Pub Date : 2020-12-23DOI: 10.1177/1847980420982119
N. R. Mohamad, M. R. Wee, M. A. Mohamed, A. A. Hamzah, P. Menon
Kretschmann-based surface plasmon resonance sensor utilizing chromium and gold nanofilms is ideal for label-free biomedical sensing. In this work, Taguchi’s L9 orthogonal array method was used to optimize the effects of three control factors and noise factor, which are the incident optical wavelength, chromium and gold nanofilm thicknesses, and their root-mean-square surface roughness, on the performance of the Kretschmann-based surface plasmon resonance sensor. The control factors were varied at three levels for a novel multi-response optimization of the Kretschmann-based surface plasmon resonance sensor for the minimum reflectivity, the full-width-at-half-maximum, and the sensitivity of 3% glucose detection, executed using Lumerical’s two-dimensional finite-difference time-domain method. Using Taguchi method, the best control factor setting in air was A3B2C2 corresponding to 785 nm optical wavelength, 0.5 nm chromium, and 50 nm gold layer thickness, respectively, with minimum reflectivity of 0.0017%, full-width-at-half-maximum of 0.4759°, and glucose-sensing sensitivity of 106.73°·RIU−1. The detection accuracy and quality factor were 0.01 and 224.26 RIU−1, respectively. It was also indicated that chromium nanofilm thickness of 0.5–3 nm and its root-mean-square surface roughness has a negligible factor effect compared to other control factors. Taguchi method’s factor effect analysis showed that for chromium layer thickness of 1–3 nm, the minimum reflectivity values are predominantly determined by the gold layer thickness with 75% factor effect, followed by optical wavelength with 11%. Factor effect of full-width-at-half-maximum is determined by optical wavelength (57%), followed by gold layer thickness (38%). Sensitivity is 88% determined by optical wavelength and 10% determined by gold layer thickness. The Kretschmann-based surface plasmon resonance glucose sensor with the best glucose-sensing sensitivity was at optical wavelength of 632.8 nm with a higher sensitivity value of 163.415°·RIU−1 but lower detection accuracy and quality factor values of 0.001 and 24.86 RIU−1, respectively, compared to near-infrared wavelength of 785 nm. In conclusion, finite-difference time-domain and Taguchi method is suitable for multi-response optimization of control and noise factors of Kretschmann-based surface plasmon resonance sensors.
{"title":"Multi-response optimization of chromium/gold-based nanofilm Kretschmann-based surface plasmon resonance glucose sensor using finite-difference time-domain and Taguchi method","authors":"N. R. Mohamad, M. R. Wee, M. A. Mohamed, A. A. Hamzah, P. Menon","doi":"10.1177/1847980420982119","DOIUrl":"https://doi.org/10.1177/1847980420982119","url":null,"abstract":"Kretschmann-based surface plasmon resonance sensor utilizing chromium and gold nanofilms is ideal for label-free biomedical sensing. In this work, Taguchi’s L9 orthogonal array method was used to optimize the effects of three control factors and noise factor, which are the incident optical wavelength, chromium and gold nanofilm thicknesses, and their root-mean-square surface roughness, on the performance of the Kretschmann-based surface plasmon resonance sensor. The control factors were varied at three levels for a novel multi-response optimization of the Kretschmann-based surface plasmon resonance sensor for the minimum reflectivity, the full-width-at-half-maximum, and the sensitivity of 3% glucose detection, executed using Lumerical’s two-dimensional finite-difference time-domain method. Using Taguchi method, the best control factor setting in air was A3B2C2 corresponding to 785 nm optical wavelength, 0.5 nm chromium, and 50 nm gold layer thickness, respectively, with minimum reflectivity of 0.0017%, full-width-at-half-maximum of 0.4759°, and glucose-sensing sensitivity of 106.73°·RIU−1. The detection accuracy and quality factor were 0.01 and 224.26 RIU−1, respectively. It was also indicated that chromium nanofilm thickness of 0.5–3 nm and its root-mean-square surface roughness has a negligible factor effect compared to other control factors. Taguchi method’s factor effect analysis showed that for chromium layer thickness of 1–3 nm, the minimum reflectivity values are predominantly determined by the gold layer thickness with 75% factor effect, followed by optical wavelength with 11%. Factor effect of full-width-at-half-maximum is determined by optical wavelength (57%), followed by gold layer thickness (38%). Sensitivity is 88% determined by optical wavelength and 10% determined by gold layer thickness. The Kretschmann-based surface plasmon resonance glucose sensor with the best glucose-sensing sensitivity was at optical wavelength of 632.8 nm with a higher sensitivity value of 163.415°·RIU−1 but lower detection accuracy and quality factor values of 0.001 and 24.86 RIU−1, respectively, compared to near-infrared wavelength of 785 nm. In conclusion, finite-difference time-domain and Taguchi method is suitable for multi-response optimization of control and noise factors of Kretschmann-based surface plasmon resonance sensors.","PeriodicalId":19018,"journal":{"name":"Nanomaterials and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2020-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1847980420982119","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49072888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-25DOI: 10.1177/1847980420965388
