Glass Density Research Articles

Light-Density Hollow-Glass-Beads Drilling Fluid Achieves High Solids-Control Efficiency

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 212470, “Full-Scale Solids-Control Testing of a Light-Density Hollow-Glass-Beads Drilling Fluid,” by Nikolay Kostov, ExxonMobil; Glenn Penny, SPE, Contractor for ExxonMobil; and James White, NOV, et al. The paper has not been peer reviewed. _ Light-density drilling fluids with hollow glass beads (HGBs) are being used increasingly in applications for drilling depleted formations with minimal losses and increasing rates of penetration. Studies about how best to use typical solids-control equipment are lacking, however, because current practices and procedures based on barite-weighted muds are inefficient. In the complete paper, the authors report a systematic full-scale test program to study and optimize solids-control efficiency with such fluids using centrifuges, hydrocyclones, and shale shakers. HGB Fluid Formulation The fluid formulation developed for the field test had a target design density of 7.2 lbm/gal. Significant effort was put into developing an HGB fluid that matched or exceeded all design requirements for the existing drilling fluid used to drill a production hole interval in a depleted field. The HGB drilling fluid showed excellent fluid loss and rheology. An overview of the composition and some of the fluid properties is provided in the complete paper. HGB 19K46 is a product with a nominal hydrostatic collapse pressure rating of 19,000 psi and a density of 0.46 g/cm3 (approximately 3.8 lbm/gal). The HGBs are almost perfectly round spheres made up of a thin shell of borosilicate glass a few micrometers thick. The glass density is approximately 2.50–2.55 SG. The hardness is approximately 5 on the Mohs scale, in between barite (3.5) and quartz (7.0). HGB Large-Batch Mixing Based on the testing time to reach steady conditions and the tanks available at the test facility, it was determined that a volume of approximately 40 bbl was required for the field-scale solids-control testing. A mixing plant was used, and the fluid was mixed over a period of 3 days. Good agitation is crucial to mix the additives and HGBs effectively into the base oil. With the exception of the process used to add HGBs, however, no special equipment or modified procedures are needed to mix the HGB fluid. For adding the HGBs, a hopper was used and an efficient additive process developed while dust was eliminated. A 100-bbl mixing tank unit mounted on a trailer was used to generate the HGB fluid for testing (Fig. 1). The unit consists of a multicompartment 100-bbl tank, a diesel-engine-driven centrifugal pump, a hopper, and a series of control valves for directing the fluid flow. One specific modification to the tank was the installation of large eductors at the ends of the feeding pipe. This ensured good circulation of the fluid in the tank, promoted good mixing, and eliminated any dead zones where fluid could become stagnant. The large-scale mixing resulted in approximately 43 bbl of HGB drilling fluid. Samples were collected, and properties were measured. All properties were within the specification window, confirming a successful operation.

Impact of the Drying Procedure and Botanical Origin on the Physico-Chemical and Potentially Bioactive Properties of Honey Powders

This study was aimed at researching the impact of the drying procedure (using the most appropriate honey–maltodextrin concentration for each drying technique) and botanical origin of honey on the physicochemical and potentially bioactive properties of honey powders that were made using maltodextrin as a carrier. The research was carried out with thyme, lavender, vetch and multifloral honey dehydrated using vacuum drying and freeze drying. The analysed parameters were moisture, water activity, colour, glass transition temperature, powder recovery, hygroscopic index and rate, tapped density, solubility, and phenolics as well as antiradical (ABTS•+, ROO•, •OH and O2•−), anti-inflammatory and antimicrobial (against Staphylococcus aureus, Escherichia coli and Listeria monocytogenes) activities. Freeze drying provided the highest recoveries. Powders obtained using freeze drying showed higher moisture and solubility as well as lower glass transition temperature, density and hygroscopicity than those obtained using vacuum drying. Hygroscopicity, glass transition temperature and antimicrobial activity against St. aureus depended on the drying procedure–honey concentration. Colour, anti-O2•− activity and antimicrobial activity against L. monocytogenes depended on the botanical origin of the raw honey. Moisture, solubility, density, total phenolic content, anti-ABTS•+ and anti-ROO• activities as well as anti-inflammatory activity and antimicrobial activity against E. coli depended on the drying procedure–honey concentration and botanical origin.

