scholarly journals Some Microstructural Properties of Zinc Borosilicate Glass as a Possible Matrix in the Immobilization of Various Wastes

2019 ◽  
Vol 92 (3) ◽  
pp. 429-433
Author(s):  
Svetozar Musić ◽  
Marijan Marciuš ◽  
Stjepko Krehula ◽  
Stanko Popović ◽  
Ernő Kuzmann ◽  
...  

Zinc borosilicate glass with optimized chemical composition was synthesized and doped with 5 wt % α-Fe2O3. XRD, 57Fe Mössbauer, FT-IR, UV/Vis/NIR and FE SEM were used as the characterization methods. XRD showed the amorphous nature of the samples synthesized. 57Fe Mössbauer spectra confirmed the superposition of Fe3+ in tetrahedral and Fe2+ in octahedral positions. FT-IR spectra showed general features characteristic of different borosilicate glasses. The NIR band at 1116 nm in the UV/Vis/NIR spectrum was assigned to the Fe2+ transition, whereas the Fe3+ transition bands could not be assigned due to the overlapping of several spectral bands of different origin in the UV region centered at 282 nm and the Vis region between 415 to 496 nm. Zinc borosilicate glass as synthesized can be considered as a possible matrix in the immobilization of nonradioactive as well as radioactive wastes.

2016 ◽  
Vol 725 ◽  
pp. 399-404
Author(s):  
Kausala Mylvaganam ◽  
Wei Dong Liu ◽  
Liang Chi Zhang

Unlike the traditional silicate glasses, borosilicate glasses behave differently because of the addition of boron atoms. Extensive studies have been carried out to understand the abnormal function of boron in glass network. However, it is not clear how the atomic structure of borosilicate glass changes under loading. This paper investigates the behaviour of borosilicate glass under uniaxial compression with the aid of ab initio simulations. Sodium borosilicate glass having 160 atoms and a mass density of 2.51 g/cm3 with composition 3Na2O-B2O3-6SiO2 were equilibrated first at 3500K, then at 2500K, 1500K, 1200K, 1000K, 825K and 625K. Structural analysis showed that at higher temperatures the sodium borosilicate liquid does not have a specific structure. At around 825 K (i.e. around Tg), boron network and silicon network form and remain stable even at a temperature of 625 K. When the supercooled sample at 825K was subjected to uniaxial compression, the stress along the compression direction first increases and then decreases with a change in boron structure, which could modify the behaviour of the borosilicate glass.


Author(s):  
Mustafa Şükrü Kurt ◽  
Mehmet Enes Arslan ◽  
Ayşenur Yazici ◽  
İlkan Mudu ◽  
Elif Arslan

AbstractIn this study, borosilicate glass and 316 L stainless steel were coated with germanium (Ge) and tungsten (W) metals using the Magnetron Sputtering System. Surface structural, mechanical, and tribological properties of uncoated and coated samples were examined using SEM, X-ray diffraction (XRD), energy-dispersive spectroscopy, and tribometer. The XRD results showed that WGe2 chemical compound observed in (110) crystalline phase and exhibited a dense structure. According to the tribological analyses, the adhesion strength of the coated deposition on 316 L was obtained 32.8 N, and the mean coefficient of friction was around 0.3. Biocompatibility studies of coated metallic biomaterials were analyzed on fibroblast cell culture (Primary Dermal Fibroblast; Normal, Human, Adult (HDFa)) in vitro. Hoescht 33258 fluorescent staining was performed to investigate the cellular density and chromosomal abnormalities of the HDFa cell line on the borosilicate glasses coated with germanium–tungsten (W–Ge). Cell viabilities of HDFa cell line on each surface (W–Ge coated borosilicate glass, uncoated borosilicate glass, and cell culture plate surface) were analyzed by using (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) cytotoxicity assay. The antibiofilm activity of W–Ge coated borosilicate glass showed a significant reduction effect on Staphylococcus aureus (ATCC 25923) and Pseudomonas aeruginosa (ATCC 27853) adherence compared to control groups. In the light of findings, tungsten and germanium, which are some of the most common industrial materials, were investigated as biocompatible and antimicrobial surface coatings and recommended as bio-implant materials for the first time.


