J. Horák, A. Nikiforov, F. Krčma, M. Březina, Z. Kozáková, L. Dostal, M. Kalina, L. Kalina
Abstract In recent years, nanoparticles have emerged as an important player in a broad range of applications, especially thanks to recent advances in their synthesis. The silver and copper nanoparticles are often used due to their antibacterial and fungicidal activities, and this article presents the results of the nanoparticle synthesis using electrical glow discharge generated directly in a volume of their salt solutions. Therefore, there is no influence of air (i.e. reactive nitrogen species) as it is usual in other commonly used approaches. Nanoparticles were prepared under various experimental conditions, and they were characterized by ultraviolet/visible spectrometry, dynamic light scattering, X-ray photoelectron spectroscopy, and high-resolution scanning electron microscopy. Particles were produced without any surfactant or stabilizing agent, and some of them showed higher resistance against agglomeration during their short-term (days) storage. The nanoparticle formation mechanism was confirmed by the fast camera imaging. Thus, the developed approach can be applied for simple environmentally friendly nanoparticle production for various applications.
{"title":"Synthesis of Ag and Cu nanoparticles by plasma discharge in inorganic salt solutions","authors":"J. Horák, A. Nikiforov, F. Krčma, M. Březina, Z. Kozáková, L. Dostal, M. Kalina, L. Kalina","doi":"10.1515/ntrev-2022-0549","DOIUrl":"https://doi.org/10.1515/ntrev-2022-0549","url":null,"abstract":"Abstract In recent years, nanoparticles have emerged as an important player in a broad range of applications, especially thanks to recent advances in their synthesis. The silver and copper nanoparticles are often used due to their antibacterial and fungicidal activities, and this article presents the results of the nanoparticle synthesis using electrical glow discharge generated directly in a volume of their salt solutions. Therefore, there is no influence of air (i.e. reactive nitrogen species) as it is usual in other commonly used approaches. Nanoparticles were prepared under various experimental conditions, and they were characterized by ultraviolet/visible spectrometry, dynamic light scattering, X-ray photoelectron spectroscopy, and high-resolution scanning electron microscopy. Particles were produced without any surfactant or stabilizing agent, and some of them showed higher resistance against agglomeration during their short-term (days) storage. The nanoparticle formation mechanism was confirmed by the fast camera imaging. Thus, the developed approach can be applied for simple environmentally friendly nanoparticle production for various applications.","PeriodicalId":18839,"journal":{"name":"Nanotechnology Reviews","volume":" ","pages":""},"PeriodicalIF":7.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42554396","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}
Siyi Chen, Shuang Yang, Sisi Chen, Fang Zuo, Pan Wang, Ying Li, Yong You
Abstract In this work, mussel-inspired surface functionalization of halloysite nanotubes (HNTs) were coated by in situ self-polymerization of polydopamine (PDA) to synthesize core-shell structural composites (HNTs@PDA), and then incorporated into polyarylene ether nitrile (PEN) matrix. Due to the strong adhesion of the PDA modification layer and the formation of hydrogen bonds between the polar nitrile group of PEN and the catechol group of PDA, the dispersion and interfacial compatibility of HNTs@PDA in the PEN matrix are improved. The results show that the dielectric constant of PEN/HNTs@PDA 20 nanocomposites reaches 11.56 (1 kHz), which is 3.2 times that of pure PEN. In addition, after heat treatment, a chemical cross-linking reaction occurred between the PEN matrix to form a cross-linked PEN (CPEN) based nanocomposites, which further improved the thermal stability of the nanocomposites. The results show that the T g of CPEN/HNTs@PDA 20 nanocomposites reaches 215.5°C, which is 47.7°C higher than that of PEN/HNTs@PDA 20. Moreover, the dielectric constant-temperature coefficient of all CPEN nanocomposites is less than 7 × 10−4°C−1 at the temperature range of 25–180°C. All in all, this work provides a simple and environmentally friendly strategy to adjust the dielectric properties of polymer-based ceramic nanocomposites, which provides a pathway for its application as a dielectric material in the film capacitors field.