N. L. Razali, M. Morsin, S. Nafisah, Nur Zehan An’nisa Md Shah, F. Mahmud, S. Fhong, T. Aziz
A simple technique of seed-mediated growth has been successfully performed to grow anisotropy gold nanoparticles on solid substrates. The growth of the gold nanoparticles has been carried out in the presence of a binary surfactant mixture of hexadecyltrimethylammonium bromide with two different molecular weights of a capping agent, namely polyvinylpyrrolidone: 40,000 and 55,000. In this study, the effect of process parameters, growth time and molecular weight of capping agent was investigated. The growth time shows a significant impact on the shape and size of nanoparticles. The shorter growth time produced small spherical to square-like shape particles, whereas bigger particles including nanorods, nanosquares and nanotriangles were formed with longer growth time. The shape controlling agent, polyvinylpyrrolidone, was used to synthesis gold nanoparticles. It was found that monodisperse gold nanoparticles with uniform shape and size are hardly obtained when polyvinylpyrrolidone 40,000 was used as capping agent. Polyvinylpyrrolidone 55,000 produced more uniform shape and size of gold nanoparticles. Thus, these process parameters were found affected to the size, shape, surface density and uniformity of gold nanoparticles. This sample was further applied as a sensing material in the detection of toxic fungicide, namely chlorothalonil. The sensitivity of the sensor system was determined by the changes in peak positions and intensities of the transverse and longitudinal surface plasmon resonance peaks on different medium, that is, air, deionized water and chlorothalonil solution. The sensor response of gold nanoparticles thin film in 30 mM chlorothalonil showed two resonance peaks in comparison to the control experiment without gold nanoparticle thin film. The gold nanoparticles thin film sensor was successfully synthesized and potentially useful as a sensing material for fungicide detection.
{"title":"Formation of anisotropic gold nanoparticles on indium tin oxide substrates as a plasmonic sensing material","authors":"N. L. Razali, M. Morsin, S. Nafisah, Nur Zehan An’nisa Md Shah, F. Mahmud, S. Fhong, T. Aziz","doi":"10.1177/1847980420965388","DOIUrl":"https://doi.org/10.1177/1847980420965388","url":null,"abstract":"A simple technique of seed-mediated growth has been successfully performed to grow anisotropy gold nanoparticles on solid substrates. The growth of the gold nanoparticles has been carried out in the presence of a binary surfactant mixture of hexadecyltrimethylammonium bromide with two different molecular weights of a capping agent, namely polyvinylpyrrolidone: 40,000 and 55,000. In this study, the effect of process parameters, growth time and molecular weight of capping agent was investigated. The growth time shows a significant impact on the shape and size of nanoparticles. The shorter growth time produced small spherical to square-like shape particles, whereas bigger particles including nanorods, nanosquares and nanotriangles were formed with longer growth time. The shape controlling agent, polyvinylpyrrolidone, was used to synthesis gold nanoparticles. It was found that monodisperse gold nanoparticles with uniform shape and size are hardly obtained when polyvinylpyrrolidone 40,000 was used as capping agent. Polyvinylpyrrolidone 55,000 produced more uniform shape and size of gold nanoparticles. Thus, these process parameters were found affected to the size, shape, surface density and uniformity of gold nanoparticles. This sample was further applied as a sensing material in the detection of toxic fungicide, namely chlorothalonil. The sensitivity of the sensor system was determined by the changes in peak positions and intensities of the transverse and longitudinal surface plasmon resonance peaks on different medium, that is, air, deionized water and chlorothalonil solution. The sensor response of gold nanoparticles thin film in 30 mM chlorothalonil showed two resonance peaks in comparison to the control experiment without gold nanoparticle thin film. The gold nanoparticles thin film sensor was successfully synthesized and potentially useful as a sensing material for fungicide detection.","PeriodicalId":19018,"journal":{"name":"Nanomaterials and Nanotechnology","volume":"10 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2020-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1847980420965388","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"65714798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-25DOI: 10.1177/1847980420966887
N. Zamani, Mohd Nuriman Nawi, D. Berhanuddin, B. Majlis, A. M. Md Zain
In this article, we report modeling, simulation, and analysis of shifting 2D photonic crystal cavity side holes in GaN-AlN-sapphire layered structure. The design was simulated with Lumerical finite-difference time-domain. A lattice constant a, 157 nm, and a hole diameter d, 106 nm, were used in the design. The cavities are based on L3, which we demonstrated by simply shifting two holes away from a line cavity with distances of 132, 142, and 152 nm, respectively. The highest quality factor, Q, value achieved is 2.25 × 104 at 152-nm cavity distance.
