Glass Solution Research Articles

Al-Doped ZnO/SiO2 Nano-glass Ceramic System: A New Composite System for Improvement in Thermal Stability and Mechanical Properties of Dental Resins

AbstractThis study aims to enhance dental resins' mechanical and thermal properties by reinforcing them with Al-doped ZnO/SiO2 nano-glass ceramic. The synthesis of the nano-glass ceramic involved the addition of Al-doped ZnO nano-powders to a diluted aqueous solution of liquid glass (25 mL) in ethanol (50 mL) at room temperature. The synthesized samples were characterized using TEM, EDS, FE-SEM, and XRD techniques. Various concentrations of the nano-glass ceramic (2, 5, 8, 10, and 15 wt.%) were then integrated with Bis-GMA and TEGDMA. The mechanical properties, including flexural strength (FS), compressive strength (CS), diameter tensile strength (DTS), and flexural modulus (FM), were evaluated. Thermal stability was assessed through TGA analysis, which indicated polymer degradation occurring between 300 and 450 °C. An increase in filler content correlated with enhanced thermal stability. The optimal mechanical properties were observed at a 7.5 wt.% filler content, showing significant improvements in FS (124.652 MPa), FM (9.87GPa), DTS (33.87 MPa), and CS (178.47 MPa).

Insights into freeze-cast hierarchical water–glass foams via in situ time-lapse phase-contrast enhanced microcomputed tomography: Correlating composition, microstructure, and compression failure

We demonstrate how continuous freeze-casting without post-treatment sintering may be successfully employed using a pure water–glass (WG) solution to fabricate hierarchically porous foams lacking a morphology gradient along the freeze direction. By adjusting the water content (dilution) and/or the alkali ratio of the solution, we achieved lamellar structures with sub-features or cellular structures, with porosities spanning ∼65% to 83%. The WG foams exhibit astounding mechanical properties; notably, foams with a relatively low density of ∼0.33 g/cm3 demonstrated the highest compressive strength (5 MPa), due to their microstructure and pore morphology. In situ uniaxial compression tests combined with phase-contrast enhanced micro-computed tomography in a synchrotron revealed bending, buckling, fracture and splitting of the lamellar structures as main failure mechanisms. Our newly developed approach of continuous freeze-casting of pure WG solutions with an improved understanding of the relationship between composition, structure, and failure mechanisms provide a basis for a customized design and manufacture of a wide range of freeze-cast WG-based materials for applications ranging from biomedicine to energy generation and storage.

Geometric Landscape Annealing as an Optimization Principle Underlying the Coherent Ising Machine

Given the fundamental importance of combinatorial optimization across many diverse domains, there has been widespread interest in the development of unconventional physical computing architectures that can deliver better solutions with lower resource costs. However, a theoretical understanding of their performance remains elusive. We develop such understanding for the case of the coherent Ising machine (CIM), a network of optical parametric oscillators that can be applied to any quadratic unconstrained binary optimization problem. We focus on how the CIM finds low-energy solutions of the Sherrington-Kirkpatrick spin glass. As the laser gain of this system is annealed, the CIM interpolates between gradient descent on coupled soft spins to descent on coupled binary spins. By combining the Kac-Rice formula, the replica method, and supersymmetry breaking, we develop a detailed understanding of the evolving geometry of the high-dimensional energy landscape of the CIM as the laser gain increases, finding several phase transitions in the landscape, from flat to rough to rigid. Additionally, we develop a novel cavity method that provides a geometric interpretation of supersymmetry breaking in terms of the reactivity of a rough landscape to specific external perturbations. Our energy landscape theory successfully matches numerical experiments, provides geometric insights into the principles of CIM operation, and yields optimal annealing schedules. Published by the American Physical Society 2024

A unifying approach to drug-in-polymer solubility prediction: Streamlining experimental workflow and analysis

