The diffusion processes involved in the accommodation of grain boundary sliding in diffusional deformation are revisited by considering the role of grain boundary curvature and of the associated grain boundary migration. A method is developed for calculating grain boundary profiles, diffusional fluxes, and the dissipation power arising from the coupling of diffusion fluxes and grain boundary migration during the quasi-steady-state stage of deformation. In conditions of dominance of Coble creep, the controlling length scale is the square root of the ratio of grain boundary diffusivity to grain boundary mobility. Zero curvature is the particular solution valid when mobility is infinite. The analysis brings the definition of a lower bound for the grain boundary viscosity parameter to be used in numerical simulations of diffusional deformation. This lower bound is consistent with previous identifications of the parameter in literature.
{"title":"The Role of Grain Boundary Curvature in Diffusional Deformation: Control of Grain Boundary Sliding by Grain Boundary Mobility","authors":"F. Delannay","doi":"10.2139/ssrn.3714495","DOIUrl":"https://doi.org/10.2139/ssrn.3714495","url":null,"abstract":"The diffusion processes involved in the accommodation of grain boundary sliding in diffusional deformation are revisited by considering the role of grain boundary curvature and of the associated grain boundary migration. A method is developed for calculating grain boundary profiles, diffusional fluxes, and the dissipation power arising from the coupling of diffusion fluxes and grain boundary migration during the quasi-steady-state stage of deformation. In conditions of dominance of Coble creep, the controlling length scale is the square root of the ratio of grain boundary diffusivity to grain boundary mobility. Zero curvature is the particular solution valid when mobility is infinite. The analysis brings the definition of a lower bound for the grain boundary viscosity parameter to be used in numerical simulations of diffusional deformation. This lower bound is consistent with previous identifications of the parameter in literature.","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75357810","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}
E. Merson, V. Poluyanov, P. Myagkikh, D. Merson, A. Vinogradov
Abstract Magnesium and its alloys are susceptible to stress-corrosion cracking (SCC), which can manifest itself during the slow-strain rate tensile (SSRT) testing in air if the specimens were pre-exposed to corrosive media. This phenomenon is generally associated with hydrogen embrittlement (HE) which is believed to be related to diffusible hydrogen penetrating into the metal during the pre-exposure. In the present study, we show that the corrosion product layer deposited on the surface of the pre-exposed specimens is crucial in the SCC mechanism. The specimens of the alloy ZK60 were SSRT tested in air, in corrosive media, in air after pre-exposure to corrosive media as well as after pre-exposure and removal of corrosion products. To vary the severity of SCC, four NaCl-based corrosion solutions were utilised. The embrittlement resulted in a marked decrease in ductility and the concurrent appearance of multiple side-surface cracks as well as brittle fragments on the fracture surface. The most striking finding of the present study is that the removal of corrosion products from the surface of the pre-exposed specimens results in complete recovery of the mechanical response and in the elimination of all harmful embrittling features regardless of the corrosive solution used. This effect is found to be inconsistent with the common viewpoint where the SCC mechanism is governed entirely by diffusible hydrogen. The obtained results shed new light on the role of diffusible hydrogen, corrosion products and irreversible corrosion damage in the SCC mechanism of Mg alloys pre-exposed to corrosive media.
