Hot corrosion and erosion are recognized as serious problems in coal based power generation plants in India. The coal used in Indian power stations has large amounts of ash (about 50%) which contain abrasive mineral s...Hot corrosion and erosion are recognized as serious problems in coal based power generation plants in India. The coal used in Indian power stations has large amounts of ash (about 50%) which contain abrasive mineral species such as hard quartz (up to 15%) which increase the erosion propensity of coal. Hot corrosion and erosion in boilers and related components are responsible for huge losses, both direct and indirect, in power generation. An understanding of these problems and thus to develop suitable protective system is essential for maximizing the utilization of such components. These problems can be prevented by either changing the material or altering the environment or by separating the component surface from the environment. Corrosion prevention by the use of coatings for separating material from the environment is gaining importance in surface engineering.展开更多
As the power density of electronic devices increases,there has been an urgent demand to develop highly conductive polymer composites to address the accompanying thermal management issues.Due to the ultra-high intrinsi...As the power density of electronic devices increases,there has been an urgent demand to develop highly conductive polymer composites to address the accompanying thermal management issues.Due to the ultra-high intrinsic thermal conductivity,graphene is considered a very promising filler to improve the thermal conductivity of polymers.However,graphene-based polymer composites prepared by the conventional mixing method generally have limited thermal conductivity,even under high graphene loading,due to the failure to construct efficient heat transfer pathways in the polymer matrix.Here,a spiral graphene framework(SGF)containing continuous and highly ordered graphene microtubes was developed based on a modified CVD method.After embedding into the epoxy(EP)matrix,the graphene microtubes can act as efficient heat pathways,endowing the SGF/EP composites with a high through-plane thermal conductivity of 1.35 W·m^(-1)·K^(-1) at an ultralow graphene loading of 0.86 wt%.This result gives a thermal conductivity enhancement per 1 wt%filler loading of 710%,significantly outperforming various graphene structures as fillers.In addition,we demonstrated the practical application of the SGF/EP composite as a thermal interface material for efficient thermal man-agement of the light-emitting diode(LED).展开更多
文摘Hot corrosion and erosion are recognized as serious problems in coal based power generation plants in India. The coal used in Indian power stations has large amounts of ash (about 50%) which contain abrasive mineral species such as hard quartz (up to 15%) which increase the erosion propensity of coal. Hot corrosion and erosion in boilers and related components are responsible for huge losses, both direct and indirect, in power generation. An understanding of these problems and thus to develop suitable protective system is essential for maximizing the utilization of such components. These problems can be prevented by either changing the material or altering the environment or by separating the component surface from the environment. Corrosion prevention by the use of coatings for separating material from the environment is gaining importance in surface engineering.
基金the National Natural Science Foundation of China(U1709205,52102055)the National Key R&D Program of China(2017YFE0128600)+7 种基金China Postdoctoral Science Foundation(2020M681965)the Project of the Chinese Academy of Sciences(XDC07030100,XDA22020602,KFZD-SW-409,ZDKYYQ20200001,and ZDRW-CN-2019-3)CAS Youth Innovation Promotion Association(2020301)Science and Technology Major Project of Ningbo(2018B10046)the Natural Science Foundation of Ningbo(2017A610010)Foundation of State Key Laboratory of Solid lubrication(LSL-1912)National Key Laboratory of Science and Technology on Advanced Composites in Special Environments(6142905192806)K.C.Wong Education Foundation(GJTD-2019-13).
文摘As the power density of electronic devices increases,there has been an urgent demand to develop highly conductive polymer composites to address the accompanying thermal management issues.Due to the ultra-high intrinsic thermal conductivity,graphene is considered a very promising filler to improve the thermal conductivity of polymers.However,graphene-based polymer composites prepared by the conventional mixing method generally have limited thermal conductivity,even under high graphene loading,due to the failure to construct efficient heat transfer pathways in the polymer matrix.Here,a spiral graphene framework(SGF)containing continuous and highly ordered graphene microtubes was developed based on a modified CVD method.After embedding into the epoxy(EP)matrix,the graphene microtubes can act as efficient heat pathways,endowing the SGF/EP composites with a high through-plane thermal conductivity of 1.35 W·m^(-1)·K^(-1) at an ultralow graphene loading of 0.86 wt%.This result gives a thermal conductivity enhancement per 1 wt%filler loading of 710%,significantly outperforming various graphene structures as fillers.In addition,we demonstrated the practical application of the SGF/EP composite as a thermal interface material for efficient thermal man-agement of the light-emitting diode(LED).