Concentration Dependence of Sm2O3 on Physical, Optical and Luminescence Properties of Na2O:Al2O3:Gd2O3:P2O5 Glass System

The Na2O:Al2O3:Gd2O3:P2O5 glasses were doped with different concentrations of Sm3+ ions and synthesized by the melt-quenching technique. These glasses were investigated to characterize physical and spectroscopy analyses that have been carried out by density, molar volume, absorption, FTIR, and photoluminescence measurements. The density and molar volume of glasses increases with the addition of Sm2O3 concentration. Glasses absorbed photons in UV, VIS, and NIR regions. The strong orange emission via the 4G5/2 to 6H7/2 radiation transition of Sm3+ was generated under 275 and 402 nm excitation. The glass has an interesting potential photonic application.

Influence of CeF3 on Ga2O3-Lu2O3-Al2O3-Y2O3-B2O3 glass for photonics material

CeF3 doped gallium lutetium aluminium yttrium borate glasses were investigated for photonics applications in this work. Their physical, structural, optical and luminescence properties were studied by the effect of CeF3 concentration. Glass density and refractive index raised with increasing CeF3 amount. The FTIR spectra and XRD pattern demonstrated that the glass network consisted of trigonal BO3 and tetragonal BO4 borate groups cooperating with metal oxides in amorphous nature, while CeF3 dopant acted as a glass modifier. Glass strongly absorbed the photons in ultraviolet region by transition of host component, superposed with the 4 f→5d transition of Ce3+ dopant. Under UV excitation, glass doped with 0.05 mol%-CeF3 performed the highest emission intensity at 391 nm by 5d→4 f transition. Due to the strong blue emission, half photons conversion ability and short decay time around 21 ns, this developed glass owns a potential for the blue light sources / medium and the ultraviolet to visible light converter.

Radiation attenuation of boro-tellurite glasses for efficient shielding applications

The borotellurite glasses whose chemical structure is (29.5–0.4x)CaO + 10CaF2 + (60–0.6x)B2O3 + xTeO2+ 0.5Yb2O3 (where x=10, 16, 22, 31, and 54 % mole. represent TCCBY1-TCCBY5, respectively) are Pb-free, thermally stable, and transparent glasses with attractive optical features for technological applications. The gamma-photons, electrons, protons, neutrons, carbon ions, fast neutrons, and fast neutron interaction parameters of these glasses are presented in this study to better understand the role of TeO2 in influencing their radiation shielding properties and radiation protection applications. The photon mass attenuation coefficient was evaluated by XCOM computation and simulation using the FLUKA code. The FLUKA code was also used to evaluate the mass stopping powers of the charged radiations, while neutrons’ cross sections were evaluated using standard expressions. For 0.015 MeV–15 MeV photons, the mass attenuation coefficients of the glasses fell from 17.9499 to 0.0246 cm2/g for TCCBY1, 20.5628 to 0.0263 cm2/g for TCCBY2, 23.2756 to 0.079 cm2/g for TCCBY3, 26.7487 to 0.0298 cm2/g for TCCBY4, and 33.3591 to 0.0335 cm2/g for TCCBY5. The photon half-value layer at 15 keV is reduced by about 19.57%, 32.68%, 48.84%, and 63.89% when the TeO2 content increases from 10 mol to 16, 22, 31, and 54 mol, respectively. TeO2 was found to suppress photon buildup in the glasses. The mass stopping powers of charged radiation increased as glass density decreased. The addition of TeO2 into the glass structure increased the ability of the TCCBY glass to absorb fast neutrons by up to 54 % mole. The gamma radiation and fast neutron moderating ability of TCCBY5 glass compared to common shields and other materials is exceptional. The glass is recommended for the design of Pb-free, transparent, and efficient radiation protection structures.

