Xiaolong Gao, Junjun Tang, Minghua Li, Chao Lin, Peijun Wang
Gadolinium-based small-molecule contrast agents are commonly utilized in clinics. However, these agents have a short retention time in vivo and possess a certain level of cytotoxicity. The reducible polymer poly(urethane-amine) can increase the relaxation rate and blood circulation time of small-molecule gadolinium chelates. Moreover, the polymer can be used as a gene carrier to bind small interfering RNA (siRNA). We synthesized an active targeting integrated diagnosis and treatment nanocomposite system with reducible poly(urethane-amine) as the carrier. This system incorporated functional units such as MRI contrast agent Gd-diethylenetriamine pentacetate (Gd-DTPA) and siRNA-vascular endothelial growth factor (siRNA-VEGF), and folic acid (FA) modified onto the surface of the polymer directed it to actively target tumor cells, thus improving the imaging effect of MRI. Meanwhlie, siRNA-VEGF carried by the system could reduce the expression of VEGF in tumor cells and inhibited tumor growth. The system showed good biocompatibility and was an integrated system of tumor diagnosis and treatment.
{"title":"Magnetic Resonance Imaging and Rna Interference of Tumor with Reducible Poly(Urethane-Amine) Nanocomposite System","authors":"Xiaolong Gao, Junjun Tang, Minghua Li, Chao Lin, Peijun Wang","doi":"10.2139/ssrn.3844708","DOIUrl":"https://doi.org/10.2139/ssrn.3844708","url":null,"abstract":"Gadolinium-based small-molecule contrast agents are commonly utilized in clinics. However, these agents have a short retention time in vivo and possess a certain level of cytotoxicity. The reducible polymer poly(urethane-amine) can increase the relaxation rate and blood circulation time of small-molecule gadolinium chelates. Moreover, the polymer can be used as a gene carrier to bind small interfering RNA (siRNA). We synthesized an active targeting integrated diagnosis and treatment nanocomposite system with reducible poly(urethane-amine) as the carrier. This system incorporated functional units such as MRI contrast agent Gd-diethylenetriamine pentacetate (Gd-DTPA) and siRNA-vascular endothelial growth factor (siRNA-VEGF), and folic acid (FA) modified onto the surface of the polymer directed it to actively target tumor cells, thus improving the imaging effect of MRI. Meanwhlie, siRNA-VEGF carried by the system could reduce the expression of VEGF in tumor cells and inhibited tumor growth. The system showed good biocompatibility and was an integrated system of tumor diagnosis and treatment.","PeriodicalId":326657,"journal":{"name":"MatSciRN: Other Nanomaterials (Topic)","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133906293","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}
Abstract We investigate the formation of Au structures by continuing fragmentation of a Au film separated from Si (100) substrate by a Ti adhesion layer. The ion-beam processing uses 2 keV Cs+ projectiles. It induces the formation of a large variety of structures with dimensions from tens of microns down to a few nanometers, and shapes that include flat Au islands and clusters of Au nanoparticles. We identify different fragmentation mechanisms. In one pathway, Au structures are formed as pinch-off droplets detached from large Au islands undergoing solid-state dewetting. In a second pathway, a continuing cracking fragmentation produces Au structures with a wide range of sizes and shows self-similarity, expressed in a power law for volume distribution of fragments Vα with α = -2.03±0.05. The measured α value is consistent with theoretical results in the literature modelling strong impact fragmentation. In the last stage of fragmentation evolution, Au nanostructures are spread over a texturized Si background. They assume shapes close to hemispherical, reflecting the increasing relevance of surface tension as dimensions decrease.
