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Salt-afected and sandy pedospheres low in complex organic and mineral matrices critical for metal sorption (e.g. humics, aluminosilicates) could exacerbate metal transfer into the food chain. To test this hypothesis, a 3- factor study with salinity (0–50 mM NaCl), humates (HA ; 0–150 mg/kg) and Cd contamination (0–9 mg/kg) was conducted in sandy substrate with strawberry. Cadmium phytoaccumulation decreased in the order roots>crowns>leaves>fruits. In comparison to the control, tissue Cd concentration was infuenced by the NaCl×HA×Cd interaction, increasing Cd in leaves (up to 241-fold) and fruits (up to 135-fold) and exceeding the European maximum limit of 0.05 mg Cd/kg w wt. Surface analyses (XRD, SEM–EDX, FTIR, SIMS) revealed that the growth substrate rich in SiO2 (>87% w/w) had uniform, nonporous and chemically unreac tive surface structure. In contrast, the more complex HA matrix featuring abundant and heterogeneous micro-porosity and a large content of reactive radicals. Chemical speciation modelling of the rhizosphere solutions showed that almost all Cd was dissolved and distributed among the bioavailable Cd2+, Cl-complexed and HA-complexed pools, with small amounts of Cd adsorbed to K/Na-aluminosilicates. Slightly acidic pH (5.4–6.2) and complexation with Cl and HA in the rhizosphere favoured Cd solubility and its transfer to plants. The assessment of health risk of strawberry fruit consumption indicated a relatively higher the Estimated Daily Intake (EDI) in children (5% of provisional tolerable daily Cd intake) vs adults (

Thin films containing 3D-ordered semiconductor quantum wires offer a great tool to improve the properties of photosensitive devices. In the present work, we investigate the photo-generated current in thin films consisting of an interconnected 3D-ordered network of Ge quantum wires in an alumina matrix. The films are prepared using nitrogen-assisted magnetron sputtering co-deposition of Ge and Al2O3. We demonstrate a strong photocurrent generation in the films, much stronger than in similar films containing Ge quantum dots. The enhanced photocurrent generation is the consequence of the multiple exciton generation and the films’ specific structure that allows for efficient carrier transport. Thin film with the largest nitrogen content showed enhanced performance compared to other thin films with 1.6 excitons created after absorption of a single photon at an energy nearly equal to the double bandgap value. The bandgap value depends on the geometrical properties of the quantum wires, and it is close to the maximum of the solar irradiance in this case. In addition, we show that the multiple exciton generation is the most pronounced at the photon energy values equal to multiple values of the thin film bandgap.

Pure and Co

In this work, we report the first ring opening vapor to solid polymerization of cyclotrisiloxane and N-methyl-aza-2,2,4-trimethylsilacyclopentane by molecular layer deposition (MLD). This process was studied in situ with a quartz crystal microbalance and the thin film was characterized by X-ray photoelectron spectroscopy, ATR-FTIR and high-resolution transmission electron microscopy.

Organophosphorus compounds, like bisphosphonates, drugs for treatment and prevention of bone diseases, have been successfully applied in recent years as bioactive and osseoinductive coatings on dental implants. An integrated experimental-theoretical approach was utilized in this study to clarify the mechanism of bisphosphonate-based coating formation on dental implant surfaces. Experimental validation of the alendronate coating formation on the titanium dental implant surface was carried out by X-ray photoelectron spectroscopy and contact angle measurements. Detailed theoretical simulations of all probable molecular implant surface/alendronate interactions were performed employing quantum chemical calculations at the density functional theory level. The calculated Gibbs free energies of (TiO2)10–alendronate interaction indicate a more spontaneous exergonic process when alendronate molecules interact directly with the titanium surface via two strong bonds, Ti–N and Ti–O, through simultaneous participation common to both phosphonate and amine branches. Additionally, the stability of the alendronate-modified implant during 7 day-immersion in a simulated saliva solution has been investigated by using electrochemical impedance spectroscopy. The alendronate coating was stable during immersion in the artificial saliva solution and acted as an additional barrier on the implant with overall resistivity, R ~ 5.9 MΩ cm2.

The preparation of non-oxidized Ge quantum dot (QD) lattices embedded in Al

Enabling self-healing of materials is crucially important for saving resources and energy in numerous emerging applications. While strategies for the self-healing of polymers are advanced, mechanisms for semiconducting inorganic materials are scarce due to the lack of suitable healing agents. Here a concept for the self-healing of metal oxides is developed. This concept consists of metal oxide nanoparticle growth inside the bulk of halogenated polymers and their subsequent entropy-driven migration to externally induced defect sites, leading to recovery of the defect. Herein, it is demonstrated that the pool of self-healing materials is expanded to include semiconductors, thereby increasing the reliability and sustainability of functional materials through the use of metal oxides. It is revealed that electrical properties of tin-doped indium oxide can be partially restored upon healing. Such properties are of immediate interest for the further development of transparent flexible electrodes.