{"title":"Inhibiting Stress Corrosion Cracking by Removing Corrosion Products from the Mg-Zn-Zr Alloy Pre-Exposed to Corrosion Solutions","authors":"E. Merson, V. Poluyanov, P. Myagkikh, D. Merson, A. Vinogradov","doi":"10.2139/ssrn.3714499","DOIUrl":"https://doi.org/10.2139/ssrn.3714499","url":null,"abstract":"Abstract Magnesium and its alloys are susceptible to stress-corrosion cracking (SCC), which can manifest itself during the slow-strain rate tensile (SSRT) testing in air if the specimens were pre-exposed to corrosive media. This phenomenon is generally associated with hydrogen embrittlement (HE) which is believed to be related to diffusible hydrogen penetrating into the metal during the pre-exposure. In the present study, we show that the corrosion product layer deposited on the surface of the pre-exposed specimens is crucial in the SCC mechanism. The specimens of the alloy ZK60 were SSRT tested in air, in corrosive media, in air after pre-exposure to corrosive media as well as after pre-exposure and removal of corrosion products. To vary the severity of SCC, four NaCl-based corrosion solutions were utilised. The embrittlement resulted in a marked decrease in ductility and the concurrent appearance of multiple side-surface cracks as well as brittle fragments on the fracture surface. The most striking finding of the present study is that the removal of corrosion products from the surface of the pre-exposed specimens results in complete recovery of the mechanical response and in the elimination of all harmful embrittling features regardless of the corrosive solution used. This effect is found to be inconsistent with the common viewpoint where the SCC mechanism is governed entirely by diffusible hydrogen. The obtained results shed new light on the role of diffusible hydrogen, corrosion products and irreversible corrosion damage in the SCC mechanism of Mg alloys pre-exposed to corrosive media.","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78489265","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}
Wei-Tse Lee, Felix D. Bobbink, Antoine P. van Muyden, Kun-Han Lin, C. Corminboeuf, R. Zamani, P. Dyson
Summary The use of methane as one of the cleanest energy sources has attracted significant public awareness, and methane production processes with less environmental impact than fracking are receiving considerable attention. Catalytic hydrocracking of plastic materials has been considered a potential clean alternative. However, catalysts that convert heterogeneous plastic feeds into a single product under industrially relevant conditions are lacking. Here, we describe a Ru-modified zeolite that catalytically transforms polyethylene, polypropylene, and polystyrene into grid-compatible methane (>97% purity), at 300°C–350°C using near-stoichiometric amounts of H2. Mechanistic studies reveal a chain-end initiation process with limited isomerization of plastic substrates. A Ru site-dominant mechanism is proposed based on these studies and density functional theory (DFT) computations. We foresee that such a plastic-to-methane process may increase the intelligent use of plastic waste via energy recovery. There is also the potential to accommodate emerging sustainable H2 production into existing natural gas networks, while integrating waste management, fuel production, and energy storage.
{"title":"Catalytic Hydrocracking of Synthetic Polymers into Grid-Compatible Gas Streams","authors":"Wei-Tse Lee, Felix D. Bobbink, Antoine P. van Muyden, Kun-Han Lin, C. Corminboeuf, R. Zamani, P. Dyson","doi":"10.2139/ssrn.3696768","DOIUrl":"https://doi.org/10.2139/ssrn.3696768","url":null,"abstract":"Summary The use of methane as one of the cleanest energy sources has attracted significant public awareness, and methane production processes with less environmental impact than fracking are receiving considerable attention. Catalytic hydrocracking of plastic materials has been considered a potential clean alternative. However, catalysts that convert heterogeneous plastic feeds into a single product under industrially relevant conditions are lacking. Here, we describe a Ru-modified zeolite that catalytically transforms polyethylene, polypropylene, and polystyrene into grid-compatible methane (>97% purity), at 300°C–350°C using near-stoichiometric amounts of H2. Mechanistic studies reveal a chain-end initiation process with limited isomerization of plastic substrates. A Ru site-dominant mechanism is proposed based on these studies and density functional theory (DFT) computations. We foresee that such a plastic-to-methane process may increase the intelligent use of plastic waste via energy recovery. There is also the potential to accommodate emerging sustainable H2 production into existing natural gas networks, while integrating waste management, fuel production, and energy storage.","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89592682","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}
Y. Lei, Zexuan Wang, B. Zhang, Zhengping Luo, Jian Lu, K. Lu
Abstract Stainless steels with high mechanical properties and corrosion resistance are promising structural materials for the next generation of aerospace and some niche industries. In this work, we pre-formed a gradient nanostructured (GNS) surface layer on 316L stainless steel by surface mechanical rolling treatment (SMRT) and subsequently annealed it at 700 °C. Tensile tests showed that the strength-ductility synergy was enhanced in the annealed-SMRT sample, while the grain size and hardness in the GNS layer retained rather stable. In addition, a remarkable Cr-enrichment was found in the GNS surface layer after annealing, resulting in a significantly enhanced corrosion resistance. The underlying mechanisms on the microstructure, composition and phases evolutions, as well as their effects on deformation and corrosion behavior, were analyzed in the annealed-SMRT sample. This work provides insights on developing a simple thermomechanical approach to produce stainless steels with enhanced mechanical properties and corrosion resistance.