{"title":"Polyarylene ether nitrile dielectric films modified by HNTs@PDA hybrids for high-temperature resistant organic electronics field","authors":"Siyi Chen, Shuang Yang, Sisi Chen, Fang Zuo, Pan Wang, Ying Li, Yong You","doi":"10.1515/ntrev-2023-0117","DOIUrl":"https://doi.org/10.1515/ntrev-2023-0117","url":null,"abstract":"Abstract In this work, mussel-inspired surface functionalization of halloysite nanotubes (HNTs) were coated by in situ self-polymerization of polydopamine (PDA) to synthesize core-shell structural composites (HNTs@PDA), and then incorporated into polyarylene ether nitrile (PEN) matrix. Due to the strong adhesion of the PDA modification layer and the formation of hydrogen bonds between the polar nitrile group of PEN and the catechol group of PDA, the dispersion and interfacial compatibility of HNTs@PDA in the PEN matrix are improved. The results show that the dielectric constant of PEN/HNTs@PDA 20 nanocomposites reaches 11.56 (1 kHz), which is 3.2 times that of pure PEN. In addition, after heat treatment, a chemical cross-linking reaction occurred between the PEN matrix to form a cross-linked PEN (CPEN) based nanocomposites, which further improved the thermal stability of the nanocomposites. The results show that the T g of CPEN/HNTs@PDA 20 nanocomposites reaches 215.5°C, which is 47.7°C higher than that of PEN/HNTs@PDA 20. Moreover, the dielectric constant-temperature coefficient of all CPEN nanocomposites is less than 7 × 10−4°C−1 at the temperature range of 25–180°C. All in all, this work provides a simple and environmentally friendly strategy to adjust the dielectric properties of polymer-based ceramic nanocomposites, which provides a pathway for its application as a dielectric material in the film capacitors field.","PeriodicalId":18839,"journal":{"name":"Nanotechnology Reviews","volume":" ","pages":""},"PeriodicalIF":7.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44771737","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}
Ruihao Zhang, Sha Qing, Xiaohui Zhang, Zhumei Luo, Yiqing Liu
Abstract The mechanisms of thermal conductivity enhancement and the factors influencing viscosity are of great interest in the study of nanofluids, while molecular dynamics (MD) simulations considering nanofluids provide more accurate predictions of microscopic properties than conventional experimental studies. MD simulations of non-equilibrium molecular dynamics and reversing perturbation non-equilibrium molecular dynamics methods were used to study thermal conductivity and viscosity, taking into account a variety of influencing factors, as well as nanoparticle material and volume fraction. Through the analysis of the number density distribution, radial distribution function (RDF), and mean square displacement (MSD), the influences of different nanoparticles (Ag, Cu, Au, and Fe) were described and investigated: Ag particles contribute to 47.0% increase in thermal conductivity of 2.5 vol% nanofluids; Au particles improved the viscosity of 2.5 vol% nanofluids by 20.2%; the number density distribution showed positive linear relationship with the atomic mass; the results of MSD and RDF (mean square displacement and radial distribution function) in combination indicated a positive effect of interfacial nanolayer. The results of this research provide important perspectives for comprehending the impacts of multiple nanoparticles on the micro-thermal properties of nanofluids and also highlight the simulation potential of Au–Ar nanofluids.
