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Seong H. Kim - One of the best experts on this subject based on the ideXlab platform.
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characterization of surface structures of dealkalized soda lime silica Glass using x ray photoelectron specular reflection infrared attenuated total reflection infrared and sum frequency generation spectroscopies
Journal of Non-crystalline Solids, 2017Co-Authors: Nisha Sheth, Carlo G. Pantano, Jiawei Luo, Joy Banerjee, Seong H. KimAbstract:Abstract This paper reports a comprehensive spectroscopic characterization of soda lime silica (SLS) Glass surfaces with various thermal histories and dealkalization chemical treatments. While many studies have investigated elemental composition changes after dealkalization treatments, the work reported here focuses on identification and quantification of the associated structural changes in terms of non-bridging oxygen (NBO), bridging oxygen (BO) and hydrous species (Si OH and H 2 O). X-ray photoelectron spectroscopy (XPS) was used to determine the average areal densities of BOs, NBOs, and OH groups at the top 10 nm of the surface. Specular reflection infrared (SR-IR) spectroscopy was used to probe the Si O Si asymmetric stretch vibration mode of the silicate network of the top
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Effects of fictive temperature on the leaching of soda lime silica Glass surfaces
Journal of the American Ceramic Society, 2017Co-Authors: Shin-ichi Amma, Seong H. Kim, Jiawei Luo, Carlo G. PantanoAbstract:The fictive temperature of Glass characterizes the Glass network structure and its thermal history, and thereby can influence ion and water transport in the Glass surface. In this study, IR specular reflectance (SR), refractive index, and density measurements were used to characterize and confirm the effects of Glass sample processing, especially the fictive temperature/thermal-history variations. The subsequent acid leaching of these Glasses created leached surface layers due to interdiffusion and reaction of hydrous species in the surface; the hydrogen depth profiles obtained with secondary ion mass spectrometry (SIMS) confirmed enhanced leaching with increasing fictive temperature. Attenuated total reflectance (ATR) in the mid- and near-IR indicated increases in both SiOH and H2O species with increasing fictive temperature. The relative intensities and shapes of the ATR peaks were found to vary between the samples suggesting that speciation of the hydrous reaction products (eg, strong and weakly hydrogen-bonded OH) is also influenced by the original fictive temperature of the Glass, but could not be quantitatively determined.
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hydrothermal reactions of soda lime silica Glass revealing subsurface damage and alteration of mechanical properties and chemical structure of Glass surfaces
Journal of Non-crystalline Solids, 2016Co-Authors: Jiawei Luo, Carlo G. Pantano, Hoang Huynh, Seong H. KimAbstract:Abstract Hydrothermal treatment provides a unique way to reveal subsurface damage of soda lime silica (SLS) float Glass. During the hydrothermal treatment, the penetration of water, ion-exchange, and hydrolysis reaction can take place. These reactions are accelerated at locations where subsurface damage exists. Interestingly, the hydrothermally-treated Glass surface exhibits higher fracture toughness, lower hardness, and less resistance to mechanochemical wear at high humidity compared to the pristine SLS float Glass. These property changes can be explained by the leaching and polymerization of the silicate network and the chemical environment of hydrous species in the surface region of SLS Glass.
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thermal poling of soda lime silica Glass with nonblocking electrodes part 2 effects on mechanical and mechanochemical properties
Journal of the American Ceramic Society, 2016Co-Authors: Jiawei Luo, Linmao Qian, Carlo G. Pantano, Seong H. KimAbstract:The mechanical and mechanochemical properties of soda lime silica (SLS) Glass surfaces can vary with the sodium ion (Na+) concentration in the subsurface region. Changes in these properties were studied upon modification of Na+ concentrations in the SLS Glass by thermal poling. In Part-1, it is found that the Na+-depleted and Na+-gradient layers could be formed at the anode and cathode sides, respectively. Here in Part-2, we show that Na+ ions play a pivotal role in the mechanochemical wear property upon lateral shear stress. The Na+-depleted Glass wear more readily as relative humidity (RH) increases, while Na+-gradient Glass becomes resistant to wear at high RH. It is also found that the Na+-gradient Glass surface has a higher elastic modulus and hardness with very little change in fracture toughness compared to the pristine surface. The Na+-depleted Glass surface shows a lower elastic modulus and hardness; but its fracture toughness is significantly improved, which might be due to a larger densification capacity of Na+-depleted layer.
