characterized using scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis, X-ray photoelectron spectroscopy (XPS), infra-red (FTIR) spectroscopy, X-ray diffractometry (XRD) and water droplet contact angle measurements. KEYWORDS

Transforming a Simple Commercial Glue into Highly Robust Superhydrophobic Surfaces via Aerosol-Assisted Chemical Vapor Deposition

“…[31][32][33] Likewise it has been used in the preparation of numerous polymer films. [34][35][36][37] In this paper, we use the unique AACVD method to deposit coatings of epoxy resin from a vapour-phase stream of the aerosolised precursor towards the heated glass substrate. This method confers a hierarchical micro/nano-scopically rough structure to the epoxy resin coating, enabling superhydrophobicity upon post-treatment with PDMS while the adhesive strength of the epoxy resin on the glass confers its mechanical durability.…”

“…Precursors for AACVD need only be soluble in suitable media; this gives AACVD a distinct advantage over traditional CVD methods in terms of precursor availability. It has demonstrated success in preparing a myriad of materials, including n-type ZnO, TiO 2 , GaAs, BiOX (where X = Cl, Br, I), and SnO 2 :F, suiting many useful functional purposes. − Likewise, it has been used in the preparation of numerous polymer films. − …”

Sonochemical Routes to Superhydrophobic Soft Matter Coatings: Comparing Silica and Copper Oxide Coatings on Polyester Fabric

“…For fibrous hydrophobic surfaces, water forms bead-like drops, minimizing the solid–liquid contact area, to reduce surface free energy, when the fabric surface tension (γ C ) is lower than the liquid surface tension (γ L ). , For textile substrates, γ C also depends on the material properties such as yarn composition, fabric structure (i.e., synthetic material vs natural, thread density, floats), and surface features (i.e., being composed of microfibers possessing inherent binary nano- and microscaled textures) that allow for hydrophobic and even superhydrophobic characteristics to be achieved (often in combination with modifying hydrophobic agents). , Thus, while rough surfaces are usually fragile due to the high local pressures under mechanical load, a hierarchical, dual-scale surface roughness can yield both coating durability and high hydrophobicity while any impinging water droplets are firmly pinned to the surface due to air trapped within the nanoscale structures. , Dendritic copper-based structures offer high surface areas due to this hierarchical roughness and higher amplitude of asperity that allows control of surface wettability . In addition to the material focus in this paper, alternative materials (e.g., PDMS, ZnO, TiO 2 , among many others) have been explored by other authors, due to similar hierarchical properties. − …”

Durable Antimicrobial Behaviour from Silver-Graphene Coated Medical Textile Composites

“…A version of these fabrics are already used in healthcare environments with high reported efficacy [22]. As such, techniques based on functionalised medical textiles, that are essentially self-sterilising, are now areas of focus, including various routes towards nanoparticles (NP) incorporated into polymers and coatings [23][24][25][26][27][28]. Silver (Ag) and copper (Cu) compounds are among the most studied metallo-pharmaceuticals, with textiles, implants, catheters, etc., currently using Ag-species and engineered delivery systems involving Ag-derivatives, as antimicrobial agents against E. coli, S. aureus, etc.…”