Graphene oxide(GO)has proven to be an effective reinfor-cing filler for rubber[1].GO has superior mechanical properties,barrier properties,large specific surface area and abundant oxygen-containing functional groups[2...Graphene oxide(GO)has proven to be an effective reinfor-cing filler for rubber[1].GO has superior mechanical properties,barrier properties,large specific surface area and abundant oxygen-containing functional groups[2].However,the change in the oxidation degree of GO has a great effect on its chemical properties,the interaction between GO and the matrix,and the dispersion uniformity in the rubber matrix,which has a great effect on the reinforcement of rubber[3].展开更多
Lightweight yet strong paper with high toughness is desirable especially for impact protection. Herein we demonstrated electrically conductive and mechanically robust paper(AP/PB-GP) made of reduced graphene oxide via...Lightweight yet strong paper with high toughness is desirable especially for impact protection. Herein we demonstrated electrically conductive and mechanically robust paper(AP/PB-GP) made of reduced graphene oxide via interfacial crosslinking with 1-aminopyrene(AP) and 1-pyrenebutyrat(PB) small molecules. The AP/PB-GP with thickness of over ten micrometer delivers a record-high toughness(~69.67 ± 15.3 MJ m^(-3) in average), simultaneously with superior strength(close to 1 GPa), allowing an impressive specific penetration energy absorption(~0.17 MJ kg^(-1)) at high impact velocities when used for ballistic impact protection. Detailed interfacial and structural analysis reveals that the reinforcement is synergistically determined by π-π interaction and H-bonding linkage between adjacent graphene lamellae. Especially, the defective pores within the graphene platelets benefit the favorable adsorption of the pyrene-containing molecules, which imperatively maximizes the interfacial binding, facilitating deflecting crack and plastic deformation under loading. Density functional theory simulation suggests that the coupling between the polar functional groups, e.g., –COOH, at the edges of graphene platelets and –NH_(2) and –COOH of AP/PB are critical to the formation of hydrogen bonding network.展开更多
Chemically exfoliated nanosheets have exhibited great potential for applications in various electronic devices.Solution-based processing strategies such as inkjet printing provide a low-cost,environmentally friendly,a...Chemically exfoliated nanosheets have exhibited great potential for applications in various electronic devices.Solution-based processing strategies such as inkjet printing provide a low-cost,environmentally friendly,and scalable route for the fabrication of flexible devices based on functional inks of twodimensional nanosheets.In this study,chemically exfoliated high-k perovskite nanosheets(i.e.,Ca_(2)Nb_(3)O_(10)and Ca_(2)NaNb_(4)O_(13))are well dispersed in appropriate solvents to prepare printable inks,and then,a series of microcapacitors with Ag and graphene electrodes are printed.The resulting microcapacitors,Ag/Ca_(2)Nb_(3)O_(10)/Ag,graphene/Ca_(2)Nb_(3)O_(10)/graphene,and graphene/Ca_(2)NaNb_(4)O_(13)/graphene,demonstrate high capacitance densities of 20,80,and 150 nF/cm^(2) and high dielectric constants of 26,110.and 200,respectively.Such dielectric enhancement in the microcapacitors with graphene electrodes is possibly attributed to the dielectric/graphene interface.In addition,these microcapacitors also exhibit good insulating performance with a moderate electrical breakdown strength of approximately 1 MV/cm,excellent flexibility,and thermal stability up to 200℃.This work demonstrates the potential of high-k perovskite nanosheets for additive manufacturing of flexible high-performance dielectric capacitors.展开更多
基金Supported by Shanghai Aerospace Science and Technology Innovation Fund Project (SAST 2022-097)。
文摘Graphene oxide(GO)has proven to be an effective reinfor-cing filler for rubber[1].GO has superior mechanical properties,barrier properties,large specific surface area and abundant oxygen-containing functional groups[2].However,the change in the oxidation degree of GO has a great effect on its chemical properties,the interaction between GO and the matrix,and the dispersion uniformity in the rubber matrix,which has a great effect on the reinforcement of rubber[3].
基金supported by the National Natural Science Foundation of China (51772282,51972299)funding from Hefei Center for Physical Science and Technology。
文摘Lightweight yet strong paper with high toughness is desirable especially for impact protection. Herein we demonstrated electrically conductive and mechanically robust paper(AP/PB-GP) made of reduced graphene oxide via interfacial crosslinking with 1-aminopyrene(AP) and 1-pyrenebutyrat(PB) small molecules. The AP/PB-GP with thickness of over ten micrometer delivers a record-high toughness(~69.67 ± 15.3 MJ m^(-3) in average), simultaneously with superior strength(close to 1 GPa), allowing an impressive specific penetration energy absorption(~0.17 MJ kg^(-1)) at high impact velocities when used for ballistic impact protection. Detailed interfacial and structural analysis reveals that the reinforcement is synergistically determined by π-π interaction and H-bonding linkage between adjacent graphene lamellae. Especially, the defective pores within the graphene platelets benefit the favorable adsorption of the pyrene-containing molecules, which imperatively maximizes the interfacial binding, facilitating deflecting crack and plastic deformation under loading. Density functional theory simulation suggests that the coupling between the polar functional groups, e.g., –COOH, at the edges of graphene platelets and –NH_(2) and –COOH of AP/PB are critical to the formation of hydrogen bonding network.
基金supported by the Basic Science Center Program of National Natural Science Foundation of China(51788104)the National Natural Science Foundation of China(52172124 and51872214)the Fundamental Research Funds for the Central Universities(WUT:2021III019JC,2018III041GX)。
文摘Chemically exfoliated nanosheets have exhibited great potential for applications in various electronic devices.Solution-based processing strategies such as inkjet printing provide a low-cost,environmentally friendly,and scalable route for the fabrication of flexible devices based on functional inks of twodimensional nanosheets.In this study,chemically exfoliated high-k perovskite nanosheets(i.e.,Ca_(2)Nb_(3)O_(10)and Ca_(2)NaNb_(4)O_(13))are well dispersed in appropriate solvents to prepare printable inks,and then,a series of microcapacitors with Ag and graphene electrodes are printed.The resulting microcapacitors,Ag/Ca_(2)Nb_(3)O_(10)/Ag,graphene/Ca_(2)Nb_(3)O_(10)/graphene,and graphene/Ca_(2)NaNb_(4)O_(13)/graphene,demonstrate high capacitance densities of 20,80,and 150 nF/cm^(2) and high dielectric constants of 26,110.and 200,respectively.Such dielectric enhancement in the microcapacitors with graphene electrodes is possibly attributed to the dielectric/graphene interface.In addition,these microcapacitors also exhibit good insulating performance with a moderate electrical breakdown strength of approximately 1 MV/cm,excellent flexibility,and thermal stability up to 200℃.This work demonstrates the potential of high-k perovskite nanosheets for additive manufacturing of flexible high-performance dielectric capacitors.
