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This paper reports the synthesis and characterization of silver oxide films for use as bactericidal coatings. Synthesis parameters, dissolution/elution rate, and bactericidal efficacy are reported. Synthesis conditions were developed to create AgO, Ag₂O, or mixtures of AgO and Ag₂O on surfaces by reactive magnetron sputtering. The coatings demonstrate strong adhesion to many substrate materials and impede the growth of all bacterial strains tested. The coatings are effective in killing Escherichia coli and Staphylococcus aureus , demonstrating a clear zone-of-inhibition against bacteria growing on solid media and the ability to rapidly inhibit bacterial growth in planktonic culture. Additionally, the coatings exhibit very high elution of silver ions under conditions that mimic dynamic fluid flow ranging between 0.003 and 0.07 ppm/min depending on the media conditions. The elution of silver ions from the AgO/Ag₂O surfaces was directly impacted by the complexity of the elution media, with a reduction in elution rate when examined in complex cell culture media. Both E. coli and S. aureus were shown to bind ~1 ppm Ag⁺/mL culture. The elution of Ag⁺ resulted in no increases in mammalian cell apoptosis after 24 h exposure compared to control, but apoptotic cells increased to ~35% by 48 and 72 h of exposure. Taken together, the AgO/Ag₂O coatings described are effective in eliciting antibacterial activity and have potential for application on a wide variety of surfaces and devices., Competing Interests: The authors declare no conflict of interest.

LaSrCoO4, LaSrNiO4 and LaSrCuO4 were synthesised by the reverse micellar route by using three different microemulsion compositions. The as prepared nanostructures were characterised by powder X‐ray diffraction (PXRD), field emission scanning electron microscopy, energy dispersive X‐ray spectroscopy and transmission electron microscopy. The PXRD of all samples indicate pure phases which crystallize into a tetragonal system. The particle size and shape of nanoparticles varies with microemulsion system. Magnetisation studies suggested that two of the LaSrCoO4 samples display canted antiferromagnetism while the others showed no sign of long‐range ordering. The LaSrNiO4 and LaSrCuO4 samples seemed to show spin glass behaviour. Some of these materials were successfully used as catalysts for organic transformations. The esterification of aldehydes in the presence of alkyl halides and alcohols has been made mild and practicable with a copper catalysed TBHP/DTBP promoting reaction. This approach is suitable to a wide variety of aldehydes, including those that are notoriously difficult to convert through the C(sp2)−H bond scission to produce the required esters in good to outstanding yield. [ABSTRACT FROM AUTHOR]

Nanoparticles of complex manganites (viz. LaMnO3, La0.67Sr0.33MnO3 and La0.67Ca0.33MnO3) have been synthesized using the reverse micellar route. These manganites are prepared at 800°C and the monophasic nature of all the oxides has been established by powder X-ray diffraction studies. TEM studies show an average grain size of 68, 80 and 50 nm for LaMnO3, La0.67Sr0.33MnO3 and La0.67Ca0.33MnO3 respectively. Ferromagnetic ordering is observed at around 250 K for LaMnO3, 350 K for La0.67Sr0.33MnO3 and 200 K for La0.67Ca0.33MnO3. These Curie temperatures correspond well with those reported for bulk materials with similar composition. [ABSTRACT FROM AUTHOR]

A new perovskite-based titano-manganate, (La0.4Ba0.4Ca0.2)(Mn0.4Ti0.6)O3, has been prepared by the ceramic route at 1100°C. This oxide was found to possess the cubic perovskite structure with ‘a’=3.9477(23) Å (space group Pm&3macr;m). The refined composition as obtained by Rietveld analysis of powder X-ray data was found to be (La0.44Ba0.38Ca0.18)(Mn0.43Ti0.57)O2.91(3) (Rp=0.0704, wRp=0.0828). The composition was also ascertained by Energy dispersive X-ray analysis. Iodometric studies led to a slightly higher oxygen content (compared to Rietveld refinement) corresponding to an average manganese oxidation state of 3.05. The above oxide was found to exhibit high dielectric constant (#x03B5;) of 6980 at 1 kHz decreasing to 590 at 100 kHz. At high temperatures (200°C) it shows an unusually high dielectric constant of 20,000 at 1 kHz. In addition to the dielectric properties, detailed magnetic studies show evidence of long-range antiferromagnetic interactions near 5 K. The presence of unusually high dielectric constant coupled with the long-range magnetic interactions may open up interesting applications. [Copyright &y& Elsevier]