{"title":"Design of 2D GaN photonic crystal based on hole displacement for L3 cavity","authors":"N. Zamani, Mohd Nuriman Nawi, D. Berhanuddin, B. Majlis, A. M. Md Zain","doi":"10.1177/1847980420966887","DOIUrl":"https://doi.org/10.1177/1847980420966887","url":null,"abstract":"In this article, we report modeling, simulation, and analysis of shifting 2D photonic crystal cavity side holes in GaN-AlN-sapphire layered structure. The design was simulated with Lumerical finite-difference time-domain. A lattice constant a, 157 nm, and a hole diameter d, 106 nm, were used in the design. The cavities are based on L3, which we demonstrated by simply shifting two holes away from a line cavity with distances of 132, 142, and 152 nm, respectively. The highest quality factor, Q, value achieved is 2.25 × 104 at 152-nm cavity distance.","PeriodicalId":19018,"journal":{"name":"Nanomaterials and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2020-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1847980420966887","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47750107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-19DOI: 10.1177/1847980420961697
P. Anbu, S. Gopinath, S. Jayanthi
Gold nanoparticles have many applications in the biomedical field, mainly for drug delivery, cancer therapy, and detection of pathogenic microorganisms. In this study, gold nanoparticles synthesized using Platycodon grandiflorum (Balloon flower plant) extracts were evaluated for their antibacterial potential. Gold nanoparticles were synthesized at 20–50°C using different volumes of the leaf extract. Biosynthesis of gold nanoparticles was confirmed by ultraviolet–visible spectral absorption at 545 nm by surface plasmon resonance. The morphology and size of the P. grandiflorum gold nanoparticles were further characterized as spherical in shape with an average size of 15 nm in diameter by scanning electron microscopy and transmission electron microscopy. Energy-dispersive X-ray analysis clearly displayed the presence of gold particles. The structural analysis results with face central cubic crystalline nature and elemental composition, including gold, were confirmed by X-ray diffraction and X-ray photoelectron spectroscopy, respectively. In addition, Fourier transform infrared results identified the functional group in P. grandiflorum that is involved in the reduction of metal ions to gold nanoparticles. The synthesized P. grandiflorum gold nanoparticles exhibited efficient antibacterial activity against Escherichia coli (16 mm) and Bacillus subtilis (11 mm). This report confirms the synthesis of gold nanoparticle from balloon flower plant extracts, which can be used as a reducing and stabilizing agent and demonstrates its antibacterial applications.
