检索结果-南通市图书馆

Impact of Carbon Chain Structures in the Backbone on the Flexibility of Modified Polyarylene Sulfide Resins: Molecular Dynamics Simulations and Mesoscopic Analysis

引用

Chinese Journal of Polymer Science 2024年第4期42卷 544-557页

作者： Chi Zhang Rong Liu Jing-Yuan Liu Wen-Wei Jiang key laboratory of Fine chemical engineering and functional materials School of Chemical EngineeringSichuan UniversityChengdu610065China

In the domain of high-performance engineering polymers, the enhancement of mechanical flexibility in poly(phenylene sulfide) (PPS) resins has long posed a significant challenge. A novel molecular structure, designated as PP-He-IS, wherein imide rings and an aliphatic hexylene chain are covalently incorporated into the PPS backbone to enhance its flexibility, is introduced in this study. Molecular dynamics (MD) simulations are employed to systematically explore the effects of diversifying the backbone chain structures by substituting phenyl units with alkyl chains of varying lengths, referred to as PP-A-IS where “A” signifies the distinct intermediary alkyl chain configurations. Computational analyses reveal a discernable decrement in the glass transition temperature (Tg) and elastic modulus, counterbalanced by an increment in yield strength as the alkyl chain length is extended. Notably, the PP-He-IS variant is shown to exhibit superior yield strength while simultaneously maintaining reduced elastic modulus and Tg values, positioning it as an advantageous candidate for flexible PPS applications. Mesoscopic analyses further indicate that structures such as PP-He-IS, PP-Pe-IS, and PP-Bu-IS manifest remarkable flexibility, attributable to the presence of freely rotatable carbon-carbon single bonds. Experimental validation confirms that a melting temperature of 504 K which is lower than that of conventional PPS, and lower crystallinity are exhibited by PP-He-IS, thereby affording enhanced processability without compromising inherent thermal stability. Novel insights into the strategic modification of PPS for mechanical flexibility are thus furnished by this study, which also accentuates the pivotal role played by molecular dynamics simulations in spearheading high-throughput investigations in polymer material modifications.

关键词： Molecular dynamics simulations Polyarylene Sulfide Main-chain modifications Flexibility Aliphatic hexylene chain

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Construction of remote cyano-substituted quaternary carbon centers via nickel-catalyzed migratory hydrocyanation of unconjugated dienes

引用

Science China Chemistry 2024年第10期67卷 3397-3405页

作者： Yidan Xing Rongrong Yu Mingdong Jiao Ting Wang Xianjie Fang Shanghai key laboratory for Molecular engineering of Chiral Drugs School of Chemistry and Chemical EngineeringShanghai Jiao Tong University key laboratory of Organosilicon Chemistry and material Technology of Ministry of Education Key Laboratory of Organosilicon Material Technology of Zhejiang ProvinceCollege of MaterialChemistry and Chemical EngineeringHangzhou Normal University

The transition-metal-catalyzed migratory functionalization has emerged as a robust protocol for the building of C–C bonds remote from the “initiation” position. However, a similar strategy for the construction of quaternary carbon centers is still underdeveloped and only a limited number of reports exist. Herein, we report a nickel-catalyzed migratory hydrocyanation of unconjugated dienes to construct remote cyano-substituted quaternary carbon centers. This transformation features exceptional regioselectivity, mild reaction conditions, broad substrate scope and high yields. The synthetic utility of this method has been highlighted by a series of product derivatizations, and the potential of this transformation has been extended to synthesize TRPV1 antagonist and the key intermediate in the total synthesis of quebrachamine. Density functional theory(DFT) studies unveiled that the specific catalytic pocket assumed a significant role in the selective formation of cyano-substituted quaternary carbon centers.

关键词： chain-walking regioselectivity remote cyanation quaternary carbon centers unconjugated dienes

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Tuning the crystalline and electronic structure of ZrO_(2)via oxygen vacancies and nano-structuring for polysulfides conversion in lithium-sulfur batteries

引用

Journal of Energy Chemistry 2024年第1期88卷 82-93,I0003页

作者： Shengnan Fu Chaowei Hu Jing Li Hongtao Cui Yuanyuan Liu Kaihua Liu Yanzhao Yang Meiri Wang Shandong key laboratory for chemical engineering and Processing School of Chemistry&Chemical EngineeringYantai UniversityYantai 264000ShandongChina key laboratory for Special functional Aggregate materials of Education Ministry School of Chemistry and Chemical EngineeringShandong UniversityJinan 250100ShandongChina

The recent emergence of tetragonal phases zirconium dioxide(ZrO_(2))with vacancies has generated significant interest as a highly efficient and stable electrocatalyst with potential applications in trapping polysulfides and facilitating rapid conversion in lithium-sulfur batteries(LSBs).However,the reduction of ZrO_(2)is challenging,even under strong reducing atmospheres at high temperatures and ***,the limited presence of oxygen vacancies results in insufficient active sites and reaction interfaces,thereby hindering practical ***,we successfully introduced abundant oxygen vacancies into ZrO_(2)at the nanoscale with the help of carbon nanotubes(CNTs-OH)through hydrogen-etching at lower temperatures and *** introduced oxygen vacancies on ZrO_(2-x)/CNTs-OH can effectively rearrange charge distribution,enhance sulfiphilicity and increase active sites,contributing to high ionic and electronic transfer kinetics,strong binding energy and low redox barriers between polysulfides and ZrO_(2-x).These findings have been experimentally validated and supported by theory *** a result,LSBs assembled with the ZrO_(2-x)/CNTs-OH modified separators demonstrate excellent rate performance,superior cycling stability,and ultra-high sulfur ***,at high sulfur loading of 6 mg cm^(-2),the area capacity is still up to 6.3 mA h cm^(-2).This work provides valuable insights into the structural and functional optimization of electrocatalysts for batteries.