This method paper describes currently used experimental methods to predict the drug-in-polymer solubility of amorphous solid dispersions and offers a combined approach for applying the Melting-point-depression method, the Recrystallization method, and the Melting-and-mixing method. It aims to describe and expand on the theoretical basis as well as the analytical methodology of the recently published Melting-and-mixing method. This solubility method relies on determining the relationship between drug loads and the enthalpy of melting and mixing of a crystalline drug in the presence of an amorphous polymer. This relationship is used to determine the soluble drug load of an amorphous solid dispersion from the recorded enthalpy of melting and mixing of the crystalline drug portion in a drug-polymer sample at equilibrium solubility. Due to the complex analytical methodology of the Melting-and-mixing method, a software solution called the Glass Solution Companion app was developed. Using this new tool, it is possible to calculate the predicted drug-in-polymer solubility and Flory-Huggins interaction parameter from experimental samples, as well as to generate the resulting solubility-temperature curve. This software can be used for calculations for all three experimental methods, which would be useful for comparing the applicability of the methods on a given drug-polymer system. Since it is difficult to predict the suitability of these drug-in-polymer solubility methods for a specific drug-polymer system in silico, some experimental investigation is necessary. By optimizing the experimental protocol, it is possible to collect data for the three experimental methods simultaneously for a specific drug-polymer system. These results can then be readily analyzed using the Glass Solution Companion app to find the most appropriate method for the drug-polymer system, and therefore, the most reliable drug-in-polymer solubility prediction.

Study on preparation and properties of steel slag based composite gel for mine fire prevention and extinguishing

A novel fire-preventing composite gel, mainly made from steel slag (SS) and silica fume (SF), was created for a coal mine’s spontaneous combustion. The gelation mechanism of the steel slag-based composite gel (SSG) was investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (SEM). The findings suggest that SSG is generated through the processes of hydration and geopolymerization involving SS and SF. And in the alkaline milieu of a 1.5 M water glass solution, SSG manifests enhanced strength and water retention capacities. Moreover, the fire prevention and extinguishing performance of the SSG was analyzed and verified using low-temperature oxidation, thermogravimetry, and low temperature nitrogen adsorption experiment (LTNA). The SSG has proven highly effective in suppressing spontaneous coal combustion by inhibiting CO production, raising the coal oxidation temperature, and reducing the contact area between oxygen and the coal body.

Assessment and analysis of polydimethylsiloxane-coated solar photovoltaic panels for cost-efficient solutions

Solar photovoltaic (PV) is a crucial renewable energy source in the fight against carbon dioxide emissions, aligning well with growing energy demands. However, solar PV efficiency naturally degrades over time, primarily due to uncontrollable outdoor factors such as irradiance, humidity, shading, soiling, aging, and temperature. These collectively lead to decreased efficiency in PV systems. Soiling on PV glass surfaces significantly impacts light penetration and subsequently reduces power generation. To combat this, a self-cleaning nano-calcium carbonate coating has been proposed. The effectiveness of this method is compared with a developed solar PV thermal (PV/T) system, evaluating both performance and cost-effectiveness. After six months of outdoor exposure, the coated glass solar PV achieved an efficiency of 7.6%, surpassing bare glass solar PV at 6.0%. Moreover, the coated glass solution boasts exceptional cost-effectiveness, incurring only an annual expense of 17.6 USD per panel compared to the PV/T system of 59.8 USD per panel. These findings highlight the potential of coatings to enhance solar PV performance and economics, particularly in addressing challenging uncontrollable factors like soiling.

Influence of Na-Al phosphate glass leachates in clays sorption behavior toward radionuclides

The article presents the results of the study of the sorption of 90Sr, 137Cs, 233U, 237Np, 239Pu,and 241Am radionuclides from model groundwater, model leachate of aluminophosphate glass and Na2HPO4 solutions of different concentrations on bentonite clays of Kamalinskoye (Krasnoyarsk Territory), Desyaty Khutor (Republic of Khakassia), and Dinozavrovoye (Republic of Kazakhstan) deposits. We determined that the presence of aluminophosphate glass leachate in the liquid phase reduced the sorption activity of the studied clays towards caesium. The distribution coefficients of strontium depend more on the clay properties than on the liquid phase composition. However, with increasing concentration of phosphate ion, we observed an increase in the strength of sorbed strontium retention by clay. The sorption of uranium, neptunium, plutonium and americium, increased in the presence of components leached from the aluminophosphate glass-like matrix, and the strength of their fixation by clay increased.