{"title":"Synthesis of gold nanoparticles using Platycodon grandiflorum extract and its antipathogenic activity under optimal conditions","authors":"P. Anbu, S. Gopinath, S. Jayanthi","doi":"10.1177/1847980420961697","DOIUrl":"https://doi.org/10.1177/1847980420961697","url":null,"abstract":"Gold nanoparticles have many applications in the biomedical field, mainly for drug delivery, cancer therapy, and detection of pathogenic microorganisms. In this study, gold nanoparticles synthesized using Platycodon grandiflorum (Balloon flower plant) extracts were evaluated for their antibacterial potential. Gold nanoparticles were synthesized at 20–50°C using different volumes of the leaf extract. Biosynthesis of gold nanoparticles was confirmed by ultraviolet–visible spectral absorption at 545 nm by surface plasmon resonance. The morphology and size of the P. grandiflorum gold nanoparticles were further characterized as spherical in shape with an average size of 15 nm in diameter by scanning electron microscopy and transmission electron microscopy. Energy-dispersive X-ray analysis clearly displayed the presence of gold particles. The structural analysis results with face central cubic crystalline nature and elemental composition, including gold, were confirmed by X-ray diffraction and X-ray photoelectron spectroscopy, respectively. In addition, Fourier transform infrared results identified the functional group in P. grandiflorum that is involved in the reduction of metal ions to gold nanoparticles. The synthesized P. grandiflorum gold nanoparticles exhibited efficient antibacterial activity against Escherichia coli (16 mm) and Bacillus subtilis (11 mm). This report confirms the synthesis of gold nanoparticle from balloon flower plant extracts, which can be used as a reducing and stabilizing agent and demonstrates its antibacterial applications.","PeriodicalId":19018,"journal":{"name":"Nanomaterials and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2020-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1847980420961697","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46262373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-03DOI: 10.1177/1847980420970052
A. Belay, Melaku Mekuria, Getachew Adam
The textile materials functionalized with nanostructures have proven to be useful for many applications, such as antimicrobial, ultraviolet (UV) light protection, and self-cleaning substrates. The objective of this research is to synthesize and characterize zinc oxide (ZnO) nanoparticles (NPs) for the applications of UV absorbers and antibacterial activities. ZnO NPs were synthesized at different temperatures and reaction media of water (S-1) and 1,2-ethanediol (S-2) using precipitation and in situ methods on the surface of cotton fabric. The average crystalline size of the ZnO NPs estimated from the Debye Scherrer formula was found to be 32 and 26 nm for S-1 and S-2, respectively. The morphology of ZnO NPs characterized by scanning electron microscope revealed that agglomerated nanostructures were homogeneously formed on the fabric surface for S-1 and S-2; on the other hand, bundle-/flower-like particles having different sizes were observed for synthesis using an in situ method. The UV protection ability of ZnO NPs coated on textiles was investigated using UV-Vis spectroscopy by measuring the UV protection factor (UPF) in the range of 280–400 nm. Higher values of UPF were obtained for ZnO NPs prepared using an in situ method. The UPF value obtained by this method was found to be 320, which demonstrates its excellent ability to block UV radiation. The antibacterial activities of ZnO NPs synthesized by the two methods possess very good bacteriostatic activity against Staphylococcus aureus and Escherichia coli bacteria demonstrated by the zone of inhibition.
{"title":"Incorporation of zinc oxide nanoparticles in cotton textiles for ultraviolet light protection and antibacterial activities","authors":"A. Belay, Melaku Mekuria, Getachew Adam","doi":"10.1177/1847980420970052","DOIUrl":"https://doi.org/10.1177/1847980420970052","url":null,"abstract":"The textile materials functionalized with nanostructures have proven to be useful for many applications, such as antimicrobial, ultraviolet (UV) light protection, and self-cleaning substrates. The objective of this research is to synthesize and characterize zinc oxide (ZnO) nanoparticles (NPs) for the applications of UV absorbers and antibacterial activities. ZnO NPs were synthesized at different temperatures and reaction media of water (S-1) and 1,2-ethanediol (S-2) using precipitation and in situ methods on the surface of cotton fabric. The average crystalline size of the ZnO NPs estimated from the Debye Scherrer formula was found to be 32 and 26 nm for S-1 and S-2, respectively. The morphology of ZnO NPs characterized by scanning electron microscope revealed that agglomerated nanostructures were homogeneously formed on the fabric surface for S-1 and S-2; on the other hand, bundle-/flower-like particles having different sizes were observed for synthesis using an in situ method. The UV protection ability of ZnO NPs coated on textiles was investigated using UV-Vis spectroscopy by measuring the UV protection factor (UPF) in the range of 280–400 nm. Higher values of UPF were obtained for ZnO NPs prepared using an in situ method. The UPF value obtained by this method was found to be 320, which demonstrates its excellent ability to block UV radiation. The antibacterial activities of ZnO NPs synthesized by the two methods possess very good bacteriostatic activity against Staphylococcus aureus and Escherichia coli bacteria demonstrated by the zone of inhibition.","PeriodicalId":19018,"journal":{"name":"Nanomaterials and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2020-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1847980420970052","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41816153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-27DOI: 10.1177/1847980420957555