{"title":"Ion-Beam-Induced Structure Fragmentation and Dewetting in Au/Ti Films","authors":"C. Codeço, S. Mello, B. F. Magnani, M. Sant'Anna","doi":"10.2139/ssrn.3859734","DOIUrl":"https://doi.org/10.2139/ssrn.3859734","url":null,"abstract":"Abstract We investigate the formation of Au structures by continuing fragmentation of a Au film separated from Si (100) substrate by a Ti adhesion layer. The ion-beam processing uses 2 keV Cs+ projectiles. It induces the formation of a large variety of structures with dimensions from tens of microns down to a few nanometers, and shapes that include flat Au islands and clusters of Au nanoparticles. We identify different fragmentation mechanisms. In one pathway, Au structures are formed as pinch-off droplets detached from large Au islands undergoing solid-state dewetting. In a second pathway, a continuing cracking fragmentation produces Au structures with a wide range of sizes and shows self-similarity, expressed in a power law for volume distribution of fragments Vα with α = -2.03±0.05. The measured α value is consistent with theoretical results in the literature modelling strong impact fragmentation. In the last stage of fragmentation evolution, Au nanostructures are spread over a texturized Si background. They assume shapes close to hemispherical, reflecting the increasing relevance of surface tension as dimensions decrease.","PeriodicalId":326657,"journal":{"name":"MatSciRN: Other Nanomaterials (Topic)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115161938","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. Taha, D. Murcia, C. Minnig, Jocelyn Gisiger, U. Rösli, J. Stormont
Wellbore integrity is an important consideration for the viability of subsurface CO2 sequestration. Wellbores may leak due to micro annuli that develop between annular cement and steel casing and/or the host formation, as well as fractures and flaws in the cement itself. Leakage pathways may be problematic for the long-term containment of CO2. To address the need for a repair material that can effectively seal and repair wellbores, a new nanotechnology-based sealant has been developed at the University of New Mexico, USA. The sealant, referred to TS-Nano 20™, has superior flowability, excellent bond strength to steel and rock, is very ductile, and is thermally stable. Moreover, the sealant has been demonstrated to readily flow into microcracks below 20 µm under modest pressure gradients. The sealant showed excellent bond strength and superior fatigue resistance to debonding under stress cycles than microfine cement and other sealants.
TS-Nano 20™ was used in a field test at the Mont Terri Underground Research Laboratory (MT-URL) located in NW Switzerland. This experimental work at MT-URL was performed under the auspices of the CO2 Capture Project (CCP), a three-company collaboration comprising Chevron, BP, and Petrobras. The CCP effort is directed to develop more cost-effective and efficient processes for CO2 concentration, capture and sequestration applied to the energy, refining, chemical, and power generation industries in order to reduce greenhouse gas emissions. A wellbore with a cemented annulus was located beneath the floor of the underground laboratory. The wellbore was intentionally damaged by thermal cycling inside the casing to produce leakage pathways in the wellbore system. The wellbore system included injection ports at several locations along its length to allow pressure and flow tests to be conducted to document the leakage along the length of the wellbore system. Subsequently, various sealants were injected into the injection ports to seal the leakage pathways within the wellbore system. The sealant was then successfully injected into two of the intervals on site. After injection of sealants, the entire wellbore system needed to be stabilized for eventual overcoring and forensic analyses. To this end, a large open hole test interval (uncemented) at the bottom of the wellbore was first filled with a very flowable cement slurry to chase out water and reduce the dead volume, and then the sealant was injected on top of the cement and squeezed into leakage pathways that remained near the bottom of the wellbore system and cracks in the clay formation. Additionally, the sealant was used to further stabilize portions of the wellbore by injecting into all the previously used injection ports. We report on the ability of the nano sealant to maintain its flowability and mechanical characteristics under relatively low temperature and meet all field injection requirements, including having a relatively long-time to gel while hardening
{"title":"Nano Sealant for CO2 Seal Integrity and Overcoring at Mont Terri","authors":"M. Taha, D. Murcia, C. Minnig, Jocelyn Gisiger, U. Rösli, J. Stormont","doi":"10.2139/ssrn.3819742","DOIUrl":"https://doi.org/10.2139/ssrn.3819742","url":null,"abstract":"Wellbore integrity is an important consideration for the viability of subsurface CO2 sequestration. Wellbores may leak due to micro annuli that develop between annular cement and steel casing and/or the host formation, as well as fractures and flaws in the cement itself. Leakage pathways may be problematic for the long-term containment of CO2. To address the need for a repair material that can effectively seal and repair wellbores, a new nanotechnology-based sealant has been developed at the University of New Mexico, USA. The sealant, referred to TS-Nano 20™, has superior flowability, excellent bond strength to steel and rock, is very ductile, and is thermally stable. Moreover, the sealant has been demonstrated to readily flow into microcracks below 20 µm under modest pressure gradients. The sealant showed excellent bond strength and superior fatigue resistance to debonding under stress cycles than microfine cement and other sealants. <br><br>TS-Nano 20™ was used in a field test at the Mont Terri Underground Research Laboratory (MT-URL) located in NW Switzerland. This experimental work at MT-URL was performed under the auspices of the CO2 Capture Project (CCP), a three-company collaboration comprising Chevron, BP, and Petrobras. The CCP effort is directed to develop more cost-effective and efficient processes for CO2 concentration, capture and sequestration applied to the energy, refining, chemical, and power generation industries in order to reduce greenhouse gas emissions. A wellbore with a cemented annulus was located beneath the floor of the underground laboratory. The wellbore was intentionally damaged by thermal cycling inside the casing to produce leakage pathways in the wellbore system. The wellbore system included injection ports at several locations along its length to allow pressure and flow tests to be conducted to document the leakage along the length of the wellbore system. Subsequently, various sealants were injected into the injection ports to seal the leakage pathways within the wellbore system. The sealant was then successfully injected into two of the intervals on site. After injection of sealants, the entire wellbore system needed to be stabilized for eventual overcoring and forensic analyses. To this end, a large open hole test interval (uncemented) at the bottom of the wellbore was first filled with a very flowable cement slurry to chase out water and reduce the dead volume, and then the sealant was injected on top of the cement and squeezed into leakage pathways that remained near the bottom of the wellbore system and cracks in the clay formation. Additionally, the sealant was used to further stabilize portions of the wellbore by injecting into all the previously used injection ports. We report on the ability of the nano sealant to maintain its flowability and mechanical characteristics under relatively low temperature and meet all field injection requirements, including having a relatively long-time to gel while hardening ","PeriodicalId":326657,"journal":{"name":"MatSciRN: Other Nanomaterials (Topic)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114697200","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 following report comprises of data from several reports. The project gives a review of the previous works done in the concerned topic. The report introduces the scope of modern research and goes through the critical ideas of research of the concerned topic. It gives the practical utility, physical property, molding ideas of the composite materials, the future scope and the present status of research. It also deals with the fabrication processes that are commonly used till date. This report does not deal with aiming any new idea of synthesis and application for future use and provides a critical review of the topic.
{"title":"Nano Composite Material With Multiwall Carbon Nano Tubes As Composite, Glass Fibre As Fibre With the Help of Epoxy Resin As Resin","authors":"Atharva Abhijeet Kale","doi":"10.2139/ssrn.3779179","DOIUrl":"https://doi.org/10.2139/ssrn.3779179","url":null,"abstract":"The following report comprises of data from several reports. The project gives a review of the previous works done in the concerned topic. The report introduces the scope of modern research and goes through the critical ideas of research of the concerned topic. It gives the practical utility, physical property, molding ideas of the composite materials, the future scope and the present status of research. It also deals with the fabrication processes that are commonly used till date. This report does not deal with aiming any new idea of synthesis and application for future use and provides a critical review of the topic.","PeriodicalId":326657,"journal":{"name":"MatSciRN: Other Nanomaterials (Topic)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116053838","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 : 2020-10-30DOI: 10.15587/1729-4061.2020.214533
A. Dykha, V. Svidersky, I. Danilenko, V. Bilichenko, Y. Kukurudzyak, Ludmila Kirichenko
This paper reports the analytical and experimental studies aimed at designing and modeling fluoropolymer anti-friction materials. The optimal ratios of the total surface of polymer particles to the total surface of filler particles for different brands of fluoropolymer-4 have been determined, as well as the critical concentrations of the modifiers of fluoropolymer anti-friction materials. The calculations of antifriction carboplastics' elasticity modules indicate the existence of adhesion between carbon fiber and polytetrafluoroethylene. When constructing composites that combine high durable and tribotechnical characteristics, it is advisable to combine modifiers with different dispersion and polymer-oligomeric matrices, which enables the implementation of the principle of multilevel modifying. It has been established that the adhesion between carbon fiber and polytetrafluoroethylene can be improved by applying a fluoropolymer coating onto the surface of carbon fibers or by modifying with zirconium oxide nanopowders. The binary fluoropolymer matrix applied to the surface of carbon fiber can be used as an effective base for composite materials. This study has demonstrated that filling polytetrafluoroethylene (PTFE) with coke, carbon fibers (18‒19.5 % by weight), and zirconium oxide nanopowders in the amount of up to 2 % by weight produces materials with high mechanical characteristics and durability. It has been shown that the existence of an oligomer component improves the thermodynamic compatibility at the interface and promotes the plasticization of the PTFE boundary layers. Molecular structure with a certain orientation of coke and carbon fiber in the interphase areas is inherent in the materials with improved physical and mechanical properties.
