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Supported Ziegler-Natta catalysts from MgCl_(2)·nROH precursors and its catalytic behaviors for diene copolymerization
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作者 FAN Xun-zhang ZHAO Yuan-jin +1 位作者 LUO Shu-fang HE Ai-hua 《合成橡胶工业》 CAS 2024年第4期348-348,共1页
Heterogeneous TiCl4/MgCl_(2) type Ziegler-Natta(Z-N)catalysts with unique advantages like low cost,high activity,high stereoregularity and pretty particle morphology,contribute to more than 130 Mt polyolefin large-sca... Heterogeneous TiCl4/MgCl_(2) type Ziegler-Natta(Z-N)catalysts with unique advantages like low cost,high activity,high stereoregularity and pretty particle morphology,contribute to more than 130 Mt polyolefin large-scale production.However,most researches related with heterogeneous Z-N catalysts focused onα-olefin polymerizations like ethylene,propylene,etc. 展开更多
关键词 CATALYSTS REGULARITY PROPYLENE
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Thermal conductivity of natural rubber nanocomposites with hybrid fillers 被引量:3
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作者 Junping Song Xiteng Li +3 位作者 Kaiyan Tian Lianxiang Ma Wei Li Shichune Yao 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2019年第4期928-934,共7页
Natural rubber nanocomposites filled with hybrid fillers of multi-walled carbon nanotubes(CNTs) and carbon black(CB) were prepared. CNTs were ultrasonically modified in mixture of hydrogen peroxide(H2O2) and distilled... Natural rubber nanocomposites filled with hybrid fillers of multi-walled carbon nanotubes(CNTs) and carbon black(CB) were prepared. CNTs were ultrasonically modified in mixture of hydrogen peroxide(H2O2) and distilled water(H2O). The functional groups on the surface of CNTs, changes in nanotube structure and morphology were characterized by Fourier transform infrared spectroscopy(FT-IR), Raman Spectroscopy, and transmission electron microscopy(TEM). It shows that hydroxyl(OH·) is successfully introduced. The surface defects of modified CNTs were obviously higher than those of original CNTs, and the degree of agglomeration was greatly reduced. Thermal conductivity of the composites was tested by protection heat flow meter method. Compared with unmodified CNTs/CB filling system, the thermal conductivity of hybrid composites is improved by an average of 5.8% with 1.5 phr(phr is parts per hundred rubber) of hydroxyl CNTs and 40 phr of CB filled. A three-dimensional heat conduction network composed of hydroxyl CNTs and CB, as observed by TEM, contributes to the good properties. Thermal conductivity of the hybrid composites increases as temperature rises. The mechanical properties of hybrid composites are also good with hydroxyl CNTs filled nanocomposites;the tensile strength, 100% and 300% tensile stress are improved by 10.1%, 22.4% and 26.2% respectively. 展开更多
关键词 Modified CARBON NANOTUBE CARBON black HYBRID FILLER Natural rubber Thermal CONDUCTIVITY
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Lithium bis(oxalate)borate crosslinked polymer electrolytes for high-performance lithium batteries 被引量:2
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作者 Xiao Wang Jujie Sun +8 位作者 Changhao Feng Xiujuan Wang Minghan Xu Jingjiang Sun Ning Zhang Jun Ma Qingfu Wang Chengzhong Zong Guanglei Cui 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第4期228-235,共8页
Solid electrolytes play a vital role in solid-state Li secondary batteries,which are promising high-energy storage devices for new-generation electric vehicles.Nevertheless,obtaining a suitable solid electrolyte by a ... Solid electrolytes play a vital role in solid-state Li secondary batteries,which are promising high-energy storage devices for new-generation electric vehicles.Nevertheless,obtaining a suitable solid electrolyte by a simple and residue-free preparation process,resulting in a stable interface between electrolyte and electrode,is still a great challenge for practical applications.Herein,we report a self-crosslinked polymer electrolyte(SCPE)for high-performance lithium batteries,prepared by a one-step method based on 3-methoxysilyl-terminated polypropylene glycol(SPPG,a liquid