S. Adamopoulos, E. Voulgaridis, C. Passialis, D. Foti
Cellulosic fibrous mats were impregnated with various water-repellent formulations based on reclaimed polystyrene (5, 10, 15, and 20%), alkyd resin (5%), gum rosin (5%), and paraffin wax (0.5%). The mats were tested for their bursting strength and resistance to bending. They were also subjected to the ring crush test and short-span compression test. By increasing the concentration of total solid ingredients (5, 10, 15, 20, and 25.5%), the retention and grammage of the mats were increased, and all strength properties were improved. All formulations containing 20% reclaimed polystyrene had the highest strength properties. The formulations containing alkyd resin had higher bursting and bending strength than gum rosin. However, the formulations with gum rosin exhibited higher strength than those with alkyd resin in the ring crush test and the short-span compression test. Adding paraffin wax in formulations with 20% reclaimed polystyrene and gum rosin did not affect the strength properties.
{"title":"Strength Properties of Cellulosic Fibrous Mats Impregnated with Water Repellents Based on Reclaimed Polystyrene","authors":"S. Adamopoulos, E. Voulgaridis, C. Passialis, D. Foti","doi":"10.21926/rpm.2204022","DOIUrl":"https://doi.org/10.21926/rpm.2204022","url":null,"abstract":"Cellulosic fibrous mats were impregnated with various water-repellent formulations based on reclaimed polystyrene (5, 10, 15, and 20%), alkyd resin (5%), gum rosin (5%), and paraffin wax (0.5%). The mats were tested for their bursting strength and resistance to bending. They were also subjected to the ring crush test and short-span compression test. By increasing the concentration of total solid ingredients (5, 10, 15, 20, and 25.5%), the retention and grammage of the mats were increased, and all strength properties were improved. All formulations containing 20% reclaimed polystyrene had the highest strength properties. The formulations containing alkyd resin had higher bursting and bending strength than gum rosin. However, the formulations with gum rosin exhibited higher strength than those with alkyd resin in the ring crush test and the short-span compression test. Adding paraffin wax in formulations with 20% reclaimed polystyrene and gum rosin did not affect the strength properties.","PeriodicalId":87352,"journal":{"name":"Recent progress in materials","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41857103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
New lubrication events can be predicted using improved pathological non-Newtonian physiological fluids coupled to phospholipid-based bilayers in variable time-dependent magnetic fields under random non-steady conditions. In this study, we investigated nanofluid lubrication systems for synovial joints. The particles of PSPMA-g-HSNPs were used as nanoparticles. The hydrodynamic interaction between the knee bones separated by a nanofluid film was considered here for various nanofluid concentrations. The simulation indicated solid mechanics on the bones being pushed by 45 kg-force. The lubricant layer was squeezed by the approaching bones, which increased the pressure on the lubricant. The calculated maximum lubricant pressure and the change in film height with time were compared to analytical solutions. The results showed that the application of the nanofluid technology on non-conventional lubrication systems for synovial joints was feasible. Finally, we also found that with an increase in the nanoparticle concentration, the maximum pressure on the squeeze film decreased, which introduced a new type of bio-fluid to non-conventional lubrication systems for synovial joints.
