Spectroscopy and Microscopy of Corundum from Primary Deposits Found in Greece

Corundum primary deposits in Greece occur in four locations: Paranesti in Drama and Gorgona in Xanthi, both belonging to the wider Rhodope Massif, as well as, Ikaria island and Kinidaros in Naxos island, both belonging to Attic-Cycladic Massif. Eight samples were examined with spectroscopic methods (FTIR, UV-Vis, EDXRF) in order to better characterize these four primary deposits: two pink sapphires from Paranesti, a pink and a blue sapphire from Gorgona, two blue sapphires from Ikaria and three blue sapphires from Kinidaros. Under the microscope, all samples present characteristics linked to post-crystallization deformation, decreasing their gem quality. The FTIR absorption spectra of all samples present in different relative intensities, bands of boehmite, diaspore, goethite, mica and/or chlorite inclusions and CO2 in fluid inclusions. Boehmite and diaspore inclusions are most likely epigenetic. In the UV-Vis spectra, the pink color of the samples is linked with Cr3+ absorptions and the blue color with absorptions due to Fe2+-Ti4+ intervalence charge transfer. EDXRF analyses in the studied samples show relatively high titanium and iron concentrations that are related with mineral inclusions. Gallium is slightly variable in samples from different regions; also, different colored samples from Gorgona present diverse gallium content.

Photocatalytic Degradation of Methylene Blue Using Zinc Oxide/Styrene Butadiene Rubber Photocatalyst

The zinc oxide/styrene butadiene rubber (ZnO/SBR) photocatalyst was successfully prepared via mechanical mixing at 30 °C. ZnO/SBR square shaped (3 x 3 cm) with 0.54 mm thickness was investigated towards photocatalytic degradation of methylene blue (MB) solution under visible light irradiation and compared with bare ZnO and raw SBR. FTIR absorption spectra reveal the characteristic peaks and estimated intensity of conjugated carbon for ZnO/SBR. ZnO/SBR showed excellent photocatalytic performance nearly as good as bare ZnO.

Optical properties of soda-lime-silica glasses doped with peanut shell powder

Purpose: Aim of this paper is to investigate the optical properties of soda-lime-silica (SLS) glasses which doped with different quantities of peanut shell (PS) powder.Design/methodology/approach: UV-Vis and Fourier transform infrared (FTIR) spectroscopy techniques are used to determine optical properties of glass.Findings: It was observed that the colorless and transparent pure SLS glass turned dark green in color with the addition of the PS powder. The glasses doped with PS powder contents 1 wt.% were translucent. The maximum absorption in the UV spectrum was observed at wavelengths of 306.20, 292.40, 280.20, and 303.20 nm for SLS glasses doped with PS powder contents of 0.5, 1, 3, and 5 wt.%, respectively. The UV-Vis spectroscopy results also indicated that the amount of light transmitted by the SLS glass decreased with increasing PS powder content. The FTIR absorption spectra of the PS powder-doped SLS glasses exhibited various bands corresponding to the symmetric and asymmetric stretching of the bridging oxygen atoms between the tetrahedra.Research limitations/implications: With the addition of the PS to the SLS glass, samples turned to dark green because of Fe2O3. Future researches must focus on this matter.Originality/value: PS powders are doped to investigate optical properties of glass. Thus, glasses, which have good properties such as economically cheap, bio-friendly, are produced from food wastes.

Preparation of Nanosized Fe3O4 Powders by Solvothermal Method

Nanosized Fe3O4 particles were prepared in glycol medium through a solvothermal method and the morphologies, structures, surface properties, and magnetism of the samples were characterized by SEM, XRD, FTIR absorption spectra and VSM. The experimental results show that the nanoparticle has a typical diameter of ca. 20 nm. The Fe3O4 nanoparticle diameters increased with increase of PEG content and PEG molecular weight under the case of other unchanged reaction conditions. The XRD pattern confirms that the Fe3O4 nanoparticles belong to cubic structure. The FTIR results indicate that the surface of the Fe3O4 nanoparticles are coated organic matter. Magnetic investigation reveals that the Fe3O4 nanoparticles have higher saturation magnetization and negligible coercivity at room temperature.

Solvothermal Synthesis and Magnetic Properties of Fe3O4 Microspheres

We synthesized Fe3O4 microspheres using a solvothermal method and characterized their morphologies, structures, surface property and magnetism by field emission scanning electron microscopy (FE-SEM), powder X-ray diffraction (XRD) patterns, Fourier transform infrared (FTIR) absorption spectra, and vibrating sample magnetometer (VSM). The results showed that the synthesized Fe3O4 microspheres with a tunable size range of ca. 80–200 nm are composed of many Fe3O4 collective nanoparticles. XRD pattern confirmed that the Fe3O4 microspheres belong to cubic structure. Magnetic investigation reveals that the Fe3O4 microspheres have higher saturation magnetization and negligible coercivity at room temperature.

Synthesis and Characterization of MFe2O4(M=Co,Ni) Nanoparticles

The magnetic MFe2O4 (M=Co, Ni) nanoparticles are synthesized using a hydrothermal synthesis method in ethylene glycol (EG) solution. Their morphologies, structures, surface properties and magnetism are characterized by field emission scanning electron microscopy (FE-SEM), powder X-ray diffraction (XRD), fourier transform infrared (FTIR) absorption spectra, and vibrating sample magnetometer (VSM), respectively. The nickel ferrite and the cobalt ferrite samples are nearly spherical and homogeneous nanoparticles with average size range of about 90 nm (NiFe2O4) and 30 nm (CoFe2O4). XRD patterns confirm that the NiFe2O4 samples belong to the cubic structure and the CoFe2O4 samples are the rhombohedral structure. The NiFe2O4 nanoparticles are superparamagnetic at room temperature, while the CoFe2O4 nanoparticles are sub-ferromagnetic at room temperature and possess higher saturation magnetization.

Structural Study of Microporous Xerogels Prepared by Polycondensation of Pyrogallol with Formaldehyde

Microporous xerogels were prepared by polycondensation of pyrogallol with formaldehyde catalyzed by perchloric acid in aqueous medium. The samples were characterized by FTIR absorption spectra. The micro-porosity and the specific surface area are characterized by nitrogen adsorption - desorption isotherms. The obtained characteristics depend on the conditions of polycondensation.

Atmospheric carbonyl sulfide (OCS) variation from 1992–2004 by ground-based solar FTIR spectrometry

Analysis of ground-based high-resolution solar FTIR absorption spectra from four sites was performed to determine trends and variability in OCS columns over the period 1992–2004. The sites were Wollongong, Australia (34.45° S, 150.88° E), Lauder, New Zealand (45.0° S, 169.7° E), Arrival Heights, Antarctica (77.8° S, 166.6° E) and Mauna Loa, Hawaii (19.5° N, 155.6° W). Small but significant long-term trends of −0.18±0.02% yr-1 above Hawaii, −0.30±0.12% yr-1 above Wollongong and −0.29±0.14% yr-1 above Lauder, were seen. No significant trend was seen above Arrival Heights. A large peak-to-peak seasonal difference observed in 1996–1997 above Wollongong and reported earlier was confirmed, but not repeated in later years. This seasonal feature correlated with particularly high water vapour columns present during late summer and early autumn, and suggests a link to warm oceanic airmasses. Seasonal variation of approximately 6% per year is observed in the total column in other years for all four locations.