Siyanand Kumar Chaudhary, Nabina Chaudhary, R. Chaudhary, N. Chaudhary
The COVID-19 pandemic caused by SARS-CoV-2 has become a global public health concern. Recently, vaccines have been developed to treat this infectious disease. However, these newly developed vaccines are not widely available and not suitable for all age groups. In such circumstances, it is wise to wear personal protective equipment (PPE) such as masks, gloves, and gowns to better protect against COVID-19. Face masks have long been recommended as a means of preventing respiratory infections. However, inappropriate use of masks may undermine their effectiveness. The antimicrobial and antiviral properties of graphene have sparked interest in the development of medical devices such as face masks, gloves, and gowns with extra filtering ability to curb the effects of the coronaviruses. Their hydrophobicity, nanosize, large surface area, high electrical and thermal conductivities, and virulence are notable features that reduce the transmission of viruses from person to person via respiratory routes. Graphene-enhanced face masks are intended to encourage travelers to wear them at work and during recreational activities. Moreover, graphene can pose health hazards if inhaled during respiration. In this review, we summarize the current status of graphene and its promising applications for combating COVID-19. Additionally, this review aims to explore the quality of this biomaterial and possible suggestions for the better and safer use of graphene structured respirators.
{"title":"Review on benefits, toxicity, challenges, and future of graphene-based face masks in the prevention of COVID-19 pandemic","authors":"Siyanand Kumar Chaudhary, Nabina Chaudhary, R. Chaudhary, N. Chaudhary","doi":"10.7717/peerj-matsci.20","DOIUrl":"https://doi.org/10.7717/peerj-matsci.20","url":null,"abstract":"The COVID-19 pandemic caused by SARS-CoV-2 has become a global public health concern. Recently, vaccines have been developed to treat this infectious disease. However, these newly developed vaccines are not widely available and not suitable for all age groups. In such circumstances, it is wise to wear personal protective equipment (PPE) such as masks, gloves, and gowns to better protect against COVID-19. Face masks have long been recommended as a means of preventing respiratory infections. However, inappropriate use of masks may undermine their effectiveness. The antimicrobial and antiviral properties of graphene have sparked interest in the development of medical devices such as face masks, gloves, and gowns with extra filtering ability to curb the effects of the coronaviruses. Their hydrophobicity, nanosize, large surface area, high electrical and thermal conductivities, and virulence are notable features that reduce the transmission of viruses from person to person via respiratory routes. Graphene-enhanced face masks are intended to encourage travelers to wear them at work and during recreational activities. Moreover, graphene can pose health hazards if inhaled during respiration. In this review, we summarize the current status of graphene and its promising applications for combating COVID-19. Additionally, this review aims to explore the quality of this biomaterial and possible suggestions for the better and safer use of graphene structured respirators.","PeriodicalId":219314,"journal":{"name":"PeerJ Materials Science","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133804079","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}
Zhihui Han, Wenjuan Liu, Yang Sun, Qianrong Zhou, Yue Zhao, Jian Sun, B. Zhu, Youcheng Yu
The NOVARON, a silver-based antimicrobial agent derived from inorganic ion exchangers developed by Toagosei and registered by FDA, has effectively indicated the antimicrobial power of silver against a variety of microbes. The objective of this study was to investigate the effect of a silver-supported material (Novaron (N)) on the mechanical behaviour, antimicrobial properties, cytotoxicity and colour of light-cured resin composites. Silanized aluminum borate whisker (ABWs) (4 wt%) and nano-zirconia (nano-ZrO2) (2 wt%) were mixed with the resin matrix to obtain the control groups; 4 wt% surface-modified Novaron particles were incorporated into the above matrices as the experimental groups. The surface hardness was tested. Furthermore, the antimicrobial abilities evaluated in vitro with Streptococcus mutans (S. mutans), Fusobacterium nucleatum (F. nucleatum) and Candida albicans (C. albicans) using the live/dead, MTT and colony-forming units (CFUs) assay. Furthermore, the effects on fibroblast growth and colour were test in this study. The data of the Novaron and control groups were analyzed by Student’s t-test. The results showed that the activities of S. mutans, F. nucleatum and C. albicans biofilms on the composites surface were greatly reduced (p < 0.05) and no significant difference was found in the culture medium (p > 0.05). Extracts taken from the cell culture medium of the specimens were used to evaluate cell viability. The composites did not have an adverse effect on fibroblast growth and colour in this study. The results showed that 4 wt% Novaron incorporated into the resin composites could increase the surface hardness (p < 0.05). Therefore, Novaron is a potential antimicrobial agent applying in light-cured and inorganic nanoparticles reinforced dental resin materials.