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thermal poling of soda lime silica Glass with nonblocking electrodes part 1 effects of sodium ion migration and water ingress on Glass surface structure
Journal of the American Ceramic Society, 2016Co-Authors: Jiawei Luo, Linmao Qian, Carlo G. Pantano, Nikolas J Podraza, Seong H. KimAbstract:It is generally well known that not only the sodium itself, but also the non-bridging oxygen (NBO) sites associated with sodium ions are largely responsible for the surface reactivity of Soda-Lime-Silica (SLS) Glass. Thermal poling can modify the distribution of sodium in the subsurface region. In this work, a commercial SLS float Glass was thermally poled using nonblocking electrodes in air. The Na+−depleted anode surface and the Na+−gradient cathode surface were characterized using a variety of methods to find the compositional, structural and morphological effects of thermal poling. Of particular significance is the use of nondestructive vibrational spectroscopy methods, which can lead to new and improved understanding of water interactions with sodium and its sites in the Glass. It was found that during thermal poling, the Na+−depleted Glass network on the anode side undergoes condensation reactions of NBO sites accompanied by the increase in concentrations of silanol (SiOH) groups and molecular water species. In contrast, silanol and water species do not increase and the silicate network change is negligible in the Na+−gradient cathode side. Vibrational sum frequency generation (SFG) spectroscopy analysis revealed the difference in distributions of hydrous species in the Na+−depleted and Na+−gradient surfaces. The structural information of the thermally-poled surfaces provides critical insights needed to understand the mechanical and mechanochemical properties of the Na+−concentration modified SLS Glass surfaces reported in the Part 2 companion paper.
Eric Huysecom - One of the best experts on this subject based on the ideXlab platform.
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A Phoenician Glass eye bead from 7th–5th c. cal BCE Nin-Bèrè 3, Mali: Compositional characterisation by LA–ICP–MS
Journal of Archaeological Science: Reports, 2019Co-Authors: Miriam Truffa Giachet, Bernard Gratuze, Sylvain Ozainne, Anne Mayor, Eric HuysecomAbstract:The so-called Phoenician or Punic eye beads are a well-known type of Glass artefacts circulating all over the Mediterranean Basin and Europe for most of the 1st millennium BCE. Glass beads were mostly produced in secondary workshops from imported raw Glass or recycled artefacts but the specific sites of manufacture remain difficult to locate. Nevertheless, numerous chemical studies of Glass from the area of interest proved that natron-based Soda-Lime-Silica Glass was the most widespread from 10th–9th century BCE to 8th–9th century CE. A Glass eye bead typologically consistent with the Phoenician ones was unearthed during the archaeological excavation of the Nin-Bèrè 3 settlement site in Mali in a context dating between the 7th and the 5th centuries cal BCE. The chemical analysis by means of Laser Ablation – Inductively Coupled Plasma – Mass Spectrometry (LA–ICP–MS) has been carried out in order to confirm the characteristic composition of Mediterranean Iron Age Glass. Results show the bead to be soda-lime silica Glass fluxed with mineral soda, and coloured and opacified with cobalt, copper, and antimony. The minor and trace elements are also consistent with said composition. This exceptional find this far south expands greatly the area of distribution of these artefacts and it suggests a very early indirect contact between sub-Saharan Africa and the Mediterranean Basin. At the current state of research, this is the most ancient Glass bead found south of the Sahara desert.
Kyuseog Hwang - One of the best experts on this subject based on the ideXlab platform.
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photoluminescence of zno layer on commercial Glass substrate prepared by sol gel process
Ceramics International, 2008Co-Authors: Seung Hwangbo, Kyuseog HwangAbstract:Abstract Amorphous ZnO thin film on soda–lime–silica Glass substrate was prepared by the sol–gel process at low-temperature processing, i.e., 100 °C. No distinct grain structure was observable in the surface of the film. The photoluminescence spectrum of the ZnO thin film with an intense near band edge emission was observed while the defect-related broad green emission was nearly quenched.
