Direct synthesis of graphene on nonmetallic substrates via chemical vapor deposition (CVD) has become a frontier research realm targeting transfer-free applications of CVD graphene.However,the stable mass production o...Direct synthesis of graphene on nonmetallic substrates via chemical vapor deposition (CVD) has become a frontier research realm targeting transfer-free applications of CVD graphene.However,the stable mass production of graphene with a favorable growth rate and quality remains a grand challenge.Herein,graphene glass fiber fabric (GGFF) was successfully developed through the controllable growth of graphene on non-catalytic glass fiber fabric,employing a synergistic binary-precursor CVD strategy to alleviate the dilemma between growth rate and quality.The binary precursors consisted of acetylene and acetone,where acetylene with high decomposition efficiency fed rapid graphene growth while oxygencontaining acetone was adopted for improving the layer uniformity and quality.Notably,the bifurcating introducing-confluent premixing (BI-CP) system was self-built for the controllable introduction of gas and liquid precursors,enabling the stable production of GGFF.GGFF features solar absorption and infrared emission properties,based on which the self-adaptive dual-mode thermal management film was developed.This film can automatically switch between heating and cooling modes by spontaneously perceiving the temperature,achieving excellent thermal management performances with heating and cooling power of~501.2 and~108.6 W m-2,respectively.These findings unlock a new strategy for the large-scale batch production of graphene materials and inspire advanced possibilities for further applications.展开更多
Bismuth （Bi）-doped laser glasses and fiber devices have aroused wide attentions due to their unique potential to work in the new spectral range of 1 to 1.8 μm traditional laser ions, such as rare earth, cannot reac...Bismuth （Bi）-doped laser glasses and fiber devices have aroused wide attentions due to their unique potential to work in the new spectral range of 1 to 1.8 μm traditional laser ions, such as rare earth, cannot reach. Current Bi-dopcd silica glass fibers have to be made by modified chemical vapor deposition at a temperature higher than 2000℃. This unavoidably leads to the tremendous loss of Bi by evaporation, since the temperature is several hundred degrees Celsius higher than the Bi boiling temperature, and, therefore, trace Bi （-50 ppm） resides within the final product of silica fiber. So, the gain of such fiber is usually extremely low. One of the solutions is to make the fibers at a temperature much lower than the boiling temperature of Bi. The challenge for this is to find a lower melting point glass, which can stabilize Bi in the near infrared emission center and, meanwhile, does not lose glass transparency during fiber fabrication. None of previously reported Bi-doped multicomponent glasses can meet the prerequisite. Here, we, after hundreds of trials on optimization over glass components, activator content, melting temperature, etc., find a novel Bi-doped gallogermanate glass, which shows good tolerance to thermal impact and can accommodate a higher content of Bi. Consequently, we successfully manu- facture the germanate fiber by a rod-in-tube technique at 850℃. The fiber exhibits similar luminescence to the bulk glass, and it shows saturated absorption at 808 nm rather than 980 nm as the incident power becomes higher than 4 W. Amplified spontaneous emissions are observed upon the pumps of either 980 or 1064 nm from ger- manate fiber.展开更多
Seven kinds of weft knitted fabrics from glass fiber yarns were used as reinforcement to make fabric/epoxy composite laminates. Tensile tests were carried out to examine and compare the mechanical properties in course...Seven kinds of weft knitted fabrics from glass fiber yarns were used as reinforcement to make fabric/epoxy composite laminates. Tensile tests were carried out to examine and compare the mechanical properties in course and wale direction of these composites. On the basis of experimental results, attempts have been made to analyze some main factors influencing stress-strain curve, ultimate tensile strength and initial elastic modulus of specimens.展开更多
Several different kinds of weft knitted fabrics from glass fiber yarns were used as reinforcement to make fabric/polyester composite laminates. Flexural tests were carried out to examine stress- deflection process and...Several different kinds of weft knitted fabrics from glass fiber yarns were used as reinforcement to make fabric/polyester composite laminates. Flexural tests were carried out to examine stress- deflection process and compare the mechanical properties in course and wale directions of these composites. The experimental results indicate that the numbers of load-bearing yarn in course and wale direction and the fabric density are the main factors influencing the ultimate tensile strength and initial elastic modulus of specimens.展开更多
The field of electromagnetic wave absorption(EWA)requires the adaptability,tenability,and multifunction of high-performance materials in the future.The design and preparation of EWA materials aiming at performance req...The field of electromagnetic wave absorption(EWA)requires the adaptability,tenability,and multifunction of high-performance materials in the future.The design and preparation of EWA materials aiming at performance requirements is the latest research hotspot.Here,a performancedriven strategy for simultaneously coordinating different target performances was proposed to optimize the structure of the periodical long continuous carbon/glass fiber fabric(PCGF)materials through algorithm and simulation.The optimized structure of the PCGF not only improves the impedance matching,but also introduces the induced orientation effect for a high cooperative loss of conductivity,resonance,and periodic structure.The flexible PCGF shows a broad effective absorption bandwidth(EAB)of 32.7 GHz covering a part of the C-band and the whole X-,Ku-,K-,and Ka-bands with a thickness(d)of only 0.92 mm and a density of 5.6×10^(−4) kg·cm^(−3).This highly designable fabric is promising for the EWA practical application owing to integrating the characteristics of good flexibility,acid and alkali resistance,bending resistance,excellent mechanical properties,and easy large-scale preparation.展开更多
基金National Natural Science Foundation of China (52272032, T2188101, and 52021006)Beijing Nova Program of Science and Technology (20220484079)。
文摘Direct synthesis of graphene on nonmetallic substrates via chemical vapor deposition (CVD) has become a frontier research realm targeting transfer-free applications of CVD graphene.However,the stable mass production of graphene with a favorable growth rate and quality remains a grand challenge.Herein,graphene glass fiber fabric (GGFF) was successfully developed through the controllable growth of graphene on non-catalytic glass fiber fabric,employing a synergistic binary-precursor CVD strategy to alleviate the dilemma between growth rate and quality.The binary precursors consisted of acetylene and acetone,where acetylene with high decomposition efficiency fed rapid graphene growth while oxygencontaining acetone was adopted for improving the layer uniformity and quality.Notably,the bifurcating introducing-confluent premixing (BI-CP) system was self-built for the controllable introduction of gas and liquid precursors,enabling the stable production of GGFF.GGFF features solar absorption and infrared emission properties,based on which the self-adaptive dual-mode thermal management film was developed.This film can automatically switch between heating and cooling modes by spontaneously perceiving the temperature,achieving excellent thermal management performances with heating and cooling power of~501.2 and~108.6 W m-2,respectively.These findings unlock a new strategy for the large-scale batch production of graphene materials and inspire advanced possibilities for further applications.