Huixin Xiong, Xiancai Lu, Rucheng Wang
Schwertmannite has been considered as the host mineral and potentially excellent adsorbent of contaminates from waters, and it has various morphologies of spheroid with pincushions, whiskers, hedge-hogs, and needles. In this work, using the (high-resolution transmission and field-emission scanning) electron microscopes, we studied nanostructure, morphological evolution, and difference in chemical composition for the produced schwertmannites in the cell-rich iron solutions. All analysis results showed within cellular 36-h reproduction period, the production of only schwertmannite was examined in iron solutions at the Cl−/SO4 2− molar ratios of 0–10 and pH 3.0 ± 0.1. There were differences in two typical morphologies of “pincushions” (Cl−/SO4 2− = 0 and 3) and “hedge-hogs” (Cl−/SO4 2− = 6 and 10) for the schwertmannite nanostructures. And all final schwertmannite particles had the chemical formulas of Fe8O8(OH)8−2x (SO4) x (1.08 ≤ x ≤ 1.66), especially as Cl−/SO4 2− = 0, the visible “pincushions” only being the outermost sections of the whole needles existing in a tightly spherical assemblage of schwertmannite. Moreover, the absence of ferrihydrite and goethite was determined in the nanodimension of these needles, though the initial Fe and SO4 2− were 5600 and of 9600 µg/mL, respectively. It could be induced by the amounts and activities of aqueous Fe, SO4 2−, and Cl− associated with cellular activities and mineral precipitation. This study will be useful for understanding the actual occurrence of iron oxyhydroxide nanostructure and better developing its potential environmental application.
{"title":"Anionic effect on nanostructure and morphology of bio-schwertmannite dynamically produced within cellular reproduction","authors":"Huixin Xiong, Xiancai Lu, Rucheng Wang","doi":"10.1177/1847980420957555","DOIUrl":"https://doi.org/10.1177/1847980420957555","url":null,"abstract":"Schwertmannite has been considered as the host mineral and potentially excellent adsorbent of contaminates from waters, and it has various morphologies of spheroid with pincushions, whiskers, hedge-hogs, and needles. In this work, using the (high-resolution transmission and field-emission scanning) electron microscopes, we studied nanostructure, morphological evolution, and difference in chemical composition for the produced schwertmannites in the cell-rich iron solutions. All analysis results showed within cellular 36-h reproduction period, the production of only schwertmannite was examined in iron solutions at the Cl−/SO4 2− molar ratios of 0–10 and pH 3.0 ± 0.1. There were differences in two typical morphologies of “pincushions” (Cl−/SO4 2− = 0 and 3) and “hedge-hogs” (Cl−/SO4 2− = 6 and 10) for the schwertmannite nanostructures. And all final schwertmannite particles had the chemical formulas of Fe8O8(OH)8−2x (SO4) x (1.08 ≤ x ≤ 1.66), especially as Cl−/SO4 2− = 0, the visible “pincushions” only being the outermost sections of the whole needles existing in a tightly spherical assemblage of schwertmannite. Moreover, the absence of ferrihydrite and goethite was determined in the nanodimension of these needles, though the initial Fe and SO4 2− were 5600 and of 9600 µg/mL, respectively. It could be induced by the amounts and activities of aqueous Fe, SO4 2−, and Cl− associated with cellular activities and mineral precipitation. This study will be useful for understanding the actual occurrence of iron oxyhydroxide nanostructure and better developing its potential environmental application.","PeriodicalId":19018,"journal":{"name":"Nanomaterials and Nanotechnology","volume":"10 1","pages":""},"PeriodicalIF":3.7,"publicationDate":"2020-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1847980420957555","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41407974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-20DOI: 10.1177/1847980420955093
A. Verma, Federico Raffone, G. Cicero
Two-dimensional transition metal dichalcogenides have gained great attention because of their peculiar physical properties that make them interesting for a wide range of applications. Lately, alloying between different transition metal dichalcogenides has been proposed as an approach to control two-dimensional phase stability and to obtain compounds with tailored characteristics. In this theoretical study, we predict the phase diagram and the electronic properties of Mo x Ti1−x S2 at varying stoichiometry and show how the material is metallic, when titanium is the predominant species, while it behaves as a p-doped semiconductor, when approaching pure MoS2 composition. Correspondingly, the thermodynamically most stable phase switches from the tetragonal to the hexagonal one. Further, we present an example which shows how the proposed alloys can be used to obtain new vertical two-dimensional heterostructures achieving effective electron/hole separation.