Evaluation of self-compacting geopolymer concrete properties containing different water glass solutions

This research investigates how water glass solutions (Ms 1.99 and Ms 2.92) impact the standard consistency, setting time, rheological properties, and mechanical and microstructural characteristics of self-compacting geopolymer concrete (SCGC) with various amounts of fly ash, ground granulated blast furnace slag (GGBFS), and rice husk ash (RHA). Six Self compacting geopolymer concrete (SCGC) samples were prepared from each of the two glass water solutions. Mechanical properties, such as compressive, split tensile, and flexural properties, were evaluated for the blends. Compared to Ms 1.99, concrete using water glass solution Ms 2.92 had a standard consistency of 49%, and the setting time was increased from 1100 to 1250 min. The Ms. 2.92 combine improves workability. Mechanical properties revealed that 28-day-cured concrete with Ms 2.92 water glass solution had the highest compressive strength of 55.6 MPa and achieved the highest split tensile and flexural strengths, 6.67 MPa and 10 MPa, respectively. XRD, SEM, EDX, and FTIR are used to investigate SCGC's microstructures.

Re-Glass: Product Development Pathways for Post-Consumer Glass

Our research examines the viability of recycling soda lime glass from post-consumer Insulated Glass Units (IGU), mixing various types of architectural glass cullet and fusing them into flat plates by using electric kilns. Those kilns operate at lower temperatures than standard float glass production, which significantly reduces manufacturing emissions. The research outcomes suggest the potential for near-site operations, reducing transportation logistics, costs, and emissions. Strength and emissivity tests were performed on the recycled glass samples, to assess challenges arising from various production parameters including: glass types, processing methods, annealing temperatures and schedules, cullet sizes and distribution. These explorations offer high-level perspectives for developing post-consumer glass solutions driven by emissions and logistics primarily, and tectonics secondarily, exploring the cost-effective diversion of glass products from landfill to generate solutions staying within the built environment. The research examines performance aspects of recycled glass as emblematic of sustainability in design and underscores the role (and implications) of texture in architectural materiality. Performance and viability are weighted with considerations for the US market (hauling distances, energy grid emissivity across states, market culture, labor rates, incentives, or lack thereof). This exploration proposes innovative avenues for integrating distinctive, sustainable recycled glass as a hallmark into architectural frameworks.

A study on composite carbonaceous reducing agent pellets based on low-order unbonded coal

To minimize the cost of carbon-reducing agents and reduce the waste of powder in production, a novel composite carbonaceous reducing agent pellet was prepared through cold pressing, utilizing low-rank unbonded coal (NC) as the primary raw material and incorporating petroleum coke (PC) and high-bonding coal (HVC). This study investigated the influence of different material composition ratios, the addition of organic binder (OBD) and inorganic binder (IBD) (water glass solution), forming moisture ranging from 2 to 12 %, holding temperatures of 60 to 100 ℃, holding times of 2 to 6 h, and material particle sizes ranging from 40 to 250 mesh (0.063–0.420 mm). Additionally, forming pressures of 5 to 30 MPa were analyzed concerning their impact on the cold consolidation strength (CCS) of the resulting pellets. The primary and secondary effects of forming pressure, forming moisture, binder content, and raw material size on pellet strength were examined. According to the actual production situation, the optimum technological conditions were determined. The primary and secondary effects on CCS were ranked as follows: forming pressure > particle size of raw material > binder ratio of 4 % content > forming moisture. External morphology and internal structures of different carbon materials were characterized via FESEM, BET, FTIR, XRD, and XPS. Mechanisms affecting the pellet strength were analyzed. The newly developed composite carbon-reducing agent pellets were suitable for industrial silicon production. This study presented a pathway for the clean and efficient utilization of low-rank unbonded coal and low-viscosity coal, offering substantial economic and social benefits.

