Two-dimensional(2D)materials are promising for next-generation electronic devices and systems due to their unique physical properties.The interfacial adhesion plays a vital role not only in the synthesis,transfer and ...Two-dimensional(2D)materials are promising for next-generation electronic devices and systems due to their unique physical properties.The interfacial adhesion plays a vital role not only in the synthesis,transfer and manipulation of 2D materials but also in the manufacture,integration and performance of the functional devices.However,the atomic thickness and limited lateral dimensions of 2D materials make the accurate measurement and modulation of their interfacial adhesion energy challenging.In this review,the recent advances in the measurement and modulation of the interfacial adhesion properties of 2D materials are systematically combed.Experimental methods and relative theoretical models for the adhesion measurement of 2D materials are summarized,with their scope of application and limitations discussed.The measured adhesion energies between 2D materials and various substrates are described in categories,where the typical adhesion modulation strategies of 2D materials are also introduced.Finally,the remaining challenges and opportunities for the interfacial adhesion measurement and modulation of 2D materials are presented.This paper provides guidance for addressing the adhesion issues in devices and systems involving 2D materials.展开更多
The imaging of particulate media – encompassing both the imaging of the particles themselves,as well as the study of their dynamics and bulk properties and behaviours – is crucial to improving our understanding of a...The imaging of particulate media – encompassing both the imaging of the particles themselves,as well as the study of their dynamics and bulk properties and behaviours – is crucial to improving our understanding of a diverse range of phenomena and processes spanning numerous scientific disciplines and industrial sectors.Despite interdisciplinary interest in the field and the availability,and continuous development,of a wide range of different imaging techniques,there exist nonetheless a number of limitations of these techniques,and open challenges – both technical and non-technical – facing the field as a whole.In this perspective,we discuss in detail five such challenges,identified by a team of interdisciplinary experts spanning both academia and industry: how can we work toward the imaging of systems which are more ‘real-world-relevant’,both in terms of composition and scale? How can we extract detailed,quantitative information regarding stresses from such systems? How can we image processes which are both rapid and transient,when most current technologies can manage (at best) only one of these states? How can we ensure closer and more fruitful collaboration between the academics developing particle imaging technologies and the potential industrial end-users who stand to benefit from them? How can we improve the visibility of the field and the educational opportunities available to the potential next generation of particle technologists? As one may expect for such a broad range of questions,the answers to the above are diverse and numerous.However,there are certain key themes running through them.Above all,our work highlights a need for improved collaboration,be that in terms of experts in multiple different imaging technologies working together to perform multi-modal studies so as to address the technical limitations highlighted above,researchers and industry professionals finding new ways to engage,or academics co-creating open-source educational tools to support the next generation of particle imaging experts.展开更多
The dynamic behaviour of granular flows is important in geo-mechanics and industrial applications,yet poorly understood.We studied the effects of liquid viscosity and particle size on the dynamics of wet granular mate...The dynamic behaviour of granular flows is important in geo-mechanics and industrial applications,yet poorly understood.We studied the effects of liquid viscosity and particle size on the dynamics of wet granular material flowing in a slowly rotating drum,in order to detect the transition from the avalanching to the continuous flow regime.A discrete element method(DEM)model,in which contact forces and cohesive forces were considered,was employed to simulate this flow behaviour.The model was validated experimentally,using glass beads in a wooden drum and water–glycerol mixtures to tune the liquid viscosity.The DEM simulations showed comparable results to the experiments in terms of average slope angle and avalanche amplitude.We observed that the avalanche amplitude,flow layer velocity and granular temperature decrease as the liquid viscosity increases.This effect is more pronounced for smaller sized particles.The increase in viscous forces causes the flowing particles to behave as a bulk,pushing the free surface towards a convex shape.In addition,avalanches become less pronounced and the granular flow transitions from the avalanching regime to the continuous regime.The avalanching flow regime is marked by intermittent rigid body movement of the particulate bed and near-zero drops in the granular temperature,while no rigid body movement of the bed occurs in the continuous flow regime.We identified the avalanching-continuous flow transition region as a function of a dimensionless granular Galileo number.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12002133,12372109,and 11972171)the Natural Science Foundation of Jiangsu Province(Grant Nos.BK20200590 and BK20180031)+4 种基金the Fundamental Research Funds for the Central Universities(Grant No.JUSRP121040)the National Key R&D Program of China(Grant No.2023YFB4605101)the 111 project(Grant No.B18027)the Open Fund of Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education(Grant No.NJ2020003)the Sixth Phase of Jiangsu Province“333 High Level Talent Training Project”Second Level Talents.