二维过渡金属二硫族化合物因其独特的物理性质而受到广泛关注。最近，不同过渡金属二硫族化合物之间的合金化被提出作为控制二维相稳定性和获得具有定制特性的化合物的一种方法。在这项理论研究中，我们预测了Mo x Ti1−x S2在不同化学计量下的相图和电子性质，并展示了当钛是主要物种时，该材料是金属的，而当接近纯MoS2成分时，它表现为p掺杂半导体。相应地，热力学上最稳定的相从四方相转变为六边形相。此外，我们还举了一个例子，展示了如何使用所提出的合金来获得新的垂直二维异质结构，从而实现有效的电子/空穴分离。
{"title":"Prediction of the structural and electronic properties of Mo x Ti1−x S2 monolayers via first principle simulations","authors":"A. Verma, Federico Raffone, G. Cicero","doi":"10.1177/1847980420955093","DOIUrl":"https://doi.org/10.1177/1847980420955093","url":null,"abstract":"Two-dimensional transition metal dichalcogenides have gained great attention because of their peculiar physical properties that make them interesting for a wide range of applications. Lately, alloying between different transition metal dichalcogenides has been proposed as an approach to control two-dimensional phase stability and to obtain compounds with tailored characteristics. In this theoretical study, we predict the phase diagram and the electronic properties of Mo x Ti1−x S2 at varying stoichiometry and show how the material is metallic, when titanium is the predominant species, while it behaves as a p-doped semiconductor, when approaching pure MoS2 composition. Correspondingly, the thermodynamically most stable phase switches from the tetragonal to the hexagonal one. Further, we present an example which shows how the proposed alloys can be used to obtain new vertical two-dimensional heterostructures achieving effective electron/hole separation.","PeriodicalId":19018,"journal":{"name":"Nanomaterials and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2020-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1847980420955093","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49494394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-09DOI: 10.1177/1847980420964368
M. Gouda, A. H. Konsowa, H. Farag, Noha A. Elessawy, T. Tamer, M. S. Mohy Eldin
Developing low cost and highly active fuel cell is one of the high-priority research directions for fuel cell commercialization, whereas durable electrodes and electrolyte membranes are keys for its optimization. Herein, a novel nanocomposite electrolyte membranes for direct methanol fuel cell were prepared from eco-friendly polymer blend composed of poly(vinyl alcohol) (PVA) and iota carrageenan (IC). Sulfated titania (SO4TiO2) nanotubes are synthesized by impregnation–calcination method and incorporated as doping agents into the polymer matrix with different percentage ranged between 1 wt% and .5 wt%. The PVA/IC/SO4TiO2 nanocomposite membranes exhibited reduction in water and methanol uptake compared to that of undoped membrane, while the thermal properties and oxidative stability increased as the doping agent content increased. Methanol permeability of PVA/IC/ S O 4 2 − -TiO2-7.5 membrane was 0.62 × 10−7 cm2 s−1, which is 43 times lower than Nafion 117 (26.9 × 10−7 cm2 s−1). Furthermore, it was noticed that the ion exchange capacity and mechanical properties of the nanocomposite membranes are higher than that of Nafion 117.
