Two cyclic olefin copolymers with the same comonomers and different monomer molar ratios were blended,and then the blends were satura ted in supercritical CO 2 at 20?MPa and various temperatures to prepare microc ellu...Two cyclic olefin copolymers with the same comonomers and different monomer molar ratios were blended,and then the blends were satura ted in supercritical CO 2 at 20?MPa and various temperatures to prepare microc ellular cyclic olefin copolymer blends by means of pressure quench.The cell dens ity and cell diameter of microcellular polymers were calculated to investigate t he effects of temperature and blending ratio on cell structures.The higher tempe rature results in larger cell sizes and smaller cell densities.The cell density increases remarkably and cell diameter decreases with increase in the content of the ingredient with higher T g.It is found that the stiffness of the matri x is the only possible material property that accounts for the differences in ce ll structure of micorocellular cyclic olefin copolymer blends with different ble nding ratio.展开更多
Hybrid organic-inorganic perovskites have been the subject of recent intense interest due to advances in photovoltaic and other optoelectronic applications. However, their poor stability limits commercial market appli...Hybrid organic-inorganic perovskites have been the subject of recent intense interest due to advances in photovoltaic and other optoelectronic applications. However, their poor stability limits commercial market application We enhance water stability by post treatment preparation of hybrid metal halide perovskite nanocrystal-embedded polymethylmethacrylate （PM- MA） blend films. Through blending process without any cleaning of nanocrystals, crystalline hybrid organic-inorganic perovs-kite nanocrystals were incorporated into PMMA matrix with well-dispersion Passivation of PMMA on the surface of the per-ovskite nanocrystals results in decreased traps and a long photoluminescence （PL） lifetime despite the bromine vacancies in the crystal lattice. Moreover, such color purity and inherent high transmittance for fluorescence emission of perovskite nanocrystals will endow the films with promising potentials in diverse practice photonic applications.展开更多
The viability of polyvinyl acetate (PVA) membranes blended with acrylic ester-co-acrylic acid copolymers (AE-co-AA), for ethanol dehydration was examined. The effects of the operating temperature on the permeate flux ...The viability of polyvinyl acetate (PVA) membranes blended with acrylic ester-co-acrylic acid copolymers (AE-co-AA), for ethanol dehydration was examined. The effects of the operating temperature on the permeate flux and separation factor of the membranes were investigated. The pervaporation separation characteristics of PVA/(AE-co-AA) membranes were related to the blend ratio, the dose of crosslinking agents and the operating temperature.展开更多
Gamma-ray radiation has always been a convenient and effective way to modify the inter- facial properties in polymer blends. In this work, a small amount of trimethylolpropane triacrylate （TMPTA） was incorporated in...Gamma-ray radiation has always been a convenient and effective way to modify the inter- facial properties in polymer blends. In this work, a small amount of trimethylolpropane triacrylate （TMPTA） was incorporated into poly（ethylene terephthalate） （PET）/random terpolymer elastomer （ST2000） blends by melt-blending. The existence of TMPTA would induce the crosslinking of PET and ST2000 molecular chains at high temperatures of blend- ing, resulting in the improvement in the impact strength but the loss in the tensile strength. When the PET/ST2000 blends were irradiated by gamma-ray radiation, the integrated me- chanical properties could be enhanced significantly at a high absorbed dose. The irradiated sample at a dose of 100 kGy even couldn＇t be broken under the impact test load, and at the same time, has nearly no loss of tensile strength. Based on the analysis of the impact- fractured surface morphologies of the blends, it can be concluded that gamma-ray radiation at high absorbed dose can further in situ enhance the interfacial adhesion by promoting the crosslinking reactions of TMPTA and polymer chains. As a result, the toughness and strength of PET/ST2000 blend could be dramatically improved. This work provides a facial and practical way to the fabrication of polymer blends with high toughness and strength.展开更多
A series of P3HT：PC71BM polymer solar cells （PSCs） with different PIDTDTQx doping concentrations were fabricated to in- vestigate the effect of the PIDTDTQx as a complementary electron donor on the performance of P...A series of P3HT：PC71BM polymer solar cells （PSCs） with different PIDTDTQx doping concentrations were fabricated to in- vestigate the effect of the PIDTDTQx as a complementary electron donor on the performance of PSCs. The power conversion efficiency （PCE） of the optimized ternary blend PSCs （with 2 wt% PIDTDTQx） reached 3.87%, which is 28% higher than that of the PSCs based on P3HT：PCvlBM （control cells）. The short-circuit current density （J^c） was increased to 10.20 mA/cm2 compared with the control cells. The PCE improvement could be attributed to more photon harvest and charge carrier transport by appropriate doping PIDTDTQx. The energy transfer from P3HT to PIDTDTQx was demonstrated from the 650 nm emis- sion intensity decrease and the red-shifted emission peaks from 725 nm to 737 nm along with the increase of PIDTDTQx dop- ing concentrations.展开更多
文摘Two cyclic olefin copolymers with the same comonomers and different monomer molar ratios were blended,and then the blends were satura ted in supercritical CO 2 at 20?MPa and various temperatures to prepare microc ellular cyclic olefin copolymer blends by means of pressure quench.The cell dens ity and cell diameter of microcellular polymers were calculated to investigate t he effects of temperature and blending ratio on cell structures.The higher tempe rature results in larger cell sizes and smaller cell densities.The cell density increases remarkably and cell diameter decreases with increase in the content of the ingredient with higher T g.It is found that the stiffness of the matri x is the only possible material property that accounts for the differences in ce ll structure of micorocellular cyclic olefin copolymer blends with different ble nding ratio.