{"title":"Antimicrobial properties, cytotoxicity, colour and mechanical behavior of light-cured resin composites containing modified Novaron","authors":"Zhihui Han, Wenjuan Liu, Yang Sun, Qianrong Zhou, Yue Zhao, Jian Sun, B. Zhu, Youcheng Yu","doi":"10.7717/peerj-matsci.19","DOIUrl":"https://doi.org/10.7717/peerj-matsci.19","url":null,"abstract":"\u0000\u0000The NOVARON, a silver-based antimicrobial agent derived from inorganic ion exchangers developed by Toagosei and registered by FDA, has effectively indicated the antimicrobial power of silver against a variety of microbes. The objective of this study was to investigate the effect of a silver-supported material (Novaron (N)) on the mechanical behaviour, antimicrobial properties, cytotoxicity and colour of light-cured resin composites.\u0000\u0000\u0000\u0000Silanized aluminum borate whisker (ABWs) (4 wt%) and nano-zirconia (nano-ZrO2) (2 wt%) were mixed with the resin matrix to obtain the control groups; 4 wt% surface-modified Novaron particles were incorporated into the above matrices as the experimental groups. The surface hardness was tested. Furthermore, the antimicrobial abilities evaluated in vitro with Streptococcus mutans (S. mutans), Fusobacterium nucleatum (F. nucleatum) and Candida albicans (C. albicans) using the live/dead, MTT and colony-forming units (CFUs) assay. Furthermore, the effects on fibroblast growth and colour were test in this study.\u0000\u0000\u0000\u0000The data of the Novaron and control groups were analyzed by Student’s t-test. The results showed that the activities of S. mutans, F. nucleatum and C. albicans biofilms on the composites surface were greatly reduced (p < 0.05) and no significant difference was found in the culture medium (p > 0.05). Extracts taken from the cell culture medium of the specimens were used to evaluate cell viability. The composites did not have an adverse effect on fibroblast growth and colour in this study. The results showed that 4 wt% Novaron incorporated into the resin composites could increase the surface hardness (p < 0.05). Therefore, Novaron is a potential antimicrobial agent applying in light-cured and inorganic nanoparticles reinforced dental resin materials.\u0000","PeriodicalId":219314,"journal":{"name":"PeerJ Materials Science","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125870409","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}
Respiratory protection devices such as face masks and respirators minimize the transmission of infectious diseases by providing a physical barrier to respiratory virus particles. The level of protection from a face mask and respirator depends on the nature of filter material, the size of infectious particle, breathing and environmental conditions, facial seal, and user compliance. The ongoing COVID‒19 pandemic has resulted in the global shortage of surgical face mask and respirator. In such a situation, significant global populations have either reused the single‒use face mask and respirator or used a substandard face mask fabricated from locally available materials. At the same time, researchers are actively exploring filter materials having novel functionalities such as antimicrobial, enhanced charge holding, and heat regulating properties to design potentially better face mask. In this work, we reviewed research papers and guidelines published primarily in last decade focusing on, (a) virus filtering efficiency, (b) impact of type of filter material on filtering efficiency, (c) emerging technologies in mask design, and (d) decontamination approaches. Finally, we provide future prospective on the need of novel filter materials and improved design.