{"title":"Elastohydrodynamic Squeeze-film Interaction in Synovial Joints with Nanofluid Lubrication","authors":"M. A. Abdollahzadeh Jamalabadi","doi":"10.21926/rpm.2204021","DOIUrl":"https://doi.org/10.21926/rpm.2204021","url":null,"abstract":"New lubrication events can be predicted using improved pathological non-Newtonian physiological fluids coupled to phospholipid-based bilayers in variable time-dependent magnetic fields under random non-steady conditions. In this study, we investigated nanofluid lubrication systems for synovial joints. The particles of PSPMA-g-HSNPs were used as nanoparticles. The hydrodynamic interaction between the knee bones separated by a nanofluid film was considered here for various nanofluid concentrations. The simulation indicated solid mechanics on the bones being pushed by 45 kg-force. The lubricant layer was squeezed by the approaching bones, which increased the pressure on the lubricant. The calculated maximum lubricant pressure and the change in film height with time were compared to analytical solutions. The results showed that the application of the nanofluid technology on non-conventional lubrication systems for synovial joints was feasible. Finally, we also found that with an increase in the nanoparticle concentration, the maximum pressure on the squeeze film decreased, which introduced a new type of bio-fluid to non-conventional lubrication systems for synovial joints.","PeriodicalId":87352,"journal":{"name":"Recent progress in materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46205931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. DeCoster, Tasneem Khasru, Kelly McMahen, Navya Uppu
Green synthesis of nanomaterials endeavors to reduce the use of high energy methods with those that may include lower temperatures and pressures, use of natural products, and bottom-up self-assembly. Here we describe the generation of metal-organic biohybrids (MOBs) with nanoscale features synthesized at physiological (37°C) and room temperature (25°C). These MOBs utilized the naturally occurring amino acid dimer cystine as the biological component, and a series of metals, including copper, silver, and cobalt. The copper- and silver- based nanomaterials generated were distinct in size and shape. Copper formed elongated high-aspect ratio structures which we have named CuHARS. In contrast, the self-assembly of cystine and silver formed nanoparticles which we designate as AgCysNPs, and cobalt formed particles which we designate as CoMOBs. Both cobalt and silver could be combined with copper in the same reaction vessel to carry out green synthesis of different nanomaterials simultaneously. Post-synthesis the polarization of light by CuHARS provided one measure to distinguish the size and shape of different MOBs generated simultaneously.
{"title":"Green Synthesis of Metal-Organic Biohybrid (Mob) Nanomaterials","authors":"M. DeCoster, Tasneem Khasru, Kelly McMahen, Navya Uppu","doi":"10.21926/rpm.2204020","DOIUrl":"https://doi.org/10.21926/rpm.2204020","url":null,"abstract":"Green synthesis of nanomaterials endeavors to reduce the use of high energy methods with those that may include lower temperatures and pressures, use of natural products, and bottom-up self-assembly. Here we describe the generation of metal-organic biohybrids (MOBs) with nanoscale features synthesized at physiological (37°C) and room temperature (25°C). These MOBs utilized the naturally occurring amino acid dimer cystine as the biological component, and a series of metals, including copper, silver, and cobalt. The copper- and silver- based nanomaterials generated were distinct in size and shape. Copper formed elongated high-aspect ratio structures which we have named CuHARS. In contrast, the self-assembly of cystine and silver formed nanoparticles which we designate as AgCysNPs, and cobalt formed particles which we designate as CoMOBs. Both cobalt and silver could be combined with copper in the same reaction vessel to carry out green synthesis of different nanomaterials simultaneously. Post-synthesis the polarization of light by CuHARS provided one measure to distinguish the size and shape of different MOBs generated simultaneously.","PeriodicalId":87352,"journal":{"name":"Recent progress in materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45828616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
W. Vargas, M. Hernández-Jiménez, Victoria Quirós-Cordero, Esteban Avendaño, F. Muñoz-Rojas
Spectrophotometry has been widely used to retrieve the dielectric function of a bulk iridium sample using an extended version of the Drude–Lorentz model. The parameters of the model are optimized using a spectral-projected-gradient-method-assisted acceptance-probability-controlled simulated annealing approach. Furthermore, optimized values of Drude parameters corresponding to the optical response of electrons and holes (scattering frequency of electrons, the ratio between scattering frequencies of holes and electrons, the ratio between effective masses of electrons and holes, the ratio between the number densities of holes and electrons, and electron volume plasma frequency) are used to evaluate charge transport and magnetic properties. These include static and dynamic conductivities, intrinsic mean free paths, the effective mass of charge carriers and their number densities, Fermi velocities and energies, densities of states at Fermi energies, mobilities, specific heats, Hall’s coefficient, thermal conductivities, charge carrier coupling constant, paramagnetic and diamagnetic susceptibilities, and the number of Bohr magnetons. In addition, optimized resonance energy values of the Lorentz contribution to the dielectric function were compared with the background information provided by density-functional-theory calculations for iridium. A decomposition of the energy loss function was used as the starting point to calculate the effective numbers of bound electrons involved in interband transitions, as well as the densities of states at the final energies of the sets of transitions considered. The Drude–Lorentz model involves charge carrier parameters for both electrons and holes, as well as the resonance energies correlating with the energies associated with quantum transitions. To a large extent, several physical quantities calculated from optimized parameters exhibit values close to those obtained from measurements or by applying other models, including quantum mechanics formulations.
