Meral Yildirim

The Synthesis and Physical Properties of Magnesium Borate Mineral of Admontite Synthesized from Sodium Borates

Magnesium borates are significant compounds due to their advanced mechanical and thermal durability properties. This group of minerals can be used in ceramic industry, in detergent industry, and as neutron shielding material, phosphor of thermoluminescence by dint of their extraordinary specialties. In the present study, the synthesis of magnesium borate via hydrothermal method from sodium borates and physical properties of synthesized magnesium borate minerals were investigated. The characterization of the products was carried out by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and Raman spectroscopies, and differential thermal analysis and thermal gravimetry (DTA/TG). The surface morphology was examined by scanning electron microscopy (SEM). B2O3 content was determined through titration. The electrical resistivity/conductivity properties of products were measured by Picoammeter Voltage Source. UV-vis spectrometer was used to investigate optical absorption characteristics of synthesized minerals in the range 200–1000 nm at room temperature. XRD results identified the synthesized borate minerals as admontite [MgO(B2O3)3·7(H2O)] with code number “01-076-0540” and mcallisterite [Mg2(B6O7(OH)6)2·9(H2O)] with code number “01-070-1902.” The FT-IR and Raman spectra of the obtained samples were similar with characteristic magnesium borate bands. The investigation of the SEM images remarked that both nano- and microscale minerals were produced. The reaction yields were between 75.1 and 98.7%.

Characterization and physical properties of hydrated zinc borates synthesized from sodium borates

Abstract In this study, Zn3B6O12·3.5H2O, a type of a zinc borate hydrate, was synthesized from the sodium borate mineral Na2B4O7·5H2O. Two different zinc sources, i.e. ZnSO4·7H2O and ZnCl2, were used in the hydrothermal synthesis. Products were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy. Product morphologies were studied using scanning electron microscopy (SEM). Then optical absorption characteristics and electrical properties were investigated. Based on these results, Zn3B6O12·3.5H2O was obtained under many synthetic conditions as a single phase with high reaction efficiencies and sub-micrometer (100 nm to 1 μm) particle sizes. The electrical resistivity and optical energy gap were found as 8.8×1010 Ω cm and 4.13 eV, respectively. The novelty obtained in this study is the synthesis of zinc borate hydrate compound with high crystallinity without using any modification agent or organic solvent.

Sonochemical-assisted magnesium borate synthesis from different boron sources

Abstract In this study, sonochemical-assisted magnesium borate synthesis is studied from different boron sources. Various reaction parameters are successfully applied by a simple and green method. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and Raman spectroscopies are used to characterize the synthesized magnesium borates on the other hand surface morphologies are investigated by using scanning electron microscope (SEM). The XRD analyses showed that the products were admontite [MgO(B2O3)3 · 7(H2O)] with JCPDS (Joint Committee on Powder Diffraction Standards) no. of 01-076-0540 and mcallisterite [Mg2(B6O7(OH)6)2 · 9(H2O)] with JCPDS no. of 01-070-1902. The results that found in the spectroscopic studies were in a good agreement with characteristic magnesium borate bands in both regions of infra-red and visible. According to SEM results, obtained borates were in micro and sub-micro scales. By the use of ultrasonication, reaction yields were found between 84.2 and 97.9%. As a result, it is concluded that the sonochemical approach is a practicable synthesis method to get high efficiency and high crystallinity in the synthesis magnesium borate compounds.