{"title":"Investigation of different nanoparticles properties on the thermal conductivity and viscosity of nanofluids by molecular dynamics simulation","authors":"Ruihao Zhang, Sha Qing, Xiaohui Zhang, Zhumei Luo, Yiqing Liu","doi":"10.1515/ntrev-2022-0562","DOIUrl":"https://doi.org/10.1515/ntrev-2022-0562","url":null,"abstract":"Abstract The mechanisms of thermal conductivity enhancement and the factors influencing viscosity are of great interest in the study of nanofluids, while molecular dynamics (MD) simulations considering nanofluids provide more accurate predictions of microscopic properties than conventional experimental studies. MD simulations of non-equilibrium molecular dynamics and reversing perturbation non-equilibrium molecular dynamics methods were used to study thermal conductivity and viscosity, taking into account a variety of influencing factors, as well as nanoparticle material and volume fraction. Through the analysis of the number density distribution, radial distribution function (RDF), and mean square displacement (MSD), the influences of different nanoparticles (Ag, Cu, Au, and Fe) were described and investigated: Ag particles contribute to 47.0% increase in thermal conductivity of 2.5 vol% nanofluids; Au particles improved the viscosity of 2.5 vol% nanofluids by 20.2%; the number density distribution showed positive linear relationship with the atomic mass; the results of MSD and RDF (mean square displacement and radial distribution function) in combination indicated a positive effect of interfacial nanolayer. The results of this research provide important perspectives for comprehending the impacts of multiple nanoparticles on the micro-thermal properties of nanofluids and also highlight the simulation potential of Au–Ar nanofluids.","PeriodicalId":18839,"journal":{"name":"Nanotechnology Reviews","volume":" ","pages":""},"PeriodicalIF":7.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45558072","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}
M. Mansor, N. H. Zainol Abidin, N. Mohd Yusoff, K. Lau, J. Chyi, V. Janyani, A. Garg, M. Alresheedi, M. Mahdi
Abstract This work demonstrates the employment of tungsten trioxide/polydimethylsiloxane nanocomposite saturable absorber (WO3/PDMS-SA) in realizing mode-locked conventional soliton (CS) and noise-like pulse (NLP) laser generation in net anomalous dispersion. The switching formation from CS regime of 970.0 fs pulse duration to NLP regime of 182.0 fs coherent spike with 65.3 ps pedestal was achieved by varying its pump power. The pulse laser exhibited good stability of 50.76 and 49.82 dB signal-to-noise ratio at 9.09 MHz fundamental repetition rate and trivial variation during stability test for CS and NLP regime, respectively. This work expresses the feasibility of WO3/PDMS-SA in attaining various types of mode-locked pulse phenomena using a fixed cavity configuration conceivably beneficial for compact dual-purpose laser systems.
{"title":"Tungsten trioxide nanocomposite for conventional soliton and noise-like pulse generation in anomalous dispersion laser cavity","authors":"M. Mansor, N. H. Zainol Abidin, N. Mohd Yusoff, K. Lau, J. Chyi, V. Janyani, A. Garg, M. Alresheedi, M. Mahdi","doi":"10.1515/ntrev-2022-0535","DOIUrl":"https://doi.org/10.1515/ntrev-2022-0535","url":null,"abstract":"Abstract This work demonstrates the employment of tungsten trioxide/polydimethylsiloxane nanocomposite saturable absorber (WO3/PDMS-SA) in realizing mode-locked conventional soliton (CS) and noise-like pulse (NLP) laser generation in net anomalous dispersion. The switching formation from CS regime of 970.0 fs pulse duration to NLP regime of 182.0 fs coherent spike with 65.3 ps pedestal was achieved by varying its pump power. The pulse laser exhibited good stability of 50.76 and 49.82 dB signal-to-noise ratio at 9.09 MHz fundamental repetition rate and trivial variation during stability test for CS and NLP regime, respectively. This work expresses the feasibility of WO3/PDMS-SA in attaining various types of mode-locked pulse phenomena using a fixed cavity configuration conceivably beneficial for compact dual-purpose laser systems.","PeriodicalId":18839,"journal":{"name":"Nanotechnology Reviews","volume":" ","pages":""},"PeriodicalIF":7.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43883970","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}
Abstract Terahertz (THz) quantum cascade laser (QCL) is an electrically pumped unipolar photonic device in which light emission takes place due to electronic transitions between subbands formed by multiple strongly coupled quantum wells. THz QCL is arguably the most promising solid-state source to realize various THz applications, such as high-resolution spectroscopy, real-time imaging, chemical and biological sensing, and high-speed wireless communication. To date, THz QCLs have covered emitting frequency from 1.2 to 5.4 THz when operating without the assistance of an external magnetic field. The highest output power is in hundreds milliwatt and watt levels continuous-mode and pulsed-mode operations, respectively. THz QCL-based local oscillators have been implemented in astronomy for the identification of atoms and ions. However, there are also limitations, including under room-temperature operation, large divergent beam, narrow single-mode frequency tuning range, incomplete polarization control, and narrow-range frequency comb operation that hinder the widespread applications of THz QCLs. Continuous efforts have been made to improve those THz QCL properties in order to satisfy the requirements of different THz applications. This report will review the key output characteristic developments of THz QCLs in the past few years, which aim to speed up THz QCLs toward practical applications.