{"title":"Optical, Charge Transport, Thermal, Magnetic, Plasmonic, and Quantum Mechanical Properties of Iridium","authors":"W. Vargas, M. Hernández-Jiménez, Victoria Quirós-Cordero, Esteban Avendaño, F. Muñoz-Rojas","doi":"10.21926/rpm.2204019","DOIUrl":"https://doi.org/10.21926/rpm.2204019","url":null,"abstract":"Spectrophotometry has been widely used to retrieve the dielectric function of a bulk iridium sample using an extended version of the Drude–Lorentz model. The parameters of the model are optimized using a spectral-projected-gradient-method-assisted acceptance-probability-controlled simulated annealing approach. Furthermore, optimized values of Drude parameters corresponding to the optical response of electrons and holes (scattering frequency of electrons, the ratio between scattering frequencies of holes and electrons, the ratio between effective masses of electrons and holes, the ratio between the number densities of holes and electrons, and electron volume plasma frequency) are used to evaluate charge transport and magnetic properties. These include static and dynamic conductivities, intrinsic mean free paths, the effective mass of charge carriers and their number densities, Fermi velocities and energies, densities of states at Fermi energies, mobilities, specific heats, Hall’s coefficient, thermal conductivities, charge carrier coupling constant, paramagnetic and diamagnetic susceptibilities, and the number of Bohr magnetons. In addition, optimized resonance energy values of the Lorentz contribution to the dielectric function were compared with the background information provided by density-functional-theory calculations for iridium. A decomposition of the energy loss function was used as the starting point to calculate the effective numbers of bound electrons involved in interband transitions, as well as the densities of states at the final energies of the sets of transitions considered. The Drude–Lorentz model involves charge carrier parameters for both electrons and holes, as well as the resonance energies correlating with the energies associated with quantum transitions. To a large extent, several physical quantities calculated from optimized parameters exhibit values close to those obtained from measurements or by applying other models, including quantum mechanics formulations.","PeriodicalId":87352,"journal":{"name":"Recent progress in materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44822104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An Interview with Prof. José Ignacio Álvarez Galindo","authors":"","doi":"10.21926/rpm.2203016","DOIUrl":"https://doi.org/10.21926/rpm.2203016","url":null,"abstract":"","PeriodicalId":87352,"journal":{"name":"Recent progress in materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42135322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We describe here the coherent formulation of electromagnetism in the non-relativistic quantum-mechanical many-body theory of interacting charged particles. We use the mathematical frame of the field theory and its quantization in the spirit of the quantum electrodynamics (QED). This is necessary because a manifold of misinterpretations emerged especially regarding the magnetic field and gauge invariance. The situation was determined by the historical development of quantum mechanics, starting from the Schrödinger equation of a single particle in the presence of given electromagnetic fields, followed by the many-body theories of many charged identical particles having just Coulomb interactions. Our approach to the non-relativistic QED emphasizes the role of the gauge-invariance and of the external fields. We develop further the approximation of this theory allowing a closed description of the interacting charged particles without photons. The resulting Hamiltonian coincides with the quantized version of the Darwin Hamiltonian containing besides the Coulomb also a current-current diamagnetic interaction. We show on some examples the importance of this extension of the many-body theory.
