Graphene has been extensively explored to enhance functional and mechanical properties of metalmatrix nanocomposites for wide-range applications due to their superior mechanical,electrical and thermal properties.This ...Graphene has been extensively explored to enhance functional and mechanical properties of metalmatrix nanocomposites for wide-range applications due to their superior mechanical,electrical and thermal properties.This article discusses recent advances of key mechanisms,synthesis,manufacture,modelling and applications of graphene metal matrix nanocomposites.The main strengthening mechanisms include load transfer,Orowan cycle,thermal mismatch,and refinement strengthening.Synthesis technologies are discussed including some conventional methods(such as liquid metallurgy,powdermetallurgy,thermal spraying and deposition technology)and some advanced processing methods(such as molecular-level mixing and friction stir processing).Analytical modelling(including phenomenological models,semi-empirical models,homogenization models,and self-consistent model)and numerical simulations(including finite elements method,finite difference method,and boundary element method)have been discussed for understanding the interface bonding and performance characteristics between graphene and different metal matrices(Al,Cu,Mg,Ni).Key challenges in applying graphene as a reinforcing component for the metal matrix composites and the potential solutions as well as prospectives of future development and opportunities are highlighted.展开更多
Understanding working principles and thermodynamics behind phase separations,which have significant influences on condensed molecular structures and their performances,can inspire to design and fabricate anomalously a...Understanding working principles and thermodynamics behind phase separations,which have significant influences on condensed molecular structures and their performances,can inspire to design and fabricate anomalously and desirably mechanoresponsive hydrogels.However,a combination of techniques from physicochemistry and mechanics has yet been established for the phase separation in hydrogels.In this study,a thermodynamic model is firstly formulated to describe solvent-aided phase and microphase separations in the hydrogels,which present significantly improved mechanoresponsive strengths.Flory-Huggins theory and interfacial energy equation have further been applied to model the thermodynamics of concentration-dependent and temperature-dependent phase separations.An intricately detailed phase map has finally been formulated to explore the working principle.The thermodynamic methodology of phase separations,combined with the constitutive stress-strain relationships,has a great potential to explore the working mechanisms in mechanoresponsive hydrogels.展开更多
基金The authors would like to acknowledge the financial supports from Xi'an Science Research Project of China(No.2020KJRC0089)Shaanxi Coal Industry Group United Fund of China(No.2019JLM-2)+4 种基金National Natural Science Foundation of China,China(No.51901192)Key Research and Development Projects of Shaanxi Province(No.2019GY-164)Science and Technology Project of Weiyang District of Xi'an City(No.201857)Shaanxi Youth Star Program of Science and Technology(No.2020KJXX-061)as well as Newton Mobility Grant(No.IE161019)through Royal Society and the National Natural Science Foundation of China.
文摘Graphene has been extensively explored to enhance functional and mechanical properties of metalmatrix nanocomposites for wide-range applications due to their superior mechanical,electrical and thermal properties.This article discusses recent advances of key mechanisms,synthesis,manufacture,modelling and applications of graphene metal matrix nanocomposites.The main strengthening mechanisms include load transfer,Orowan cycle,thermal mismatch,and refinement strengthening.Synthesis technologies are discussed including some conventional methods(such as liquid metallurgy,powdermetallurgy,thermal spraying and deposition technology)and some advanced processing methods(such as molecular-level mixing and friction stir processing).Analytical modelling(including phenomenological models,semi-empirical models,homogenization models,and self-consistent model)and numerical simulations(including finite elements method,finite difference method,and boundary element method)have been discussed for understanding the interface bonding and performance characteristics between graphene and different metal matrices(Al,Cu,Mg,Ni).Key challenges in applying graphene as a reinforcing component for the metal matrix composites and the potential solutions as well as prospectives of future development and opportunities are highlighted.
基金financially supported by the National Natural Science Foundation of China NSFC(Grant 11725208)Newton Mobility(Grant IE161019)through Royal SocietyNSFC.
文摘Understanding working principles and thermodynamics behind phase separations,which have significant influences on condensed molecular structures and their performances,can inspire to design and fabricate anomalously and desirably mechanoresponsive hydrogels.However,a combination of techniques from physicochemistry and mechanics has yet been established for the phase separation in hydrogels.In this study,a thermodynamic model is firstly formulated to describe solvent-aided phase and microphase separations in the hydrogels,which present significantly improved mechanoresponsive strengths.Flory-Huggins theory and interfacial energy equation have further been applied to model the thermodynamics of concentration-dependent and temperature-dependent phase separations.An intricately detailed phase map has finally been formulated to explore the working principle.The thermodynamic methodology of phase separations,combined with the constitutive stress-strain relationships,has a great potential to explore the working mechanisms in mechanoresponsive hydrogels.