oligomer).It is worth noting that lithium bis(oxalate)borate(Li BOB)can react with SPPG to form a crosslinked structure via a curing reaction.This self-formed polymer electrolyte exhibits excellent properties,including high roomtemperature ionic conductivity(2.6×10^(-4) S cm^(-1)),wide electrochemical window(4.7 V),and high Li ion transference number(0.65).The excellent cycling stability(500 cycles,83%)further highlights the improved interfacial stability after the in situ formation of SCPE on the electrode surface.Moreover,this self-formation strategy enhances the safety of the battery under mechanical deformation.Therefore,the present self-crosslinked polymer electrolyte shows great potential for applications in high-performance lithium batteries. 展开更多
关键词 Self-formed Crosslinking structure Polymer electrolyte Lithium batteries
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Molten salt assisted fabrication of Fe@Fe_(SA)-N-C oxygen electrocatalyst for high performance Zn-air battery 被引量:2
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作者 Wenjun Zhang Kaicai Fan +5 位作者 Cheng-Hao Chuang Porun Liu Jian Zhao Dongchen Qi Lingbo Zong Lei Wang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第10期612-621,I0016,共11页
Non-noble-metal-based electrocatalysts with superior oxygen reduction reaction(ORR)activity to platinum(Pt)are highly desirable but their fabrications are challenging and thus impeding their applications in metal-air ... Non-noble-metal-based electrocatalysts with superior oxygen reduction reaction(ORR)activity to platinum(Pt)are highly desirable but their fabrications are challenging and thus impeding their applications in metal-air batteries and fuel cells.Here,we report a facile molten salt assisted two-step pyrolysis strategy to construct carbon nanosheets matrix with uniformly dispersed Fe_(3) N/Fe nanoparticles and abundant nitrogen-coordinated Fe single atom moieties(Fe@Fe_(SA)-N-C).Thermal exfoliation and etching effect of molten salt contribute to the formation of carbon nanosheets with high porosity,large surface area and abundant uniformly immobilized active sites.Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy(HAADF-STEM)image,X-ray absorption fine spectroscopy,and X-ray photoelectron spectroscopy indicate the generation of Fe(mainly Fe_(3) N/Fe)and Fe_(SA)-N-C moieties,which account for the catalytic activity for ORR.Further study on modulating the crystal structure and composition of Fe_(3) N/Fe nanoparticles reveals that proper chemical environment of Fe in Fe_(3) N/Fe notably optimizes the ORR activity.Consequently,the presence of abundant Fe_(SA)-N-C moieties,and potential synergies of Fe_(3) N/Fe nanoparticles and carbon shells,markedly promote the reaction kinetics.The as-developed Fe@Fe_(SA)-N-C-900 electrocatalyst displays superior ORR performance with a half-wave potential(E_(1/2))of 0.83 V versus reversible hydrogen electrode(RHE)and a diffusion limited current density of 5.6 mA cm^(-2).In addition,a rechargeable Zn-air battery device assembled by the Fe@Fe_(SA)-N-C-900 possesses remarkably stable performance with a small voltage gap without obvious voltage loss after500 h of operation.The facile synthesis strategy for the high-performance composites represents another viable avenue to stable and low-cost electrocatalysts for ORR catalysis. 展开更多
关键词 Molten salt Oxygen reduction reaction Long-term durability Zn-air batteries
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Ultrafine Fe/Fe3C decorated on Fe-N_(x)-C as bifunctional oxygen electrocatalysts for efficient Zn-air batteries 被引量:2
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作者 Lingbo Zong Xin Chen +17 位作者 Siliang Liu Kaicai Fan Shuming Dou Jie Xu Xiaoxian Zhao Wenjun Zhang Yaowen Zhang Weicui Wu Fenghong Lu Lixiu Cui Xiaofei Jia Qi Zhang Yu Yang Jian Zhao Xia Li Yida Deng Yanan Chen Lei Wang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第5期72-79,共8页