{"title":"Review of materials and testing methods for virus filtering performance of face mask and respirator","authors":"B. Neupane, Basant Giri","doi":"10.7717/peerj-matsci.17","DOIUrl":"https://doi.org/10.7717/peerj-matsci.17","url":null,"abstract":"Respiratory protection devices such as face masks and respirators minimize the transmission of infectious diseases by providing a physical barrier to respiratory virus particles. The level of protection from a face mask and respirator depends on the nature of filter material, the size of infectious particle, breathing and environmental conditions, facial seal, and user compliance. The ongoing COVID‒19 pandemic has resulted in the global shortage of surgical face mask and respirator. In such a situation, significant global populations have either reused the single‒use face mask and respirator or used a substandard face mask fabricated from locally available materials. At the same time, researchers are actively exploring filter materials having novel functionalities such as antimicrobial, enhanced charge holding, and heat regulating properties to design potentially better face mask. In this work, we reviewed research papers and guidelines published primarily in last decade focusing on, (a) virus filtering efficiency, (b) impact of type of filter material on filtering efficiency, (c) emerging technologies in mask design, and (d) decontamination approaches. Finally, we provide future prospective on the need of novel filter materials and improved design.","PeriodicalId":219314,"journal":{"name":"PeerJ Materials Science","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131759267","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}
TiO2 nanoparticles were successfully synthesized by the sol-gel method employing different glycols (ethylene glycol, diethylene glycol or polyethylene glycol 300), which were heat-treated in conventional oven or by hydrothermal via, obtaining photocatalysts with particle sizes and distinct crystalline structures. HRTEM analyses showed that the oxides submitted to hydrothermal treatment featured spherical morphology, being formed by partially aggregated particles with sizes varying between 2 and 5 nm. X-ray diffractograms and Raman spectroscopy confirm that anatase was predominant in all synthesized compounds, with presence of brookite phase for samples that received hydrothermal treatment or were synthesized in the presence of polyethylene glycol with heat treatment in conventional oven. The amount of brookite as well as the cell volume, deformation, network parameters and crystallinity were estimated by Rietveld refinement. The surface area and porosity of the materials were higher when the synthesis involved the use of hydrothermal treatment. These oxides are mesoporous with porosity between 14 and 31%. The oxide synthesized in the presence of ethylene glycol with hydrothermal thermal treatment (TiO2G1HT) exhibited the highest photocatalytic activity in terms of mineralization of azo-dye Ponceau 4R (C.I. 16255), under UV-Vis irradiation. This higher photocatalytic activity can be attributed to the formation of binary oxides composed by anatase and brookite and by its optimized morphological and electronic properties.
{"title":"Synthesis of nano-TiO2 assisted by glycols and submitted to hydrothermal or conventional heat treatment with promising photocatalytic activity","authors":"L. Santos, A. Machado","doi":"10.7717/PEERJ-MATSCI.13","DOIUrl":"https://doi.org/10.7717/PEERJ-MATSCI.13","url":null,"abstract":"TiO2 nanoparticles were successfully synthesized by the sol-gel method employing different glycols (ethylene glycol, diethylene glycol or polyethylene glycol 300), which were heat-treated in conventional oven or by hydrothermal via, obtaining photocatalysts with particle sizes and distinct crystalline structures. HRTEM analyses showed that the oxides submitted to hydrothermal treatment featured spherical morphology, being formed by partially aggregated particles with sizes varying between 2 and 5 nm. X-ray diffractograms and Raman spectroscopy confirm that anatase was predominant in all synthesized compounds, with presence of brookite phase for samples that received hydrothermal treatment or were synthesized in the presence of polyethylene glycol with heat treatment in conventional oven. The amount of brookite as well as the cell volume, deformation, network parameters and crystallinity were estimated by Rietveld refinement. The surface area and porosity of the materials were higher when the synthesis involved the use of hydrothermal treatment. These oxides are mesoporous with porosity between 14 and 31%. The oxide synthesized in the presence of ethylene glycol with hydrothermal thermal treatment (TiO2G1HT) exhibited the highest photocatalytic activity in terms of mineralization of azo-dye Ponceau 4R (C.I. 16255), under UV-Vis irradiation. This higher photocatalytic activity can be attributed to the formation of binary oxides composed by anatase and brookite and by its optimized morphological and electronic properties.","PeriodicalId":219314,"journal":{"name":"PeerJ Materials Science","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115579967","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}
Pub Date : 2020-11-23DOI: 10.20944/preprints202011.0573.v1
A. Ramanathan, J. Khalifeh
The density functional theory (DFT) full potential linearized augmented plane wave (FP-LAPW) method with the modified Becke–Johnson (mBJ) approximation is used to perform spin polarised calculations of the transition metal perovskites MoScO3 and WScO3. Both depict half metallic behaviour with semiconducting and metallic in the minority and majority spins respectively. MoScO3 and WScO3 have indirect R− Γ band gaps in the minority spin channels of 3.61 and 3.82 eV respectively. Moreover, they both show substantial integer magnetic moments of 3μB with 100% spin polarization typical to half metals. In addition, we calculate the dielectric function, optical conductivity and the optical constants, namely, the refractive index, the reflectivity, the extinction and absorption coefficients.