{"title":"Design and Study of Nanomodified Composite Fluoropolymer Materials for Tribotechnical Purposes","authors":"A. Dykha, V. Svidersky, I. Danilenko, V. Bilichenko, Y. Kukurudzyak, Ludmila Kirichenko","doi":"10.15587/1729-4061.2020.214533","DOIUrl":"https://doi.org/10.15587/1729-4061.2020.214533","url":null,"abstract":"This paper reports the analytical and experimental studies aimed at designing and modeling fluoropolymer anti-friction materials. The optimal ratios of the total surface of polymer particles to the total surface of filler particles for different brands of fluoropolymer-4 have been determined, as well as the critical concentrations of the modifiers of fluoropolymer anti-friction materials. The calculations of antifriction carboplastics' elasticity modules indicate the existence of adhesion between carbon fiber and polytetrafluoroethylene. When constructing composites that combine high durable and tribotechnical characteristics, it is advisable to combine modifiers with different dispersion and polymer-oligomeric matrices, which enables the implementation of the principle of multilevel modifying. It has been established that the adhesion between carbon fiber and polytetrafluoroethylene can be improved by applying a fluoropolymer coating onto the surface of carbon fibers or by modifying with zirconium oxide nanopowders. The binary fluoropolymer matrix applied to the surface of carbon fiber can be used as an effective base for composite materials. This study has demonstrated that filling polytetrafluoroethylene (PTFE) with coke, carbon fibers (18‒19.5 % by weight), and zirconium oxide nanopowders in the amount of up to 2 % by weight produces materials with high mechanical characteristics and durability. It has been shown that the existence of an oligomer component improves the thermodynamic compatibility at the interface and promotes the plasticization of the PTFE boundary layers. Molecular structure with a certain orientation of coke and carbon fiber in the interphase areas is inherent in the materials with improved physical and mechanical properties.","PeriodicalId":326657,"journal":{"name":"MatSciRN: Other Nanomaterials (Topic)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123153474","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}
X. Liao, Jiasheng Zhang, Jiayi He, W. Fan, Hongya Yu, X. Zhong, Zhongwu Liu
Here we report the fully abundant rare earth-based nanocrystalline multi-component (Ce,La,Y)17Fe,sub>78B6 alloys containing no critical Nd/Pr/Dy/Tb with good combinations of room-temperature magnetic properties and thermal stability. The roles of La and Y substitutions for Ce have been fully understood. The enhanced coercivity Hcj by partial substitution of La is attributed to the increases of anisotropy field HA and the formation of continuously distributed grain boundaries resulting from the suppression of CeFe2 phase. Although Y substitution is not benefit for Hcj, the thermal stability has been effectively improved since Y2Fe14B shows weak temperature dependence of HA.