开发低成本、高活性的燃料电池是燃料电池商业化的重点研究方向之一，而耐用的电极和电解质膜是优化燃料电池的关键。以聚乙烯醇(PVA)和角叉菜胶(IC)为原料，制备了一种新型的直接甲醇燃料电池纳米复合电解质膜。采用浸渍-煅烧法制备了硫酸钛(SO4TiO2)纳米管，并将其作为掺杂剂掺入到聚合物基体中，掺杂剂的掺量在1 ~ 0.5 wt%之间。与未掺杂PVA/IC/SO4TiO2纳米复合膜相比，PVA/IC/SO4TiO2纳米复合膜的水和甲醇吸收率降低，而随着掺杂剂含量的增加，其热性能和氧化稳定性提高。PVA/IC/ S O 4 2−-TiO2-7.5膜的甲醇渗透率为0.62 × 10−7 cm2 S−1，比Nafion 117 (26.9 × 10−7 cm2 S−1)低43倍。此外，纳米复合膜的离子交换能力和力学性能均高于Nafion 117。
{"title":"Novel nanocomposite membranes based on cross-linked eco-friendly polymers doped with sulfated titania nanotubes for direct methanol fuel cell application","authors":"M. Gouda, A. H. Konsowa, H. Farag, Noha A. Elessawy, T. Tamer, M. S. Mohy Eldin","doi":"10.1177/1847980420964368","DOIUrl":"https://doi.org/10.1177/1847980420964368","url":null,"abstract":"Developing low cost and highly active fuel cell is one of the high-priority research directions for fuel cell commercialization, whereas durable electrodes and electrolyte membranes are keys for its optimization. Herein, a novel nanocomposite electrolyte membranes for direct methanol fuel cell were prepared from eco-friendly polymer blend composed of poly(vinyl alcohol) (PVA) and iota carrageenan (IC). Sulfated titania (SO4TiO2) nanotubes are synthesized by impregnation–calcination method and incorporated as doping agents into the polymer matrix with different percentage ranged between 1 wt% and .5 wt%. The PVA/IC/SO4TiO2 nanocomposite membranes exhibited reduction in water and methanol uptake compared to that of undoped membrane, while the thermal properties and oxidative stability increased as the doping agent content increased. Methanol permeability of PVA/IC/ S O 4 2 − -TiO2-7.5 membrane was 0.62 × 10−7 cm2 s−1, which is 43 times lower than Nafion 117 (26.9 × 10−7 cm2 s−1). Furthermore, it was noticed that the ion exchange capacity and mechanical properties of the nanocomposite membranes are higher than that of Nafion 117.","PeriodicalId":19018,"journal":{"name":"Nanomaterials and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2020-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1847980420964368","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43183792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-29DOI: 10.1177/1847980420950988
N. Alhakamy, H. Aldawsari, K. Hosny, J. Ahmad, S. Akhter, Ahmed K. Kammoun, Adel F. Alghaith, Hani Asfour, Mohammed W Al-Rabia, Shadab Md
Docosahexaenoic acid is a omega-3-fatty acid which together with other long-chain omega-3-fatty acid known to have protective effect against various diseases including hypertension, myocardial infarction, Alzheimer disease, and cancers. Poor bioavailability owning to limited aqueous solubility limits its effective therapeutic delivery. Self-nanoemulsifying drug delivery systems are known to enhance the systemic absorption of poorly bioavailable lipophilic bioactive/therapeutics compounds. The purpose of this work was to investigate the potential of self-nanoemulsifying drug delivery systems produced by spontaneous nanoemulsification to enhance the oral bioavailability of docosahexaenoic acid. Initially, the screening of oil, surfactant, and cosurfactant was carried out by determining the miscibility and emulsifiability of the component with docosahexaenoic acid. Docosahexaenoic acid-containing self-nanoemulsifying drug delivery systems were prepared using Capryol 90, Tween 20, and polyethylene glycol 200 due to their excellent miscibility and emulsifiability with docosahexaenoic acid. Docosahexaenoic acid-containing self-nanoemulsifying drug delivery systems’ droplet size, size distribution, and zeta potential were found to be 111.5 ± 4.2 nm, 0.269 ± 0.05 nm, and −23.53 ± 2.9 mV, respectively. The in vitro drug release and ex vivo absorption studies showed better in vitro release and intestinal absorption as compared to docosahexaenoic acid aqueous dispersion. In vivo studies demonstrated a significant increase (p < 0.001) in the oral bioavailability of docosahexaenoic acid-containing self-nanoemulsifying drug delivery systems in comparison to a docosahexaenoic acid aqueous dispersion. This indicated the potential of self-nanoemulsifying drug delivery systems as an effective unit dosage form for the oral delivery of docosahexaenoic acid.