{"title":"Electronic, magnetic and optical properties of XScO3 (X=Mo, W) perovskites","authors":"A. Ramanathan, J. Khalifeh","doi":"10.20944/preprints202011.0573.v1","DOIUrl":"https://doi.org/10.20944/preprints202011.0573.v1","url":null,"abstract":"The density functional theory (DFT) full potential linearized augmented plane wave (FP-LAPW) method with the modified Becke–Johnson (mBJ) approximation is used to perform spin polarised calculations of the transition metal perovskites MoScO3 and WScO3. Both depict half metallic behaviour with semiconducting and metallic in the minority and majority spins respectively. MoScO3 and WScO3 have indirect R− Γ band gaps in the minority spin channels of 3.61 and 3.82 eV respectively. Moreover, they both show substantial integer magnetic moments of 3μB with 100% spin polarization typical to half metals. In addition, we calculate the dielectric function, optical conductivity and the optical constants, namely, the refractive index, the reflectivity, the extinction and absorption coefficients.","PeriodicalId":219314,"journal":{"name":"PeerJ Materials Science","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124541047","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 photocatalysts based on TiO2 were synthesized and characterized. The synthesis involved the controlled hydrolysis of titanium tetraisopropoxide using water containing different proportions of acetone. X-ray diffraction analyses combined with Raman spectroscopy revealed crystalline oxides characterized by the coexistence of the anatase and brookite phases. The Rietveld refinement of diffractograms showed that the presence of acetone in the synthesis process influenced the composition of these crystalline phases, with the proportion of brookite growing from 13% to 22% with the addition of this solvent in the synthesis process. The BET isotherms revealed that these materials are mesoporous with surface area approximately 12% higher than that of the oxide prepared from hydrolysis using pure water. The photocatalytic potential of these oxides was evaluated by means degradation tests using the dyes Ponceau 4R and Reactive Red 120 as oxidizable substrates. The values achieved using the most efficient photocatalyst among the synthesized oxides were, respectively, 83% and 79% for mineralization, and 100% for discoloration of these dyes. This same oxide loaded with 0.5% of platinum and suspended in a 5:1 v/v water/methanol mixture, produced 56 mmol of gaseous hydrogen in 5 h of reaction, a specific hydrogen production rate of 138.5 mmol h−1g−1, a value 60% higher than that achieved using TiO2 P25 under similar conditions.
{"title":"Characterization and evaluation of the photocatalytic activity of oxides based on TiO2 synthesized by hydrolysis controlled by the use of water/acetone mixtures","authors":"Werick Alves Machado, A. E. da Hora Machado","doi":"10.7717/peerj-matsci.11","DOIUrl":"https://doi.org/10.7717/peerj-matsci.11","url":null,"abstract":"New photocatalysts based on TiO2 were synthesized and characterized. The synthesis involved the controlled hydrolysis of titanium tetraisopropoxide using water containing different proportions of acetone. X-ray diffraction analyses combined with Raman spectroscopy revealed crystalline oxides characterized by the coexistence of the anatase and brookite phases. The Rietveld refinement of diffractograms showed that the presence of acetone in the synthesis process influenced the composition of these crystalline phases, with the proportion of brookite growing from 13% to 22% with the addition of this solvent in the synthesis process. The BET isotherms revealed that these materials are mesoporous with surface area approximately 12% higher than that of the oxide prepared from hydrolysis using pure water. The photocatalytic potential of these oxides was evaluated by means degradation tests using the dyes Ponceau 4R and Reactive Red 120 as oxidizable substrates. The values achieved using the most efficient photocatalyst among the synthesized oxides were, respectively, 83% and 79% for mineralization, and 100% for discoloration of these dyes. This same oxide loaded with 0.5% of platinum and suspended in a 5:1 v/v water/methanol mixture, produced 56 mmol of gaseous hydrogen in 5 h of reaction, a specific hydrogen production rate of 138.5 mmol h−1g−1, a value 60% higher than that achieved using TiO2 P25 under similar conditions.","PeriodicalId":219314,"journal":{"name":"PeerJ Materials Science","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124383237","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}
C. Cholmaitri, A. Uthairatanakij, N. Laohakunjit, P. Jitareerat, W. Mingvanish
The efficiencies of rice flour (RF) and rice husk (RH) as agents of the controlled release of methyl salicylate (RF-MeSA and RH-MeSA, respectively) were investigated. The adsorption percentage of RH-MeSA was significantly higher (two-fold) than that of RF-MeSA owing to its higher specific surface area and total pore volume. However, both materials are classified as mesoporous materials. Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetric analysis confirmed that MeSA diffused toward the pores and covered the surfaces of RF and RH. A temperature increase from 25 °C to 40 °C and an increase in relative humidity from 75% to 95% stimulated the release of MeSA. The kinetically controlled release of RF-MeSA and RH-MeSA was in line with a Fickian diffusion mechanism. Both RF-MeSA and RH-MeSA significantly delayed the ripening of banana fruit compared to the control. The results indicate that RF and RH can be used as biosorbent materials for the adsorption and controlled release of MeSA without chemical and mechanical modification.