{"title":"Development of Nanocrystalline Multi-Component (Ce,La,Y)-Fe-B Alloys Without Critical Rare Earth Elements for Cost-Effective Permanent Magnets","authors":"X. Liao, Jiasheng Zhang, Jiayi He, W. Fan, Hongya Yu, X. Zhong, Zhongwu Liu","doi":"10.2139/ssrn.3595036","DOIUrl":"https://doi.org/10.2139/ssrn.3595036","url":null,"abstract":"Here we report the fully abundant rare earth-based nanocrystalline multi-component (Ce,La,Y)17Fe,sub>78B6 alloys containing no critical Nd/Pr/Dy/Tb with good combinations of room-temperature magnetic properties and thermal stability. The roles of La and Y substitutions for Ce have been fully understood. The enhanced coercivity Hcj by partial substitution of La is attributed to the increases of anisotropy field HA and the formation of continuously distributed grain boundaries resulting from the suppression of CeFe2 phase. Although Y substitution is not benefit for Hcj, the thermal stability has been effectively improved since Y2Fe14B shows weak temperature dependence of HA.","PeriodicalId":326657,"journal":{"name":"MatSciRN: Other Nanomaterials (Topic)","volume":"105 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121410861","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}
Laura J. Fox, L. Matthews, H. Stockdale, Supakit Pichai, T. Snow, R. Richardson, W. Briscoe
Understanding interactions between nanoparticles and model membranes is relevant to functional nano-composites and the fundamentals of nanotoxicity. In this study, the effect of polyamidoamine (PAMAM) dendrimers as model nanoparticles (NP) on the mesophase behaviour of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) has been investigated using high-pressure small-angle X-ray scattering (HP-SAXS). The pressure-temperature (p-T) diagrams for POPE mesophases in excess water were obtained in the presence and absence of G2 and G4 polyamidoamine (PAMAM) dendrimers (29 Å and 45 Å in diameter, respectively) at NP-lipid number ratios 0.0002-0.02) over the pressure range p = 1-3000 bar and temperature range T = 20-80 °C. The p-T phase diagram of POPE exhibited the Lβ, Lα and HII phases. Complete analysis of the phase diagrams, including the relative area pervaded by different phases, phase transition temperatures (Tt) and pressures (pt), the lattice parameters (d-spacing), the pressure-dependence of d-spacing (Δd/Δp), and the structural ordering in the mesophase as gauged by the Scherrer coherence length L, permitted insights into the size- and concentration-dependent interactions between the dendrimers and the model membrane system. The addition of dendrimers changed the phase transition pressure and temperature and resulted in the emergence of highly swollen lamellar phases, dubbed Lβ-den and Lα-den. G4 PAMAM dendrimers at the highest number ratio (0.02) suppressed the formation of the HII phase within the temperature range studied, whereas the addition of G2 PAMAM dendrimers at number ratio = 0.02 promoted an extended mixed lamellar region in which Lα and Lβ phases coexisted.
{"title":"Interactions between Dendritic Polymer Nanoparticles and Lipid Mesophases: Swollen Lamellae, Suppressed Curvature, and Augmented Structural Disorder","authors":"Laura J. Fox, L. Matthews, H. Stockdale, Supakit Pichai, T. Snow, R. Richardson, W. Briscoe","doi":"10.2139/ssrn.3436428","DOIUrl":"https://doi.org/10.2139/ssrn.3436428","url":null,"abstract":"Understanding interactions between nanoparticles and model membranes is relevant to functional nano-composites and the fundamentals of nanotoxicity. In this study, the effect of polyamidoamine (PAMAM) dendrimers as model nanoparticles (NP) on the mesophase behaviour of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE) has been investigated using high-pressure small-angle X-ray scattering (HP-SAXS). The pressure-temperature (p-T) diagrams for POPE mesophases in excess water were obtained in the presence and absence of G2 and G4 polyamidoamine (PAMAM) dendrimers (29 Å and 45 Å in diameter, respectively) at NP-lipid number ratios 0.0002-0.02) over the pressure range p = 1-3000 bar and temperature range T = 20-80 °C. The p-T phase diagram of POPE exhibited the L<sub>β</sub>, L<sub>α</sub> and H<sub>II</sub> phases. Complete analysis of the phase diagrams, including the relative area pervaded by different phases, phase transition temperatures (T<sub>t</sub>) and pressures (p<sub>t</sub>), the lattice parameters (d-spacing), the pressure-dependence of d-spacing (Δd/Δp), and the structural ordering in the mesophase as gauged by the Scherrer coherence length L, permitted insights into the size- and concentration-dependent interactions between the dendrimers and the model membrane system. The addition of dendrimers changed the phase transition pressure and temperature and resulted in the emergence of highly swollen lamellar phases, dubbed L<sub>β-den</sub> and L<sub>α-den</sub>. G4 PAMAM dendrimers at the highest number ratio (0.02) suppressed the formation of the H<sub>II</sub> phase within the temperature range studied, whereas the addition of G2 PAMAM dendrimers at number ratio = 0.02 promoted an extended mixed lamellar region in which L<sub>α</sub> and L<sub>β</sub> phases coexisted.","PeriodicalId":326657,"journal":{"name":"MatSciRN: Other Nanomaterials (Topic)","volume":"38-40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132109182","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}
As a new two-dimensional nanomaterial composed of sp2 carbon atom, graphene has unique electrical, optical and mechanical properties. At present, the research on graphene and its derivatives is mainly concentrated in the field of physics research. The chemical and material science research of graphene is also developing rapidly, and the research work of graphene in biomedicine field has just begun. Graphene oxide is a derivative of graphene, which has a high specific surface area and a rich functional group: the bottom surface contains a hydroxyl group and an epoxy group, and the edge contains a carboxyl group. These functional groups impart good hydrophilicity, dispersibility and biocompatibility to graphene oxide, are easy to modify and functionalize, and combined with their excellent optical properties, make graphene oxide have broad application prospects in the biomedical field. We herein briefly describe the recent advances in graphene, especially graphene oxide, in the biological and medical fields, including targeted drug delivery, cell imaging, bioassays, oncology, and graphene biosafety.
{"title":"Graphene: A Promising Candidate for Biomedical Use","authors":"Eva Clithy","doi":"10.2139/ssrn.3430841","DOIUrl":"https://doi.org/10.2139/ssrn.3430841","url":null,"abstract":"As a new two-dimensional nanomaterial composed of sp2 carbon atom, graphene has unique electrical, optical and mechanical properties. At present, the research on graphene and its derivatives is mainly concentrated in the field of physics research. The chemical and material science research of graphene is also developing rapidly, and the research work of graphene in biomedicine field has just begun. Graphene oxide is a derivative of graphene, which has a high specific surface area and a rich functional group: the bottom surface contains a hydroxyl group and an epoxy group, and the edge contains a carboxyl group. These functional groups impart good hydrophilicity, dispersibility and biocompatibility to graphene oxide, are easy to modify and functionalize, and combined with their excellent optical properties, make graphene oxide have broad application prospects in the biomedical field. We herein briefly describe the recent advances in graphene, especially graphene oxide, in the biological and medical fields, including targeted drug delivery, cell imaging, bioassays, oncology, and graphene biosafety.","PeriodicalId":326657,"journal":{"name":"MatSciRN: Other Nanomaterials (Topic)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115906927","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}
Abstract The issue, structural response of the amorphous-nanocrystalline alloys (ANA) under neutron irradiation, has been investigated by a series of simulations and calculations. It is found that the irradiation-induced vacancies are fully annihilated by the migration of the phase boundary between the nanocrystal and amorphous or liquid zones. In addition, there is an effective self-recovery in the amorphous zone and in particular the nanocrystal region, because the nanocrystal phase is more competitive than the amorphous phase during quenching. This work reveals a unique and effective structural self-healing mechanism in the ANA materials, and will shed light on the development of new materials with high irradiation resistance.
