A detailed characterization of phase transformations in the heat-treated commercial 7075 aluminum alloys without/with low Sc–Zr addition was carried out. Mechanical and electrical properties, thermal and corrosion behavior were compared to the microstructure development. The eutectic phase consists of four parts: MgZn₂ phase, Al₂CuMg phase (S-phase), Al₂Zn₃Mg₃ phase (T-phase), and primary λ-Al(Mn,Fe,Si) phase. Strengthening during non-isothermal (isochronal) annealing is caused by a combination of formation of the GP zones, η’-phase, T-phase and co-presence of the primary and secondary Al₃(Sc,Zr)-phase particles. Positive influence on corrosion properties is owing to the addition of Sc–Zr. Positron annihilation showed an evolution of solute Zn,Mg-(co-)clusters into (precursors of) the GP zones in the course of natural ageing. The concentration of the (co-)clusters is slightly negatively affected by the low Sc–Zr addition. A combination of both precipitation sequences of the Al–Zn–Mg–Cu-based system was observed. The apparent activation energy values for dissolution/formation of the clusters/GP zones and for formation of the metastable η’-phase, stable T-phase and stable η-phase were calculated.

This article studies the photocatalytic activity of three types of industrially produced TiO₂ powder (P25, CG100 and CG300) incorporated into a parent geopolymer matrix, and their pure counterparts, based on the decomposition of Rhodamine B dye. Rhodamine B dye is applied as a model substance because it is frequently used in the textile industry and thus may be present in the wastewater. The average particle size, specific surface area and mineralogical composition of TiO₂ powders have been determined. The geopolymer matrix works well as a supporting material for the CG100 and P25 pure types of TiO₂ powder as these input materials have better properties such as a higher average particle size, lower specific surface area, mineralogicalcomposition, etc., than the CG300 TiO₂ powder. These properties (or their combination) affect the photocatalytic activity of the resulting materials, which may thus become advanced composites with an additional purifying ability, e.g., materials that can be used for wastewater treatment or air purification.

In this study, we propose a promising photoprotective additive that combines the advantages of both organic UV absorbers and inorganic particles without compromising the properties of the paint material. This additive involves the intercalation of a well-known organic UV absorber, 2-phenylbenzimidazole-5-sulfonic acid (PBISA), into zinc-aluminum layered double hydroxide (ZnAl-LDH). Three ZnAl-LDH intercalates with PBISA were prepared using various methods based on either anion exchange or direct synthesis. The intercalates were characterized using powder X-ray diffraction, thermogravimetry, elemental analysis, and IR and UV-Vis spectroscopies. The composition and basal spacings of all three intercalates are very similar. An effective UV protection film was prepared when the ZnAl–PBISA–1 intercalate was incorporated into polyurethane-acrylate lacquer. The resultant UV protective film exhibited stability and uniform distribution of the intercalated fillers. Some minimal particle sedimentation and aggregation were observed on the cured film’s underside, but did not compromise the films’ UV protective properties. The prepared lacquers with intercalated fillers offer a viable solution for the surface modification of plastic products.

This study deals with the preparation and characterization of metallic nanoinclusions on the surface of semiconducting Bi2Se3 that could be used for an enhancement of the efficiency of thermoelectric materials. We used Au forming a 1D alloy through diffusion (point nanoinclusion) and Mo forming thermodynamically stable layered MoSe2 nanosheets through the reaction with the Bi2Se3. The Schottky barrier formed by the 1D and 2D nanoinclusions was characterized by means of atomic force microscopy (AFM). We used Kelvin probe force microscopy (KPFM) in ambient atmosphere at the nanoscale and compared the results to those of ultraviolet photoelectron spectroscopy (UPS) in UHV at the macroscale. The existence of the Schottky barrier was demonstrated at +120 meV for the Mo layer and −80 meV for the Au layer reflecting the formation of MoSe2 and Au/Bi2Se3 alloy, respectively. The results of both methods (KPFM and UPS) were in good agreement. We revealed that long-time exposure (tens of seconds) to the electrical field leads to deep oxidation and the formation of perturbations greater than 1 µm in height, which hinder the I–V measurements.

Guanidinium-intercalated derivatives of α- and γ-zirconium hydrogen phosphate, zirconium 2-sulfoethylphosphonate, and zirconium 4-sulfophenylphosphonate were successfully synthesized by treatment of the host materials with aqueous guanidine carbonate solutions at room temperature. In contrast, hydrothermal treatment at 180 °C proved unsuitable for the preparation, as guanidine underwent decomposition, leading predominantly to the formation of ammonium-intercalated phases and, in some cases, partial degradation of the host structure. The synthesized materials were characterized by powder X-ray diffraction, elemental analysis, thermogravimetric analysis, and infrared spectroscopy. The combined results confirmed the incorporation of guanidinium ions into the interlayer space together with variable amounts of co-intercalated water. Spectroscopic data further indicated the formation of extensive hydrogen-bonding networks involving guanidinium ions, water molecules, and acidic groups of the host frameworks. Proton conductivity measurements revealed a pronounced dependence on relative humidity, with conductivity increasing as the water content of the materials increased. Nevertheless, the conductivities of all guanidinium intercalates remained lower than those of the corresponding parent zirconium phosphates and phosphonates. Temperature-dependent conductivity measurements suggested that proton transport proceeds predominantly via a vehicle mechanism in both hydrated and dehydrated states. The prepared intercalates exhibited reversible dehydration and rehydration behavior and retained their structural integrity during conductivity measurements.