Efficient bifunctional oxygen electrocatalysts for ORR and OER are fundamental to the development of high performance metal-air batteries.Herein,a facile cost-efficient two-step pyrolysis strategy for the fabrication ... Efficient bifunctional oxygen electrocatalysts for ORR and OER are fundamental to the development of high performance metal-air batteries.Herein,a facile cost-efficient two-step pyrolysis strategy for the fabrication of a bifunctional oxygen electrocatalyst has been proposed.The efficient non-preciousmetal-based electrocatalyst,Fe/Fe_(3)C@Fe-N_(x)-C consists of highly curved onion-like carbon shells that encapsulate Fe/Fe_(3)C nanoparticles,distributed on an extensively porous graphitic carbon aerogel.The obtained Fe/Fe_(3)C@Fe-N_(x)-C aerogel exhibited superb electrochemical activity,excellent durability,and high methanol tolerance.The experimental results indicated that the assembly of onion-like carbon shells with encapsulated Fe/Fe_(3)C yielded highly curved carbon surfaces with abundant Fe-Nxactive sites,a porous structure,and enhanced electrocatalytic activity towards ORR and OER,hence displaying promising potential for application as an air cathode in rechargeable Zn-air batteries.The constructed Zn-air battery possessed an exceptional peak power density of~147 mW cm^(-2),outstanding cycling stability(200 cycles,1 h per cycle),and a small voltage gap of 0.87 V.This study offers valuable insights regarding the construction of low-cost and highly active bifunctional oxygen electrocatalysts for efficient air batteries. 展开更多
关键词 Non-precious metal Nitrogen-rich carbon Fe/Fe_(3)C Fe-N_(x)-C Bifunctional oxygen electrocatalysts
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Damping Properties of Ethylene-Vinyl Acetate Rubber/Polylactic Acid Blends 被引量:2
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作者 Xiaozhen He Ming Qu Xinyan Shi 《Journal of Materials Science and Chemical Engineering》 2016年第3期15-22,共8页
In this research, ethylene-vinyl acetate rubber (EVM)/polylactic acid (PLA) = 80/20 by weight blend was compounded with silica in a Haake torque rheometer. The effects of hindered phenol (AO-60), super branched polyol... In this research, ethylene-vinyl acetate rubber (EVM)/polylactic acid (PLA) = 80/20 by weight blend was compounded with silica in a Haake torque rheometer. The effects of hindered phenol (AO-60), super branched polyol, petroleum resin C9, polyvinyl chloride (PVC) and acrylic rubber (ACM) on the damping properties of blends were investigated by dynamic mechanic analyzer (DMA). The results showed that 20 phr super branched polyol significantly increased the damping factor of PLA to widen the effective damping temperature range from 42.1℃to 102.5℃. 15 phr AO-60 and 10 phr petroleum resin C9 both dramatically raised the blend’s damping factor to broaden the effective damping temperature range to 98.0℃ and 102.6℃, respectively. ACM and PVC are compatible with EVM, and both improved the damping properties of EVM/PLA blends. 展开更多
关键词 DMA EVM/PLA DAMPING Organic Hybrid
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Spectrophotometric and Voltammetric Studies on the Interaction of Heparin with Phenosafranine
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作者 Wei SUN Ya Qin DING Kui JIAO 《Chinese Chemical Letters》 SCIE CAS CSCD 2005年第11期1515-1518,共4页
The interaction of phenosafranine (PSF) with a glycosaminoglycans of heparin (Hep) in aqueous solution has been characterized by UV-Vis absorption spectrophotometry and cyclic voltammetry in pH 1.5 Britton-Robins... The interaction of phenosafranine (PSF) with a glycosaminoglycans of heparin (Hep) in aqueous solution has been characterized by UV-Vis absorption spectrophotometry and cyclic voltammetry in pH 1.5 Britton-Robinson (B-R) buffer solution. The addition of Hep caused decrease of the absorbance of PSF at 532 nm and the redox peak current of PSF. The study showed that an supramolecular complex of PSF-Hep was formed because of the electrostatic attraction of negatively charged Hep with the positively charged PSF, which resulted in the decrease of the equilibrium concentration of PSF in solutions, and the decrease of the absorbance or the peak current of PSF. The stoichiometry of the Hep/PSF complex was further calculated by voltammetric data with the result of 1:1 complex. 展开更多
关键词 HEPARIN PHENOSAFRANINE interaction VOLTAMMETRY spectrophotometry.
