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In this work, plasma electrolytic oxidation (PEO) ceramic coatings were prepared on magnesium AZ31B alloy. Various electrolyte solutions including phosphate, aluminate and silicate as additives and NaOH [Formula: see text] Na2SiF6 as constant agent were used to prepare the coatings. Influence of the additives on chemical composition and structure of the PEO coatings were examined by means of scanning electron microscope (SEM) and XRD. From structural analysis it was found that coatings prepared in the aluminate-based electrolyte have the best structural features. Microhardness and tribological characteristics of the PEO coatings were investigated using Vickers hardness test and pin-on-disc test. Microhardness for aluminate-based coating was found to be 1169.63[Formula: see text]HV while those for silicate-and phosphate-based coatings were 1093.42[Formula: see text]HV and 285.91[Formula: see text]HV, respectively. Wear rate of the aluminate-based coating was found to be lowest than all other coatings having a value of [Formula: see text][Formula: see text]mg/Nm.

Zinc oxide (ZnO) is well-recognized as a biocompatible multifunctional material with outstanding properties as well as low toxicity and biodegradability. In this work, a simple and versatile technique was developed to prepare highly crystalline ZnO nanorods by introducing egg white to a bio-inspired approach. X-ray diffraction (XRD) and selected area electron diffraction (SAED) pattern results indicated that the ZnO nanorods have single phase nature with the wurtzite structure. Field emission scanning electron microscopy (FESEM) and Transmission electron microscopy (TEM) results showed the nanometer dimension of the nanorods. Raman, FTIR, and TGA/DTA analyses revealed the formation of wurtzite ZnO. The antibacterial properties of ZnO nanorods were investigated using both Gram-positive and Gram-negative microorganisms. These studies demonstrate that ZnO nanorods have a wide range of antibacterial activities toward various microorganisms that are commonly found in environmental settings. Survival ratio of bacteria decreased with increasing powder concentration, i.e., increase in antibacterial activity. The antibacterial activity of the ZnO nanorods toward Pseudomonas aeruginosa was stronger than that of Escherichia coli and Staphylococcus aureus. Surprisingly, the antibacterial activity did not require specific UV activation using artificial lamps, rather activation was achieved under ambient lighting conditions. Overall, the experimental results suggest that ZnO nanorods could be developed as antibacterial agents against a wide range of microorganisms to control and prevent the spreading and persistence of bacterial infections. This research introduces a new concept to synthesize ZnO nanorods by using egg white as a biological template for various applications including food science, animal science, biochemistry, microbiology and medicine.

MAO ceramic coatings were prepared on AZ61 magnesium alloy for various processing times ranging from 5 to 60 min, in an electrolyte solution based on silicate-fluoride. The mechanical, electrochemical and, microstructural properties and the phase compositions of the coating layers were investigated. In this work, unlike previous studies, coatings with high amounts of the Mag 2 SiO 4 phase were formed which contained small amounts of MgO and MgF 2 at a processing condition of 30 min. A microstructural analysis revealed that the porosity of the coatings was reduced considerably with an increase in the processing time, together with a change in the pore geometry from an irregular to a spherical shape. Potentiodynamic polarization and mechanical testing results showed that the coatings acquired after a processing time of 30 min were superior to all of the others.

We report the magnetic transition and large magnetic entropy change in Sr doped lanthanum manganites. Polycrystalline La1-xSrxMnO3(0.20x0.35) samples were prepared using the conventional solid-state reaction method. The results of X-ray diffraction indicates perovskite phase without any impurity. The magnetic study has revealed that the Curie temperature is influenced by Sr-concentration. The doping of Sr at La site affects the Mn-O bond length and Mn-O-Mn bond angle due to the difference in their ionic radii, consequently, the Curie temperature changed. A large magnetic entropy change has been observed for La0.8Sr0.2MnO3sample, the value of the maximum entropy change (SMmax) increases from 1.42 to 2.74 J/kgK as magnetic field increases from 1 to 2.5 T. This investigation suggests that La1-xSrxMnO3can be used as a potential magnetic refrigeration material.