{"title":"Controlled release of methyl salicylate by biosorbents delays the ripening of banana fruit","authors":"C. Cholmaitri, A. Uthairatanakij, N. Laohakunjit, P. Jitareerat, W. Mingvanish","doi":"10.7717/peerj-matsci.12","DOIUrl":"https://doi.org/10.7717/peerj-matsci.12","url":null,"abstract":"The efficiencies of rice flour (RF) and rice husk (RH) as agents of the controlled release of methyl salicylate (RF-MeSA and RH-MeSA, respectively) were investigated. The adsorption percentage of RH-MeSA was significantly higher (two-fold) than that of RF-MeSA owing to its higher specific surface area and total pore volume. However, both materials are classified as mesoporous materials. Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetric analysis confirmed that MeSA diffused toward the pores and covered the surfaces of RF and RH. A temperature increase from 25 °C to 40 °C and an increase in relative humidity from 75% to 95% stimulated the release of MeSA. The kinetically controlled release of RF-MeSA and RH-MeSA was in line with a Fickian diffusion mechanism. Both RF-MeSA and RH-MeSA significantly delayed the ripening of banana fruit compared to the control. The results indicate that RF and RH can be used as biosorbent materials for the adsorption and controlled release of MeSA without chemical and mechanical modification.","PeriodicalId":219314,"journal":{"name":"PeerJ Materials Science","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126225424","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. Karna, C. Saunders, R. Karna, D. Guragain, S. Mishra, P. Karna
A set of experiments was conducted to synthesize doped and undoped sodium tantalates with carbon and sulfur in energy efficient single-step hydrothermal process. Undoped sodium tantalate nanocubes were synthesized at 140 °C and doped one at 180 °C for 12 h in rich alkaline atmosphere. The sizes of undoped, carbon-doped, and sulfur-doped sodium tantalate nanocubes were 38 nm, 45 nm, and 40 nm, respectively. The morphological, elemental, compositional, structural, thermal, and photophysical properties of as-synthesized doped and undoped sodium tantalate (NaTaO3) were characterized using scanning electron microscope (SEM), energy dispersive x-ray spectroscope (EDS), Raman spectroscopy, X-ray powder diffraction (XRD), thermal gravimetric analysis (TGA), Fourier transform infrared spectrophotometer (FTIR), and UV-vis spectrophotometer. The sulfur doped NaTaO3 shows a higher photocatalytic activity in degradation of methylene blue than carbon doped and the undoped NaTaO3. The band gaps of undoped NaTaO3, carbon doped c-NaTaO3, and sulfur doped s-NaTaO3 were calculated to be 3.94 eV, 3.8 eV, and 3.52 eV, respectively using Tauc plot.