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The Assembly of C60 in Semicrystalline PLLA Matrix
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作者 Li Chen Xiujiang Pang 《Nano-Micro Letters》 SCIE EI CAS 2012年第1期30-33,共4页
It has increasingly become a research focus to build higher structure composed of C60. However, there has been very few reports on the influence of polymer addition on the self-assembling behavior of fullerene in orga... It has increasingly become a research focus to build higher structure composed of C60. However, there has been very few reports on the influence of polymer addition on the self-assembling behavior of fullerene in organic solvents. In this research, big needle-like C60 assemblings have been obtained in the form of PLLA/C60 composites. The largest C60 needles can be observed by naked eyes. The amount of C60 in the composite influences the length of C60 needles to some extent. DSC results indicate C60 accelerates the crystallization and lift the relative crystallinity of PLLA matrix. the results also imply the addition of semicrystalline PLLA influence the assembling behavior of C60. i.e., the crystallization of PLLA accelerated by C60 also act a driving force for the enriching and the linear assembling of C60 in PLLA matrix via Van der Waals force. 展开更多
关键词 C60 Poly(L-lactide acid)(PLLA) ASSEMBLING
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Preparation of high vinyl polybutadiene/sepiolite nanocomposite by in-situ polymerization with new molybdenum-based catalyst
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作者 WANG Xiao-tong XIE Ting-hao +1 位作者 TANG Jian HUA Jing 《合成橡胶工业》 CAS 北大核心 2022年第4期329-329,共1页
The dispersion of functional nanometer materials in polyolefin/clay nanocomposites is a key factor to determine the performances of mate-rials[1].In this research,the sepiolite with high specific surface area and good... The dispersion of functional nanometer materials in polyolefin/clay nanocomposites is a key factor to determine the performances of mate-rials[1].In this research,the sepiolite with high specific surface area and good adsorption was introduced into the molybdenum-based butadiene polymerization system.Sepiolite-supporting MoCl5(Mo)function as the main catalysts,together with the alkyl aluminum(Al)substituted by m-cresol to form the butadiene coordination polymerization catalyst system to prepare high vinyl polybutadiene(HVPB)/sepiolite(Sep)nanocomposite. 展开更多
关键词 POLYMERIZATION MOLYBDENUM CATALYST
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Effects of Fillers on the Damping Property of Ethylene Vinyl-Acetate/Polylactic Acid Blends
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作者 Xinyan Shi Lingyan Jia +1 位作者 Yan Ma Chengliang Li 《Journal of Materials Science and Chemical Engineering》 2016年第2期89-96,共8页
New and high performance damping materials from ethylene vinyl-acetate copolymer (VA content over 40%, shorted as EVM) and polylactic acid (PLA) blends were prepared with dicumyl peroxide (DCP) as the curing agent and... New and high performance damping materials from ethylene vinyl-acetate copolymer (VA content over 40%, shorted as EVM) and polylactic acid (PLA) blends were prepared with dicumyl peroxide (DCP) as the curing agent and triallyl isocyanurate (TAIC) as the curing coagent. The effects of silica, mesoporous silica and glass beads on the damping of the EVM/PLA blends were examined using a dynamic mechanical analyzer (DMA). The microstructures of the silica, mesoporous silica and glass beads were observed by transmission electron microscope (TEM). The dispersion of the fillers in the matrix was studied using a Rubber Process Analyzer (RPA). The results showed that silica filled blend had an effective damping temperature range (EDTR, tan &delta;> 0.3) of 81℃, while the mesoporous silica/silica and glass beads/silica filled blends had EDTR of 86℃ and 85℃, respectively. Mixtures of mesoporous silica and silica as well as glass beads and silica exhibited a more improved dispersion in the blends than silica alone. Blends filled with mesoporous silica and glass beads retained good mechanical properties as well as improved damping performance. 展开更多
关键词 EVM 700 PLA Damping Silica Mesoporous Silica Glass Beads
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Impact of Annealing on the Melt Recrystallization of a-PDLA/α-PLLA Double-layered Films
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作者 Yun-Peng Li Hao-Ran Shen +5 位作者 Shao-Juan Wang Hao Zhang Jian Hu Rui Xin Xiao-Li Sun Shou-Ke Yan 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2024年第2期230-238,I0009,共10页
