Combination of Functional Nanoengineering and Nanosecond Laser Texturing for Design of Superhydrophobic Aluminum Alloy with Exceptional Mechanical and Chemical Properties

Industrial application of metallic materials is hindered by several shortcomings, such as proneness to corrosion, erosion under abrasive loads, damage due to poor cold resistance, or weak resistance to thermal shock stresses, <i>etc</i>. In this study, using the aluminum-magnesium alloy as an example of widely spread metallic materials, we show that a combination of functional nanoengineering and nanosecond laser texturing with the appropriate treatment regimes can be successfully used to transform a metal into a superhydrophobic material with exceptional mechanical and chemical properties. It is demonstrated that laser chemical processing of the surface may be simultaneously used to impart multimodal roughness and to modify the composition and physicochemical properties of a thick surface layer of the substrate itself. Such integration of topographical and physicochemical modification leads to specific surface nanostructures such as nanocavities filled with hydrophobic agent and hard oxynitride nanoinclusions. The combination of superhydrophobic state, nano- and micro features of the hierarchical surface, and the appropriate composition of the surface textured layer allowed us to provide the surface with the outstanding level of resistance of superhydrophobic coatings to external chemical and mechanical impacts. In particular, experimental data presented in this study indicate high resistance of the fabricated coatings to pitting corrosion, superheated water vapor, sand abrasive wear, and rapid temperature cycling from liquid nitrogen to room temperatures, without notable degradation of superhydrophobic performance

Data from: Effect of Hf-doping on electrochemical performance of anatase TiO2 as an anode material for lithium storage

Hafnium-doped titania (Hf/Ti = 0.01; 0.03; 0.05) had been facilely synthesized via a template sol-gel method on carbon fiber. Physicochemical properties of the as-synthesized materials were characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, energy-dispersive X-ray analysis, scanning transmission electron microscopy, X-ray photoelectron spectroscopy, thermogravimetry analysis, and Brunauer−Emmett−Teller measurements. It was confirmed that Hf4+ substitute in the Ti4+ sites, forming Ti1–xHfxO2 (x = 0.01; 0.03; 0.05) solid solutions with an anatase crystal structure. The Ti1–xHfxO2 materials are hollow microtubes (length of 10–100 μm, outer diameter of 1–5 μm) composed of nanoparticles (average size of 15–20 nm) with surface area of 80–90 m2 g–1 and pore volume of 0.294–0.372 cm3 g–1. The effect of hafnium ions incorporation on electrochemical behavior of anatase TiO2 as Li-ion battery anode was investigated by galvanostatic charge/discharge and electrochemical impedance spectroscopy. It was established that Ti0.95Hf0.05O2 shows significantly higher reversibility (154.2 mAh g–1) after 35-fold cycling at C/10 rate in comparison with undoped titania (55.9 mAh g–1). The better performance offered by Hf4+ substitution of the Ti4+ into anatase TiO2 mainly results from more open crystal structure, which has been achieved via the difference in ionic radius values of Ti4+ (0.604 Å) and Hf4+ (0.71 Å). The obtained results are in a strong accordance with ones for anatase TiO2 doped via Zr4+ (0.72 Å) published earlier. Furthermore, improved electrical conductivity of Hf-doped anatase TiO2 materials due to charge redistribution in the lattice and enhanced interfacial lithium storage due to increased surface area directly depending on Hf/Ti atomic ratio have beneficial effect on electrochemical properties

Effective Antibacterial Nanotextured Surfaces Based on Extreme Wettability and Bacteriophage Seeding

A method based on nanosecond laser treatment was used to design superhydrophobic and superhydrophilic aluminum alloy substrates showing enhanced cytotoxic activity with respect to <i>Escherichia coli</i> K12 C600 strain. It was shown that the survival of cells adhered to the superhydrophobic substrates was significantly affected by the presence of organic contaminants, which are ubiquitous in hospital practice and the food industry. The peculiarities of the texture also played a notable role in antibactericidal activity. It was found that the superhydrophilic surfaces had much higher toxicity than the superhydrophobic ones, which was explained by the mechanisms of adhesion of cells to the surface. Scanning electron microscopy and tomographic reconstruction of the adhered cells were used to study the variation of cell morphology after attachment to surfaces with different wettability. It was shown that the cytotoxicity of superhydrophobic surfaces could be significantly enhanced by using the combined antimicrobial action of bacteriophages and the superhydrophobicity of the objects

Supplementary Figures and Tables from Effect of Hf-doping on electrochemical performance of anatase TiO₂ as an anode material for lithium storage

Figure S1: SEM image and elemental mapping of Ti, O, and Hf for Ti_0.95Hf_0.05O₂; Figure S2: XPS high-resolution spectra of (a) Ti 2p, (b) O 1s, (c) Hf 4f, and (d) C 1s regions for Ti_0.95Hf_0.05O₂ sample; Figure S3: Dependence of Z^' on ω^–1/2 at low frequencies; Table S1: Binding energy and atomic concentration of elements in Ti_0.95Hf_0.05O₂ sample; Table S2: Dependence of <i>E</i>_g(1), <i>B</i>_1<i>g</i>(1), and <i>E</i>_<i>g</i>(3) peaks positions on Hf/Ti atomic rati