Mechanical Properties of Geo-Polymer Concrete by using Water Glass Solution

The environmental concerns related to the production of cement in terms of the energy consumption and the emission of CO2 lead to the search for more environmentally viable alternatives to the cement. One of those alternative materials is Fly ash and GGBS Where Fly ash (FA) and Ground Granulated Blast Furnace Slag (GGBS) is used not as a partial replacement to cement but as the sole binder in the production of concrete. The performance of fly ash and GGBS based materials with sodium silicate (water glass) as an activator was studied

Silicophosphate fireproof coatings for building materials

The composition of silicophosphate fire-resistant coatings for wooden building structures was developed and their properties were investigated. Fireproof compositions were obtained by mixing aqueous solutions of liquid glass and acetic acid. As a phosphate-containing additive, phosphate buffer solutions were used, which were added to the silicic acid sol in different amounts and with different ratios of the components of the buffer pair. Adjusting the ratio of the components of the buffer solution led to a change in the pH of the buffer solutions, but adding them to the sol did not change its acidity, which was in the pH range of 5.5–6. The effect of the content and ratio of the components of the buffer pair on the change in the optical density of the obtained sols over time was studied. The highest durability of the flame retardant composition was recorded when using a buffer solution with a pH of 7 at a content of 20%. The embedding of phosphate ions into the siloxane framework of experimental gels has been chemically proven, which increases their fire resistance. It is shown that the amount of free phosphate anion in the intermicellar liquid of the experimental gels is less than 5%. The mechanism of the strengthening effect of the acetate buffer solution, which is formed during the mixing of the liquid glass solution with acetic acid, on the phosphate buffer solution is proposed. Fire-retardant compositions were applied to wood samples by the bath method and dried at temperatures of 80–100 ˚С in a drying cabinet. The fire protection effect of coatings was determined during fire tests in a ceramic pipe. The effect of the content of phosphate buffer solution on the fire-retardant properties of experimental coatings was studied. It is shown that increasing the content of the phosphate buffer solution reduces mass loss during fire tests, allows to increase the fire resistance of wood and transfer it to the group of "highly flammable".

Durability evaluation of a high-performance red mud-based composite material

The industrial solid waste red mud (RM) was served as a raw material, supplemented with high activity of high-calcium fly ash (HCFA) and low-calcium fly ash (LCFA), a red mud-based composite material (RBC) was obtained. Through the activation of a mixed solution (MS) of NaOH and water glass and the optimization of the preparation process, the prepared RBC possessed a high-performance with high strength and environmental protection. The chemical corrosion and freeze-thaw properties of the RBC were investigated by full immersion and rapid freeze-thaw methods. The strength and durability mechanisms of the RBC were explored by micro-testing techniques. The results indicated that adjusting the operated temperature of the alkaline activator can ensure paste compatibility and shorten the initial setting time. According to the integrity, economy and mechanics properties of the RBC, it is comprehensively determined that the method of wrapped steam-cured, the optimum curing time of RM-HCFA-MS and RM-LCFA-MS was 14 d and 21 d, respectively, and the corresponding compressive strength was 52.8 MPa and 58.9 MPa, respectively. When immersed in acidic, alkaline, or saline environments, the RBC consistently maintained its original structural morphology exhibiting strong corrosion resistance performance. Additionally, the maximum compressive strength was decreased by 19.5%, the maximum mass loss rate was 1.74%, and the corrosion resistance coefficients exceeded 75% after corrosion. The RBC was freeze-swelled and ruptured under repeated actions of hydrostatic and infiltration pressures, and the frost resistance ratings of RM-HCFA-MS and RM-LCFA-MS were F105 and F120, respectively. In conclusion, the RBC has good corrosion resistance and frost-thaw resistance.

Glasslike caging with random planes.

The richness of the mean-field solution of simple glasses leaves many of its features challenging to interpret. A minimal model that illuminates glass physics in the same way that the random energy model clarifies spin glass behavior would therefore be beneficial. Here we propose such a real-space model that is amenable to infinite-dimensional d→∞ analysis and is exactly solvable in finite d in some regimes. By joining analysis with numerical simulations, we uncover geometrical signatures of the dynamical and jamming transitions and obtain insight into the origin of activated processes. Translating these findings into the context of standard glass formers further reveals the role played by nonconvexity in the emergence of Gardner and jamming physics.