{"title":"Effective Self-Healing Behavior of Amorphous-Nanocrystalline Alloy Under Neutron Irradiation","authors":"Fan Xiong, Ming-fei Li, Liang Yang","doi":"10.2139/ssrn.3415190","DOIUrl":"https://doi.org/10.2139/ssrn.3415190","url":null,"abstract":"Abstract The issue, structural response of the amorphous-nanocrystalline alloys (ANA) under neutron irradiation, has been investigated by a series of simulations and calculations. It is found that the irradiation-induced vacancies are fully annihilated by the migration of the phase boundary between the nanocrystal and amorphous or liquid zones. In addition, there is an effective self-recovery in the amorphous zone and in particular the nanocrystal region, because the nanocrystal phase is more competitive than the amorphous phase during quenching. This work reveals a unique and effective structural self-healing mechanism in the ANA materials, and will shed light on the development of new materials with high irradiation resistance.","PeriodicalId":326657,"journal":{"name":"MatSciRN: Other Nanomaterials (Topic)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130625776","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}
D. Bowden, J. Ward, S. Middleburgh, S. M. Shubeita, E. Zapata-Solvas, T. Lapauw, J. Vleugels, K. Lambrinou, W. E. Lee, M. Preuss, P. Frankel
This work is a first assessment of the radiation tolerance of the nanolayered ternary carbides (MAX phases), Zr3AlC2, Nb4AlC3 and (Zr0.5,Ti0.5)3AlC2, using proton irradiation followed by post-irradiation examination based primarily on x-ray diffraction analysis. These specific MAX phase compounds are being evaluated as candidate coating materials for fuel cladding applications in advanced nuclear reactor systems. The aim of using a MAX phase coating is to protect the substrate fuel cladding material from corrosion damage during its exposure to the primary coolant. Proton irradiation was used in this study as a surrogate for neutron irradiation in order to introduce radiation damage into these ceramics at reactor-relevant temperatures. The post-irradiation examination of these materials revealed that the Zr-based 312-MAX phases, Zr3AlC2 and (Zr0.5,Ti0.5)3AlC2 have a superior ability for defect-recovery above 400 °C, whilst the Nb4AlC3 does not demonstrate any appreciable defect recovery below 600 °C. Density functional theory calculations have demonstrated that the structural differences between the 312 and 413-MAX phase structures govern the variation of the irradiation tolerance of these materials.
{"title":"The Stability of Irradiation-Induced Defects in Zr 3AlC 2, Nb 4AlC 3 and (Zr 0.5,Ti 0.5) 3AlC 2 Max Phase-Based Ceramics","authors":"D. Bowden, J. Ward, S. Middleburgh, S. M. Shubeita, E. Zapata-Solvas, T. Lapauw, J. Vleugels, K. Lambrinou, W. E. Lee, M. Preuss, P. Frankel","doi":"10.2139/ssrn.3414012","DOIUrl":"https://doi.org/10.2139/ssrn.3414012","url":null,"abstract":"This work is a first assessment of the radiation tolerance of the nanolayered ternary carbides (MAX phases), Zr<sub>3</sub>AlC<sub>2</sub>, Nb<sub>4</sub>AlC<sub>3</sub> and (Zr<sub>0.5</sub>,Ti<sub>0.5</sub>)<sub>3</sub>AlC<sub>2</sub>, using proton irradiation followed by post-irradiation examination based primarily on x-ray diffraction analysis. These specific MAX phase compounds are being evaluated as candidate coating materials for fuel cladding applications in advanced nuclear reactor systems. The aim of using a MAX phase coating is to protect the substrate fuel cladding material from corrosion damage during its exposure to the primary coolant. Proton irradiation was used in this study as a surrogate for neutron irradiation in order to introduce radiation damage into these ceramics at reactor-relevant temperatures. The post-irradiation examination of these materials revealed that the Zr-based 312-MAX phases, Zr<sub>3</sub>AlC<sub>2</sub> and (Zr<sub>0.5</sub>,Ti<sub>0.5</sub>)<sub>3</sub>AlC<sub>2</sub> have a superior ability for defect-recovery above 400 °C, whilst the Nb<sub>4</sub>AlC<sub>3</sub> does not demonstrate any appreciable defect recovery below 600 °C. Density functional theory calculations have demonstrated that the structural differences between the 312 and 413-MAX phase structures govern the variation of the irradiation tolerance of these materials.","PeriodicalId":326657,"journal":{"name":"MatSciRN: Other Nanomaterials (Topic)","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122733887","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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