文摘Two-dimensional(2D)materials are promising for next-generation electronic devices and systems due to their unique physical properties.The interfacial adhesion plays a vital role not only in the synthesis,transfer and manipulation of 2D materials but also in the manufacture,integration and performance of the functional devices.However,the atomic thickness and limited lateral dimensions of 2D materials make the accurate measurement and modulation of their interfacial adhesion energy challenging.In this review,the recent advances in the measurement and modulation of the interfacial adhesion properties of 2D materials are systematically combed.Experimental methods and relative theoretical models for the adhesion measurement of 2D materials are summarized,with their scope of application and limitations discussed.The measured adhesion energies between 2D materials and various substrates are described in categories,where the typical adhesion modulation strategies of 2D materials are also introduced.Finally,the remaining challenges and opportunities for the interfacial adhesion measurement and modulation of 2D materials are presented.This paper provides guidance for addressing the adhesion issues in devices and systems involving 2D materials.
文摘The imaging of particulate media – encompassing both the imaging of the particles themselves,as well as the study of their dynamics and bulk properties and behaviours – is crucial to improving our understanding of a diverse range of phenomena and processes spanning numerous scientific disciplines and industrial sectors.Despite interdisciplinary interest in the field and the availability,and continuous development,of a wide range of different imaging techniques,there exist nonetheless a number of limitations of these techniques,and open challenges – both technical and non-technical – facing the field as a whole.In this perspective,we discuss in detail five such challenges,identified by a team of interdisciplinary experts spanning both academia and industry: how can we work toward the imaging of systems which are more ‘real-world-relevant’,both in terms of composition and scale? How can we extract detailed,quantitative information regarding stresses from such systems? How can we image processes which are both rapid and transient,when most current technologies can manage (at best) only one of these states? How can we ensure closer and more fruitful collaboration between the academics developing particle imaging technologies and the potential industrial end-users who stand to benefit from them? How can we improve the visibility of the field and the educational opportunities available to the potential next generation of particle technologists? As one may expect for such a broad range of questions,the answers to the above are diverse and numerous.However,there are certain key themes running through them.Above all,our work highlights a need for improved collaboration,be that in terms of experts in multiple different imaging technologies working together to perform multi-modal studies so as to address the technical limitations highlighted above,researchers and industry professionals finding new ways to engage,or academics co-creating open-source educational tools to support the next generation of particle imaging experts.
文摘The dynamic behaviour of granular flows is important in geo-mechanics and industrial applications,yet poorly understood.We studied the effects of liquid viscosity and particle size on the dynamics of wet granular material flowing in a slowly rotating drum,in order to detect the transition from the avalanching to the continuous flow regime.A discrete element method(DEM)model,in which contact forces and cohesive forces were considered,was employed to simulate this flow behaviour.The model was validated experimentally,using glass beads in a wooden drum and water–glycerol mixtures to tune the liquid viscosity.The DEM simulations showed comparable results to the experiments in terms of average slope angle and avalanche amplitude.We observed that the avalanche amplitude,flow layer velocity and granular temperature decrease as the liquid viscosity increases.This effect is more pronounced for smaller sized particles.The increase in viscous forces causes the flowing particles to behave as a bulk,pushing the free surface towards a convex shape.In addition,avalanches become less pronounced and the granular flow transitions from the avalanching regime to the continuous regime.The avalanching flow regime is marked by intermittent rigid body movement of the particulate bed and near-zero drops in the granular temperature,while no rigid body movement of the bed occurs in the continuous flow regime.We identified the avalanching-continuous flow transition region as a function of a dimensionless granular Galileo number.
