Effects caused by glutamic acid and hydrogen peroxide on the morphology of hydroxyapatite, calcium hydrogen phosphate, and calcium pyrophosphate

Reacting hydroxyapatite with H2O2 vapor at 10°C and brushite CaHPO4 · 2H2O with 90% H2O2 solution at 0°C (the hydroxyapatite and brushite were both prepared in the presence of glutamic acid) yielded the relevant peroxo solvates containing up to 18% hydrogen peroxide. The peroxo compounds and their degradation products obtained at 170–960°C were morphologically studied (using SEM). The factors influencing particle sizes are considered

Synthesis of inorganic dyes based on plasmonic silver nanoparticles for the visible and infrared regions of the spectrum

The effect of various technological factors during the multistage synthesis of plasmonic silver particles in aqueous solutions on nanoparticle size, morphology, and color is studied. The synthesized suspensions are found to contain tabular silver nanoparticles of hexagonal and triangular shape. The foundations of the technology for synthesizing stable silver colloids with a high silver concentration for the visible and nearinfrared regions of the spectrum are developed

Methyltrimethoxysilane-based elastic aerogels: effects of the supercritical medium on structure-sensitive properties

Effects caused by the type of solvent used for supercritical drying on the properties of methyltrimethoxysilane-based aerogels were studied. All of the aerogel samples studied were found to be hydrophobic and to efficiently adsorb nonpolar organic compounds

New insights into polymer mediated formation of anatase mesocrystals

The reaction between (NH4)2TiF6 and H3BO3 in the presence of varying quantities of PEG-6000 was used to form NH4TiOF3 mesocrystals (MCs). The amount of PEG-6000, employed as a template, is crucial to the formation of defect free, non-agglomerated NH4TiOF3 MCs; high concentrations lead to MC agglomeration, lower ones result in centralized defects. This polymer-mediated formation process may be understood using an analogy with known polymerization reactions. The oxofluorotitanate MCs readily undergo a thermal topotactic transformation to give anatase MCs with photocatalytic activity. The TiO2 MCs are porous, with highly orientated lamellar crystallites that form part of the larger mesocrystal structure

Crystalline WO3 nanoparticles for No2 sensing

This study shows excellent NO2-sensing properties of tungsten oxide nanoparticles, prepared using a facile procedure which includes dissolution of metallic tungsten in hydrogen peroxide with subsequent low-temperature (400 °C) heating. We also conducted a thorough literature survey on sensor properties of tungsten oxide prepared by various means and found that the sensor response towards NO2 registered in this work achieved the highest level. The most intriguing feature of the material obtained was a highly reproducible sensor signal at room temperature which was more than 100 times higher than any reported previously for WO3. The probable reason for such high sensor response was the presence of two WO3 polymorphs (-WO3 and h-WO3) in the material synthesized using a peroxide-assisted route. In order to further investigate synthesizedWO3 materials, sophisticated experimental (XRD, SEM, TEM, BET) and theoretical (B3LYP, HSE) methods have been used, as well as resistance and sensor response measurements at various temperatures

Electrorheological Properties of Polydimethylsiloxane/TiO2-Based Composite Elastomers

Electrorheological elastomers based on polydimethylsiloxane filled with hydrated titanium dioxide with a particle size of 100–200 nm were obtained by polymerization of the elastomeric matrix, either in the presence, or in the absence, of an external electric field. The viscoelastic and dielectric properties of the obtained elastomers were compared. Analysis of the storage modulus and loss modulus of the filled elastomers made it possible to reveal the influence of the electric field on the Payne effect in electrorheological elastomers. The elastomer vulcanized in the electric field showed high values of electrorheological sensitivity, 250% for storage modulus and 1100% for loss modulus. It was shown, for the first time, that vulcanization of filled elastomers in the electric field leads to a significant decrease in the degree of crosslinking in the elastomer. This effect should be taken into account in the design of electroactive elastomeric materials

Cinnamate-Intercalated Layered Yttrium Hydroxide: UV Light-Responsive Switchable Material

In recent years, there has been an increasing interest in stimuli-responsive host–guest materials due to the high potential for their application in switchable devices. Light is the most convenient stimulus for operating these materials; a light-responsive guest affects the host structure and the functional characteristics of the entire material. UV-transparent layered rare earth hydroxides intercalated with UV-switchable anions are promising candidates as stimuli-responsive host–guest materials. The interlayer distance in the layered rare earth hydroxides depends on the size of the intercalated anions, which could be changed in situ, e.g., via anion isomerisation. Nevertheless, for layered rare earth hydroxides, the possibility of such changes has not been reported yet. A good candidate anion that is capable of intercalating into the interlayer space is the cinnamate anion, which undergoes UV-assisted irreversible trans–cis isomerisation. In this work, both trans- and cis-cinnamate anions were intercalated in layered yttrium hydroxide (LYH). Upon UV-irradiation, the interlayer distance of trans-cinnamate-intercalated layered yttrium hydroxide suspended in isopropanol changed from 21.9 to 20.6 Å. For the first time, the results obtained demonstrate the possibility of using layered rare earth hydroxides as stimuli-responsive materials

Cerium fluoride nanoparticles protect cells against oxidative stress

A novel facile method of non-doped and fluorescent terbium-doped cerium fluoride stable aqueous sols synthesis is proposed. Intense green luminescence of CeF3:Tb nanoparticles can be used to visualize these nanoparticles' accumulation in cells using confocal laser scanning microscopy. Cerium fluoride nanoparticles are shown for the first time to protect both organic molecules and living cells from the oxidative action of hydrogen peroxide. Both non-doped and terbium-doped CeF3 nanoparticles are shown to provide noteworthy protection to cells against the vesicular stomatitis virus

Cerium fluoride nanoparticles protect cells against oxidative stress

A novel facile method of non-doped and fluorescent terbium-doped cerium fluoride stable aqueous sols synthesis is proposed. Intense green luminescence of CeF3:Tb nanoparticles can be used to visualize these nanoparticles' accumulation in cells using confocal laser scanning microscopy. Cerium fluoride nanoparticles are shown for the first time to protect both organic molecules and living cells from the oxidative action of hydrogen peroxide. Both non-doped and terbium-doped CeF3 nanoparticles are shown to provide noteworthy protection to cells against the vesicular stomatitis virus