文摘Hybrid organic-inorganic perovskites have been the subject of recent intense interest due to advances in photovoltaic and other optoelectronic applications. However, their poor stability limits commercial market application We enhance water stability by post treatment preparation of hybrid metal halide perovskite nanocrystal-embedded polymethylmethacrylate （PM- MA） blend films. Through blending process without any cleaning of nanocrystals, crystalline hybrid organic-inorganic perovs-kite nanocrystals were incorporated into PMMA matrix with well-dispersion Passivation of PMMA on the surface of the per-ovskite nanocrystals results in decreased traps and a long photoluminescence （PL） lifetime despite the bromine vacancies in the crystal lattice. Moreover, such color purity and inherent high transmittance for fluorescence emission of perovskite nanocrystals will endow the films with promising potentials in diverse practice photonic applications.
文摘The viability of polyvinyl acetate (PVA) membranes blended with acrylic ester-co-acrylic acid copolymers (AE-co-AA), for ethanol dehydration was examined. The effects of the operating temperature on the permeate flux and separation factor of the membranes were investigated. The pervaporation separation characteristics of PVA/(AE-co-AA) membranes were related to the blend ratio, the dose of crosslinking agents and the operating temperature.
文摘Gamma-ray radiation has always been a convenient and effective way to modify the inter- facial properties in polymer blends. In this work, a small amount of trimethylolpropane triacrylate （TMPTA） was incorporated into poly（ethylene terephthalate） （PET）/random terpolymer elastomer （ST2000） blends by melt-blending. The existence of TMPTA would induce the crosslinking of PET and ST2000 molecular chains at high temperatures of blend- ing, resulting in the improvement in the impact strength but the loss in the tensile strength. When the PET/ST2000 blends were irradiated by gamma-ray radiation, the integrated me- chanical properties could be enhanced significantly at a high absorbed dose. The irradiated sample at a dose of 100 kGy even couldn＇t be broken under the impact test load, and at the same time, has nearly no loss of tensile strength. Based on the analysis of the impact- fractured surface morphologies of the blends, it can be concluded that gamma-ray radiation at high absorbed dose can further in situ enhance the interfacial adhesion by promoting the crosslinking reactions of TMPTA and polymer chains. As a result, the toughness and strength of PET/ST2000 blend could be dramatically improved. This work provides a facial and practical way to the fabrication of polymer blends with high toughness and strength.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.2013JBZ004)the National Natural Science Foundation of China(Grant No.61377029)+1 种基金the Beijing Natural Science Foundation(Grant No.2122050)the State Key Laboratory of Catalysis,Chinese Academy of Sciences(Grant No.n-11-09)
文摘A series of P3HT：PC71BM polymer solar cells （PSCs） with different PIDTDTQx doping concentrations were fabricated to in- vestigate the effect of the PIDTDTQx as a complementary electron donor on the performance of PSCs. The power conversion efficiency （PCE） of the optimized ternary blend PSCs （with 2 wt% PIDTDTQx） reached 3.87%, which is 28% higher than that of the PSCs based on P3HT：PCvlBM （control cells）. The short-circuit current density （J^c） was increased to 10.20 mA/cm2 compared with the control cells. The PCE improvement could be attributed to more photon harvest and charge carrier transport by appropriate doping PIDTDTQx. The energy transfer from P3HT to PIDTDTQx was demonstrated from the 650 nm emis- sion intensity decrease and the red-shifted emission peaks from 725 nm to 737 nm along with the increase of PIDTDTQx dop- ing concentrations.