{"title":"About Non-relativistic Quantum Mechanics and Electromagnetism","authors":"Ladislaus Alexander B'anyai, M. Bundaru","doi":"10.21926/rpm.2204027","DOIUrl":"https://doi.org/10.21926/rpm.2204027","url":null,"abstract":"We describe here the coherent formulation of electromagnetism in the non-relativistic quantum-mechanical many-body theory of interacting charged particles. We use the mathematical frame of the field theory and its quantization in the spirit of the quantum electrodynamics (QED). This is necessary because a manifold of misinterpretations emerged especially regarding the magnetic field and gauge invariance. The situation was determined by the historical development of quantum mechanics, starting from the Schrödinger equation of a single particle in the presence of given electromagnetic fields, followed by the many-body theories of many charged identical particles having just Coulomb interactions. Our approach to the non-relativistic QED emphasizes the role of the gauge-invariance and of the external fields. We develop further the approximation of this theory allowing a closed description of the interacting charged particles without photons. The resulting Hamiltonian coincides with the quantized version of the Darwin Hamiltonian containing besides the Coulomb also a current-current diamagnetic interaction. We show on some examples the importance of this extension of the many-body theory.","PeriodicalId":87352,"journal":{"name":"Recent progress in materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42457613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. D. Grazia, C. Trottier, S. Dantas, Y. Nagaraju, R. Ziapour, Hian F Macedo, L. Sanchez
The ever-growing urgency to combat climate change has led the civil construction industry to develop and adopt sustainable construction materials and methods. The so-called recycled concrete aggregate (RCA) emerges as an alternative to decrease the carbon footprint of new concrete construction, the disposal of waste concrete, and the use of non-renewable natural resources such as cement and aggregates. RCA can be produced from crushing waste concrete; yet challenges remain when using RCA in concrete especially its fresh state behaviour due to its distinct multi-phase nature and microstructure (i.e., presence of residual mortar (RM)/residual cement paste (RCP)). In this context, this work presents a comprehensive study of the rheological behaviour of recycled concrete mixtures through the use of a planetary rheometer (IBB). The recycled mixtures were proportioned using the Equivalent Volume (EV) method, a mixture proportioning technique that accounts for the RM and RCP, respectively, and improves the recycled mixture's hardened state properties, incorporating distinct: 1) coarse RCA having various inner qualities (i.e., 25 MPa, 35 MPa and 45 MPa) and mineralogy (i.e., limestone and granite) and 2) fine RCA made from natural or manufactured sand while having different degrees of processing (i.e., crushed once vs continuously crushed). All recycled mixtures produced in this study present shear-thinning profiles, suggesting that these mixtures are suitable for applications under high torque regimes such as vibrated or pumped concrete. Additionally, they were produced with 100% recycled concrete aggregate (either fine or coarse RCA), classifying them as low embodied energy mixtures.
{"title":"Influence of Recycled Concrete Aggregate Type on Rheological Behaviour of Mixtures Proportioned Using the Equivalent Volume Method","authors":"M. D. Grazia, C. Trottier, S. Dantas, Y. Nagaraju, R. Ziapour, Hian F Macedo, L. Sanchez","doi":"10.21926/rpm.2203017","DOIUrl":"https://doi.org/10.21926/rpm.2203017","url":null,"abstract":"The ever-growing urgency to combat climate change has led the civil construction industry to develop and adopt sustainable construction materials and methods. The so-called recycled concrete aggregate (RCA) emerges as an alternative to decrease the carbon footprint of new concrete construction, the disposal of waste concrete, and the use of non-renewable natural resources such as cement and aggregates. RCA can be produced from crushing waste concrete; yet challenges remain when using RCA in concrete especially its fresh state behaviour due to its distinct multi-phase nature and microstructure (i.e., presence of residual mortar (RM)/residual cement paste (RCP)). In this context, this work presents a comprehensive study of the rheological behaviour of recycled concrete mixtures through the use of a planetary rheometer (IBB). The recycled mixtures were proportioned using the Equivalent Volume (EV) method, a mixture proportioning technique that accounts for the RM and RCP, respectively, and improves the recycled mixture's hardened state properties, incorporating distinct: 1) coarse RCA having various inner qualities (i.e., 25 MPa, 35 MPa and 45 MPa) and mineralogy (i.e., limestone and granite) and 2) fine RCA made from natural or manufactured sand while having different degrees of processing (i.e., crushed once vs continuously crushed). All recycled mixtures produced in this study present shear-thinning profiles, suggesting that these mixtures are suitable for applications under high torque regimes such as vibrated or pumped concrete. Additionally, they were produced with 100% recycled concrete aggregate (either fine or coarse RCA), classifying them as low embodied energy mixtures.","PeriodicalId":87352,"journal":{"name":"Recent progress in materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46417020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stable levitation of systems consisting of a magnetic source and a superconductor is actively investigated due to the promising applications of this technology. While huge efforts have been made for modeling these setups with numerical simulations, analytical models, in spite of their use being limited to devices with a high degree of symmetry, can bring precious information on certain characteristics of levitating systems. Summarizing our previous work in the field, we present the mean-field model that we have proposed to reproduce the interactions between a magnetic source and a superconductor. We show that the model provides an estimation of the surface critical current density of the shielding currents flowing in the superconductor and an estimation of the thickness, t, of the layer carrying the currents. We emphasize that the calculated values of t are an increasing function of temperature, which tend toward the Meissner limit at low temperatures. Finally, we determine the condition that ensures stable levitation of axisymmetric systems.
