{2,2′-[(Benzyl­aza­nedi­yl)dimethylene]diphenolato}(methano­lato)boron

The title compound, C22H22BNO3, was unintentionally obtained from salicyl­aldehyde benzyl­amine and sodium borohydride. The B—O bond lengths lie in the range 1.425 (2)–1.463 (2) Å, and B—N = 1.641 (2) Å. In the crystal, weak inter­molecular C—H⋯O hydrogen bonds link the mol­ecules into chains in the [010] direction

Study on the Behaviors and Mechanism of Ni(II) Adsorption at the Hydroxyapatite-Water Interface: Effect of Particle Size

Hydroxyapatite (HAP) was a highly efficient decontamination material for its strong adsorption capacity used in the immobilization of heavy metals, while the particle-size effect was insufficiently investigated during the sorption process. In the present study, the mechanisms of nickel (Ni(II)) adsorption on HAPs with two different particle sizes were investigated by combing batch experiments, desorption, and XRD analysis. The results showed that the adsorption capacity of 20 nm HAP (nano-HAP) was much higher than that of 12 μm HAP (micro-HAP). It was noticed that the results of the present study also clarified the distinct mechanisms in each adsorption process. As for micro-HAP, Ni2+ adsorbed through slow diffusion and replacement with Ca2+ and then incorporated in the lattice at pH between 6.5 and 9.0, which was confirmed by the results of kinetics, thermodynamics, and desorption. And a more compact crystalline structure and irreversible desorption behavior of micro-HAP after Ni(II) adsorption was confirmed by results of XRD and desorption isotherms, respectively. At pH>9.0, lattice incorporation and precipitation controlled together. However, for nano-HAP, the sharp increase of Ni(II) adsorption and ionic strength dependent at pH 6.5 to 9.0 revealed that the dominant mechanisms were ionic exchange and inner-sphere complexation. XRD results showed that characteristic peaks of cassidyite appeared in Ni(II)-loading nano-HAP. At pH>9.0, a precipitate of Ni(II) was the dominant mechanism. The experimental finds demonstrated that nanoscale HAP was a more fast, efficient, and desorbable adsorbent than micro-HAP for Ni(II) removal. These findings would be favorable for investigating the removal mechanisms of heavy metals on the HAP materials and designing the synthesis methods

Interactions between Silicon Oxide Nanoparticles (SONPs) and U(VI) Contaminations: Effects of pH, Temperature and Natural Organic Matters.

The interactions between contaminations of U(VI) and silicon oxide nanoparticles (SONPs), both of which have been widely used in modern industry and induced serious environmental challenge due to their high mobility, bioavailability, and toxicity, were studied under different environmental conditions such as pH, temperature, and natural organic matters (NOMs) by using both batch and spectroscopic approaches. The results showed that the accumulation process, i.e., sorption, of U(VI) on SONPs was strongly dependent on pH and ionic strength, demonstrating that possible outer- and/or inner-sphere complexes were controlling the sorption process of U(VI) on SONPs in the observed pH range. Humic acid (HA), one dominated component of NOMs, bounded SONPs can enhance U(VI) sorption below pH~4.5, whereas restrain at high pH range. The reversible sorption of U(VI) on SONPs possibly indicated that the outer-sphere complexes were prevalent at pH 5. However, an irreversible interaction of U(VI) was observed in the presence of HA (Fig 1). It was mainly due to the ternary SONPs-HA-U(VI) complexes (Type A Complexes). After SONPs adsorbed U(VI), the particle size in suspension was apparently increased from ~240 nm to ~350 nm. These results showed that toxicity of both SONPs and U(VI) will decrease to some extent after the interaction in the environment. These findings are key for providing useful information on the possible mutual interactions among different contaminants in the environment

Biodistribution of 60Co–Co/Graphitic-Shell Nanocrystals In Vivo

The magnetic nano-materials, Co/graphitic carbon- (GC-) shell nanocrystals, were made via chemicalvapour deposition (CVD) method, and their biodistribution and excretion in mice were studied by using postintravenously (i.v.) injecting with 60Co–Co/GC nanocrystals. The results showed that about 5% of Co was embedded into graphitic carbon to form multilayer Co/GC nanocrystals and the size of the particle was ~20 nm, the thickness of the nanocrystal cover layer was ~4 nm, and the core size of Co was ~14 nm. Most of the nanocrystals were accumulated in lung, liver, and spleen after 6, 12, 18, and 24 h after i.v. with 60Co–Co/GC nanocrystals. The nanoparticles were cleared rapidly from blood and closed to lower level in 10 min after injection. The 60Co–Co/GC nanocrystals were eliminated slowly from body in 24 h after injection, ~6.09% of 60Co–Co/GC nanocrystals were excreted by urine, ~1.85% by feces in 24 h, and the total excretion was less than 10%

Environmentally Friendlier Approach to Nuclear Industry: Recovery of Uranium from Carbonate Solutions Using Ionic Liquids

A green solvent extraction process with nonfluorinated quaternary phosphonium ionic liquids for removing uranium from carbonate solutions has been developed. The main advantage of this extraction process is that no molecular diluent and ligand need be added to the organic phase, so the use of volatile organic compounds can be avoided. Uranium was extracted into the ionic liquid (IL) phase as the [Na₃UO₂(CO₃)₃]⁻, [Na₃UO₂(CO₃)₂Cl₂]⁻, and [NaUO₂CO₃Cl₂]⁻ anion complexes, and the composition of the IL, Cl^– ions, went into aqueous phase, which was determined by electrospin ionization–mass spectroscopy (ESI-MS) and Cl^– ion test experiment. The extraction mechanism is anion exchange. The maximum loading capacity of the IL is 11.23 g/L. F^– ions have no effect on the extraction efficiency for uranium extraction. The stripping of uranium from the IL phase after extraction is difficult using dilute nitric acid and other stripping reagents. The 1 mol/L NaOH solution was used to deposit uranium and this operation was repeated three times to remove uranium from the IL thoroughly

Influence of FeCl_3 on radiation stability of ionic liquid BmimCl

This study investigates the effect FeCl_3 on the radiation stability of the ionic liquid,1-butyl-3-methylimidazolium chloride(BmimCl) over a wide dose range of 0 to 1000 kGy under γ-ray radiation.The ionic liquid species,BmimFeCl_4,was formed by adding FeCl_3 into BmimCl.The results showed that the presence of FeCl_4~ -significantly improved the radiation resistance of BmimCl,wherein the effect was more pronounced at higher FeCl_4~- content.Meanwhile,under irradiation,Fe(Ⅱ) was generated from Fe(Ⅲ),which was reduced by solvated electron.In addition,the concentration of Fe(Ⅱ) increased with low level of absorbed dose,but leveled off at higher doses.Moreover,the radiation yield of the solvated electrons of BmimCl was further estimated at approximately 0.358±0.01 μmol/J in BmimCl-7 mol% FeCl_3 system