{"title":"Hydrothermal synthesis of carbon and sulfur mono-doped sodium tantalates","authors":"S. Karna, C. Saunders, R. Karna, D. Guragain, S. Mishra, P. Karna","doi":"10.7717/peerj-matsci.10","DOIUrl":"https://doi.org/10.7717/peerj-matsci.10","url":null,"abstract":"A set of experiments was conducted to synthesize doped and undoped sodium tantalates with carbon and sulfur in energy efficient single-step hydrothermal process. Undoped sodium tantalate nanocubes were synthesized at 140 °C and doped one at 180 °C for 12 h in rich alkaline atmosphere. The sizes of undoped, carbon-doped, and sulfur-doped sodium tantalate nanocubes were 38 nm, 45 nm, and 40 nm, respectively. The morphological, elemental, compositional, structural, thermal, and photophysical properties of as-synthesized doped and undoped sodium tantalate (NaTaO3) were characterized using scanning electron microscope (SEM), energy dispersive x-ray spectroscope (EDS), Raman spectroscopy, X-ray powder diffraction (XRD), thermal gravimetric analysis (TGA), Fourier transform infrared spectrophotometer (FTIR), and UV-vis spectrophotometer. The sulfur doped NaTaO3 shows a higher photocatalytic activity in degradation of methylene blue than carbon doped and the undoped NaTaO3. The band gaps of undoped NaTaO3, carbon doped c-NaTaO3, and sulfur doped s-NaTaO3 were calculated to be 3.94 eV, 3.8 eV, and 3.52 eV, respectively using Tauc plot.","PeriodicalId":219314,"journal":{"name":"PeerJ Materials Science","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129552389","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}
Wang Xiaochen, Rui Ai, Quan Yang, Wang Shang, Yanjie Zhang, Y. Meng, Xianghong Ma
The effect of oxide scale composition of hot-rolled strip (Q235) on shot blasting is studied in this article. The properties of the oxide scale on the strip surface change during storage. The shot blasting is an important on-line acid-less descaling technology. The effect of shot blasting is affected by many factors, among which the composition of oxide scale may play an important role. However, there are few studies on the relationship between the oxide layer content and the descaling effect. The morphologies of oxide scales at different storage times are observed by scanning electron microscopy (SEM), and the compositions are analyzed by X-ray diffraction. These strips are then shot blasted and descaled with different amounts of abrasive, and the descaling effects are compared by SEM. The results show that the eutectoid structure Fe3O4/Fe in the oxide scale will gradually transform into Fe3O4. In the case of short storage time, the content of the eutectoid structure is high, and it is difficult to remove the oxide scale. While the strip with a long storage time has no eutectoid structure Fe3O4/Fe and FeO, it is easy to remove the oxide scale during the shot blasting process. The composition of the oxide scale has a significant effect on the effect of shot blasting, and it provides significant guidance to the optimization of the descaling process parameters.
{"title":"Effect of oxide scale structure on shot-blasting of hot-rolled strip steel","authors":"Wang Xiaochen, Rui Ai, Quan Yang, Wang Shang, Yanjie Zhang, Y. Meng, Xianghong Ma","doi":"10.7717/PEERJ-MATSCI.9","DOIUrl":"https://doi.org/10.7717/PEERJ-MATSCI.9","url":null,"abstract":"\u0000\u0000The effect of oxide scale composition of hot-rolled strip (Q235) on shot blasting is studied in this article. The properties of the oxide scale on the strip surface change during storage. The shot blasting is an important on-line acid-less descaling technology. The effect of shot blasting is affected by many factors, among which the composition of oxide scale may play an important role. However, there are few studies on the relationship between the oxide layer content and the descaling effect.\u0000\u0000\u0000\u0000The morphologies of oxide scales at different storage times are observed by scanning electron microscopy (SEM), and the compositions are analyzed by X-ray diffraction. These strips are then shot blasted and descaled with different amounts of abrasive, and the descaling effects are compared by SEM.\u0000\u0000\u0000\u0000The results show that the eutectoid structure Fe3O4/Fe in the oxide scale will gradually transform into Fe3O4. In the case of short storage time, the content of the eutectoid structure is high, and it is difficult to remove the oxide scale. While the strip with a long storage time has no eutectoid structure Fe3O4/Fe and FeO, it is easy to remove the oxide scale during the shot blasting process. The composition of the oxide scale has a significant effect on the effect of shot blasting, and it provides significant guidance to the optimization of the descaling process parameters.\u0000","PeriodicalId":219314,"journal":{"name":"PeerJ Materials Science","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124903740","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}
Tanzila Islam, C. Booker, D. Tolkatchev, S. Ha, A. Kostyukova
Glucose oxidating enzymes have a tremendous potential for various energy, healthcare and environmental sensing applications. In this work, we studied the effect of reducing the size of pyranose 2-oxidase (POx) on stability and enzymatic activity of proteolyzed POx. Limited proteolysis of the POx was performed using trypsin to remove flexible structural regions without significant damage to the overall conformation and catalytic activity of the enzyme. Enzymatic activities of the modified and wild-type POx were measured by colorimetric coupled reaction assay and compared. The enzymatic activity of the modified POx showed 90% activity compared to the wild-type POx. This result indicates that reducing the size of the protein can be done without losing enzymatic activity and such enzymes potentially could provide a larger gain in electrochemical activity compared with wild-type enzymes.
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