Удосконалення механізму притирання вільним абразивом за допомогою використання силікатного складу

The results of an experimental study are presented that explain and confirm the mechanism of lapping friction surfaces with a silicate abrasive composition.
 It is shown that the stability of the silicate lapping paste over time can be achieved by introducing ferric trichloride (FeCl3), which in this case is a thickener of liquid glass and also has high hygroscopic properties. The adhesive properties of the silicate paste are improved by the addition of lubricant 1-13. This grease was chosen due to its water solubility. To increase the abrasive ability of the silicate paste, an abrasive powder was introduced. 
 It was found that the lapping performance of the silicate composition and the quality of surfaces are higher than when treated with the «KT» paste, which is currently used for lapping automobile engine valves. Based on the results of the study, the mechanism of lapping friction surfaces with a silicate paste is presented. The mutual movement of the surfaces results in cutting and scratching of the highest peaks of the bumps by the abrasive grains. When silicon oxide (SiO2) is added to the abrasive material, its particles are coated with silicon oxide. This is because liquid glass solutions have a high adhesive force and low surface tension. At the points of contact between the abrasive particles, the temperature rises, and since there is SiO2 around the abrasive, when the latter enters the contact zone, amorphous silica (SiO2) is formed. Since the abrasive grains are coated with a silicon oxide film, SiO2 penetrates into the cavities of micro-irregularities and adheres to the surface under repeated exposure to the abrasive. Thus, the surface to be treated is saturated with silicon oxide, which leads to an increase in its quality after grinding with a silicate composition.
 It has been proven that high surface quality is formed by amorphous silica. To confirm this mechanism, chemical and X-ray spectral analyses of the samples were performed, which showed the presence of SiO2 on the treated surface and a "strong bond" of silicon compounds with the metal surface layer. 
 It was found that the high quality of the surface is also due to the shape of abrasive particles and wear products. It has been confirmed that with the variable movement of surfaces relative to each other, abrasive grains take on a new position each time. At the same time, they are worn from all sides and acquire a rounded shape, and are simultaneously enveloped by a SiO2 foil.

Final irrigation with bioglass solution in regenerative endodontic procedure induces tissue formation inside the root canals, collagen maturation, proliferation cell and presence of osteocalcin.

To evaluate the influence of an experimental solution of cobalt-doped F18 bioactive glass (F18Co) on tissue repair following regenerative endodontic procedure (REP) in rat molars. The F18Co solution was prepared at a ratio of 1:5 F18Co powder to distilled water. The right or left upper first molars of 12 Wistar rats were used, where the pulps were exposed, removed, and irrigated with 2.5% sodium hypochlorite (NaOCl), followed by 17% ethylenediaminetetraacetic acid (EDTA) (5 min each). Subsequently, the molars were divided into two groups (n = 6): REP-SS and REP-F18Co, where they received a final irrigation (5 min) with saline solution (SS) or F18Co solution, respectively. Then, intracanal bleeding was induced, and the tooth was sealed. Untreated molars were used as controls (n = 3). At 21 days, the rats were euthanized, and the specimens were processed for analysis of mineralized tissue and soft tissue formation inside the root canal using haematoxylin-eosin. The presence and maturation of collagen were evaluated by Masson's trichrome and picrosirius red staining. Immunolabelling analyses of proliferating cell nuclear antigen (PCNA) and osteocalcin (OCN) were performed. The data were submitted to the Mann-Whitney U-test (p < .05). There was a similar formation of mineralized tissue in thickness and length in REP-SS and REP-F18Co groups (p > .05). Regarding the presence of newly formed soft tissue, most specimens of the REP-F18Co had tissue formation up to the cervical third of the canal, whilst the REP-SS specimens showed formation up to the middle third (p < .05), and there was higher maturation of collagen in REP-F18Co (p < .05). The number of PCNA-positive cells found in the apical third of the root canal was significantly higher in the F18Co group, as well as the OCN immunolabelling, which was severe in most specimens of REP-F18Co, and low in most specimens of REP-SS. The final irrigation with F18Co bioactive glass solution in REP did not influence mineralized tissue formation but induced soft tissue formation inside the root canals, with higher collagen maturation, and an increase in PCNA-positive cells and OCN immunolabelling.