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hydrophilic hydrophobic conversion of ni doped tio2 thin films on Glass substrates
Ceramics International, 2006Co-Authors: Kyuseog Hwang, Juhyun Jeong, Junhyung Ahn, Byunghoon KimAbstract:Abstract Nickel-doped titanium oxide thin films were prepared on soda–lime–silica Glass substrates by using a metal naphthenate. Films prefired at 500 °C for 10 min were finally annealed at 600 °C for 30 min in air. Contact angle measurement was used for analyzing hydrophilic/hydrophobic conversion. NiTiO 3 , rutile and anatase peaks were obtained for the film after nickel doping. The film containing nickel showed a shift towards the visible in the absorption threshold.
Carlo G. Pantano - One of the best experts on this subject based on the ideXlab platform.
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characterization of surface structures of dealkalized soda lime silica Glass using x ray photoelectron specular reflection infrared attenuated total reflection infrared and sum frequency generation spectroscopies
Journal of Non-crystalline Solids, 2017Co-Authors: Nisha Sheth, Carlo G. Pantano, Jiawei Luo, Joy Banerjee, Seong H. KimAbstract:Abstract This paper reports a comprehensive spectroscopic characterization of soda lime silica (SLS) Glass surfaces with various thermal histories and dealkalization chemical treatments. While many studies have investigated elemental composition changes after dealkalization treatments, the work reported here focuses on identification and quantification of the associated structural changes in terms of non-bridging oxygen (NBO), bridging oxygen (BO) and hydrous species (Si OH and H 2 O). X-ray photoelectron spectroscopy (XPS) was used to determine the average areal densities of BOs, NBOs, and OH groups at the top 10 nm of the surface. Specular reflection infrared (SR-IR) spectroscopy was used to probe the Si O Si asymmetric stretch vibration mode of the silicate network of the top
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Effects of fictive temperature on the leaching of soda lime silica Glass surfaces
Journal of the American Ceramic Society, 2017Co-Authors: Shin-ichi Amma, Seong H. Kim, Jiawei Luo, Carlo G. PantanoAbstract:The fictive temperature of Glass characterizes the Glass network structure and its thermal history, and thereby can influence ion and water transport in the Glass surface. In this study, IR specular reflectance (SR), refractive index, and density measurements were used to characterize and confirm the effects of Glass sample processing, especially the fictive temperature/thermal-history variations. The subsequent acid leaching of these Glasses created leached surface layers due to interdiffusion and reaction of hydrous species in the surface; the hydrogen depth profiles obtained with secondary ion mass spectrometry (SIMS) confirmed enhanced leaching with increasing fictive temperature. Attenuated total reflectance (ATR) in the mid- and near-IR indicated increases in both SiOH and H2O species with increasing fictive temperature. The relative intensities and shapes of the ATR peaks were found to vary between the samples suggesting that speciation of the hydrous reaction products (eg, strong and weakly hydrogen-bonded OH) is also influenced by the original fictive temperature of the Glass, but could not be quantitatively determined.
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hydrothermal reactions of soda lime silica Glass revealing subsurface damage and alteration of mechanical properties and chemical structure of Glass surfaces
Journal of Non-crystalline Solids, 2016Co-Authors: Jiawei Luo, Carlo G. Pantano, Hoang Huynh, Seong H. KimAbstract:Abstract Hydrothermal treatment provides a unique way to reveal subsurface damage of soda lime silica (SLS) float Glass. During the hydrothermal treatment, the penetration of water, ion-exchange, and hydrolysis reaction can take place. These reactions are accelerated at locations where subsurface damage exists. Interestingly, the hydrothermally-treated Glass surface exhibits higher fracture toughness, lower hardness, and less resistance to mechanochemical wear at high humidity compared to the pristine SLS float Glass. These property changes can be explained by the leaching and polymerization of the silicate network and the chemical environment of hydrous species in the surface region of SLS Glass.
