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In this study, amino-functionalized magnetic particles (iron oxide@SiO2-NH2) with core-shell structures were synthesized and evaluated for rapid boron removal from aqueous solutions. The results showed that the specific surface area of the iron oxide@SiO2-NH2 (131.24 m2⋅g−1) increased greatly compared to pure iron oxide (30.98 m2⋅g−1). The adsorption equilibrium was less than 2 h, with an adsorption capacity of 29.76 mg⋅g−1 at pH = 6 at 15 °C. The quasi-second-order kinetic model described the boron adsorption process well, and both the Langmuir and Freundlich models were suitable for characterizing the adsorption isotherms. The zeta potential and XPS analysis before and after adsorption revealed that the main adsorption mechanism was the hydrogen bonding formation between the terminal -NH2 groups of the adsorbent and the boric acid. In addition, the adsorbent still maintained a high adsorption performance after five adsorption–desorption cycles, which illustrated that the iron oxide@SiO2-NH2 may be a potential adsorbent for environmental boron removal treatment. [ABSTRACT FROM AUTHOR]

A new acentric mixed metal borate of composition K2Ba[B4O5(OH)4]2·10H2O, has been successfully obtained by slow evaporation solution method. The compound crystallizes in the Orthorhombic space group Pna21 (No.33) witha= 16.8668(7) Å,b= 13.0903(5) Å,c= 11.5529(5) Å andZ= 4. [B4O5(OH)4]2−clusters serve as fundamental building unit linking with BaO8, K1O6, K2O7by common O atoms to form three-dimensional layer structure. The second harmonic generation measurements in the powder samples reveal that the compound exhibits approximately 0.5 times that of KH2PO4(KDP) and phase matching. [ABSTRACT FROM PUBLISHER]

Pinnoite (MgB2O(OH)6) for the first time was synthesized using the solid–liquid–solid conversion method. The effects of reaction time, pH value and concentrations of magnesium and borate were investigated. Pinnoite was synthesized under the optimum condition of 8 mmol hungtsaoite and 1% boric acid solution at 80 °C. The products were determined using X-ray diffraction, Fourier-transform infrared spectroscopy, TG-DSC and a UV–vis spectrometer. The change processes of the surface morphology of pinnoite were investigated using scanning electron microscopy. In addition, the formation mechanism of pinnoite was discussed according to the changes in the content of precipitation and pH value. [ABSTRACT FROM AUTHOR]

The solubility and nucleation ofborax decahydrate in the presenceof Cl–and SO42–ionshave been studied by two different methods: polythermal crystallizationand isothermal crystallization. The results revealed that both anionshad a salt-in effect on the solubility. A noticeable widening of themetastable zone was observed after the addition of the two anion impurities.For the isothermal crystallization, two different nucleation mechanismswere obtained. When the supersaturation ratio S>1.3, the nucleation appears to be homogeneous, whereas at the supersaturationratio S< 1.25, heterogeneous nucleation predominates.From the prolonged induction period in the presence of the two anions,we conclude that the nucleation of borax decahydrate was suppressedafter the addition of impurities. The values of the interfacial energyγ calculated by isothermal method are lower than those obtainedby polythermal method due to the underestimated values of ln S. [ABSTRACT FROM AUTHOR]

Thesolubility of sodium chromate tetrahydrate has been investigatedin the temperature range from 290.15 K to 325.15 K using the conventionalpolythermal method by means of the laser technique. The metastablezone width (MZW) and the apparent nucleation order of sodium chromatetetrahydrate were calculated. The effects of cooling rate, initialcomposition, stirring rate, and seed particles on the MZW were alsostudied. The results show that the MZW of sodium chromate tetrahydratefirst increases and then narrows with increasing initial composition.The MZW becomes wider by reducing the cooling rate and the mass ofseed particles, whereas the MZW will be reduced by enhancing the rotationfrequency of stirring and the diameter of seed particles. [ABSTRACT FROM AUTHOR]

Thesolubility and the metastable zone width of sodium tetraboratedecahydrate in solutions containing lithium chloride have been measuredat temperature a range of (20 to 35) °C. It is found that thelithium impurity has a salt-in effect on the solubility of sodiumtetraborate decahydrate. The metastable zone width broadens with anincrease of the impurity concentrations. This increase can be attributedto the absorption mechanism on the crystal surface. The apparent nucleationorder of sodium tetraborate decahydrate with and without impuritywas calculated by a modified regression method. The results show thatthe addition of lithium impurity has no great effect on the apparentnucleation order of sodium tetraborate decahydrate. [ABSTRACT FROM AUTHOR]

The solubility and ultra solubility of borax decahydrateboth inpure and impure solutions have been determined in the temperaturerange from (0 to 30) °C by means of the conventional polythermalmethod using the laser technique. The metastable zone width and theapparent nucleation order of borax were calculated. The effects andthe action mechanism of KCl on metastable zone property of borax werestudied. It was found that the presence of KCl made an increase inthe solubility and a decrease in the metastable zones of borax. However,the trends in the changes of metastable zone width at low impurityconcentrations were different from high concentrations because ofthe adsorption equilibria on the crystals. [ABSTRACT FROM AUTHOR]

Measurements of the solubility and metastable zone width (MZW) of borax decahydrate in sodium carbonate and sodium hydroxide aqueous were obtained. The onsets of nucleation were detected by the turbidity technique with the temperature range from 285 to 315 K. The results showed that the solubility of borax gradually decreased and the MZW broadened with the mass percentage of sodium carbonate increasing from 0% up to 9.22%. Correspondingly, the solubility and MZW had the same trend with the addition of sodium hydroxide. Meanwhile, the nucleation parameters of borax were determined and analysed to explain the trends obtained. Applying the classical three-dimensional nucleation theory approach, it was found that the addition of carbonate and hydroxide ions led to the values of solid-liquid interfacial energy ( γ ) increasing, which indicated the CO 3 2- and OH - ions adsorbed on the nuclei but suppressed nucleation rate., Competing Interests: The authors have no competing interests.