Impact of CaO addition on physico-chemical properties, crystallization, chemical durability and in vitro behavior of Na2O-ZnO-TiO2-P2O5 glasses

This work investigates the effect of CaO addition on physico-chemical properties, crystallization, chemical durability and bioactivity of phosphate-based glasses. To this end, five glass compositions in the system (40-x)Na2O-xCaO-10ZnO-20TiO2-30P2O5 with x = 0, 5, 10, 15 and 20 mol % have been elaborated by the conventional melt-quenching technique. Replacing Na2O with CaO oxide in the studied glasses increased remarkably the glass transition temperature Tg and density (ρ), while VM decreased with increasing CaO content indicating the high strength in the glass network. The existence of PO3 and PO4 units with P-O-P and P-O-Ti linkages in the glassy network was revealed by Infrared spectroscopy. The chemical durability was improved with increasing calcium content, indicating that replacing Na-O bonds with more covalent and stronger Ca-O bonds strengthen and crosslink the glassy network. The in vitro bioactivity of the two glass samples (x = 0 and 15 mol %) was studied using SBF solution. XRD, Infrared, ICP, and pH measurements proved the formation of a hydroxyapatite layer on the glass surface after interaction with the SBF medium, which is a crucial property of a potential bioactive glass. The correlation between XRD, Infrared, and ICP techniques indicated that glass containing calcium is more bioactive than free-calcium glass.

Radiation shielding capacity and machine learning density prediction of boro-bismuth cadmium zinc glasses

Bismuth borate cadmium zinc glasses were prepared using melt quenching technique for shielding applications. The glasses had the composition (80-x)B2O3-xBi2O3-10CdO-10ZnO, where 0<x<20mol%. The densities of the glasses were predicted using machine learning tools and were found to increase with increasing Bi2O3 content. This increase in density was correlated with changes in the infrared spectrum of the glasses. The density of the glass changed from 4.410 g/cm³ to 6.9830 g/cm³ when bismuth oxide (Bi2O3) was added to the glass network. This is because Bi2O3 changes the structure of the glass. The presence of octahedral BiO6 units in the glass is confirmed by the peak at 514 cm-1 in the infrared spectrum. This peak shifts to a lower wavenumber as the amount of Bi2O3 in the glass increases. The shift of the infrared peak from 688 cm-1 to 596 cm-1 indicates that Bi2O3 is actively participating in the glass network, which results in a decrease in the number of BO3 units. The shift of the infrared peak from 1060 cm-1 to 1137 cm-1 is attributed to B-O stretching vibrations in BO4- units, and also confirms that the number of BO4 units is increasing. The density of the glass was predicted using machine learning algorithms that are trained on the chemical composition and experimental density of glasses. Polynomial regression and artificial neural networks (ANNs) were used to predict the density of glass from its chemical composition. Polynomial regression performed best with a 10th-degree polynomial, with an R2 value of 0.8820. ANNs performed best with a tanh activation function, with an R2 value of 0.8923. Random forest regression performed better than other machine learning models at predicting the density of glass, with an R2 value of 0.920. The predicted values were very close to the experimental values. The mass (MAC) and linear (LAC) attenuation coefficients of radiation shielding followed the following trend: (MAC, LAC)0 < (MAC, LAC)5 < (MAC, LAC)10 < (MAC, LAC)15 < (MAC, LAC)20. The half value layer followed the trend: HVL followed as: (HVL)0 > (HVL)5 > (HVL)10 > (HVL)15 > (HVL)20. The Radiation Protection Effectiveness (RPE) reinforces the superiority of BBCZ-20 glasses in shielding against gamma radiation, making them promising candidates for radiation protection applications.

