Photoreactive composite coating with composition dependent wetting properties

Abstract

Photoreactive composite thin layers with tunable wetting properties from superhydrophilic to superhydrophobic nature were prepared. To achieve extreme wetting properties, the adequate surface roughness is a crucial factor, which was achieved by the incorporation of plasmonic Ag-TiO 2 particles, as polymer filler, into the smooth polymer film with adjusted hydrophilicity. The initial copolymer films were synthesized from hydrophilic 2-hydroxyethyl-acrylate (HEA) and hydrophobic perfluorodecyl-acrylate (PFDAc) monomers. In the case of hydrophobic PFDAc, the photocatalyst-roughened thin films displayed superhydrophobic behavior (γ s tot~ 2.3±1.7 mJ/m 2 , Θ > 150°), while the roughened hydrophilic pHEA layers possessed superhydrophilicity (γ s tot~ 72.1±0.2 mJ/m 2 , Θ~ 0°). The photoactivity of the composites was presented both in solid/ gas (S/G) and solid/ liquid (S/L) interfaces. According to the light-emitting diode (LED) light photodegradation tests on ethanol (EtOH) as volatile organic compound (VOC) model-molecules at the S/L interface, the superhydrophobic hybrid layer was photooxidized 88.3% of the initial EtOH (0.36 mM). At S/L interface the photocatalytic efficiency was depended on the polarity of the model pollutant molecules: the photooxidation of hydrophobic SUDAN IV (c 0 = 0.25 mg/mL) dye reached 80%, while in the case of the hydrophilic Methylene Blue dye (c 0 = 0.002 mg/mL) it was only 17.3% after 90 min blue LED light (λ = 405 nm) illumination.

Preparation of sulfur hydrophobized plasmonic photocatalyst towards durable superhydrophobic coating material

“…It was also presented earlier that the used blue LED light source with 405 nm emission maximum is sufficient for excitation of the Ag-TiO 2 catalyst [31,32]. In this work the photocatalytic efficiency of the sulfur hydrophobized composite photocatalyst layers were studied using the same blue LED lamp and ethanol as model volatile organic compound ( Fig.…”

“…Two polymer based composites were chosen as reference: the Ag-TiO 2 / polyacrylate hybrid layer contains poly(ethylacrylate-co-methyl methacrylate) copolymer [4], while the polymer component of the Ag-TiO 2 /fluoropolymer composite was poly(perfluorodecyl acrylate) fluoropolymer [31,32,34]. As a results, the initial  of the Ag-TiO 2 / polyacrylate hybrid layer was 85.2 • ±1.75 • which was drastically changed to 0 • just after two days irradiation.…”

Fast optical method for characterizing plasmonic nanoparticle adhesion on functionalized surfaces

“…The (theoretically calculated) maximal monoparticular (Θ = 1) adhered amount of nanoparticles can be determined by the ratio of these two values, as described by eq. (6). The results are presented in Table 1.…”

“…In the last few decades, several fields of application arose, including sensitized solar cells [1], optical circuits [2], and analytical methods, such as surface-enhanced raman spectroscopy and surface plasmon resonance spectroscopy [3,4]. Visible-light photocatalysis also deserves a mention: the presence of Au or Ag nanoparticles can tune the bandgap energy of semiconductors like anatase TiO 2 , which is originally excitable by near-UV electromagnetic radiation [5][6][7].…”

A Stimulus-Responsive Polymer Composite Surface with Magnetic Field-Governed Wetting and Photocatalytic Properties

“…To broaden the range of surface functionalities, hydrophobic polymer-based surfaces can also be enhanced with photocatalyst particles, resulting in photocatalytic and even antimicrobial properties; besides, they can also be utilized to induce changes in wetting properties through surface roughness modification [18]. In our previous works, spray-coated hydrophobic fluoropolymer-and PDMS-based layers were enhanced with visible light-active plasmonic Ag-TiO 2 photocatalyst nanoparticles to obtain bifunctional (superhydrophobic and visible light-active) [19,20] and trifunctional (with extra self-healing ability) coatings [21]. Despite there being no examples of combining the magnetic field dependent wetting and photocatalytic properties in the literature so far, these multifunctional surfaces may open new perspectives for sophisticated liquid manipulation techniques.…”