Before densification by chemical vapor infiltration,carbon or SiC nanofibers were grown on the surface of carbon fibers by catalytic chemical vapor deposition using electroplated Ni as catalyst.The modification and me...Before densification by chemical vapor infiltration,carbon or SiC nanofibers were grown on the surface of carbon fibers by catalytic chemical vapor deposition using electroplated Ni as catalyst.The modification and mechanism of nanofibers on the pyrocarbon deposition during chemical vapor infiltration were investigated.The results show that the nanofibers improve the surface activity of the carbon fibers and become active nucleation centers during chemical vapor infiltration.They can induce the ordered deposition of pyrocarbon and adjust the interface bonding between pyrocarbon and carbon fibers during the infiltration.展开更多
Multifunctionalization is the development direction of personal thermal energy regulation equipment in the future.However,it is still a huge challenge to effectively integrate multiple functionalities into one materia...Multifunctionalization is the development direction of personal thermal energy regulation equipment in the future.However,it is still a huge challenge to effectively integrate multiple functionalities into one material.In this study,a simple thermochemical process was used to prepare a multifunctional SiC nanofiber aerogel spring(SiC NFAS),which exhibited ultralow density(9 mg/cm3),ultralow thermal conductivity(0.029 W/(m·K)at 20℃),excellent ablation and oxidation resistance,and a stable three-dimensional(3D)structure that composed of a large number of interlacing 3C-SiC nanofibers with diameters of 300–500 nm and lengths in tens to hundreds of microns.Furthermore,the as-prepared SiC NFAS displayed excellent mechanical properties,with a permanent deformation of only 1.3%at 20℃after 1000 cycles.Remarkably,the SiC NFAS exhibited robust hyperelasticity and cyclic fatigue resistance at both low(~-196℃)and high(~700℃)temperatures.Due to its exceptional thermal insulation performance,the SiC NFAS can be used for personal thermal energy regulation.The results of the study conclusively show that the SiC NFAS is a multifunctional material and has potential insulation applications in both low-and high-temperature environments.展开更多
基金Project(12JJ6051) supported by the Natural Science Foundation of Hunan Province,ChinaProject(2011CB605806) supported by the National Basic Research Program of China
文摘Before densification by chemical vapor infiltration,carbon or SiC nanofibers were grown on the surface of carbon fibers by catalytic chemical vapor deposition using electroplated Ni as catalyst.The modification and mechanism of nanofibers on the pyrocarbon deposition during chemical vapor infiltration were investigated.The results show that the nanofibers improve the surface activity of the carbon fibers and become active nucleation centers during chemical vapor infiltration.They can induce the ordered deposition of pyrocarbon and adjust the interface bonding between pyrocarbon and carbon fibers during the infiltration.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.U2004177 and U21A2064)Outstanding Youth Fund of the National Science Fundation of Henan Province(No.212300410081).
文摘Multifunctionalization is the development direction of personal thermal energy regulation equipment in the future.However,it is still a huge challenge to effectively integrate multiple functionalities into one material.In this study,a simple thermochemical process was used to prepare a multifunctional SiC nanofiber aerogel spring(SiC NFAS),which exhibited ultralow density(9 mg/cm3),ultralow thermal conductivity(0.029 W/(m·K)at 20℃),excellent ablation and oxidation resistance,and a stable three-dimensional(3D)structure that composed of a large number of interlacing 3C-SiC nanofibers with diameters of 300–500 nm and lengths in tens to hundreds of microns.Furthermore,the as-prepared SiC NFAS displayed excellent mechanical properties,with a permanent deformation of only 1.3%at 20℃after 1000 cycles.Remarkably,the SiC NFAS exhibited robust hyperelasticity and cyclic fatigue resistance at both low(~-196℃)and high(~700℃)temperatures.Due to its exceptional thermal insulation performance,the SiC NFAS can be used for personal thermal energy regulation.The results of the study conclusively show that the SiC NFAS is a multifunctional material and has potential insulation applications in both low-and high-temperature environments.