Effect of K2WO4 on structure and properties of low melting glasses in K2O–Fe2O3–P2O5 system as sealing materials

New phosphate glasses based on the K2O–Fe2O3–P2O5 system, with variable K2WO4 content in place of Fe2O3, are prepared through the melt quenching route. The thermal and structural characteristics and water resistance properties are studied for sealing applications by means of XRD, DSC, and FTIR spectroscopic and dilatometry measurements. The results showed an amorphous nature and a linear increase in the parameters of the glass density and molar volume with the addition of K2WO4. While the glass transition (Tg), crystallization (Tc) temperatures, the thermal stability (ΔT), and the relative criterion (H) values were decreased are decreased. Inversely, the ΔCp values were markedly increased with growing NBO bonds that led to markedly increase in the O/P ratio. Also, the coefficient of thermal expansion (CTE) is increased (from 124 to 211 × 10−7/oC). The glass with high K2WO4 content is a suitable sample for excellent sealing properties with a low transition temperature (Tg < 300 °C), a very low melting point, and a high thermal expansion value (211 × 10−7/oC). As well, the durability values of the examined samples decreased, but they were in the range of those for commercial sealing glass. The study offers fresh suggestions for the development of sealant materials that are both low-temperature and environmentally safe.

Alkali ionic state behavior in γ-Irradiated borate glasses for medical ultrasonic transducer fabrication

Lenses could be added to ultrasonic transducers used in medical applications to improve them. They may solve some limiting factors, like the acoustic impedance mismatch between the transducer and the tissues, the wave collimation difficulty, the wave scattering, etc. Novel ultrasonic transducers were developed that contained lenses made from new glass systems. Al2O3, MgO, and Li2O alkali-borate glass systems were prepared via the melt-quenching technique. Structural, electrical, and ultrasonic measurements were done with regard to the effect of gamma radiation. The XRD pattern showed the glassy, amorphous nature of the lenses. FTIR absorption spectra revealed the large stability of the main structural units of borate. Electron spin resonance (ESR) spectra clarified the low distortions caused by irradiation with g-values ∼ 2.025–2.026 and recognized the formation of oxygen hole centers (OHC) caused by breaking B–O connectivity. Al ions produced the most compact glass network, resulting in the highest ultrasonic velocity and wave passage. The characteristics of transducers with and without the lens were measured. The transducers with Al2O3 lenses demonstrated the lowest signal-to-noise ratio, the greatest beam diameter, and the highest sensitivity. The results ensured the effectiveness of the prepared glass as a lens in high-frequency ultrasonic transducers that are mainly used in medical applications.

Silicate glass fracture surface energy calculated from crystal structure and bond-energy data

We present a novel method to predict the fracture surface energy, γ, of isochemically crystallizing silicate glasses using readily available crystallographic structure data of their crystalline counterpart and tabled diatomic chemical bond energies, D0. The method assumes that γ equals the fracture surface energy of the most likely cleavage plane of the crystal. Calculated values were in excellent agreement with those calculated from glass density, network connectivity and D0 data in earlier work. This finding demonstrates a remarkable equivalence between crystal cleavage planes and glass fracture surfaces.

Compositional dependency of transparency, optical and radiation shielding parameters inside Gd2O3–Fe2O3–Na2O–SiO2–B2O3 glass

Radiation shielding glass is a promising material in the radiation shielding domain with enhanced radiation shielding properties. However, glass still has some drawbacks, such as low transparency with diverse modifier types. This low level of transparency requires essential developments. In this work, we study gadolinium oxide (Gd2O3), sodium oxide (Na2O) and iron oxide (Fe2O3) embedded in borosilicate glass for radiation shielding purposes. This glass system is characterized by high transparency and enhanced radiation shielding properties. The structural observations show that the glass density gradually increases from 2.303 to 3.42 g cm−3 with further additives of Gd2O3. Moreover, the glass transparency exhibits enhanced behavior over the studied range of Gd2O3 additions. Based on optical results, we obtained increased optical band gaps from 2.97 to 3.51 eV with higher concentrations of Gd2O3 inside the glass matrix. This increased optical band gap was attributed to the decreasing behavior of basicity and the decreased behavior of polarizability. Also, the linear and nonlinear refractive indices show decreased behavior with additional contents of Gd2O3. This behavior was discussed by the diminishing behavior of basicity and polarizability. While the inclusion of higher concentrations of Gd2O3 leads to improved radiation shielding capabilities, as seen by the increased values of the mass attenuation coefficient and half-value layer. Herein, the investigated glass samples are both more transparent and more effective at shielding radiation, making them prime candidates for use in this field.