Poly(lactic acid)(PLA) as a bio-based polymer with biodegradability and biocompatibility has attracted much attention. To manipulate its properties for different applications, regulation of crystal structure and cryst... Poly(lactic acid)(PLA) as a bio-based polymer with biodegradability and biocompatibility has attracted much attention. To manipulate its properties for different applications, regulation of crystal structure and crystalline morphology becomes an attractive research topic. In this work, the structure evolution of layered samples containing an amorphous poly(D-lactide)(PDLA) layer and a crystalline poly(L-lactide)(PLLA)layer with highly oriented edge-on α lamellar crystals after annealing at 150 ℃ or/and after melt-recrystallization has been studied by AFM, FTIR,and TEM combined with electron diffraction. The results demonstrate that melt recrystallization of the as-prepared sample leads to the formation of abundant randomly oriented PLA stereo-complex(PLA SC) crystals. Annealing at 150 ℃ results in the formation of a small amount of oriented PLA SC crystals at the interface. These PLA SC crystals show great impact on the recrystallization behavior of sample after melting at 190 ℃ and then crystallizing at 90 ℃. First, they impede the mutual diffusion of the overlying PDLA and underlying PLLA, and thus reduce their stereocomplexation ability as manifested by the decreased amount of PLA SC crystals. Second, they act as substrate to initiate the epitaxial crystallization of the overlying PDLA and underlying PLLA, which ensures the production of a highly oriented structure of PDLA and PLLA after melt recrystallization again. 展开更多
关键词 Poly(L-lactide) Poly(D-lactide) Double layer STEREOCOMPLEX
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Light-responsive Self-Immolative L-glutamic Acid-based Polyester Nanoparticles for Controlled Drug Release via Passerini Three-Component Polymerization
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作者 Xiao-Fei Sun Xu Zhang +5 位作者 Shu-Ping Song Ya-Qun Yao Yan Zhang Cheng-Liang Wang Jing-Jiang Sun Qing-Fu Wang 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2024年第5期570-578,I0005,共10页
L-glutamic acid(LA)is a bio-based,non-toxic,environmentally friendly material derived from biomass.The present study reports the application of Passerini three-component polymerization(P-3CP)for the straightforward pr... L-glutamic acid(LA)is a bio-based,non-toxic,environmentally friendly material derived from biomass.The present study reports the application of Passerini three-component polymerization(P-3CP)for the straightforward preparation of LA-based light-responsive polyesters(PLTDs)under mild conditions.PLTDs with molar masses up to 8500 g/mol and high yields exceeding 90%are obtained.The chemical structures and light-responsive self-immolative behavior of PLTDs are comprehensively characterized by employing ultraviolet-visible(UV-Vis)spectroscopy,size exclusion chromatography(SEC),nuclear magnetic resonance(NMR)spectroscopy,and liquid chromatography mass spectrometry(LC-MS).Meanwhile,monodisperse PLTD-based doxorubicin-loaded nanoparticles(PLTD-DOX-NP)(size=193 nm,PDI=0.018)are formulated by nanoprecipitation method.Upon light-induced depolymerization,the PLTD-DOX-NP undergoes rapid decomposition,resulting in a burst release of 80%cargo within 13 s.Furthermore,according to biological toxicity tests,the PLTD-NP possesses adequate biosafety,both before and after irradiation.Overall,the incorporation of P-3CP with biorenewable LA-based monomer adheres to the principles of green chemistry,significantly simplifying the synthetic pathway of light-responsive polymers. 展开更多
关键词 L-glutamic acid Passerini three-component polymerization Light-responsive POLYESTER NANOPARTICLES
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Highly efficient and stable 2D/3D perovskite solar cells based on surface reconstruction and energy level alignment
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作者 Qiaohui Li Hang Liu Tong Zhou 《Science China Chemistry》 SCIE EI CAS CSCD 2024年第9期3083-3090,共8页
Realizing simultaneous adjustment of energy levels and work functions in two-dimensional/three-dimensional(2D/3D)perovskite solar cells(PSCs)is a challenge.Here,a pseudohalide 3,5-bis(trifluoromethyl)benzylammonium te... Realizing simultaneous adjustment of energy levels and work functions in two-dimensional/three-dimensional(2D/3D)perovskite solar cells(PSCs)is a challenge.Here,a pseudohalide 3,5-bis(trifluoromethyl)benzylammonium tetrafluoroborate(TFPMABF_(4))was used to react with unreacted Pb I2on the surface of 3D bulky perovskite to form a mixed halide of 2D perovskite denoted(TF-PMA)_(2)FA_(2)Pb_(3)I_(8)(BF_(4))_(2).This novel 2D/3D perovskite enables the simultaneous adjustment of energy levels and work functions on the surface of active layers.Due to the significantly enhanced quality of 2D/3D perovskite film,decreased surface defects and increased charge carrier lifetime,the 2D/3D PSCs exhibit an outstanding power conversion efficiency(PCE)of 25.15%and a high V_(OC)of 1.194 V.Importantly,2D/3D PSCs exhibit remarkable enhancements in environmental stability,unencapsulated devices retaining more than 90%of their initial PCE at 50%humidity for 2,280 h. 展开更多
关键词 2D/3D perovskite perovskite solar cells organic spacers energy levels alignment
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MOF-templated tubular Ni_(1−x)Co_(x)S_(2)-CdS heterojunction with intensified direct Z-scheme charge transmission for highly promoted visible-light photocatalysis