Optical and chemical properties of As–Se and As–S–Se solution processed thin films prepared via As50Se50 source solution modification

This work presents the prospect of As–S–Se and As–Se thin film preparation from a modified solution of As50Se50 chalcogenide glass in ethylenediamine.

Effect of Bioactive Glasses and Basic Fibroblast Growth Factor on Dental Pulp Cells.

Ideal regeneration of hard tissue and dental pulp has been reported with the use of a combination of bioactive glass and basic fibroblast growth factor (bFGF). However, no previous study has investigated the molecular mechanisms underlying the processes induced by this combination in dental pulp cells. This study aimed to examine the cellular phenotype and transcriptional changes induced by the combination of bioactive glass solution (BG) and bFGF in dental pulp cells using phase-contrast microscopy, a cell counting kit-8 assay, alkaline phosphatase staining, and RNA sequence analysis. bFGF induced elongation of the cell process and increased the number of cells. Whereas BG did not increase ALP activity, it induced extracellular matrix-related genes in the dental pulp. In addition, the combination of BG and bFGF induces gliogenesis-related genes in the nervous system. This is to say, bFGF increased the viability of dental pulp cells, bioactive glass induced odontogenesis, and a dual stimulation with bioactive glass and bFGF induced the wound healing of the nerve system in the dental pulp. Taken together, bioactive glass and bFGF may be useful for the regeneration of the dentin-pulp complex.

SODIUM SILICATE GELS FOR WATER SHUT-OFF IN OIL RESERVOIRS

This work is dedicated to the problem of reducing the permeability of oil reservoirs to water. An experimental study was conducted, the results of which show that the gel based on liquid glass and hydrochloric acid is partially washed out from the model of water flooded oil reservoir under a pressure gradient of approximately 14 MPa/m, which in practice will lead to a decrease in efficiency. However, adding laponite nano-clay to the solution of liquid glass and hydrochloric acid allows solving this problem and achieving a 400-fold reduction in the permeability of the model of water flooded oil reservoir at a pressure gradient of approximately 33 MPa/m. This result can be explained by the fact that adding laponite to the solution of liquid glass and hydrochloric acid leads to an increase in the mechanical strength of the gel. For example, adding 1% laponite to the solution of liquid glass and hydrochloric acid increased the Young’s modulus from 550 to 1280 Pa. The results of this work demonstrate the potential application of liquid glass gels with fillers to increase the efficiency of plugging agents in operations to reduce water production in oil wells. Future research will focus on conducting filtration experiments on fractured models.

Application of Industrial Waste Materials by Alkaline Activation for Use as Geopolymer Binders.

The purpose of this study is to synthesize geopolymer binders as an environmentally friendly alternative to conventional cement using available local raw materials. Waste materials such as chalcedonite (Ch), amphibolite (A), fly ash from lignite combustion (PB), and diatomite dust (D) calcined at 900 °C were used to produce geopolymer binders. Metakaolin (M) was used as an additional modifier for binders based on waste materials. The base materials were subjected to fluorescence X-ray fluorescence (XRF) analysis and X-ray diffractometry (XRD) to determine chemical and phase composition. A laser particle size analysis was also performed. The various mixtures of raw materials were activated with a 10 M solution of NaOH and sodium water glass and then annealed for 24 h at 60 °C. The produced geopolymer binders were conditioned for 28 days under laboratory conditions and then subjected to microstructural analysis (SEM) and flexural and compressive strength tests. The best compressive strength results were obtained by the Ch + PB samples-more than 57 MPa, while the lowest results were obtained by the Ch + D+A + M samples-more than 20 MPa. On the other hand, as a result of the flexural strength tests, the highest flexural results were obtained by D + A + M + PB binders-more than 12 MPa, and the lowest values were obtained by binders based on Ch + D+A + M-about 4.8 MPa.