A study of the interfacial behavior and internal thermal stress distribution in fiber-reinforced composites is essential to assess their performance and reliability.CNT/carbon fiber(CF)hybrid fibers were constructed u...A study of the interfacial behavior and internal thermal stress distribution in fiber-reinforced composites is essential to assess their performance and reliability.CNT/carbon fiber(CF)hybrid fibers were constructed using electrophoretic deposition.The interfacial properties of CF/epoxy and CNT/CF/epoxy composites were statistically investigated and compared using in-situ thermal Raman mapping by dispersing CNTs as a Raman sensing medium(CNT_(R))in a resin.The associated local thermal stress changes can be simulated by capturing the G'band position distribution of CNT_(R) in the epoxy at different temperatures.It was found that the G'band shifted to lower positions with increasing temperature,reaching a maximum difference of 2.43 cm^(−1) at 100℃.The interfacial bonding between CNT/CF and the matrix and the stress distribution and changes during heat treatment(20-100℃)were investig-ated in detail.This work is important for studying thermal stress in fiber-reinforced composites by in-situ thermal Raman mapping technology.展开更多
Organic-inorganic nanohybrid materials repre- sent a wide range of nanoscaled synthetic materials con- sisting of both organic and inorganic components that are linked together by covalent or non-covalent interactions...Organic-inorganic nanohybrid materials repre- sent a wide range of nanoscaled synthetic materials con- sisting of both organic and inorganic components that are linked together by covalent or non-covalent interactions, which have been widely employed in various fields such as optoelectronics, catalysis and biomedicine. As a result of this special combination, nanohybrid materials assemble numerous extraordinary features that provide great opportunities to improve their stability, multifunctions, biocom- patibility, eco-friendliness and other physical and mechanical properties. This review highlights recent re- search developments of functional organic-inorganic nanohybrid materials and their specific applications in bioimaging including fluorescent, Raman, photoacoustic and combined bioimaging. Future research directions and perspectives in this rapidly developing field are also discussed.展开更多
Electrochemical reductive exfoliation of graphite to few layered graphene(FLG) in presence of 1-ethyl-2,3-dimethyl imidazolium bis(trifluoromethylsulfonyl) imide ionic liquid and redox ionic liquid based ferrocene has...Electrochemical reductive exfoliation of graphite to few layered graphene(FLG) in presence of 1-ethyl-2,3-dimethyl imidazolium bis(trifluoromethylsulfonyl) imide ionic liquid and redox ionic liquid based ferrocene has been investigated. Thus, by applying a mild negative potential(-2.7 V vs. Fc/Fc^+) to carbon electrode in ionic liquid graphene flakes could be generated. The generated materials have been characterized by X-ray photoelectron spectroscopy, Raman spectroscopy, high resolution transmission electron microscopy and atomic force microscopy. XPS and Raman analysis show that the electrochemical reductive exfoliation provides the formation of FLG. The thickness of the resulting FLG was found to be ranged between 4 and1 nm. HR-TEM images reveal the formation of few graphene layers and in some cases single graphene layer was observed.Moreover, this electrochemical route conduces to the formation of ionic liquid functionalized FLG. Finally, the reductive exfoliation was further investigated in the presence of redox ionic liquid. XPS and electrochemical measurements confirm the presence of ferrocene.展开更多
文摘A study of the interfacial behavior and internal thermal stress distribution in fiber-reinforced composites is essential to assess their performance and reliability.CNT/carbon fiber(CF)hybrid fibers were constructed using electrophoretic deposition.The interfacial properties of CF/epoxy and CNT/CF/epoxy composites were statistically investigated and compared using in-situ thermal Raman mapping by dispersing CNTs as a Raman sensing medium(CNT_(R))in a resin.The associated local thermal stress changes can be simulated by capturing the G'band position distribution of CNT_(R) in the epoxy at different temperatures.It was found that the G'band shifted to lower positions with increasing temperature,reaching a maximum difference of 2.43 cm^(−1) at 100℃.The interfacial bonding between CNT/CF and the matrix and the stress distribution and changes during heat treatment(20-100℃)were investig-ated in detail.This work is important for studying thermal stress in fiber-reinforced composites by in-situ thermal Raman mapping technology.
基金supported by the National Research Foundation(NRF),Prime Minister’s Office,Singapore,under its NRF Fellowship(NRF2009NRF-RF001-015)Campus for Research Excellence and Technological Enterprise(CREATE)Programme-Singapore Peking University Research Centre for a Sustainable Low-Carbon Future+1 种基金the NTU-A*STAR Silicon Technologies Centre of Excellence under the program Grant No.11235150003the NTU-Northwestern Institute for Nanomedicine
文摘Organic-inorganic nanohybrid materials repre- sent a wide range of nanoscaled synthetic materials con- sisting of both organic and inorganic components that are linked together by covalent or non-covalent interactions, which have been widely employed in various fields such as optoelectronics, catalysis and biomedicine. As a result of this special combination, nanohybrid materials assemble numerous extraordinary features that provide great opportunities to improve their stability, multifunctions, biocom- patibility, eco-friendliness and other physical and mechanical properties. This review highlights recent re- search developments of functional organic-inorganic nanohybrid materials and their specific applications in bioimaging including fluorescent, Raman, photoacoustic and combined bioimaging. Future research directions and perspectives in this rapidly developing field are also discussed.
基金supported by the European Community Seventh Framework Programme(266391)
文摘Electrochemical reductive exfoliation of graphite to few layered graphene(FLG) in presence of 1-ethyl-2,3-dimethyl imidazolium bis(trifluoromethylsulfonyl) imide ionic liquid and redox ionic liquid based ferrocene has been investigated. Thus, by applying a mild negative potential(-2.7 V vs. Fc/Fc^+) to carbon electrode in ionic liquid graphene flakes could be generated. The generated materials have been characterized by X-ray photoelectron spectroscopy, Raman spectroscopy, high resolution transmission electron microscopy and atomic force microscopy. XPS and Raman analysis show that the electrochemical reductive exfoliation provides the formation of FLG. The thickness of the resulting FLG was found to be ranged between 4 and1 nm. HR-TEM images reveal the formation of few graphene layers and in some cases single graphene layer was observed.Moreover, this electrochemical route conduces to the formation of ionic liquid functionalized FLG. Finally, the reductive exfoliation was further investigated in the presence of redox ionic liquid. XPS and electrochemical measurements confirm the presence of ferrocene.
