Surface Characteristics of TiO2 and Their Effect on Specific Capacity in Lithium and Sodium Systems

The paper presents the results of studies of nanosized titanium dioxide (TiO2) samples synthesized by alkaline hydrolysis. The surface properties of the samples were modified using high-temperature annealing. As a result, samples with a specific surface area of 31-203 m2/g were obtained. The specific capacity of TiO2 in lithium and sodium cells was determined. It is noted that the nature of the curves obtained, the specific capacity and its stability during cycling depend on the nature of the alkali metal cation and the surface properties of TiO2.

Effects of copper in Daphnia are modulated by nanosized titanium dioxide and natural organic matter: what is the impact of aging duration?

During its aquatic life cycle, nanosized titanium dioxide (nTiO2) may interact with natural organic matter (NOM) ultimately altering the ecotoxicity of co-occurring chemical stressors such as heavy metals (e.g. copper (Cu)). In this context, the following hypotheses were tested: (1) aging of nTiO2 along with Cu reduces Cu toxicity, (2) nTiO2 agglomerates have a lower potential to reduce Cu toxicity and (3) aging of nTiO2 in presence of NOM reduces Cu toxicity further. A multifactorial test design crossing three nTiO2 levels (0.0, 0.6 and 3.0 mg/L) with two levels of NOM (0 versus 8 mg total organic carbon (TOC)/L) and seven nominal Cu concentrations (ranging from 0 to 1536 μg/L) aged in ASTM medium for 0, 1, 3 and 6 days was realised, while two aging scenarios were applied (type 1: nTiO2 jointly aged with Cu; type 2: Cu added after nTiO2 aging). Subsequently, Cu toxicity was assessed using the immobility of Daphnia magna after 48 h of exposure as response variable. The experiments revealed that neither aging duration nor the extent of agglomeration (type 1 vs. type 2 aging) has a substantial impact on Cu induced toxicity. Moreover, it was confirmed that the presence of NOM substantially reduced Cu induced toxicity, independent of the aging scenario and duration. More importantly, the data suggest the ingestion of Cu loaded nTiO2 as additional exposure pathway contributing to Cu toxicity. In conclusion, it seems unlikely that nTiO2 concentrations currently detected in or predicted for aquatic ecosystems, which are at least one order of magnitude below the concentration tested here, influence Cu toxicity meaningfully.

Silver Nanoparticles Protect Skin from Ultraviolet B-Induced Damage in Mice

Ultraviolet (UV) radiation from sunlight has various adverse effects; thus, UV blockage is recommended for preventing sunburn. Common sunscreen ingredients, such as nanosized titanium dioxide and zinc oxide, offer effective protection and enhance cosmetic appearance; however, health concerns have been raised regarding their photocatalytic activity, which generates reactive oxygen species under UV illumination. Silver nanoparticles (AgNPs) are known as safe materials for use in a wide spectrum of biomedical applications. In vitro studies have revealed that AgNPs may have a protective effect against UV irradiation, but the effects in animal studies remain unclear. The present study demonstrated that AgNPs effectively protect against UVB-induced skin damage both in cell cultures and mouse models. These results suggested that AgNPs are feasible and safe as sunscreen ingredients for protection against UVB-induced skin damage.

Composition and Properties of TiO2 Sol to Produce a Photocatalytic Composite Material

The paper presents the process of sol-gel synthesis of titanium dioxide nanoparticles, the peculiarities of the influence of component composition (titanium precursor content, solvent and stabilizer − surfactant) on the properties of sol and powder obtained on its basis. As a result of the study, the nature of the influence of the type and content of the surfactant in the solution of tetrabutoxytitanium in ethanol on the size of the synthesized particles of titanium dioxide was revealed. The optimal composition of the reaction mixture of TiO–R sol was obtained and the optimal ratio of tetrabutoxytitanium and ethyl alcohol was revealed using which a material with a high content of nanosized titanium dioxide was obtained.