{"title":"Enhanced Mechanical Properties and Corrosion Resistance of 316l Stainless Steel by Pre-Forming a Gradient Nanostructured Surface Layer and Annealing","authors":"Y. Lei, Zexuan Wang, B. Zhang, Zhengping Luo, Jian Lu, K. Lu","doi":"10.2139/ssrn.3692992","DOIUrl":"https://doi.org/10.2139/ssrn.3692992","url":null,"abstract":"Abstract Stainless steels with high mechanical properties and corrosion resistance are promising structural materials for the next generation of aerospace and some niche industries. In this work, we pre-formed a gradient nanostructured (GNS) surface layer on 316L stainless steel by surface mechanical rolling treatment (SMRT) and subsequently annealed it at 700 °C. Tensile tests showed that the strength-ductility synergy was enhanced in the annealed-SMRT sample, while the grain size and hardness in the GNS layer retained rather stable. In addition, a remarkable Cr-enrichment was found in the GNS surface layer after annealing, resulting in a significantly enhanced corrosion resistance. The underlying mechanisms on the microstructure, composition and phases evolutions, as well as their effects on deformation and corrosion behavior, were analyzed in the annealed-SMRT sample. This work provides insights on developing a simple thermomechanical approach to produce stainless steels with enhanced mechanical properties and corrosion resistance.","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84265029","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 : 2020-10-01DOI: 10.15587/1729-4061.2020.211495
O. Semeshko, Yulia Saribyekova, T. Asaulyuk, Nataliia Skalozubova, S. Myasnikov
Mathematical planning of the experiment was used to develop a formulation for light stabilizers to improve the lightfastness of cotton knitwear coloration, dyed with active dyes, in order to produce comfortable and high-quality knitted clothes. The variance and factor analyses of the experiment's results were performed, which was carried out according to the scheme of the Latin cube of the first order involving the variation of factors – the type of light stabilizers and their concentration. The technological mode of application of light stabilizers implied the impregnation of knitted fabric, drying, and thermal fixation of the material. For the dyed knitwear samples, we have investigated the individual influence of light stabilizers on changing the color of the dyed knitted fabric and the kinetics of coloration photodegradation. The samples were insolated using the device with mercury-tungsten lamp RF 1201 BS ("REFOND", China). Following the treatment and insolation, the general color differences of knitwear samples were determined in comparison with the non-treated material, using the TCR-200 colorimeter ("PCE Instruments", Germany). The effectiveness of the developed formulation for light stabilizers was confirmed in the study of the lightfastness of knitted fabrics such as pique weave, 1+1 eraser, smooth surface, dyed with active dyes of the brand Bezaktiv ("CHT Bezema", Czech Republic). The result of our study is the developed formulation of light stabilizers consisting of 2,4-dihydroxy benzophenone, a UV-absorber, and hydroquinone, an antioxidant, at concentrations of 2 and 1 % of the material weight, respectively, which ensures an increase in the lightfastness of cotton knitwear coloration by 52.9‒66.8 % regardless of weave and active dye
{"title":"Development of a Formulation for Light Stabilizers To Protect Dyed Cotton Knitted Fabrics Against Light","authors":"O. Semeshko, Yulia Saribyekova, T. Asaulyuk, Nataliia Skalozubova, S. Myasnikov","doi":"10.15587/1729-4061.2020.211495","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.211495","url":null,"abstract":"Mathematical planning of the experiment was used to develop a formulation for light stabilizers to improve the lightfastness of cotton knitwear coloration, dyed with active dyes, in order to produce comfortable and high-quality knitted clothes. The variance and factor analyses of the experiment's results were performed, which was carried out according to the scheme of the Latin cube of the first order involving the variation of factors – the type of light stabilizers and their concentration. The technological mode of application of light stabilizers implied the impregnation of knitted fabric, drying, and thermal fixation of the material. For the dyed knitwear samples, we have investigated the individual influence of light stabilizers on changing the color of the dyed knitted fabric and the kinetics of coloration photodegradation. The samples were insolated using the device with mercury-tungsten lamp RF 1201 BS (\"REFOND\", China). Following the treatment and insolation, the general color differences of knitwear samples were determined in comparison with the non-treated material, using the TCR-200 colorimeter (\"PCE Instruments\", Germany). The effectiveness of the developed formulation for light stabilizers was confirmed in the study of the lightfastness of knitted fabrics such as pique weave, 1+1 eraser, smooth surface, dyed with active dyes of the brand Bezaktiv (\"CHT Bezema\", Czech Republic). The result of our study is the developed formulation of light stabilizers consisting of 2,4-dihydroxy benzophenone, a UV-absorber, and hydroquinone, an antioxidant, at concentrations of 2 and 1 % of the material weight, respectively, which ensures an increase in the lightfastness of cotton knitwear coloration by 52.9‒66.8 % regardless of weave and active dye","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83281074","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}