Two-photon polymerization of silica glass diffractive micro-optics with minimal lateral shrinkage.

Three-dimensional printing enables the fabrication of silica glass optics with complex structures. However, shrinkage remains a significant obstacle to high-precision 3D printing of glass optics. Here we 3D-printed Dammann gratings (DGs) with low lateral shrinkage (<4%) using a two-photon polymerization (2PP) technique. The process consists of two steps: patterning two-photon polymerizable glass slurry with a 515 nm femtosecond laser to form desired structures and debinding/sintering the structures into transparent and dense silica glass. The sintered structures exhibited distinct shrinkage rates in the lateral against longitudinal directions. As the aspect ratio of the structures increased, the lateral shrinkage decreased, while the longitudinal shrinkage increased. Specifically, the structure with an aspect ratio of approximately 60 achieved a minimal lateral shrinkage of 1.1%, the corresponding longitudinal shrinkage was 61.7%. The printed DGs with a surface roughness below 20 nm demonstrated good beam-shaping performance. The presented technique opens up possibilities for rapid prototyping of silica diffractive optical elements.

Numerical investigation of the influence of temperature and composition on the thermophysical properties of an innovative environmentally friendly glass obtained from mineral coal bottom ash

The purpose of this work is to investigate, through numerical simulation, the influence of temperature and chemical composition on the heat capacity, density, and thermal conductivity of a novel eco-friendly glass from mineral coal bottom ash. The modeling used to represent the system is based on the heat transfer in solids with phase-change. The numerical resolution was performed by the finite element method, and the variation of physical properties with temperature and composition was represented by theoretical and empirical equations introduced in the model. After the model is experimentally validated, the behavior of these properties during cooling process was investigated, pointing out higher ash content levels resulted in higher values of heat capacity, and lower values for density and thermal conductivity. Thus, this study brings contributions in the investigation of physical properties of a novel glass obtained by reuse of mineral coal bottom ash from a thermoelectric plant.

Lymphoma Accompanyıng Pneumoconıosıs; Case Report

Non-Hodgkin Lymphoma (NHL) is the most common hematological malignancy, and Diffuse Large B-Cell Lymphoma (DLBCL) is the most common histological type. A 56-year-old male patient was admitted to our clinic with complaints of shortness of breath and fatigue for 1 month. It was learned in his professional history that he had been a dental technician for 30 years. He was diagnosed with pneumoconiosis in 2020 and his chest radiograph was q/t 3/3 according to the International Labor Organization (ILO) International Classification of pneumoconiosis radiographs. Laboratory examinations revealed an increase in erythrocyte sedimentation rate (ESR 50 mm/h) and serum lactate dehydrogenase (LDH 368 IU/L) levels. On thoracic computed tomography (CT), enlarged lymph nodes and lymphadenopathies (LAP) with local conglomeration and calcifications in the mediastinal, subcarinal and bilateral hilar areas were seen. Widely disseminated inhomogeneous mass-like consolidation areas, including internal calcifications, extending from the hilum to the parenchyma in both lungs, were observed more prominently in the right middle zone. Diffuse interstitial thickenings, infiltrations and centrilobular nodular density increases in both lungs, nodular consolidated areas with recessed contours and nodules and ground glass densities were observed, especially in the left upper zone. In the lateral part of the left 5th rib, a heterogeneous soft tissue mass of approximately 12x5 cm, causing cortical destruction, invading the surrounding soft tissues and muscle planes, and containing internal cystic-necrotic components was observed. On abdominal CT, enlarged lymph nodes and LAPs, some of which contain calcifications, were observed in the abdomen. The pathology result was reported as Diffuse B-Cell Lymphoma in the patient who underwent transthoracic biopsy due to radiographic appearances that are not typical for PMF. Here, we presented a case of pneumoconiosis with occupational carcinogen exposure and presenting with lymphoma.

