Colored layered double hydroxides （LDHs） can be synthesized by introducing colored cations such as Fe^3＋ and Cr^3 ＋, which call be used as thermal stabilizers for polyvinyl chloride （PVC）. The yellowish Mg/Fe an...Colored layered double hydroxides （LDHs） can be synthesized by introducing colored cations such as Fe^3＋ and Cr^3 ＋, which call be used as thermal stabilizers for polyvinyl chloride （PVC）. The yellowish Mg/Fe and bluish Mg/Cr LDHs are prepared by the co-precipitation method. The results show that the MgsCr_ CO3 and Mg3Fe_ CO3 colored layered double hydroxides can stabilize PVC for more than 30 min under the thermal aging temperature of 180 ℃. The preparation can use cheap Mg（OH） 2 instead of MgCl2, which produces a much smaller amount of the by-product NH4Cl. It is known that NH4Cl is a cheap fertilizer that is difficult to sell; therefore, the preparation is much greener and more economic than the one using magnesium salt.展开更多
Abstract:Hybrid inorganic/organic white organic light emitting diodes(hybrid-WOLEDs)are fabricated by combi-ning the blue phosphorescent organic light emitting diodes(PHOLEDs)with red Sr2SiO4:Eu3+phosphor spin coateda...Abstract:Hybrid inorganic/organic white organic light emitting diodes(hybrid-WOLEDs)are fabricated by combi-ning the blue phosphorescent organic light emitting diodes(PHOLEDs)with red Sr2SiO4:Eu3+phosphor spin coatedas a color conversion layer(CCL)over the other side of glass substrate on the devices.The basic configuration of thePHOLEDs consists a host material,N,N'-dicarbazolyl-3,5-benzene(mCP)which doped with a blue phosphorescentiridium complexes iridium(Ⅲ)bis[(4,6-di-fluorophenyl)-pyridinato-N-C2'](FIrpic)to produce high efficient blueorganic light emitting diodes.The hybrid-WOLED shows maximum luminous efficiency of 22.1 cd/A,maximumpower efficiency of 11.26 lm/W,external quantum efficiency of 10.2%and CIE coordinates of(0.32,0.34).Mo-reover,the output spectra and CIE coordinates of the hybrid-WOLED have a small shift in different driving currentdensity,which demonstrate good color stability.展开更多
A series of white phosphorescent OLED devices with buffer layer and multiple dopant structure is investigated in order to obtain better electro-optic performances and color stability. The color coordinate and color st...A series of white phosphorescent OLED devices with buffer layer and multiple dopant structure is investigated in order to obtain better electro-optic performances and color stability. The color coordinate and color stability are related to the location of multiple dopants layer, and the optimized location can compensate for the change of the blue emission intensity under a high voltage and stabilize the spectrum. The electro-optic performances and color stability can be further improved by changing the composition and thickness of the buffer layer between the emitting layer and the electron transport layer.In device B2, the distance from multiple dopant layer to buffer layer is 2 nm and the thickness of buffer layer is 5 nm,the maximum luminance, current density, and power efficiency can reach 9091 cd/m^2, 364.5 mA/cm^2, and 26.74 lm/W,respectively. The variation of international commission on the illumination（CIE） coordinate of device B2 with voltage increasing from 4 V to 7 V is only（0.006, 0.004）.展开更多
The pearl or nacreous layer of mollusk shell is composed of CaCO 3 aragonite crystals. The factors affecting their color are very complex, such as metal elements, chromoprotein, and nucleation materials. we analyzed ...The pearl or nacreous layer of mollusk shell is composed of CaCO 3 aragonite crystals. The factors affecting their color are very complex, such as metal elements, chromoprotein, and nucleation materials. we analyzed the crystal orientation of nacreous layers with different color prepared from fresh water clams Hyriopsis cumingii Lea by X ray diffraction . The results show that the crystal CaCO 3 orientation on specific plane is responsible for the color of pearl and nacreous pearl color.展开更多
Fluorescence/phosphorescence hybrid white organic light-emitting devices（WOLEDs） based on double emitting layers（EMLs） with high color stability are fabricated.The simplified EMLs consist of a non-doped blue therm...Fluorescence/phosphorescence hybrid white organic light-emitting devices（WOLEDs） based on double emitting layers（EMLs） with high color stability are fabricated.The simplified EMLs consist of a non-doped blue thermally activated delayed fluorescence（TADF） layer using 9,9-dimethyl-9,10-dihydroacridine-diphenylsulfone（DMAC-DPS） and an ultrathin non-doped yellow phosphorescence layer employing bis[2-（4-tertbutylphenyl）benzothiazolato-N,C2＇]iridium（acetylacetonate）（（tbt）_2Ir（acac））.Two kinds of materials of 4,7-diphenyl-1,10-phenanthroline（Bphen） and 1,3,5-tris（2-Nphenylbenzimidazolyl） benzene（TPBi） are selected as the electron transporting layer（ETL）,and the thickness of yellow EML is adjusted to optimize device performance.The device based on a 0.3-nm-thick yellow EML and Bphen exhibits high color stability with a slight Commission International de l＇Eclairage（CIE） coordinates variation of（0.017,0.009） at a luminance ranging from 52 cd/m^2 to 6998 cd/m^2.The TPBi-based device yields a high efficiency with a maximum external quantum efficiency（EQE）,current efficiency,and power efficiency of 10%,21.1 cd/A,and 21.3 lm/W,respectively.The ultrathin yellow EML suppresses hole trapping and short-radius Dexter energy transfer,so that Forster energy transfer（FRET）from DMAC-DPS to（tbt）_2Ir（acac） is dominant,which is beneficial to keep the color stable.The employment of TPBi with higher triplet excited state effectively alleviates the triplet exciton quenching by ETL to improve device efficiency.展开更多