{"title":"Recent developments in terahertz quantum cascade lasers for practical applications","authors":"Liang Gao, Chao Feng, Xian Zhao","doi":"10.1515/ntrev-2023-0115","DOIUrl":"https://doi.org/10.1515/ntrev-2023-0115","url":null,"abstract":"Abstract Terahertz (THz) quantum cascade laser (QCL) is an electrically pumped unipolar photonic device in which light emission takes place due to electronic transitions between subbands formed by multiple strongly coupled quantum wells. THz QCL is arguably the most promising solid-state source to realize various THz applications, such as high-resolution spectroscopy, real-time imaging, chemical and biological sensing, and high-speed wireless communication. To date, THz QCLs have covered emitting frequency from 1.2 to 5.4 THz when operating without the assistance of an external magnetic field. The highest output power is in hundreds milliwatt and watt levels continuous-mode and pulsed-mode operations, respectively. THz QCL-based local oscillators have been implemented in astronomy for the identification of atoms and ions. However, there are also limitations, including under room-temperature operation, large divergent beam, narrow single-mode frequency tuning range, incomplete polarization control, and narrow-range frequency comb operation that hinder the widespread applications of THz QCLs. Continuous efforts have been made to improve those THz QCL properties in order to satisfy the requirements of different THz applications. This report will review the key output characteristic developments of THz QCLs in the past few years, which aim to speed up THz QCLs toward practical applications.","PeriodicalId":18839,"journal":{"name":"Nanotechnology Reviews","volume":" ","pages":""},"PeriodicalIF":7.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45612663","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}
Abstract Electrohydrodynamic-jet (E-jet) printing is an on-demand additive manufacturing method that allows various functional materials to be directly deposited on the target substrate. Many theoretical and experimental results indicate that E-jet has scale effect, and reducing the inner diameter of the nozzle can effectively improve printing resolution. Herein, a method for fabricating SU-8 polymer micro/nanoscale nozzle by oxygen plasma assisted room temperature bonding was proposed. It can prevent channel deformation and blockage caused by excessive bonding temperature. The surface modification parameters of silicon nano-mold were optimized, the influence of hot embossing parameters on the replication precision of nano patterns was investigated, the effect of UV lithography parameters on the micro and nanochannel was analyzed, the relationship between the oxygen plasma treatment parameters on the contact angle of SU-8 was revealed, the influence of bonding pressure on the morphology of the nanochannel was discussed, and the bonding principle at room temperature was deeply analyzed. This method can fabricate SU-8 polymer micro/nanoscale nozzle with low cost and high precision, and provide a new idea for the realization of room temperature bonding to manufacture SU-8 polymer nozzle.
