Effect of modifying agents on the hydrophobicity and yield of zinc borate synthesized by zinc oxide

The aim of this study was to synthesize zinc borate using zinc oxide, reference boric acid, and reference zinc borate （reference ZB） as the seed, and to investigate the effects of modifying agents and reaction parameters on the hydrophobicity and yield, respectively. The reaction parameters include reaction time （1-5 h）, reactant ratio （H3BO3/ZnO by mass： 2-5）, seed ratio （seed crystal/（H3BO3＋ZnO） by mass： 0-2wt%）, reaction temperature （50-120~C）, cooling temperature （10-80~C）, and stirring rate （400-700 r/min）; the modifying agents involve propylene glycol （PG, 0-6wt%）, kerosene （lwt%-6wt%）, and oleic acid （OA, lwt%-6wt%） with solvents （isopropyl alcohol （IPA）, ethanol, and methanol）. The results of reaction yield obtained from either magnetically or mechanically stirred systems were compared. Zinc borate produced was characterized by X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FT-IR）, and contact angle tests to identify the hydrophobicity. In conclusion, zinc borate is synthesized successfully under the optimized reaction conditions, and the different modifying agents with various solvents affect the hydrophobicity of zinc borate.

Production and characterization of hydrophobic zinc borate by using palm oil

Zinc borate （ZB） was synthesized using zinc oxide, boric acid synthesized from colemanite, and reference ZB as seed. The effects of reaction parameters such as reaction time, reactant ratio, and seed ratio on its yield were examined. Then, the effects of palm oil with solvents （isopropyl alcohol （IPA）, ethanol, and methanol） added to the reaction on its hydrophobicity were explored. Reactions were carried out under determined reaction conditions with magnetically and mechanically stirred systems. The produced ZB was characterized by X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FT-IR）, scanning electron microscopy （SEM）, and measurements of contact angle identified hydrophobicity. The results showed that hydrophobic ZB was successfully produced under determined reaction conditions. The change of process parameters influenced its yield and the usage of palm oil provided hydrophobicity.

The Fluorescence of Pr3+ in Zinc Lithium Bismuth Borate Glasses with Large Stimulated Emission Cross Section

Glass sample of Zinc Lithium Bismuth Borate (25-x) Bi2O3:20Li2O:20ZnO:35B2O3:xPr6O11, (where x = 1, 1.5 and 2 mol%) has been prepared by melt-quenching technique. The amorphous nature of the prepared glass samples was confirmed by X-ray diffraction. The absorption spectra of three Pr3+ doped zinc lithium bismuth borate glasses have been recorded at room temperature. The observed optical spectra are discussed in terms of energy states and the intensity of the transitions. The various interaction parameters like Slater-Condon, Lande, bonding and Racah parameters have been computed. Judd-Ofelt intensity parameters and laser parameters have also been calculated. The stimulated emission cross section (σp) for the transition (3P0 → 3F2) is found to be in the range 3.12 - 10.43 * 10-20 cm2. The σp values are comparatively large suggesting the possible utilization of these materials in laser applications.

Energy transfer from Tb^(3+) to Eu^(3+) in zinc lead borate glass

In order to sensitize the luminescence of Eu3+ ions in heavy metal glass,zinc lead borate glass samples containing various concentrations of Eu3+ and Tb3+ ions were prepared to study the Tb3+ to Eu3+ non-radiative energy transfer phenomena.Energy level structures of Tb3+ and Eu3+ ions were plotted to show the excitation and energy transfer routes.Efficient energy transfer from Tb3+ to Eu3+ was observed and studied qualitatively in terms of doping concentrations.The sensitization turned out to be less effective than expected.Further studies to characterize the oxidation of Tb3+ into tetravalent state and to examine the mechanism of energy transfer are proposed.