{"title":"Calculation of the Forces Applied to a Superconductor in Levitation in an Inhomogeneous Magnetic Field","authors":"P. Bernstein, Y. Xing, J. Noudem","doi":"10.21926/rpm.2203018","DOIUrl":"https://doi.org/10.21926/rpm.2203018","url":null,"abstract":"Stable levitation of systems consisting of a magnetic source and a superconductor is actively investigated due to the promising applications of this technology. While huge efforts have been made for modeling these setups with numerical simulations, analytical models, in spite of their use being limited to devices with a high degree of symmetry, can bring precious information on certain characteristics of levitating systems. Summarizing our previous work in the field, we present the mean-field model that we have proposed to reproduce the interactions between a magnetic source and a superconductor. We show that the model provides an estimation of the surface critical current density of the shielding currents flowing in the superconductor and an estimation of the thickness, t, of the layer carrying the currents. We emphasize that the calculated values of t are an increasing function of temperature, which tend toward the Meissner limit at low temperatures. Finally, we determine the condition that ensures stable levitation of axisymmetric systems.","PeriodicalId":87352,"journal":{"name":"Recent progress in materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46648250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Glass ionomer cements (GICs) are dental materials that were invented by Wilson & Kent in 1972. They can chemically bond to enamel and dentin and can exhibit anti-cariogenic activity that allows the release and uptake of fluoride ions. They also possess the ability to render color. The setting reaction of GICs is a neutralization reaction that results in the formation of polycarboxylate salts. The most important GIC modification process involves the addition of resin components, resulting in the development of resin-modified glass ionomer cements (RMGICs), which contain self-and photo-curing systems. Modification of conventional GICs and RMGICs can be achieved by the incorporation of nano-sized fillers into the materials. This helps reduce the size of RMGICs. Conventional GICs and RMGICs can also be modified by introducing nano-sized bioceramics to the glass powder. It has been previously reported that the incorporation of nano-sized particles helps improve the mechanical properties of conventional GICs. Conversely, the commercially available nano-filled RMGICs do not hold any significant advantage over conventional RMGICs as far as the mechanical and adhesive properties are concerned. Glass carbomer is a novel glass ionomer material, and the bioactivity of which is better than the bioactivity of the conventional GICs. However, it is more brittle and less strong than the modern conventional GICs. Additionally, clinical techniques that can be used to transfer external energy on the surface of a GIC have also been used for modification. These techniques can be used to reduce the duration of the initial setting stage and improve the rate of the setting reactions, resulting in faster development of the mechanical properties. Premature failure of the restorations can be avoided under these conditions. The lack of long-term clinical studies limits the use of nano-modified glass ionomers and glass carbomers in daily clinical practice. More randomized clinical trials are required to justify the use of these modern modified materials.