{"title":"Oxygen plasma assisted room temperature bonding for manufacturing SU-8 polymer micro/nanoscale nozzle","authors":"R. Guo, Xuan Li, Weilong Niu, Jianbo Feng","doi":"10.1515/ntrev-2023-0113","DOIUrl":"https://doi.org/10.1515/ntrev-2023-0113","url":null,"abstract":"Abstract Electrohydrodynamic-jet (E-jet) printing is an on-demand additive manufacturing method that allows various functional materials to be directly deposited on the target substrate. Many theoretical and experimental results indicate that E-jet has scale effect, and reducing the inner diameter of the nozzle can effectively improve printing resolution. Herein, a method for fabricating SU-8 polymer micro/nanoscale nozzle by oxygen plasma assisted room temperature bonding was proposed. It can prevent channel deformation and blockage caused by excessive bonding temperature. The surface modification parameters of silicon nano-mold were optimized, the influence of hot embossing parameters on the replication precision of nano patterns was investigated, the effect of UV lithography parameters on the micro and nanochannel was analyzed, the relationship between the oxygen plasma treatment parameters on the contact angle of SU-8 was revealed, the influence of bonding pressure on the morphology of the nanochannel was discussed, and the bonding principle at room temperature was deeply analyzed. This method can fabricate SU-8 polymer micro/nanoscale nozzle with low cost and high precision, and provide a new idea for the realization of room temperature bonding to manufacture SU-8 polymer nozzle.","PeriodicalId":18839,"journal":{"name":"Nanotechnology Reviews","volume":" ","pages":""},"PeriodicalIF":7.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47933959","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}
Ž. Jelen, Marcin Krajewski, F. Zupanič, P. Majerič, Tilen Švarc, I. Anžel, J. Ekar, S. Liou, J. Kubacki, M. Tokarczyk, Rebeka Rudolf
Abstract A coupled process of ultrasonic spray pyrolysis and lyophilisation was used for the synthesis of dried gold nanoparticles. Two methods were applied for determining their melting temperature: uniaxial microcompression and differential scanning calorimetry (DSC) analysis. Uniaxial microcompression resulted in sintering of the dried gold nanoparticles at room temperature with an activation energy of 26–32.5 J/g, which made it impossible to evaluate their melting point. Using DSC, the melting point of the dried gold nanoparticles was measured to be around 1064.3°C, which is close to pure gold. The reason for the absence of a melting point depression in dried gold nanoparticles was their exothermic sintering between 712 and 908.1°C. Graphical abstract
{"title":"Melting point of dried gold nanoparticles prepared with ultrasonic spray pyrolysis and lyophilisation","authors":"Ž. Jelen, Marcin Krajewski, F. Zupanič, P. Majerič, Tilen Švarc, I. Anžel, J. Ekar, S. Liou, J. Kubacki, M. Tokarczyk, Rebeka Rudolf","doi":"10.1515/ntrev-2022-0568","DOIUrl":"https://doi.org/10.1515/ntrev-2022-0568","url":null,"abstract":"Abstract A coupled process of ultrasonic spray pyrolysis and lyophilisation was used for the synthesis of dried gold nanoparticles. Two methods were applied for determining their melting temperature: uniaxial microcompression and differential scanning calorimetry (DSC) analysis. Uniaxial microcompression resulted in sintering of the dried gold nanoparticles at room temperature with an activation energy of 26–32.5 J/g, which made it impossible to evaluate their melting point. Using DSC, the melting point of the dried gold nanoparticles was measured to be around 1064.3°C, which is close to pure gold. The reason for the absence of a melting point depression in dried gold nanoparticles was their exothermic sintering between 712 and 908.1°C. Graphical abstract","PeriodicalId":18839,"journal":{"name":"Nanotechnology Reviews","volume":" ","pages":""},"PeriodicalIF":7.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48405814","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}
Muhammad Atif Shahzad, B. Safaei, S. Sahmani, M. Basingab, A. Hameed
Abstract Through reduction of thickness value in nanostructures, the features of surface elasticity become more prominent due to having a high surface-to-volume ratio. The main aim of this research work was to examine the surface residual stress effect on the three-dimensional nonlinear stability characteristics of geometrically perfect and imperfect cylindrical shells at nanoscale under axial compression. To do so, an unconventional three-dimensional shell model was established via combination of the three-dimensional shell formulations and the Gurtin–Murdoch theory of elasticity. The silicon material is selected as a case study, which is the most utilized material in the design of micro-electromechanically systems. Then, the moving Kriging meshfree approach was applied to take numerically into