1995 ◽  
Vol 49 (10) ◽  
pp. 1516-1524 ◽  
Author(s):  
Alex O. Salnick ◽  
Werner Faubel

Fourier transform infrared photoacoustic spectroscopy (FT-IR/PAS) has proved to be a useful tool for nondestructive testing of copper corrosion layer (patina) formed in the atmosphere. The samples cut from a piece of the roof of the Stockholm City Hall were examined without any additional pretreatment. The components of the patina—brochantite Cu4(OH)6SO4, antlerite Cu3(OH)4SO4, and basic cupric carbonate Cu2CO3(OH)6 · H2O—as well as some other minerals were identified. The photothermal beam deflection (PBD) method was used for independent photoacoustic characterization of the samples. The depth profiling capability of FT-IR/PAS was used to determine the degree of photoacoustic saturation of the spectral bands and to evaluate the depth distribution of the main patina components. The technique thus compares favorably with more common approaches of patina examination which are more expensive and require special sample preparation.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Chandkiram Gautam

A new series of lead bismuth titanate borosilicate glasses with addition of one percent lanthanum oxide have been synthesized using melt-quench technique. X-ray diffraction patterns have been recorded to confirm the amorphous nature of the prepared glass samples. The synthesized glasses have been characterized by using various spectroscopic techniques such as UV-visible, infrared, and Raman spectroscopy. UV-visible measurements were recorded in the wavelength range from 200 to 1100 nm whereas IR and Raman spectroscopic measurements were recorded over a continuous wavenumber range from 400 to 5000 cm−1 and 1000 to 2000 cm−1 respectively. The different absorption peaks/bands were formed in IR spectral patterns. The spectral bands appear towards the lower wavenumber sides due to the Bi and Pb, content while the bands appear towards the higher wavenumber sides due to the formation of diborate and triborate network units.


2018 ◽  
Vol 283 ◽  
pp. 72-77
Author(s):  
Namthip Kingnoi ◽  
Jiratchaya Ayawanna ◽  
Nattapol Laorodphan

This work describes the performance of two glass-ceramic compositions, BaO-SiO2-B2O3 (Barium borosilicate glass: BaBS) and BaO-ZnO-SiO2-B2O3 (Barium zinc borosilicate glass: BaBS−Zn), used for joining YSZ ceramic electrolytes and Crofer22APU metallic interconnects in solid oxide fuel cells (SOFCs) working at 800°C for 50 h. ZnO had a negative effect on the thermal expansion coefficient (TEC) value of the BaBS-Zn glass-ceramic. XRD and SEM results revealed the formation of rod-shaped barium zinc silicate crystalline phases in the BaBS-Zn glass, which was accompanied by cracks and poor adherence at the YSZ/BaBS-Zn joint interface after working at 800°C for 50 h. The formation of cracks parallel to the interface between the Crofer22APU interconnect and the BaBS-Zn glass-ceramic sealant was observed due to the severe TEC mismatch. The BaBS glass–ceramic adhered well to the YSZ electrolyte as well as the pre-oxidized Crofer22APU without cracks. Chromium oxide scale developed between the pre-oxidized Crofer22APU/BaBS glass-ceramic joint interface with increasing the pre-oxidation temperature. This study shows that BaBS glass-ceramic is more effective than BaBS-Zn as a sealant for joining YSZ electrolytes and Crofer22APU metallic interconnects in SOFCs working at 800°C for 50 h.


Rare Metals ◽  
2011 ◽  
Vol 30 (3) ◽  
pp. 298-303 ◽  
Author(s):  
Fengfeng Li ◽  
Mingxi Zhang ◽  
Guiqin Hou ◽  
Yi Shen ◽  
Zhigang Liu ◽  
...  

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 583 ◽  
Author(s):  
Stella A. Ordoudi ◽  
Maria Papapostolou ◽  
Stella Kokkini ◽  
Maria Z. Tsimidou

The last years, non-targeted fingerprinting by Fourier-transform infrared (FT-IR) spectroscopy has gained popularity as an alternative to classical gas chromatography (GC)-based methods because it may allow fast, green, non-destructive and cost-effective assessment of quality of essential oils (EOs) from single plant species. As the relevant studies for Laurus nobilis L. (bay laurel) EO are limited, the present one aimed at exploring the diagnostic potential of FT-IR fingerprinting for the identification of its botanical integrity. A reference spectroscopic dataset of 97 bay laurel EOs containing meaningful information about the intra-species variation was developed via principal component analysis (PCA). This dataset was used to train a one-class model via soft independent modelling class analogy (SIMCA). The model was challenged against commercial bay laurel and non-bay laurel EOs of non-traceable production history. Overall, the diagnostic importance of spectral bands at 3060, 1380–1360, 1150 and 1138 cm−1 was assessed using GC-FID-MS data. The findings support the introduction of FT-IR as a green analytical technique in the quality control of these often mislabeled and/or adulterated precious products. Continuous evaluation of the model performance against newly acquired authentic EOs from all producing regions is needed to ensure validity over time.


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