{"title":"Formulation design and pharmacokinetic evaluation of docosahexaenoic acid containing self-nanoemulsifying drug delivery system for oral administration","authors":"N. Alhakamy, H. Aldawsari, K. Hosny, J. Ahmad, S. Akhter, Ahmed K. Kammoun, Adel F. Alghaith, Hani Asfour, Mohammed W Al-Rabia, Shadab Md","doi":"10.1177/1847980420950988","DOIUrl":"https://doi.org/10.1177/1847980420950988","url":null,"abstract":"Docosahexaenoic acid is a omega-3-fatty acid which together with other long-chain omega-3-fatty acid known to have protective effect against various diseases including hypertension, myocardial infarction, Alzheimer disease, and cancers. Poor bioavailability owning to limited aqueous solubility limits its effective therapeutic delivery. Self-nanoemulsifying drug delivery systems are known to enhance the systemic absorption of poorly bioavailable lipophilic bioactive/therapeutics compounds. The purpose of this work was to investigate the potential of self-nanoemulsifying drug delivery systems produced by spontaneous nanoemulsification to enhance the oral bioavailability of docosahexaenoic acid. Initially, the screening of oil, surfactant, and cosurfactant was carried out by determining the miscibility and emulsifiability of the component with docosahexaenoic acid. Docosahexaenoic acid-containing self-nanoemulsifying drug delivery systems were prepared using Capryol 90, Tween 20, and polyethylene glycol 200 due to their excellent miscibility and emulsifiability with docosahexaenoic acid. Docosahexaenoic acid-containing self-nanoemulsifying drug delivery systems’ droplet size, size distribution, and zeta potential were found to be 111.5 ± 4.2 nm, 0.269 ± 0.05 nm, and −23.53 ± 2.9 mV, respectively. The in vitro drug release and ex vivo absorption studies showed better in vitro release and intestinal absorption as compared to docosahexaenoic acid aqueous dispersion. In vivo studies demonstrated a significant increase (p < 0.001) in the oral bioavailability of docosahexaenoic acid-containing self-nanoemulsifying drug delivery systems in comparison to a docosahexaenoic acid aqueous dispersion. This indicated the potential of self-nanoemulsifying drug delivery systems as an effective unit dosage form for the oral delivery of docosahexaenoic acid.","PeriodicalId":19018,"journal":{"name":"Nanomaterials and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2020-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1847980420950988","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46685777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-09-29DOI: 10.1177/1847980420961638
Kanyanee Sanglee, S. Chuangchote, T. Krajangsang, J. Sritharathikhun, K. Sriprapha, T. Sagawa
Perovskite solar cells have been attracted as new representatives for the third-generation photovoltaic devices. Simple strategies for high efficiency with the long-term stability of solar cells are the challenges for commercial solar cell technology. Another challenge of the development toward industrial scale in perovskite solar cells is the production under the ambient and high humidity. In this sense, we successfully fabricated perovskite solar cells via solution depositions of all layers under ambient air with a relative humidity above 50%. Titanium dioxide (TiO2) nanoparticles with the roles for efficient charge extraction and electron transportation properties were used as an electron-transporting layer in the cell fabrication. The modification of TiO2 nanoparticles for energy band adjustment was done by doping with nontoxic cadmium sulfide (CdS) quantum dots. With the variation of CdS concentrations, energy band is not only changeable, but the enhancement of the perovskite solar cells efficiency could be achieved compared with the conventional cells made of pristine-TiO2 film and TiO2 nanoparticles.
{"title":"Quantum dot-modified titanium dioxide nanoparticles as an energy-band tunable electron-transporting layer for open air-fabricated planar perovskite solar cells","authors":"Kanyanee Sanglee, S. Chuangchote, T. Krajangsang, J. Sritharathikhun, K. Sriprapha, T. Sagawa","doi":"10.1177/1847980420961638","DOIUrl":"https://doi.org/10.1177/1847980420961638","url":null,"abstract":"Perovskite solar cells have been attracted as new representatives for the third-generation photovoltaic devices. Simple strategies for high efficiency with the long-term stability of solar cells are the challenges for commercial solar cell technology. Another challenge of the development toward industrial scale in perovskite solar cells is the production under the ambient and high humidity. In this sense, we successfully fabricated perovskite solar cells via solution depositions of all layers under ambient air with a relative humidity above 50%. Titanium dioxide (TiO2) nanoparticles with the roles for efficient charge extraction and electron transportation properties were used as an electron-transporting layer in the cell fabrication. The modification of TiO2 nanoparticles for energy band adjustment was done by doping with nontoxic cadmium sulfide (CdS) quantum dots. With the variation of CdS concentrations, energy band is not only changeable, but the enhancement of the perovskite solar cells efficiency could be achieved compared with the conventional cells made of pristine-TiO2 film and TiO2 nanoparticles.","PeriodicalId":19018,"journal":{"name":"Nanomaterials and Nanotechnology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2020-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/1847980420961638","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44348281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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