account the surface free energy effects and the initial geometrical imperfection in the three-dimensional nonlinear stability curves. Accordingly, the considered cylindrical shell domain was discretized via a set of nodes together using the quadratic polynomial type of basis shape functions and an appropriate correlation function. It was found that the surface stress effects lead to an increase the critical axial buckling load of a perfect silicon nanoshell about 82.4 % 82.4 % for the shell thickness of 2 nm 2{rm{nm}} , about 32.4 % 32.4 % for the shell thickness of 5 nm 5{rm{nm}} , about 15.8 % 15.8 % for the shell thickness of 10 nm 10{rm{nm}} , and about 7.5 % 7.5 % for the shell thickness of 20 nm 20{rm{nm}} . These enhancements in the value of the critical axial buckling load for a geometrically imperfect silicon nanoshell become about 92.9 % 92.9 % for the shell thickness of 2 nm 2{rm{nm}} , about 36.5 % 36.5 % for the shell thickness of 5 nm 5{rm{nm}} , about 17.7 % 17.7 % for the shell thickness of 10 nm 10{rm{nm}} , and about 8.8 % 8.8 % for the shell thickness of 20 nm 20{rm{nm}} .
{"title":"Nonlinear three-dimensional stability characteristics of geometrically imperfect nanoshells under axial compression and surface residual stress","authors":"Muhammad Atif Shahzad, B. Safaei, S. Sahmani, M. Basingab, A. Hameed","doi":"10.1515/ntrev-2022-0551","DOIUrl":"https://doi.org/10.1515/ntrev-2022-0551","url":null,"abstract":"Abstract Through reduction of thickness value in nanostructures, the features of surface elasticity become more prominent due to having a high surface-to-volume ratio. The main aim of this research work was to examine the surface residual stress effect on the three-dimensional nonlinear stability characteristics of geometrically perfect and imperfect cylindrical shells at nanoscale under axial compression. To do so, an unconventional three-dimensional shell model was established via combination of the three-dimensional shell formulations and the Gurtin–Murdoch theory of elasticity. The silicon material is selected as a case study, which is the most utilized material in the design of micro-electromechanically systems. Then, the moving Kriging meshfree approach was applied to take numerically into account the surface free energy effects and the initial geometrical imperfection in the three-dimensional nonlinear stability curves. Accordingly, the considered cylindrical shell domain was discretized via a set of nodes together using the quadratic polynomial type of basis shape functions and an appropriate correlation function. It was found that the surface stress effects lead to an increase the critical axial buckling load of a perfect silicon nanoshell about 82.4 % 82.4 % for the shell thickness of 2 nm 2{rm{nm}} , about 32.4 % 32.4 % for the shell thickness of 5 nm 5{rm{nm}} , about 15.8 % 15.8 % for the shell thickness of 10 nm 10{rm{nm}} , and about 7.5 % 7.5 % for the shell thickness of 20 nm 20{rm{nm}} . These enhancements in the value of the critical axial buckling load for a geometrically imperfect silicon nanoshell become about 92.9 % 92.9 % for the shell thickness of 2 nm 2{rm{nm}} , about 36.5 % 36.5 % for the shell thickness of 5 nm 5{rm{nm}} , about 17.7 % 17.7 % for the shell thickness of 10 nm 10{rm{nm}} , and about 8.8 % 8.8 % for the shell thickness of 20 nm 20{rm{nm}} .","PeriodicalId":18839,"journal":{"name":"Nanotechnology Reviews","volume":" ","pages":""},"PeriodicalIF":7.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48996031","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}
Saqib Murtaza, P. Kumam, M. Bilal, T. Sutthibutpong, N. Rujisamphan, Zubair Ahmad
Abstract This study explores the unsteady hybrid nanofluid (NF) flow consisting of cobalt ferrite (CoFe2O4) and copper (Cu) nano particulates with natural convection flow due to an expanding surface implanted in a porous medium. The Cu and CoFe2O4 nanoparticles (NPs) are added to the base fluid water to synthesize the hybrid NF. The effects of second-order velocity slip condition, chemical reaction, heat absorption/generation, temperature-dependent viscosity, and Darcy Forchheimer are also assessed in the present analysis. An ordinary differential equation system is substituted for the modeled equations of the problem. Further computational processing of the differential equations is performed using the parametric continuation method. A validation and accuracy comparison are performed with the Matlab package BVP4C. Physical constraints are used for presenting and reviewing the outcomes. With the increase in second-order velocity slip condition and unsteady viscosity, the rates of heat and mass transition increase significantly with the variation in Cu and Fe2O4 NPs. The findings suggest that the uses of Cu and Fe2O4 in ordinary fluids might be useful in the aerodynamic extrusion of plastic sheets and extrusion of a polymer sheet from a dye.