The meniscus plays a critical role in maintaining the homeostasis, biomechanics, and structural stability of the knee joint. Unfortunately, it is predisposed to damages either from sports-related trauma or age-related degeneration. The meniscus has an inherently limited capacity for tissue regeneration. Self-healing of injured adult menisci only occurs in the peripheral vascularized portion, while the spontaneous repair of the inner avascular region seems never happens. Repair, replacement, and regeneration of menisci through tissue engineering strategies are promising to address this problem. Recently, many scaffolds for meniscus tissue engineering have been proposed for both experimental and preclinical investigations. Electrospinning is a feasible and versatile technique to produce nano- to micro-scale fibers that mimic the microarchitecture of native extracellular matrix and is an effective approach to prepare nanofibrous scaffolds for constructing engineered meniscus. Electrospun scaffolds are reported to be capable of inducing colonization of meniscus cells by modulating local extracellular density and stimulating endogenous regeneration by driving reprogramming of meniscus wound microenvironment. Electrospun nanofibrous scaffolds with tunable mechanical properties, controllable anisotropy, and various porosities have shown promises for meniscus repair and regeneration and will undoubtedly inspire more efforts in exploring effective therapeutic approaches towards clinical applications. In this article, we review the current advances in the use of electrospun nanofibrous scaffolds for meniscus tissue engineering and repair and discuss prospects for future studies.
{"title":"Advances in Electrospun Scaffolds Towards Meniscus: From Tissue Engineering to Repair and Regeneration","authors":"Xiaoyun Wang, Changlei Xia, X. Mo, Jinglei Wu","doi":"10.2139/ssrn.3676763","DOIUrl":"https://doi.org/10.2139/ssrn.3676763","url":null,"abstract":"The meniscus plays a critical role in maintaining the homeostasis, biomechanics, and structural stability of the knee joint. Unfortunately, it is predisposed to damages either from sports-related trauma or age-related degeneration. The meniscus has an inherently limited capacity for tissue regeneration. Self-healing of injured adult menisci only occurs in the peripheral vascularized portion, while the spontaneous repair of the inner avascular region seems never happens. Repair, replacement, and regeneration of menisci through tissue engineering strategies are promising to address this problem. Recently, many scaffolds for meniscus tissue engineering have been proposed for both experimental and preclinical investigations. Electrospinning is a feasible and versatile technique to produce nano- to micro-scale fibers that mimic the microarchitecture of native extracellular matrix and is an effective approach to prepare nanofibrous scaffolds for constructing engineered meniscus. Electrospun scaffolds are reported to be capable of inducing colonization of meniscus cells by modulating local extracellular density and stimulating endogenous regeneration by driving reprogramming of meniscus wound microenvironment. Electrospun nanofibrous scaffolds with tunable mechanical properties, controllable anisotropy, and various porosities have shown promises for meniscus repair and regeneration and will undoubtedly inspire more efforts in exploring effective therapeutic approaches towards clinical applications. In this article, we review the current advances in the use of electrospun nanofibrous scaffolds for meniscus tissue engineering and repair and discuss prospects for future studies.","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79572842","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}
In this work, polymorphic models of the structures of ZnO is considered. We have studied the defects and defects behaviours in Wurtzite, zinc blende, and rocksalt ZnO by using first principles and quantum simulation methods. We used density functional theory (DFT) and molecular dynamics (MD) simulation methods to investigate the structural and electronic properties of defect ZnO.
