This study compares the tribological and thermophysical features of the lubricating oil using MoS₂ and ZnO nano-additives. The average size of MoS₂ and ZnO nanoparticles were 90 nm and 30 nm, respectively. The nanoparticles were suspended using Triton X-100 in three different concentrations (0.1, 0.4 and 0.7 wt.%) in a commercial diesel oil. Tribological properties such as mass loss of the pins, friction coefficient, and worn surface morphologies and thermophysical properties such as viscosity, viscosity index, flash point and pour point of resulting nano lubricant were evaluated and compared with those of pure diesel oil. The tribological behavior of nano lubricants was evaluated using a pin-on-disc tribometer. The worn surface morphologies were observed by scanning electron microscopy. The overall results of this experiment reveal that the addition of nano-MoS₂ reduces the mass loss values of the pins in 93% due to the nano-MoS₂ lubricant effect. With 0.7 wt.% in nanoparticles content, the viscosity of MoS₂ and ZnO nano lubricants at 100 °C increased by about 9.58% and 10.14%, respectively. Pure oil containing 0.7 wt.% of each nanoparticle increased the flash point because of its small size and surface modifying behavior compared to the pure oil. Moreover, the addition of ZnO nanoparticles with pure oil lubricant is more suitable than MoS₂ nanoparticles for improving the thermophysical properties of pure oil.

This study aimed to assess the UV-shielding features of the PMMA-based thin film coatings with the addition of TiO₂ and ZnO nanoparticles as nanofillers considering different contents. Furthermore, the effect of TiO₂/ZnO nanohybrids at different ratios and concentrations was examined. The XRD, FTIR, SEM, and EDX analyses characterized the prepared films' functional groups, structure, and morphology. Meanwhile, the coatings' optical properties and UV-protecting capability were investigated by ultraviolet–visible (UV–Vis) spectroscopy. The UV–Vis spectroscopic study revealed that as the concentration of nanoparticles increased in the hybrid-coated PMMA, the absorption in the UVA region increased. Overall, it can be concluded that the optimal coatings for PMMA were 0.1 wt% TiO₂, 0.1 wt% ZnO, and 0.025:0.025 wt% TiO₂: ZnO nanohybrid. Considering the acquired FT-IR of PMMA with different content of nanoparticles before and after exposure to the UV irradiation, for some films, it was confirmed that the polymer-based thin films degraded after 720 h, with either decreasing or increasing intensity of the degraded polymer, peak shifting, and band broadening. Notably, the FTIR results were in good agreement with UV–Vis outcomes. In addition, XRD diffraction peaks demonstrated that the pure PMMA matrix and PMMA coating films did not show any characteristic peaks indicating the presence of nanoparticles. All diffraction patterns were similar with and without any nanoparticles. Therefore, it depicted the amorphous nature of polymer thin film.

The primary objective of this research is to investigate the reduction of 4‐nitroaniline (4‐NA) and 2‐nitroaniline (2‐NA) using synthesized copper ferrite nanoparticles (NPs) via facile one‐step hydrothermal method as a heterogeneous nano‐catalyst. Nitroanilines were reduced in the presence and without the catalyst with a constant amount (100 mg) of reducing agent of sodium borohydride (NaBH₄) at room temperature in water to amino compounds. To characterize the functional groups, size, structure, and morphology of as‐prepared magnetic NPs, FTIR, XRD, SEM, and TEM were employed. The UV‐Vis spectrum was utilized to explore the catalytic effect of CuFe₂O₄. The outcomes revealed that the synthesized CuFe₂O₄ as a heterogeneous magnetic nano‐catalyst catalyzed the reduction of 4‐NA and 2‐NA significantly faster than other candidate catalysts. The outcomes demonstrated that the catalyst catalyzed 4‐nitroaniline to para‐phenylenediamine (p‐PDA) and 2‐nitroaniline to ortho‐phenylenediamine (o‐PDA) with a constant rate of 7.49×10⁻² s⁻¹ and 3.19×10⁻² s⁻¹, and conversion percentage of 96.5 and 95.6, in 40 s and 90 s, sequentially. Furthermore, the nanoparticles could be recovered by a magnetic separation method and reused for six consecutive cycles without remarkable loss of catalytic ability.