{"title":"Parametric simulation of hybrid nanofluid flow consisting of cobalt ferrite nanoparticles with second-order slip and variable viscosity over an extending surface","authors":"Saqib Murtaza, P. Kumam, M. Bilal, T. Sutthibutpong, N. Rujisamphan, Zubair Ahmad","doi":"10.1515/ntrev-2022-0533","DOIUrl":"https://doi.org/10.1515/ntrev-2022-0533","url":null,"abstract":"Abstract This study explores the unsteady hybrid nanofluid (NF) flow consisting of cobalt ferrite (CoFe2O4) and copper (Cu) nano particulates with natural convection flow due to an expanding surface implanted in a porous medium. The Cu and CoFe2O4 nanoparticles (NPs) are added to the base fluid water to synthesize the hybrid NF. The effects of second-order velocity slip condition, chemical reaction, heat absorption/generation, temperature-dependent viscosity, and Darcy Forchheimer are also assessed in the present analysis. An ordinary differential equation system is substituted for the modeled equations of the problem. Further computational processing of the differential equations is performed using the parametric continuation method. A validation and accuracy comparison are performed with the Matlab package BVP4C. Physical constraints are used for presenting and reviewing the outcomes. With the increase in second-order velocity slip condition and unsteady viscosity, the rates of heat and mass transition increase significantly with the variation in Cu and Fe2O4 NPs. The findings suggest that the uses of Cu and Fe2O4 in ordinary fluids might be useful in the aerodynamic extrusion of plastic sheets and extrusion of a polymer sheet from a dye.","PeriodicalId":18839,"journal":{"name":"Nanotechnology Reviews","volume":" ","pages":""},"PeriodicalIF":7.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48621346","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}
Zhenzhen Lin, Xianlei Chen, Lu Lu, Xin Yao, Chunyang Zhai, Hengcong Tao
Abstract Catalytic synthesis of value-added chemicals from sustainable biomass or biomass-derived platform chemicals is an essential strategy for reducing dependency on fossil fuels. As a precursor for the synthesis of important polymers such as polyesters, polyurethanes, and polyamides, FDCA is a monomer with high added value. Meanwhile, due to its widespread use in chemical industry, 2,5-furandicarboxylic acid (FDCA) has gained significant interest in recent years. In this review, we discuss the electrochemical oxidation of 5-hydroxymethylfurfural (HMF) and summarize the most recent advances in electrode materials from the past 5 years, including reaction mechanisms, catalyst structures, and coupling reactions. First, the effect of pH on the electrocatalytic oxidation of furfural is presented, followed by a systematic summary of the reaction mechanism (direct and indirect oxidation). Then, the advantages, disadvantages, and research progress of precious metal, non-precious metal, and non-metallic HMF electrooxidation catalysts are discussed. In addition, a coupled dual system that combines HMF electrooxidation with hydrogen reduction reaction, CO2 reduction, or N2 reduction for more effective energy utilization is discussed. This review can guide the electrochemical oxidation of furfural and the development of advanced electrocatalyst materials for the implementation and production of renewable resources. Graphical abstract
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