For DFT calculations, a computer code within QUANTUM-ESPRESSO is used. Calculations of energies versus lattice constants display the optimum values of the lattice constants for crystal systems. Results are reported using a step-by-step approach, starting from the primitive cell of bulk ZnO, going to a slab model by including a surface charge defects. Generally, the behaviour of intrinsic defects in ZnO, electronic properties, formation energies and workfunction of ZnO were investigated. The effect of different surface absorbents and surface defects on the workfunction of ZnO were studied using DFT calculations. Anisotropy and optical properties of defects have also been studied.
{"title":"Defects and Properties in Polymorph of ZnO","authors":"Kenate Nemera","doi":"10.2139/ssrn.3687642","DOIUrl":"https://doi.org/10.2139/ssrn.3687642","url":null,"abstract":"In this work, polymorphic models of the structures of ZnO is considered. We have studied the defects and defects behaviours in Wurtzite, zinc blende, and rocksalt ZnO by using first principles and quantum simulation methods. We used density functional theory (DFT) and molecular dynamics (MD) simulation methods to investigate the structural and electronic properties of defect ZnO.<br><br>For DFT calculations, a computer code within QUANTUM-ESPRESSO is used. Calculations of energies versus lattice constants display the optimum values of the lattice constants for crystal systems. Results are reported using a step-by-step approach, starting from the primitive cell of bulk ZnO, going to a slab model by including a surface charge defects. Generally, the behaviour of intrinsic defects in ZnO, electronic properties, formation energies and workfunction of ZnO were investigated. The effect of different surface absorbents and surface defects on the workfunction of ZnO were studied using DFT calculations. Anisotropy and optical properties of defects have also been studied.","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87051894","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}
N. Koga, L. Yin, O. Umezawa, Takayuki Yamashita, S. Morooka, T. Kawasaki, S. Harjo
The lattice parameter of cementite in a pearlite structure was measured using the in situ heating neutron diffraction method. The lattice parameters of the cementite phase of the b- and c- axes in the pearlite structure were smaller than those in the martensite structure and Reed’s results [3]. The lattice parameter of the a-axis in the pearlite structure was almost equal to that in the martensite structure and Reed’s results [3]. The thermal and misfit strains, caused by the differences between the thermal expansion rate and lattice parameter of the cementite and ferrite phases, should affect the lattice parameter of cementite in the pearlite structure.
{"title":"Lattice Parameter of Cementite Phase in Pearlite Structure","authors":"N. Koga, L. Yin, O. Umezawa, Takayuki Yamashita, S. Morooka, T. Kawasaki, S. Harjo","doi":"10.2139/ssrn.3674208","DOIUrl":"https://doi.org/10.2139/ssrn.3674208","url":null,"abstract":"The lattice parameter of cementite in a pearlite structure was measured using the in situ heating neutron diffraction method. The lattice parameters of the cementite phase of the b- and c- axes in the pearlite structure were smaller than those in the martensite structure and Reed’s results [3]. The lattice parameter of the a-axis in the pearlite structure was almost equal to that in the martensite structure and Reed’s results [3]. The thermal and misfit strains, caused by the differences between the thermal expansion rate and lattice parameter of the cementite and ferrite phases, should affect the lattice parameter of cementite in the pearlite structure.","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86098293","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}
Zhiwei Jiang, Danji Zhu, Ke Yu, Yue Xi, Xiaozhao Wang, Guoli Yang
Various stimuli have been applied to harvest complete cell sheets, including temperature, magnetic, pH, and electrical stimuli. Cell sheet technology is a convenient and efficient approach with beneficial effects for tissue regeneration and cell therapy. Lights of different wavelengths, such as ultraviolet (UV), visible light, and near infrared ray (NIR) light, were confirmed to aid in fabricating a cell sheet. Changes in the wettability, potential, or water content of the culturing surfaces that occur under light illumination induce conformational changes in the adhesive proteins or collagens, which then leads to cell sheet detachment. However, the current approaches face several limitations, as few standards for safe light illumination have been proposed to date, and require a careful control of the wavelength, power, and irradiation time. Future studies should aim at generating new materials for culturing and releasing cell sheets rapidly and effectively.