In this paper, an MoOx film is deposited on a polyethylene terephthalate （PET） substrate as a buffer layer to improve the surface roughness of the flexible PET substrate. With an optimized MoOx thickness of 100 nm, ...In this paper, an MoOx film is deposited on a polyethylene terephthalate （PET） substrate as a buffer layer to improve the surface roughness of the flexible PET substrate. With an optimized MoOx thickness of 100 nm, the surface roughness of the PET substrate can be reduced to a very small value of 0.273 nm （much less than 0.585 nm of the pure PET）. Flexible white top-emitting organic light-emitting diodes （TEOLEDs） with red and blue dual phosphorescent emitting layers are constructed based on a low-reflectivity Sm/Ag semi-transparent cathode. The flexible white emission exhibits the best luminance and current injection characteristics with the 100-nm-thick MoOx buffer layer and this result indicates that a smooth substrate is beneficial to the enhancement of device electrical and electroluminescence performances. However, the white TEOLED with a 50-nm-thick MoOx buffer layer exhibits a maximum current efficiency of 4.64 cd/A and a power efficiency of 1.9 lm/W, slightly higher than those with a 100-nm MoOx buffer layer, which is mainly due to an obvious intensity enhancement but limited current increases in 50-nm MoOx-based white TEOLED. The change amplitudes of the Commission International de l’Eclairage （CIE） chromaticity coordinates are less than （0.016, 0.005） for all devices in a wide luminance range over 100 cd/m2, indicating an excellent color stability in our white flexible TEOLEDs. Additionally, the flexible white TEOLED with an MoOx buffer layer shows excellent flexibility to withstand more than 500 bending times under a curvature radius of approximately 9 mm. Research demonstrates that it is mainly attributed to the high surface energy of the MoOx buffer layer, which is conducible to the improvement of the surface adhesion to the PET substrate and the Ag anode.展开更多
Adhesive layer is an essential part of tooth colored restorations which play an important role in decreasing the microleakage between the tooth and restoration material after polymerization shrinkage. The purpose of t...Adhesive layer is an essential part of tooth colored restorations which play an important role in decreasing the microleakage between the tooth and restoration material after polymerization shrinkage. The purpose of this study was to evaluate the effect of deferent adhesive system of bonding agent on microleakage of nanocomposite resin in class II cavities. Two different types of adhesive systems: universal adhesive (ExciTE) and a newly developed adhesive (Nano-Bond) and one type of light-cured resin restorative material (nanocomposite resin) were used in this study. These adhesives were applied to prepared tooth cavities by either manufactures’ instructions or by an experimental method (single or double application). Nanocomposite resin was then placed and light-cured for 40 seconds. Teeth were subjected to 500 thermal cycles between 5°C and 55°C and were immersed in 3% methylene blue solution for 24 hours;microleakage was observed microscopically. The data were analyzed by a two-way ANOVA. For comparison between groups, Tukey’s post-hoc test was used. Nanoparticles reinforced adhesive system shows low microleakage in compare with universal adhesive system, and application of two adhesive layers also can decrease the microleakage. The ability of stress absorption by adhesive layer after polymerization shrinkage of restoration material will reduce the microleakage.展开更多
基金The Fundamental Research Funds for the Central Universities,the Scientific Innovation Research of College Graduates in Jiangsu Province(No.CXLX12-0105)the Analysis and Test Fund of Southeast University(No.201226)
文摘Colored layered double hydroxides （LDHs） can be synthesized by introducing colored cations such as Fe^3＋ and Cr^3 ＋, which call be used as thermal stabilizers for polyvinyl chloride （PVC）. The yellowish Mg/Fe and bluish Mg/Cr LDHs are prepared by the co-precipitation method. The results show that the MgsCr_ CO3 and Mg3Fe_ CO3 colored layered double hydroxides can stabilize PVC for more than 30 min under the thermal aging temperature of 180 ℃. The preparation can use cheap Mg（OH） 2 instead of MgCl2, which produces a much smaller amount of the by-product NH4Cl. It is known that NH4Cl is a cheap fertilizer that is difficult to sell; therefore, the preparation is much greener and more economic than the one using magnesium salt.