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作者 Chuan Jiang Yuanxin Qiu +7 位作者 Xinxin Xin Yanyan Li Huilin Li Hui Wang Jixiang Xu Haifeng Lin Lei Wang Volodymyr Turkevych 《Nano Research》 SCIE EI CSCD 2024年第7期6281-6293,共13页
Hollow semiconductor nanostructures with direct Z-scheme heterojunction have significant advantages for photocatalytic reactions,and optimizing the interfacial charge transmission of Z-scheme heterojunction is the hin... Hollow semiconductor nanostructures with direct Z-scheme heterojunction have significant advantages for photocatalytic reactions,and optimizing the interfacial charge transmission of Z-scheme heterojunction is the hinge to achieve excellent solar conversion efficiency.In this work,tubular Ni_(1−x)Co_(x)S_(2)-CdS heterostructures with reinforced Z-scheme charge transmission were constructed through an In-metal-organic framework(MOF)templated strategy.The Z-scheme charge transfer mechanism was sufficiently confirmed by combining density functional theory(DFT)calculation,X-ray photoelectron spectroscopy(XPS),surface photovoltage spectroscopy(SPV),and radical testing results.Crucially,the use of sodium citrate complexant contributes to the formation of intimate heterointerface,and the Fermi level gap between CdS and NiS_(2)is enlarged through Co doping into NiS_(2),which enhances the built-in electric field and photo-carriers transmission driving force for Ni_(1−x)Co_(x)S_(2)-CdS heterojunction,resulting in an evidently promoted activity toward H2 evolution reaction(HER).Under visible-light(λ>400 nm)irradiation,the Ni_(1−x)Co_(x)S_(2)-CdS composite with 10 mol%Co doping and 80 wt.%CdS(NC_(0.10)S-80%CdS)achieved an outstanding HER rate up to 35.94 mmol·g^(−1)·h^(−1)(corresponding to the apparent quantum efficiency of 34.7%at 420 nm),approximately 76.4 times that of 3 wt.%Pt-loaded CdS and it is much superior to that of most CdS-based photocatalysts ever reported.Moreover,the good photocatalytic durability of Ni_(1−x)Co_(x)S_(2)-CdS heterostructures was validated by cycling and long-term HER tests.This work could inspire the development of high-performance Z-scheme heterojunction via optimizing the morphology and interfacial charge transmission. 展开更多
关键词 tubular heterostructure Z-scheme charge transmission interfacial coupling built-in electric field visible-light photocatalysis
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Bipolar Thermally Activated Delayed Fluorescence Emitter with Balanced Carrier Transport for High-Efficiency Nondoped Green Electroluminescent Devices
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作者 Yuchao Liu Zhagen Miao +5 位作者 Haikuo Gao Shian Ying Can Gao Shouke Yan Huanli Dong Zhongjie Ren 《CCS Chemistry》 CSCD 2024年第9期2346-2357,共12页
High-efficiency electroluminescent devices featuring simplified architecture have received considerable attention due to significant advantages in construction procedures and commercialized applications.However,there ... High-efficiency electroluminescent devices featuring simplified architecture have received considerable attention due to significant advantages in construction procedures and commercialized applications.However,there still remains a critical challenge with regard to the lack of organic semiconductors that simultaneously possess high luminescent efficiency and balanced carrier-transporting abilities.Herein,we design a thermally activated delayed fluorescence(TADF)emitter 4-(9,9-dimethyl-9,10-dihydroacridine)-4′-triphenylphosphineoxide-benzophenone(DMAC-BPTPO)by incorporating triphenylphosphine oxide into the donor–acceptor skeleton.The accessional electrontransporting moiety,rod-like dimer,and horizontally packing model synergistically enable DMAC-BP-TPO which possesses an excellent photoluminescence quantum yield of nearly 90%with a reverse intersystem crossing rate constant of 2.0×106 s−1,horizontal dipole ratio of 89%,and a balanced electron and hole mobilities with a small constrast ratio of 1.08.Eventually,simplified electroluminescent devices including organic lightemitting diodes(OLEDs)and organic light-emitting transistors(OLETs)incorporating DMAC-BP-TPO-based nondoped film are demonstrated due to their superior integrated optoelectronic properties along with preferable horizontal dipole orientation.A record-high external quantum efficiency value of 21.7%and 4.4%are finally achieved in the simplified nondoped OLED and OLET devices,which are among the highest values in the related research fields.This work provides a new avenue to develop a high-efficiency bipolar TADF emitter to advance the simplified electroluminescent devices. 展开更多
关键词 organic light-emitting diode organic lightemitting transistor BIPOLAR thermally activated delayed fluorescence nondoped active layer
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Effect of Phase Separation Size on the Properties of Self-healing Elastomer
