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
Interfacial adhesion between carbon fibers(CF)and polyetherketoneketone(PEKK)is a key factor that affects the mechanical performances of their composites.It is therefore of great importance to impregnate the CF bundle...Interfacial adhesion between carbon fibers(CF)and polyetherketoneketone(PEKK)is a key factor that affects the mechanical performances of their composites.It is therefore of great importance to impregnate the CF bundles with PEKK as effi-ciently as possible.We report that PEKK with a good dispersion in a mixed solution of 4-chlorophenol and 1,2-dichloroethane can be introduced onto CF surfaces by solution impregnation and curing at 280,320,340 and 360℃.The excellent wettability or infiltra-tion of the PEKK solution guarantees a full covering and its tight binding to CFs,making it possible to evaluate the interfacial shear strength(IFSS)with the microdroplet method.The interior of the CF bundles is completely and uniformly filled with PEKK by solu-tion impregnation,leading to a high interlaminar shear strength(ILSS).The maximum IFSS and ILSS reached 107.8 and 99.3 MPa,respectively.Such superior shear properties are ascribed to the formation of amorphous PEKK in the small spaces between CFs.展开更多
Building Materials Sub-council of CCPIT is the other sub-council in construction field.CCPIT Building Materials Sub- council(CCPITBM),as well as CCO1C Build- ing Materials Chamber of Commerce,is au- thorized by CCPIT ...Building Materials Sub-council of CCPIT is the other sub-council in construction field.CCPIT Building Materials Sub- council(CCPITBM),as well as CCO1C Build- ing Materials Chamber of Commerce,is au- thorized by CCPIT and state administration of building materials industry in 1992.展开更多
World trade growth slid to 5.5 per- cent last year from 8.5 percent in 2006 and may grow even more slowly in 2008-at about 4.5 percent-as sharp economic deceleration in key developed countries is only partly offset by...World trade growth slid to 5.5 per- cent last year from 8.5 percent in 2006 and may grow even more slowly in 2008-at about 4.5 percent-as sharp economic deceleration in key developed countries is only partly offset by continuing strong growth in emerging economies。展开更多
The 11th China Beijing Interna- tional High-Tech Expo,themed as'high-tech Olympics and high- tech innovation',was rounded off successfully on the afternoon of May 25.The Expo,held as planned in such a special ...The 11th China Beijing Interna- tional High-Tech Expo,themed as'high-tech Olympics and high- tech innovation',was rounded off successfully on the afternoon of May 25.The Expo,held as planned in such a special period of post-quake relief work,展开更多
Liu Xiang of China set a world mark in the 110-meter hurdles on July 12, breaking the record he shared with Britain’s Colin Jackson. Liu’s time of 12.88 seconds at the IAAF Super Grand Prix athletics meeting in Laus...Liu Xiang of China set a world mark in the 110-meter hurdles on July 12, breaking the record he shared with Britain’s Colin Jackson. Liu’s time of 12.88 seconds at the IAAF Super Grand Prix athletics meeting in Laussane, Switzerland was 0.03 better than the record he matched in winning gold at the 2004 Athens Olympics.展开更多
“Bamboo has blossomed. Held in her mother’s arms, Mimi is counting the number of stars in the sky. How beautiful the stars are and where is my breakfast tomorrow...
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.
文摘Interfacial adhesion between carbon fibers(CF)and polyetherketoneketone(PEKK)is a key factor that affects the mechanical performances of their composites.It is therefore of great importance to impregnate the CF bundles with PEKK as effi-ciently as possible.We report that PEKK with a good dispersion in a mixed solution of 4-chlorophenol and 1,2-dichloroethane can be introduced onto CF surfaces by solution impregnation and curing at 280,320,340 and 360℃.The excellent wettability or infiltra-tion of the PEKK solution guarantees a full covering and its tight binding to CFs,making it possible to evaluate the interfacial shear strength(IFSS)with the microdroplet method.The interior of the CF bundles is completely and uniformly filled with PEKK by solu-tion impregnation,leading to a high interlaminar shear strength(ILSS).The maximum IFSS and ILSS reached 107.8 and 99.3 MPa,respectively.Such superior shear properties are ascribed to the formation of amorphous PEKK in the small spaces between CFs.
文摘Building Materials Sub-council of CCPIT is the other sub-council in construction field.CCPIT Building Materials Sub- council(CCPITBM),as well as CCO1C Build- ing Materials Chamber of Commerce,is au- thorized by CCPIT and state administration of building materials industry in 1992.
文摘World trade growth slid to 5.5 per- cent last year from 8.5 percent in 2006 and may grow even more slowly in 2008-at about 4.5 percent-as sharp economic deceleration in key developed countries is only partly offset by continuing strong growth in emerging economies。
文摘The 11th China Beijing Interna- tional High-Tech Expo,themed as'high-tech Olympics and high- tech innovation',was rounded off successfully on the afternoon of May 25.The Expo,held as planned in such a special period of post-quake relief work,
文摘Liu Xiang of China set a world mark in the 110-meter hurdles on July 12, breaking the record he shared with Britain’s Colin Jackson. Liu’s time of 12.88 seconds at the IAAF Super Grand Prix athletics meeting in Laussane, Switzerland was 0.03 better than the record he matched in winning gold at the 2004 Athens Olympics.
文摘“Bamboo has blossomed. Held in her mother’s arms, Mimi is counting the number of stars in the sky. How beautiful the stars are and where is my breakfast tomorrow...