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elemental areal density calculation and oxygen speciation for flat Glass surfaces using x ray photoelectron spectroscopy
Journal of Non-crystalline Solids, 2016Co-Authors: Joy Banerjee, Carlo G. PantanoAbstract:Abstract The elemental composition of multi-component Glass surfaces is often insufficient for understanding the effects of surface treatments on properties. For this reason, a data analysis protocol has been developed to quantify the areal density of elements and to determine the oxygen speciation on Glass surfaces by X-ray photoelectron spectroscopy (XPS) for flat Glass surfaces on which other methods such as optical spectroscopy and thermal analysis cannot be applied due to their low surface area, surface contamination, insufficient signal, etc. Various oxygen species (hydroxyls, non-bridging oxygen, and bridging oxygen) are distinguished and quantified using a simple workflow involving the determination of accurate elemental relative sensitivity factors, adventitious hydrocarbon contamination correction, and the conversion of the corrected elemental Glass composition to areal elemental density. The areal density of oxygen species is obtained by a standard Glass model based stoichiometry approach and compared with a constrained peak fitting of the O 1s photoelectron spectrum. The data analytical protocol is first verified with a silica Glass, and then applied to pristine re-melt surfaces and acid-leached surfaces of commercial multi-component silicate Glasses. XPS analysis revealed that upon leaching, significant repolymerization of network oxygen is observed in the calcium aluminosilicate Glass surface in contrast to the lack of restructuring in the soda-lime silica Glass surface.
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thermal poling of soda lime silica Glass with nonblocking electrodes part 2 effects on mechanical and mechanochemical properties
Journal of the American Ceramic Society, 2016Co-Authors: Jiawei Luo, Linmao Qian, Carlo G. Pantano, Seong H. KimAbstract:The mechanical and mechanochemical properties of soda lime silica (SLS) Glass surfaces can vary with the sodium ion (Na+) concentration in the subsurface region. Changes in these properties were studied upon modification of Na+ concentrations in the SLS Glass by thermal poling. In Part-1, it is found that the Na+-depleted and Na+-gradient layers could be formed at the anode and cathode sides, respectively. Here in Part-2, we show that Na+ ions play a pivotal role in the mechanochemical wear property upon lateral shear stress. The Na+-depleted Glass wear more readily as relative humidity (RH) increases, while Na+-gradient Glass becomes resistant to wear at high RH. It is also found that the Na+-gradient Glass surface has a higher elastic modulus and hardness with very little change in fracture toughness compared to the pristine surface. The Na+-depleted Glass surface shows a lower elastic modulus and hardness; but its fracture toughness is significantly improved, which might be due to a larger densification capacity of Na+-depleted layer.
Linmao Qian - One of the best experts on this subject based on the ideXlab platform.
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thermal poling of soda lime silica Glass with nonblocking electrodes part 2 effects on mechanical and mechanochemical properties
Journal of the American Ceramic Society, 2016Co-Authors: Jiawei Luo, Linmao Qian, Carlo G. Pantano, Seong H. KimAbstract:The mechanical and mechanochemical properties of soda lime silica (SLS) Glass surfaces can vary with the sodium ion (Na+) concentration in the subsurface region. Changes in these properties were studied upon modification of Na+ concentrations in the SLS Glass by thermal poling. In Part-1, it is found that the Na+-depleted and Na+-gradient layers could be formed at the anode and cathode sides, respectively. Here in Part-2, we show that Na+ ions play a pivotal role in the mechanochemical wear property upon lateral shear stress. The Na+-depleted Glass wear more readily as relative humidity (RH) increases, while Na+-gradient Glass becomes resistant to wear at high RH. It is also found that the Na+-gradient Glass surface has a higher elastic modulus and hardness with very little change in fracture toughness compared to the pristine surface. The Na+-depleted Glass surface shows a lower elastic modulus and hardness; but its fracture toughness is significantly improved, which might be due to a larger densification capacity of Na+-depleted layer.