基金Project supported by the National Science Council of the Republic of China(101-2221-E-214-016)the financial supporitng of ISU99-01-06the MANALAB at ISU,Taiwan
文摘Abstract:Hybrid inorganic/organic white organic light emitting diodes(hybrid-WOLEDs)are fabricated by combi-ning the blue phosphorescent organic light emitting diodes(PHOLEDs)with red Sr2SiO4:Eu3+phosphor spin coatedas a color conversion layer(CCL)over the other side of glass substrate on the devices.The basic configuration of thePHOLEDs consists a host material,N,N'-dicarbazolyl-3,5-benzene(mCP)which doped with a blue phosphorescentiridium complexes iridium(Ⅲ)bis[(4,6-di-fluorophenyl)-pyridinato-N-C2'](FIrpic)to produce high efficient blueorganic light emitting diodes.The hybrid-WOLED shows maximum luminous efficiency of 22.1 cd/A,maximumpower efficiency of 11.26 lm/W,external quantum efficiency of 10.2%and CIE coordinates of(0.32,0.34).Mo-reover,the output spectra and CIE coordinates of the hybrid-WOLED have a small shift in different driving currentdensity,which demonstrate good color stability.
文摘A series of white phosphorescent OLED devices with buffer layer and multiple dopant structure is investigated in order to obtain better electro-optic performances and color stability. The color coordinate and color stability are related to the location of multiple dopants layer, and the optimized location can compensate for the change of the blue emission intensity under a high voltage and stabilize the spectrum. The electro-optic performances and color stability can be further improved by changing the composition and thickness of the buffer layer between the emitting layer and the electron transport layer.In device B2, the distance from multiple dopant layer to buffer layer is 2 nm and the thickness of buffer layer is 5 nm,the maximum luminance, current density, and power efficiency can reach 9091 cd/m^2, 364.5 mA/cm^2, and 26.74 lm/W,respectively. The variation of international commission on the illumination（CIE） coordinate of device B2 with voltage increasing from 4 V to 7 V is only（0.006, 0.004）.