The role of ZrO2 as glass-network former on radiation transmission properties of aluminoborosilicate (ABS) glasses: A glass type for nuclear waste immobilization

We report the gamma-ray shielding properties, transmission factors and, effective removal cross section values of several aluminoborosilicate glasses that have been synthesized through various glass-forming materials such as Al2O3, B2O3, SiO2, and ZrO2. The study utilized the elemental compositions and densities of eight different glass samples as input variables in theoretical calculations and Monte Carlo simulations. According to the results obtained, it was seen that the network-forming type used in aluminoborosilicate glasses had a direct effect on the radiation absorption properties of the glasses. The utilization of ZrO2 and Cs2O at the highest concentration as the network former and glass network modifier in the NCBZ-6 sample yielded the most advantageous results in relation to its gamma-ray absorption capabilities. The benefit is intrinsically related to the heightened density of glass and the incorporation of compounds with increased atomic numbers, both of which are fundamental characteristics desired in materials designed for the purpose of gamma-ray absorption. However, the enhanced capability of ZrO2 to absorb gamma-rays excludes the absorption of high-energy neutrons. The absence of boron trioxide (B2O3) in the NCBZ-6 sample can be ascribed to its restricted availability against fast neutrons. The continued existence of ZrO2 as a network forming in the investigated ABS glasses is likely to result in improved material homogeneity and progressive enhancement of gamma-ray absorption characteristics. It can be concluded that the incorporation of ZrO2 as a network-former component may be an appropriate strategy to enhance the gamma-ray shielding capabilities of aluminoborosilicate glasses.

Orientational Order in Dense Colloidal Liquids and Glasses.

We construct structural order parameters based on local angular and radial distribution functions in dense colloidal suspensions. All the order parameters show significant correlations to local dynamics in the supercooled and glass regime. In particular, the correlations between the orientational order and dynamical heterogeneity are consistently higher than those between the conventional two-body structural entropy and local dynamics. The structure-dynamics correlations can be explained by a excitation model with the energy barrier depending on local structural order. Our results suggest that in dense disordered packings, local orientational order is higher than translational order, and plays a more important role in determining the dynamics in glassy systems.

Artificial neural network approach for calculating mass attenuation coefficient of different glass systems

In this study, we propose an alternative approach using Artificial Neural Networks (ANN) for determining Mass Attenuation Coefficients (MAC) in various glass systems. This method takes into account the weights of glass compositions, density, and photon energy as input features. The ANN model was trained and tested on a dataset consisting of 650 data points and subsequently validated through a K-fold cross-validation procedure. Our findings demonstrate a high level of accuracy, with R2 values ranging from 0.90 to 0.99. Additionally, the model exhibits robust extrapolation capabilities with an R2 score of 0.87 for predicting MAC values in a new glass system. Furthermore, this approach significantly reduces the need for costly and time-consuming computations and experiments, making it a potential tool for selecting materials for effective radiation protection.

REVERSIBLE LUNG FIBROSIS FOLLOWING SEVERE COVID-19 INFECTIONA CASE REPORT

After wide spread of COVID-19 pneumonia with thousands of cases complicated with acute respiratory distress syndrome (ARDS) of which high percentage fully recovered and resumed their normal life without any disability. It was known that those patients will have residual fibrosis which may affect their daily activity on the long run.There was always paramount question about the reversibility of such fibrosis especially with well-known concept about absence of any radical treatment for such etiology.We present a case of 54 years old male patient, non-smoker with irrelevant medical history apart from well controlled hypertension. He was referred to our facility with fever, productive cough, and shortness of breath. An initial polymerase chain reaction (PCR) screening for SARS-COV2 was positive. A high-resolution CT (HRCT) chest revealed Multi-focal patchy air-space ground glass density with peripheral and basal predominance more affecting the left side, suggestive of viral pneumonia. The patient was commenced on low flow oxygen therapy and symptomatic treatment. Four days later the symptoms aggravated and oxygen requirement increased to non-rebreathing oxygen mask (NRM). We treated him according to COVID protocol withtherapeutic anticoagulation, corticosteroids and oxygen therapy which was adjusted to maintain saturation 92%, but his condition deteriorated and was shifted to intensive care unit. Later patient improved andwas shifted back to the medical ward. We were able to wean him off oxygen and he was discharged home oncorticosteroidsand scheduled for a follow up visit in the pulmonology clinic. Repeated HRCT chest showed regressive course concerning both the airway space disease and the fibrotic changes. The patient returned to his normal life activity with no residual limitation of his physical activity or development of shortness of breath with exertion. Latest HRCT was completely normal.

