A poly （ p-phenylenevinylene ） （ PPV ） alternating copolymer, poly [ （ 2, 5-diphenylene-1, 3, 4-oxadiazole ）-4-4＇ - vinylene-alt-2-methoxy-5-（ 2-ethylhexyloxy ）-1, 4-phenylenevinylene] （oxa-MEHPV）, is synth...A poly （ p-phenylenevinylene ） （ PPV ） alternating copolymer, poly [ （ 2, 5-diphenylene-1, 3, 4-oxadiazole ）-4-4＇ - vinylene-alt-2-methoxy-5-（ 2-ethylhexyloxy ）-1, 4-phenylenevinylene] （oxa-MEHPV）, is synthesized by Heck coupling reaction and characterized with UV-vis, Fourier transform infrared （ FT-IR ）, ^1H-NMR and photoluminescence （ PL ） spectroscopy, oxa-MEHPV possesses an outstanding thermal stability and shows excellent solubility in common organic solvents such as dichloromethane, chloroform, toluene, and tetrahydrofuran（THF）. The introduction of the electron-deficient 1, 3, 4-oxadiazole units into the MEH-PPV backbone also increases the electron affinities of the conjugated segment, which leads to the blue-shift of the maximum absorption wavelength and makes the polymer have a high optical band-gap energy, good electron-transporting stability and high PL quantum yield.展开更多
A diamond-like carbon （DLC） film is deposited as an electron injection layer between the polymer light-emitting layer（MEH-PPV） and aluminum （Al） cathode electrode in polymer electroluminescence devices （PLEDs）...A diamond-like carbon （DLC） film is deposited as an electron injection layer between the polymer light-emitting layer（MEH-PPV） and aluminum （Al） cathode electrode in polymer electroluminescence devices （PLEDs） using a radio frequency plasma deposition system. The source material of the DLC is n-butylamine. The devices consist of indium tin oxide （ITO）/MEH-PPV/DLC/Al. Electron injection properties are investigated through I-V characteristics,and the mechanism of electron injection enhancement due to a thin DLC layer has been studied. It is found that： （1） a DLC layer thinner than 1.0nm leads to a higher turn-on voltage and decreased electroluminescent （EL） efficiency; （2） a 5.0nm DLC layer significantly enhances the electron injection and results in the lowest turn-on voltage and the highest EL efficiency; （3） DLC layer that exceeds 5.0nm results in poor device performance;and（4） EL emission can hardly be detected when the layer exceeds 10.0nm. The properties of ITO/MEH-PPV/DLC/Al and ITO/MEH-PPV/LiF/Al are investigated comparatively.展开更多
Polyparaphenylene(PPP) is prepared by AlCl 3-CuCl 2 catalysts with benzene as the monomer and is doped by chemical method and N + ion implantation. The influences of the concentration, temperature and time of chemi...Polyparaphenylene(PPP) is prepared by AlCl 3-CuCl 2 catalysts with benzene as the monomer and is doped by chemical method and N + ion implantation. The influences of the concentration, temperature and time of chemical doping and the dose, energy and temperature of ion implantation, on PPP conductivity are investigated. The results showed that the conductivity of PPP can be improved 4～5 orders of magnitude by ion implantation and the conductivity of PPP can reach about 0.11 S·cm -1 by chemical doping. The comparison of stability of the material conductive behavior by using the two doping methods is presented. It shows that ion implantation is better than chemical doping in stabilizing the electric conductive behavior for the material.展开更多
The separate-layer injection in different interlayers and the injection of the same-molecular-weight polymer so- lution in a layer are necessary in the polymer flooding process because of heterogeneous multilayer sand...The separate-layer injection in different interlayers and the injection of the same-molecular-weight polymer so- lution in a layer are necessary in the polymer flooding process because of heterogeneous multilayer sandstone reservoirs in EOR projects. To alleviate the matching problems between the layer permeability and the injected polymer molecular weight, a molecular weight adjusting device with porous medium was designed on the basis of mechanical degradation principle. In terms of four variables （polymer concentration, pore diameter, length of shear component and flow rate ）, the theological behavior of hydrolyzed polyacrylamide （HPAM） solu- tion flowing through the device was investigated in detail. The change of these variables is able to control the shear rate of HPAM solutions through ceramic foam, and achieve the desired degree of shear degradation and the final theological parameters-viscosity loss, viscoelasticity and pressure drop. Therefore, a linear relationship between viscosity loss and shearing rate was established so as to obtain the targeted viscosity easily. Field tests in the Daqing Oil Field showed that the polymer molecular weight could drop 20% to 50%. In a word, the results could guide the industrial application of the novel device and the further study of polymer degradation flowing through the porous medium.展开更多
A series of alkali metal salts doped pluronic block copolymer F127 were used as electron injection/transport layers (ETLs) for polymer light-emitting diodes with poly[2-(4-(3′,7′-dimethyloctyloxy)-phenyl)-p-phenylen...A series of alkali metal salts doped pluronic block copolymer F127 were used as electron injection/transport layers (ETLs) for polymer light-emitting diodes with poly[2-(4-(3′,7′-dimethyloctyloxy)-phenyl)-p-phenylenevinylene] (P-PPV) as the emission layer. It was found that the electron transport capability of F127 can be effectively enhanced by doping with alkali metal salts. By using Li2CO3 (15%) doped F127 as ETL, the resulting device exhibited improved performance with a maximum luminous efficiency (LE) of 13.59 cd/A and a maximum brightness of 5529 cd/m2, while the device with undoped F127 as ETL only showed a maximum LE of 8.78 cd/A and a maximum brightness of 2952 cd/m2. The effects of the doping concentration, cations and anions of the alkali metal salts on the performance of the resulting devices were investigated. It was found that most of the alkali metal salt dopants can dramatically enhance the electron transport capability of F127 ETL and the performance of the resulting devices was greatly improved.展开更多
基金The National Basic Research Program of China(973Program)(No.2007CB936300)the High Technology Research and Devel-opment Program of Jiangsu Province(No.BG2006033).
