Condensation is an important regime of heat transfer which has wide applications in different industries such as power plants,heating,ventilating and air conditioning,and refrigeration.Condensation occurs in two diffe...Condensation is an important regime of heat transfer which has wide applications in different industries such as power plants,heating,ventilating and air conditioning,and refrigeration.Condensation occurs in two different modes including filmwise (FWC) and dropwise (DWC) condensation.DWC occurring on hydrophobic and superhydrophobic surfaces has a much higher heat transfer capacity than FWC.Therefore,wide investigations have been done to produce DWC in recent years.Superhydrophobic surfaces have micro/nano structures with low surface energy.In this study,a two-step electrodeposition process is used to produce micro/nano structures on copper specimens.The surface energy of specimens is reduced by a self-assembled monolayer using ethanol and 1-octadecanethiol solution.The results show that there is an optimum condition for electrodeposition parameters.For example,a surface prepared by 2000 s step time has 5 times greater heat transfer than FWC while a surface with 4000 s step time has nearly the same heat transfer as FWC.The surfaces of the fabricated specimens are examined using XRD and SEM analyses.The SEM analyses of the surfaces show that there are some micro-structures on the surfaces and the surface porosities are reduced by increasing the second step electrodeposition time.展开更多
The recent research progress of structure- and size-controlled micro/nano-energetic materials is reviewed, which properties are fundamentally different from those of their corresponding bulk materials. The development...The recent research progress of structure- and size-controlled micro/nano-energetic materials is reviewed, which properties are fundamentally different from those of their corresponding bulk materials. The development of the construction strategies for achieving zero-dimensional (0D), one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) micro/nanostructures from energetic molecules is introduced. Also, an overview of the unique properties induced by micro/nanostructures and size effects is provided. Special emphasis is focused on the size-dependent properties that are different from those of the conventional micro-sized energetic materials, such as thermal decomposition, sensitivity, combustion and detonation, and compaction behaviors. A conclusion and our view of the future development of micro/nano-energetic materials and devices are given.展开更多
文摘Condensation is an important regime of heat transfer which has wide applications in different industries such as power plants,heating,ventilating and air conditioning,and refrigeration.Condensation occurs in two different modes including filmwise (FWC) and dropwise (DWC) condensation.DWC occurring on hydrophobic and superhydrophobic surfaces has a much higher heat transfer capacity than FWC.Therefore,wide investigations have been done to produce DWC in recent years.Superhydrophobic surfaces have micro/nano structures with low surface energy.In this study,a two-step electrodeposition process is used to produce micro/nano structures on copper specimens.The surface energy of specimens is reduced by a self-assembled monolayer using ethanol and 1-octadecanethiol solution.The results show that there is an optimum condition for electrodeposition parameters.For example,a surface prepared by 2000 s step time has 5 times greater heat transfer than FWC while a surface with 4000 s step time has nearly the same heat transfer as FWC.The surfaces of the fabricated specimens are examined using XRD and SEM analyses.The SEM analyses of the surfaces show that there are some micro-structures on the surfaces and the surface porosities are reduced by increasing the second step electrodeposition time.
基金Sponsored by National Natural Science Foundation of China (21231002,21276026,21271023,21173021,91022006,11202193,11172276,and 11072225)the 111 Project ( B07012)+1 种基金the Program of Cooperation of the Beijing Education Commission ( 20091739006)Specialized Research Fund for the Doctoral Program of Higher Education ( 20101101110031)
文摘The recent research progress of structure- and size-controlled micro/nano-energetic materials is reviewed, which properties are fundamentally different from those of their corresponding bulk materials. The development of the construction strategies for achieving zero-dimensional (0D), one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) micro/nanostructures from energetic molecules is introduced. Also, an overview of the unique properties induced by micro/nanostructures and size effects is provided. Special emphasis is focused on the size-dependent properties that are different from those of the conventional micro-sized energetic materials, such as thermal decomposition, sensitivity, combustion and detonation, and compaction behaviors. A conclusion and our view of the future development of micro/nano-energetic materials and devices are given.