Cathodic Deposition of Thickness-Controllable ZIF-62 Film and Its Vitrification

Glass metal-organic framework (MOF) membrane is a newly developed material that is promising for separation works like ionic sieving and gas separation. Compared with its crystalline counterpart, the glass MOF membrane takes the advantage of its grain-boundary-free nature that greatly benefits the separation performance. However, the fabrication of the glass MOF membrane requires the pre-preparation of the mother crystalline MOF film, which remains a challenge. Taking the deposition of the iconic ZIF-62 (Zn-imidazole, melting point: 711 K) film as an example, this area remained silent until Jiang et al. reported the first example in 2018.1,2 They achieved the ZIF-62 deposition on anodic aluminum oxide (AAO) membrane by a solvothermal method. Nevertheless, this approach is limited by the low yield of the generated MOF crystals on the substrate and the time/energy-consuming process. To mitigate the existing dilemma, here we show an economic cathodic deposition approach to the preparation of ZIF-62 film with a controllable thickness. Thanks to the addition of hydrogen peroxide as a probase, the pure ZIF-62 film can be deposited without the co-deposition of metallic Zn. In the proposed deposition, a nucleation-Ostwald ripening-crystallization ternary process can be observed, which is different from the cathodic deposition of other MOF species like MOF-5. Also, it is found that the crystallinity of the deposited ZIF-62 film improves with the deposition temperature and the thickness of it can be well-tuned by the deposition time from a range of ~1 µm to ~15 µm. The cathodically deposited ZIF-62 film can be directly used as the mother material for the preparation of glass MOF membrane via a vitrification process. Systematic annealing experiments indicate that the heating temperature and dwelling time are crucial to the quality of the glass MOF membrane. At the optimized conditions (713 K, 4 hours), the dense and bulb-free glass MOF membrane with a flat surface can be obtained, which is ideal for separation works. Wang, Y.; Jin, H.; Ma, Q.; Mo, K.; Mao, H.; Feldhoff, A.; Cao, X.; Li, Y.; Pan, F.; Jiang, Z., A MOF glass membrane for gas separation. Angewandte Chemie 2020, 132 (11), 4395-4399. Bennett, T. D.; Yue, Y. Z.; Li, P.; Qiao, A.; Tao, H. Z.; Greaves, N. G.; Richards, T.; Lampronti, G. I.; Redfern, S. A. T.; Blanc, F.; Farha, O. K.; Hupp, J. T.; Cheetharm, A. K.; Keen, D. A., Melt-Quenched Glasses of Metal-Organic Frameworks. Journal of the American Chemical Society 2016, 138 (10), 3484-3492.

Influence of lanthanides on the melt viscosity and glass density of sodium disilicate

High temperature viscosity data for 14 sodium disilicate (NS2; Na2Si2O5) melts with equimolar (5.288 mol%) additions of lanthanum oxides (Ln2O3; Ln = La; Ce; Pr; Nd; Sm; Eu; Gd; Tb, Dy; Ho; Er; Tm; Yb; Lu) have been determined in the temperature range of 1003–1490 °C. At the highest temperatures the viscosity of Ln2O3 modified NS2 generally decreases, whereas towards lower temperatures the heaviest lanthanides effect a slight increase of melt viscosity. In general, the lanthanides behave highly coherently with respect to their viscosity reducing effect, while a “tetrad effect” might be present. Two exceptions exist, Ce and Tm, both exhibiting anomalously stronger viscosity reducing effects. For Ce we attribute this behavior to its multivalent oxidation state in the melt, while for Tm its origin remains unclear. Glass densities also correlate with the atomic number, again with exceptions for Ce- and Tm-bearing samples, which exhibit the lowest and highest densities, respectively.