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作者 Jun Xu Lei Zhu +3 位作者 Xian-Qi Feng Cong Sui Wen-Peng Zhao Shou-Ke Yan 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2024年第6期798-804,共7页
Regulation of phase structure has been recognized as one of the most effective ways to fabricate self-healing polymers with high mechanical strength.The mechanical properties of the resultant polymers are certainly af... Regulation of phase structure has been recognized as one of the most effective ways to fabricate self-healing polymers with high mechanical strength.The mechanical properties of the resultant polymers are certainly affected by the size of separated phase domain.However,the study on this aspect is absence,because it can hardly exclude the influence of variation in monomer proportion required for tuning the separated phase size.Here,we report the first study on tuning the phase size through reversible addition-fragmentation chain transfer(RAFT)polymerization without changing the proportion of monomers.As expected,the size of separated phase has been successfully mediated from 15 nm to 9 nm by tuning the molecular weight of the chain transfer agent.It is found that the mechanical strength and the self-healing efficiency of the resultant polymers increase simultaneously with the decrease of phase size.The study on the formation kinetics of hydrogen bonds reveals that the decrease of phase size can facilitate the re-bonding rate of hydrogen bonds,even if the migration of polymer chains is restricted. 展开更多
关键词 Self-healing polymers Phase separation Reversible addition-fragmentation chain transfer
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Realizing External Quantum Efficiency over 25% with Low Efficiency Roll-Off in Polymer-Based Light-Emitting Diodes Synergistically Utilizing Intramolecular Sensitization and Bipolar Thermally Activated Delayed Fluorescence Monomer 被引量:2
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作者 Yuchao Liu Yanchao Xie +4 位作者 Lei Hua Xingwen Tong Shian Ying Zhongjie Ren Shouke Yan 《CCS Chemistry》 CSCD 2023年第4期1005-1017,共13页
Since polymer-based light-emitting diodes(PLEDs)arewellsuited building blocks for large-area and low-cost flexible display equipment,state-of-the-art thermally activated delayed fluorescence(TADF)PLEDs are in high dem... Since polymer-based light-emitting diodes(PLEDs)arewellsuited building blocks for large-area and low-cost flexible display equipment,state-of-the-art thermally activated delayed fluorescence(TADF)PLEDs are in high demand.To respond to this demand,light-emitting TADF units have initially been modified with electron-transporting units to balance the carrier transport of regiorandom TADF polymers,and simultaneously,an intramolecular sensitizing strategy has also been employed by covalently incorporating TADF sensitizers with light-emitting TADF units and hosts in conjugated polymers to accelerate the spin-flip of triplet excitons.Superior photophysical properties have been achieved by a rational regulation of the proportions of each component,achieving a photoluminescence quantumyield of 90%,an extremely high rate of reverse intersystem crossing of 3×106 s−1,and a relatively low nonradiative decay rate of around 105 s−1.As a result,the solutionprocessed PLEDs can attain an external quantum efficiency(EQE)value of 25.4%with emission peaks of around 550 nm,representing record-high performance for PLEDs.The efficiency roll-off can also be significantly suppressed,maintaining an EQE value of 24.2%at 1000 cd/m2 with ideal efficiency roll-off of lower than 5%.Encouragingly,this work provides a valid strategy to tackle the imperative need for PLEDs with high EQE and low efficiency roll-off. 展开更多
关键词 thermally activated delayed fluorescence polymer light-emitting diodes intramolecular sensitizing strategy balanced carrier transports low efficiency roll-off
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Influence of Freezing Layer on the Crystallization Kinetics of PCL on Oriented PE Film 被引量:1
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作者 Hao Zhang Ying-Xiao Song +6 位作者 Na Li Shao-Juan Wang Jian Hu Rui Xin Jie Zhang Chun-Feng Song Shou-Ke Yan 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2023年第5期778-786,I0010,共10页
The effect of freezing layer on the crystallization kinetics of poly(ε-caprolactone)(PCL)thin and ultrathin films was investigated by monitor the growth process of it on oriented polyethylene(PE)and CaF_(2)with and w... The effect of freezing layer on the crystallization kinetics of poly(ε-caprolactone)(PCL)thin and ultrathin films was investigated by monitor the growth process of it on oriented polyethylene(PE)and CaF_(2)with and without freezing layer,respectively.It was found that the PCL films with similar thicknesses crystallize much faster on oriented PE than on CaF_(2)substrate.For example,the crystallization rate constant of a 102 nm thick PCL film decreases tremendously by 3 orders of magnitude from 1.1×10^(-1) on PE substrate at 50℃to 7×10^(-4)on CaF_(2)surface at 40℃.Moreover,the crystallization of PCL accelerates on CaF_(2)surface while slows down at PE surface with increasing film thickness.The ultrathin films of PCL with thickness less than 14 nm exhibits the fastest crystallization rate on oriented PE with a rate constant of about 3.5×10^(-1),which is 3 times higher than that of a ca.50 nm thick film.This illustrates the great influence of freezing layer on the crystallization process of PCL.The freezing layer thickness of PCL on PE is estimated to be in the range of 14-17 nm.Taking the radius of gyration(R_(g)~15.6 nm)of the used PCL material into account,the obtained results may imply the existence of a correlation between the R_(g)of PCL and its freezing layer thickness at PE substrate. 展开更多