{"title":"Modifications of Glass Ionomer Cements Using Nanotechnology: Recent Advances","authors":"D. Dionysopoulos, O. Gerasimidou, C. Papadopoulos","doi":"10.21926/rpm.2202011","DOIUrl":"https://doi.org/10.21926/rpm.2202011","url":null,"abstract":"Glass ionomer cements (GICs) are dental materials that were invented by Wilson & Kent in 1972. They can chemically bond to enamel and dentin and can exhibit anti-cariogenic activity that allows the release and uptake of fluoride ions. They also possess the ability to render color. The setting reaction of GICs is a neutralization reaction that results in the formation of polycarboxylate salts. The most important GIC modification process involves the addition of resin components, resulting in the development of resin-modified glass ionomer cements (RMGICs), which contain self-and photo-curing systems. Modification of conventional GICs and RMGICs can be achieved by the incorporation of nano-sized fillers into the materials. This helps reduce the size of RMGICs. Conventional GICs and RMGICs can also be modified by introducing nano-sized bioceramics to the glass powder. It has been previously reported that the incorporation of nano-sized particles helps improve the mechanical properties of conventional GICs. Conversely, the commercially available nano-filled RMGICs do not hold any significant advantage over conventional RMGICs as far as the mechanical and adhesive properties are concerned. Glass carbomer is a novel glass ionomer material, and the bioactivity of which is better than the bioactivity of the conventional GICs. However, it is more brittle and less strong than the modern conventional GICs. Additionally, clinical techniques that can be used to transfer external energy on the surface of a GIC have also been used for modification. These techniques can be used to reduce the duration of the initial setting stage and improve the rate of the setting reactions, resulting in faster development of the mechanical properties. Premature failure of the restorations can be avoided under these conditions. The lack of long-term clinical studies limits the use of nano-modified glass ionomers and glass carbomers in daily clinical practice. More randomized clinical trials are required to justify the use of these modern modified materials.","PeriodicalId":87352,"journal":{"name":"Recent progress in materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46020094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. John, Svenja Rink, Leandra Weidemann, K. Huesker, W. Niedermeier
Combining dental ceramics with other prosthetic metallic restorations might release metal ions, thus affecting the oral tissues of the patients. In this study, we evaluated the electrochemical solubility of various dental ceramics in a galvanic experimental setup in vitro. Smooth and rough feldspathic and zirconium dioxide ceramics (at pH 5.5 and pH 3.0) were exposed to an electric field. Calcium, barium, and zirconium were selected as parameters to determine the solubility of both types of ceramic materials. Among all test groups, feldspathic ceramics were more soluble than zirconium dioxide ceramics at low pH. The results indicated that the solubility of zirconium dioxide was not significantly affected by the presence of an electric field, although the solubility was higher when the pH was relatively lower. The feldspathic material had a higher sensitivity to acids and electrogalvanic processes. We found that the galvanic process increases the solubility of feldspathic ceramics. The surface quality is important in an acidic medium, especially for feldspathic ceramics. Zirconium dioxide ceramics are more resistant to an acidic medium and exposure to a clinically relevant electric field.
{"title":"Solubility of Dental Ceramics in Electric Fields","authors":"S. John, Svenja Rink, Leandra Weidemann, K. Huesker, W. Niedermeier","doi":"10.21926/rpm.2202012","DOIUrl":"https://doi.org/10.21926/rpm.2202012","url":null,"abstract":"Combining dental ceramics with other prosthetic metallic restorations might release metal ions, thus affecting the oral tissues of the patients. In this study, we evaluated the electrochemical solubility of various dental ceramics in a galvanic experimental setup in vitro. Smooth and rough feldspathic and zirconium dioxide ceramics (at pH 5.5 and pH 3.0) were exposed to an electric field. Calcium, barium, and zirconium were selected as parameters to determine the solubility of both types of ceramic materials. Among all test groups, feldspathic ceramics were more soluble than zirconium dioxide ceramics at low pH. The results indicated that the solubility of zirconium dioxide was not significantly affected by the presence of an electric field, although the solubility was higher when the pH was relatively lower. The feldspathic material had a higher sensitivity to acids and electrogalvanic processes. We found that the galvanic process increases the solubility of feldspathic ceramics. The surface quality is important in an acidic medium, especially for feldspathic ceramics. Zirconium dioxide ceramics are more resistant to an acidic medium and exposure to a clinically relevant electric field.","PeriodicalId":87352,"journal":{"name":"Recent progress in materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45831530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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