{"title":"Recent Advances in Light-Induced Cell Sheet Technology","authors":"Zhiwei Jiang, Danji Zhu, Ke Yu, Yue Xi, Xiaozhao Wang, Guoli Yang","doi":"10.2139/ssrn.3674117","DOIUrl":"https://doi.org/10.2139/ssrn.3674117","url":null,"abstract":"Various stimuli have been applied to harvest complete cell sheets, including temperature, magnetic, pH, and electrical stimuli. Cell sheet technology is a convenient and efficient approach with beneficial effects for tissue regeneration and cell therapy. Lights of different wavelengths, such as ultraviolet (UV), visible light, and near infrared ray (NIR) light, were confirmed to aid in fabricating a cell sheet. Changes in the wettability, potential, or water content of the culturing surfaces that occur under light illumination induce conformational changes in the adhesive proteins or collagens, which then leads to cell sheet detachment. However, the current approaches face several limitations, as few standards for safe light illumination have been proposed to date, and require a careful control of the wavelength, power, and irradiation time. Future studies should aim at generating new materials for culturing and releasing cell sheets rapidly and effectively.","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79612438","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}
Black phosphorus based nanomaterials (BPNMs), an emerging member of two-dimensional (2D) nanomaterials, possess excellent physicochemical properties and hold a great potential for application in advanced nanomedicines. However, the bare BPNMs easily decrease their biomedical activities due to their degradability and in vivo interactions with biological macromolecules such as plasma proteins, largely restricting their biomedical application. A variety of surface modifications, via chemical, physical or biological approaches, have been developed for the BPNMs to avoid these limitations and achieve stable, long-lasting and safe therapeutic effects, thus enlighten the development of the multifunctional BPNMs for more practical application in the field of biomedicine. The present review summarizes the recent advances in the surface modification of the BPNMs and the resultant expansion of their biomedical applications. Focus is put on the strategy and method of the modifications. The future and challenge of the surface modification of the therapeutic BPNMs are finally discussed.
{"title":"Surface Modification of the Black Phosphorus Based Nanomaterials in Biomedical Application: Strategies and Recent Advances","authors":"Guodong Zeng, Yuping Chen","doi":"10.2139/ssrn.3674137","DOIUrl":"https://doi.org/10.2139/ssrn.3674137","url":null,"abstract":"Black phosphorus based nanomaterials (BPNMs), an emerging member of two-dimensional (2D) nanomaterials, possess excellent physicochemical properties and hold a great potential for application in advanced nanomedicines. However, the bare BPNMs easily decrease their biomedical activities due to their degradability and in vivo interactions with biological macromolecules such as plasma proteins, largely restricting their biomedical application. A variety of surface modifications, via chemical, physical or biological approaches, have been developed for the BPNMs to avoid these limitations and achieve stable, long-lasting and safe therapeutic effects, thus enlighten the development of the multifunctional BPNMs for more practical application in the field of biomedicine. The present review summarizes the recent advances in the surface modification of the BPNMs and the resultant expansion of their biomedical applications. Focus is put on the strategy and method of the modifications. The future and challenge of the surface modification of the therapeutic BPNMs are finally discussed.","PeriodicalId":18341,"journal":{"name":"Materials Science eJournal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84814537","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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