关键词 Poly(ε-caprolactone) POLYETHYLENE INTERFACE Freezing layer Crystallization kinetics
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Constructing an efficient deep-blue TADF emitter by host-guest interactions towards solution-processed OLEDs with narrowband emission
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作者 Yanchao Xie Lei Hua +5 位作者 Zhi Wang Yuerong Liu Shian Ying Yuchao Liu Zhongjie Ren Shouke Yan 《Science China Chemistry》 SCIE EI CAS CSCD 2023年第3期826-836,共11页
High-efficiency thermally activated delayed fluorescence(TADF) emitters and corresponding well-designed solution-processed organic light emitting diodes(OLEDs) are presently attractive due to their potential for explo... High-efficiency thermally activated delayed fluorescence(TADF) emitters and corresponding well-designed solution-processed organic light emitting diodes(OLEDs) are presently attractive due to their potential for exploiting large-area flexible displays. In this context, we innovatively integrate 2,12-di-tert-butyl-5,9-dioxa-13b-boronaphtho [3,2,1] anthracene as the acceptor with 3,6-bis(3,6-di-tert-butylcarbazol-N-yl) carbazole as the donor to construct a rigid deep-blue emitter, TB-3t BuCz, which exhibits a narrow emission with full-width-at-half-maximum(FWHM) of 46 nm. TB-3t BuCz itself dispalys no TADF characteristics both in solution or in pure film states. However, the significant TADF behavior can be observed when TB-3t BuCz is doped with 2,6-DCzPPy host due to the formation of exciplex-like species in 2,6-DCzPPy/TB-3t BuCz system. It is also found that the discernible spin-flip of triplet excitons is feasible when the S1/T1states of the formed exciplex stay slightly lower than S1 and T1states of TB-3t BuCz for the other host/TB-3t BuCz systems. Eventually, thanks to the synergetic effect of rigid structure and favorable photophysical properties of TB-3t BuCz, the solution-processed OLEDs based on 2,6-DCzPPy/TB-3t BuCz as emitting layer has achieved the significantly improved external quantum efficiency(EQE) of 14.6% with suppressed efficiency roll-off.The CIE1931 coordinate of(0.158, 0.052) is typically in deep-blue region. Note that, this EQE value is among the highest echelon of solution-processed OLEDs with deep-blue emission by utilizing boron-containing TADF emitters. 展开更多
关键词 thermally activated delayed fluorescence oxygen-bridged cyclized boron host-guest interactions solution-processed OLEDs narrowband deep-blue emission
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Polyisoprene Bearing Dual Functionalized Mini-blocky Chain-ends Prepared from Neodymium-mediated Coordinative Chain Transfer Polymerizations
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作者 Wei-Xin Wang Wen-Peng Zhao +4 位作者 Jing Dong Hua-Qiang Zhang Feng Wang Heng Liu Xue-Quan Zhang 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2023年第5期720-727,I0008,共9页
Through neodymium-mediated coordinative chain transfer copolymerizaiton(CCTcoP),polyisoprenes bearing dual hydroxylated mini-blocky chain-ends were prepared via a three-step strategy.Kinetic studies revealed that,the ... Through neodymium-mediated coordinative chain transfer copolymerizaiton(CCTcoP),polyisoprenes bearing dual hydroxylated mini-blocky chain-ends were prepared via a three-step strategy.Kinetic studies revealed that,the polymerization demonstrated typical features of CCTcoP across the whole polymerization process,i.e.,quasi-living polymerization characteristic,tunable molecular weights,narrow molecular weight distributions,and atom economies.Comparing to previously reported CCTP homopolymerization systems,the presence of oxygen-containing IpOAl polar comonomer slowed down chain transfer rates obviously,rendering slightly higher molecular weights of the resultant PIps and smaller Np(number of polymer chains per Nd atom)values.Moreover,to mimic the structure of natural rubber,the hydroxyl end groups can be facilely modified into phosphonate,amide,and UPy,whose structures were further confirmed by NMR spectra.Incorporation these functionalities could greatly improve the hydrophilic properties of the polymers,as revealed from the significantly reduced static water contact angles. 展开更多
关键词 Functional polyisoprene NEODYMIUM Coordinative chain transfer polymerization Synthetic rubber
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