文摘A poly （ p-phenylenevinylene ） （ PPV ） alternating copolymer, poly [ （ 2, 5-diphenylene-1, 3, 4-oxadiazole ）-4-4＇ - vinylene-alt-2-methoxy-5-（ 2-ethylhexyloxy ）-1, 4-phenylenevinylene] （oxa-MEHPV）, is synthesized by Heck coupling reaction and characterized with UV-vis, Fourier transform infrared （ FT-IR ）, ^1H-NMR and photoluminescence （ PL ） spectroscopy, oxa-MEHPV possesses an outstanding thermal stability and shows excellent solubility in common organic solvents such as dichloromethane, chloroform, toluene, and tetrahydrofuran（THF）. The introduction of the electron-deficient 1, 3, 4-oxadiazole units into the MEH-PPV backbone also increases the electron affinities of the conjugated segment, which leads to the blue-shift of the maximum absorption wavelength and makes the polymer have a high optical band-gap energy, good electron-transporting stability and high PL quantum yield.
文摘A diamond-like carbon （DLC） film is deposited as an electron injection layer between the polymer light-emitting layer（MEH-PPV） and aluminum （Al） cathode electrode in polymer electroluminescence devices （PLEDs） using a radio frequency plasma deposition system. The source material of the DLC is n-butylamine. The devices consist of indium tin oxide （ITO）/MEH-PPV/DLC/Al. Electron injection properties are investigated through I-V characteristics,and the mechanism of electron injection enhancement due to a thin DLC layer has been studied. It is found that： （1） a DLC layer thinner than 1.0nm leads to a higher turn-on voltage and decreased electroluminescent （EL） efficiency; （2） a 5.0nm DLC layer significantly enhances the electron injection and results in the lowest turn-on voltage and the highest EL efficiency; （3） DLC layer that exceeds 5.0nm results in poor device performance;and（4） EL emission can hardly be detected when the layer exceeds 10.0nm. The properties of ITO/MEH-PPV/DLC/Al and ITO/MEH-PPV/LiF/Al are investigated comparatively.
文摘Polyparaphenylene(PPP) is prepared by AlCl 3-CuCl 2 catalysts with benzene as the monomer and is doped by chemical method and N + ion implantation. The influences of the concentration, temperature and time of chemical doping and the dose, energy and temperature of ion implantation, on PPP conductivity are investigated. The results showed that the conductivity of PPP can be improved 4～5 orders of magnitude by ion implantation and the conductivity of PPP can reach about 0.11 S·cm -1 by chemical doping. The comparison of stability of the material conductive behavior by using the two doping methods is presented. It shows that ion implantation is better than chemical doping in stabilizing the electric conductive behavior for the material.
基金Supported by the Program for Yangtse River Scholars and Innovative Research Terms in Universities(IRT0936)the National Basic Research Program of China(2009CB219905+2 种基金2009CB219907)the Daqing Oilfield Co.Ltd
文摘The separate-layer injection in different interlayers and the injection of the same-molecular-weight polymer so- lution in a layer are necessary in the polymer flooding process because of heterogeneous multilayer sandstone reservoirs in EOR projects. To alleviate the matching problems between the layer permeability and the injected polymer molecular weight, a molecular weight adjusting device with porous medium was designed on the basis of mechanical degradation principle. In terms of four variables （polymer concentration, pore diameter, length of shear component and flow rate ）, the theological behavior of hydrolyzed polyacrylamide （HPAM） solu- tion flowing through the device was investigated in detail. The change of these variables is able to control the shear rate of HPAM solutions through ceramic foam, and achieve the desired degree of shear degradation and the final theological parameters-viscosity loss, viscoelasticity and pressure drop. Therefore, a linear relationship between viscosity loss and shearing rate was established so as to obtain the targeted viscosity easily. Field tests in the Daqing Oil Field showed that the polymer molecular weight could drop 20% to 50%. In a word, the results could guide the industrial application of the novel device and the further study of polymer degradation flowing through the porous medium.
基金supported by the National Natural Science Foundation of China (21125419, 50990065, 51010003, 51073058, and 20904011)National Research Project (2009CB623601 and 2009CB930604)
文摘A series of alkali metal salts doped pluronic block copolymer F127 were used as electron injection/transport layers (ETLs) for polymer light-emitting diodes with poly[2-(4-(3′,7′-dimethyloctyloxy)-phenyl)-p-phenylenevinylene] (P-PPV) as the emission layer. It was found that the electron transport capability of F127 can be effectively enhanced by doping with alkali metal salts. By using Li2CO3 (15%) doped F127 as ETL, the resulting device exhibited improved performance with a maximum luminous efficiency (LE) of 13.59 cd/A and a maximum brightness of 5529 cd/m2, while the device with undoped F127 as ETL only showed a maximum LE of 8.78 cd/A and a maximum brightness of 2952 cd/m2. The effects of the doping concentration, cations and anions of the alkali metal salts on the performance of the resulting devices were investigated. It was found that most of the alkali metal salt dopants can dramatically enhance the electron transport capability of F127 ETL and the performance of the resulting devices was greatly improved.