基金supported by the National Key Research and Development Plan(No.2017YFF0104504)the National Natural Science Foundation of China(Nos.51672085 and 51322208)+2 种基金the Program for Innovative Research Team in University of Ministry of Education of China(No.IRT_17R38)the Key Program of Guangzhou Scientific Research Special Project(No.201607020009)the Fundamental Research Funds for the Central Universities
文摘Bismuth （Bi）-doped laser glasses and fiber devices have aroused wide attentions due to their unique potential to work in the new spectral range of 1 to 1.8 μm traditional laser ions, such as rare earth, cannot reach. Current Bi-dopcd silica glass fibers have to be made by modified chemical vapor deposition at a temperature higher than 2000℃. This unavoidably leads to the tremendous loss of Bi by evaporation, since the temperature is several hundred degrees Celsius higher than the Bi boiling temperature, and, therefore, trace Bi （-50 ppm） resides within the final product of silica fiber. So, the gain of such fiber is usually extremely low. One of the solutions is to make the fibers at a temperature much lower than the boiling temperature of Bi. The challenge for this is to find a lower melting point glass, which can stabilize Bi in the near infrared emission center and, meanwhile, does not lose glass transparency during fiber fabrication. None of previously reported Bi-doped multicomponent glasses can meet the prerequisite. Here, we, after hundreds of trials on optimization over glass components, activator content, melting temperature, etc., find a novel Bi-doped gallogermanate glass, which shows good tolerance to thermal impact and can accommodate a higher content of Bi. Consequently, we successfully manu- facture the germanate fiber by a rod-in-tube technique at 850℃. The fiber exhibits similar luminescence to the bulk glass, and it shows saturated absorption at 808 nm rather than 980 nm as the incident power becomes higher than 4 W. Amplified spontaneous emissions are observed upon the pumps of either 980 or 1064 nm from ger- manate fiber.
文摘Seven kinds of weft knitted fabrics from glass fiber yarns were used as reinforcement to make fabric/epoxy composite laminates. Tensile tests were carried out to examine and compare the mechanical properties in course and wale direction of these composites. On the basis of experimental results, attempts have been made to analyze some main factors influencing stress-strain curve, ultimate tensile strength and initial elastic modulus of specimens.
文摘Several different kinds of weft knitted fabrics from glass fiber yarns were used as reinforcement to make fabric/polyester composite laminates. Flexural tests were carried out to examine stress- deflection process and compare the mechanical properties in course and wale directions of these composites. The experimental results indicate that the numbers of load-bearing yarn in course and wale direction and the fabric density are the main factors influencing the ultimate tensile strength and initial elastic modulus of specimens.
基金supported by the National Natural Science Foundation of China (51772060,51672059,and 51621091)financially sponsored by Heilongjiang Touyan Team Program and the Fundamental Research Funds for the Central Universities (HIT.OCEF.2021003).
文摘The field of electromagnetic wave absorption(EWA)requires the adaptability,tenability,and multifunction of high-performance materials in the future.The design and preparation of EWA materials aiming at performance requirements is the latest research hotspot.Here,a performancedriven strategy for simultaneously coordinating different target performances was proposed to optimize the structure of the periodical long continuous carbon/glass fiber fabric(PCGF)materials through algorithm and simulation.The optimized structure of the PCGF not only improves the impedance matching,but also introduces the induced orientation effect for a high cooperative loss of conductivity,resonance,and periodic structure.The flexible PCGF shows a broad effective absorption bandwidth(EAB)of 32.7 GHz covering a part of the C-band and the whole X-,Ku-,K-,and Ka-bands with a thickness(d)of only 0.92 mm and a density of 5.6×10^(−4) kg·cm^(−3).This highly designable fabric is promising for the EWA practical application owing to integrating the characteristics of good flexibility,acid and alkali resistance,bending resistance,excellent mechanical properties,and easy large-scale preparation.