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thermal poling of soda lime silica Glass with nonblocking electrodes part 1 effects of sodium ion migration and water ingress on Glass surface structure
Journal of the American Ceramic Society, 2016Co-Authors: Jiawei Luo, Linmao Qian, Carlo G. Pantano, Nikolas J Podraza, Seong H. KimAbstract:It is generally well known that not only the sodium itself, but also the non-bridging oxygen (NBO) sites associated with sodium ions are largely responsible for the surface reactivity of Soda-Lime-Silica (SLS) Glass. Thermal poling can modify the distribution of sodium in the subsurface region. In this work, a commercial SLS float Glass was thermally poled using nonblocking electrodes in air. The Na+−depleted anode surface and the Na+−gradient cathode surface were characterized using a variety of methods to find the compositional, structural and morphological effects of thermal poling. Of particular significance is the use of nondestructive vibrational spectroscopy methods, which can lead to new and improved understanding of water interactions with sodium and its sites in the Glass. It was found that during thermal poling, the Na+−depleted Glass network on the anode side undergoes condensation reactions of NBO sites accompanied by the increase in concentrations of silanol (SiOH) groups and molecular water species. In contrast, silanol and water species do not increase and the silicate network change is negligible in the Na+−gradient cathode side. Vibrational sum frequency generation (SFG) spectroscopy analysis revealed the difference in distributions of hydrous species in the Na+−depleted and Na+−gradient surfaces. The structural information of the thermally-poled surfaces provides critical insights needed to understand the mechanical and mechanochemical properties of the Na+−concentration modified SLS Glass surfaces reported in the Part 2 companion paper.
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Effects of contact pressure, counter-surface and humidity on wear of Soda-Lime-Silica Glass at nanoscale
Tribology International, 2016Co-Authors: Hongtu He, Seong H. Kim, Linmao QianAbstract:The nanoscale friction and wear behaviors of Soda-Lime-Silica (SLS) Glass were studied using atomic force microscopy (AFM) with diamond (inert) and silica (reactive) tips in dry and humid environments. Depending on the contact pressure, counter-surface chemistry, and humidity, three distinct wear regimes were identified: mechanical wear, stress corrosion, and tribochemical wear. The mechanisms of material removal at these three wear regimes were proposed. These results provided insights into mechanical and mechanochemical wear mechanisms of the SLS Glass at nanoscale, which will be useful to optimize tribological designs of functional and engineering Glasses.
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effects of humidity and counter surface on tribochemical wear of soda lime silica Glass
Wear, 2015Co-Authors: Linmao Qian, Carlo G. Pantano, Seong H. KimAbstract:Abstract The effects of counter-surface chemistry on the friction and wear of Soda-Lime-Silica Glass were investigated using a ball-on-flat tribometer with various ball materials (stainless steel, silicon nitride, and alumina) in dry and humid environments. It was found that the interfacial wear was very sensitive to environmental humidity and counter-surface chemistry. In dry conditions, soda-lime Glass was damaged mechanically regardless of counter-surface materials, creating a rough and deep wear track. These results were consistent with the Archard relationship—a softer material would wear mechanically by a harder material. However, in humid conditions, the ball materials that were harder than the soda-lime Glass were damaged. Thus, the wear of Glass interfaces under humid conditions does not follow the Archard relationship. These results clearly show that the tribochemical reactions involving the substrate and counter-surface chemistry as well as the adsorbed water molecules are determining factors governing wear behaviors in humid environments.
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mechanochemical wear of soda lime silica Glass in humid environments
Journal of the American Ceramic Society, 2014Co-Authors: Linmao Qian, Carlo G. Pantano, Seong H. KimAbstract:The mechanochemical wear of multicomponent Glasses was studied under controlled humidity conditions using a reciprocating ball-on-flat tribometer. For dry conditions, the surfaces were extensively damaged by scratching for all of the Glasses, while for humid conditions the wear behavior varied with the Glass composition suggesting a chemical effect on scratch behaviors of Glass surfaces. The wear of soda lime silica (also called sodium calcium silicate) Glass was suppressed with increasing humidity, while the borosilicate and barium boroaluminosilicate Glasses showed an increase in wear volume with increasing humidity. The unique humidity dependence of the observed mechanochemical wear of soda lime silica Glass supports the hypothesis that hydronium ion formation in the sodium-leached sites of the soda lime Glass enhances its wear resistance.