文摘The pearl or nacreous layer of mollusk shell is composed of CaCO 3 aragonite crystals. The factors affecting their color are very complex, such as metal elements, chromoprotein, and nucleation materials. we analyzed the crystal orientation of nacreous layers with different color prepared from fresh water clams Hyriopsis cumingii Lea by X ray diffraction . The results show that the crystal CaCO 3 orientation on specific plane is responsible for the color of pearl and nacreous pearl color.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61675041 and 61605253)the Foundation for Innovation Research Groups of the National Natural Science Foundation of China(Grant No.61421002)the Science&Technology Department Program of Sichuan Province,China(Grant No.2016HH0027)
文摘Fluorescence/phosphorescence hybrid white organic light-emitting devices（WOLEDs） based on double emitting layers（EMLs） with high color stability are fabricated.The simplified EMLs consist of a non-doped blue thermally activated delayed fluorescence（TADF） layer using 9,9-dimethyl-9,10-dihydroacridine-diphenylsulfone（DMAC-DPS） and an ultrathin non-doped yellow phosphorescence layer employing bis[2-（4-tertbutylphenyl）benzothiazolato-N,C2＇]iridium（acetylacetonate）（（tbt）_2Ir（acac））.Two kinds of materials of 4,7-diphenyl-1,10-phenanthroline（Bphen） and 1,3,5-tris（2-Nphenylbenzimidazolyl） benzene（TPBi） are selected as the electron transporting layer（ETL）,and the thickness of yellow EML is adjusted to optimize device performance.The device based on a 0.3-nm-thick yellow EML and Bphen exhibits high color stability with a slight Commission International de l＇Eclairage（CIE） coordinates variation of（0.017,0.009） at a luminance ranging from 52 cd/m^2 to 6998 cd/m^2.The TPBi-based device yields a high efficiency with a maximum external quantum efficiency（EQE）,current efficiency,and power efficiency of 10%,21.1 cd/A,and 21.3 lm/W,respectively.The ultrathin yellow EML suppresses hole trapping and short-radius Dexter energy transfer,so that Forster energy transfer（FRET）from DMAC-DPS to（tbt）_2Ir（acac） is dominant,which is beneficial to keep the color stable.The employment of TPBi with higher triplet excited state effectively alleviates the triplet exciton quenching by ETL to improve device efficiency.
基金Project supported by the National Key Basic Research and Development Program of China(Grant No.2009CB930600)the National Natural Science Founda-tion of China(Grant Nos.61274065,60907047,51173081,and 61136003)the"333"and"Qing Lan"Program of Jiangsu Province,and the"Qing Lan"and"Pandeng"Project of Nanjing University of Posts and Telecommunications(Grant Nos.NY210040,NY211069,and NY 210015)
文摘In this paper, an MoOx film is deposited on a polyethylene terephthalate （PET） substrate as a buffer layer to improve the surface roughness of the flexible PET substrate. With an optimized MoOx thickness of 100 nm, the surface roughness of the PET substrate can be reduced to a very small value of 0.273 nm （much less than 0.585 nm of the pure PET）. Flexible white top-emitting organic light-emitting diodes （TEOLEDs） with red and blue dual phosphorescent emitting layers are constructed based on a low-reflectivity Sm/Ag semi-transparent cathode. The flexible white emission exhibits the best luminance and current injection characteristics with the 100-nm-thick MoOx buffer layer and this result indicates that a smooth substrate is beneficial to the enhancement of device electrical and electroluminescence performances. However, the white TEOLED with a 50-nm-thick MoOx buffer layer exhibits a maximum current efficiency of 4.64 cd/A and a power efficiency of 1.9 lm/W, slightly higher than those with a 100-nm MoOx buffer layer, which is mainly due to an obvious intensity enhancement but limited current increases in 50-nm MoOx-based white TEOLED. The change amplitudes of the Commission International de l’Eclairage （CIE） chromaticity coordinates are less than （0.016, 0.005） for all devices in a wide luminance range over 100 cd/m2, indicating an excellent color stability in our white flexible TEOLEDs. Additionally, the flexible white TEOLED with an MoOx buffer layer shows excellent flexibility to withstand more than 500 bending times under a curvature radius of approximately 9 mm. Research demonstrates that it is mainly attributed to the high surface energy of the MoOx buffer layer, which is conducible to the improvement of the surface adhesion to the PET substrate and the Ag anode.
文摘Adhesive layer is an essential part of tooth colored restorations which play an important role in decreasing the microleakage between the tooth and restoration material after polymerization shrinkage. The purpose of this study was to evaluate the effect of deferent adhesive system of bonding agent on microleakage of nanocomposite resin in class II cavities. Two different types of adhesive systems: universal adhesive (ExciTE) and a newly developed adhesive (Nano-Bond) and one type of light-cured resin restorative material (nanocomposite resin) were used in this study. These adhesives were applied to prepared tooth cavities by either manufactures’ instructions or by an experimental method (single or double application). Nanocomposite resin was then placed and light-cured for 40 seconds. Teeth were subjected to 500 thermal cycles between 5°C and 55°C and were immersed in 3% methylene blue solution for 24 hours;microleakage was observed microscopically. The data were analyzed by a two-way ANOVA. For comparison between groups, Tukey’s post-hoc test was used. Nanoparticles reinforced adhesive system shows low microleakage in compare with universal adhesive system, and application of two adhesive layers also can decrease the microleakage. The ability of stress absorption by adhesive layer after polymerization shrinkage of restoration material will reduce the microleakage.