关键词： Lithium-sulfur batteries Oxygen vacancies Zirconium dioxide/carbon nanotubes with–OH Improved redox kinetics Superior cycling stability

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Well-dispersed Sb particles embedded on N-doped carbon nanofibers toward high-performance Li-ion battery

引用

Rare Metals 2024年第7期43卷 2994-3006页

作者： Ying Li Yi-Han Zhao Lu-Lu Zhao Peng-Fei Wang Ying Xie Ting-Feng Yi school of materials Science and engineering Northeastern UniversityShenyang 110819China key laboratory of Dielectric and Electrolyte functional material Hebei Province School of Resources and MaterialsNortheastern University at QinhuangdaoQinhuangdao 066004China key laboratory of functional Inorganic material Chemistry Ministry of EducationSchool of Chemistry and Materials ScienceHeilongjiang UniversityHarbin 150080China

The alloy-type material Sb is widely used in the anode materials of lithium-ion batteries(LIBs)due to its high theoretical specific ***,its serious volume expansion problem during alloying/dealloying of Li~+limits its practical *** this work,C-Sb composite was constructed as anode material of LIBs by electrospinning route for the first time,Sb was introduced into the polyacrylonitrile-based hard carbon and coal tar pitch-based soft carbon composite amorphous carbon fiber with a diameter of 300-600 nm,which realized high cycling *** C-Sb-2(the mass ratio of polyacrylonitrile to Sb source is 1:2)electrode displayed charge capacities of 1098.5,930.3,841.7,753.5,643.9 and 545.8 mAh·g^(-1)at 0.1,0.2,0.3,0.5,1 and 2 A·g^(-1),*** when the current density returned to 0.1 A·g^(-1),the charge capacity was 939.3 mAh·g^(-1),revealing good stability and *** introduction of Sb into the amorphous carbon improved its conductivity and addressed the volume expansion issue of high specific capacity Sb during charge/***-situ XRD analysis confirmed the high reversibility of the C-Sb-2 during charging and *** functional theory(DFT)calculations revealed the gradual enhancement of the interface interaction between Sb_(x)Li_(y) and amorphous carbon(AMC)with increasing lithium content,contributing to the anchoring of alloy nanoparticles on the AMC surface and buffering the volume change of the ***,the gradual lithiation of Sb facilitated the electron transfer from Sb_(x)Li_(y) to *** findings hold promise for designing lithium storage materials with exceptional performance,highlighting the potential of C-Sb composites as anode materials for efficient next-generation lithium storage.

关键词： Li-ion battery Metallic Sb Carbon Electrospinning Cycling stability

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

In situ Hydrothermal Oxidation of Ternary FeCoNi Alloy Electrode for Overall Water Splitting

引用

Energy & Environmental materials 2024年第2期7卷 165-174页

作者： Yuwei Chen Lixia Yang Chao Li Yuqiu Wu Xiao Lν Hairen Wang Jun'e Qu key laboratory for the Green Preparation and Application of functional materials Hubei Key Laboratory of Polymer Materials School of Materials Science and Engineering Hubei University Faculty of material science and Chemistry China University of Geosciences

Exploring noble metal-free catalyst materials for high efficient electrochemical water splitting to produce hydrogen is strongly desired for renewable energy *** this article,a novel bifunctional catalytic electrode of insitu-grown type for alkaline water splitting based on FeCoNi alloy substrate has been successfully prepared via a facile one-step hydrothermal oxidation route in an alkaline hydrogen peroxide *** shows that the matrix alloy with the atom ratio 4:3:3 of Fe:Co:Ni can obtain the best catalytic performance when hydrothermally treated at 180℃ for18 h in the solution containing 1.8 M hydrogen peroxide and 3.6 M sodium *** as-prepared Fe0.4Co0.3Ni0.3-1.8 electrode exhibits small overpotentials of only 184 and 175 mV at electrolysis current density of10 mA cm-2for alkaline OER and HER processes,*** overall water splitting at electrolysis current density of 10 mA cm-2can be stably delivered at a low cell voltage of 1.62 *** characteristics including the large specific surface area,the high surface nickel content,the abundant catalyst species,the balanced distribution between bivalent and trivalent metal ions,and the strong binding of in-situ naturally growed catalytic layer to matrix are responsible for the prominent catalytic performance of the Fe0.4Co0.3Ni0.3-1.8 electrode,which can act as a possible replacement for expensive noble metal-based materials.

关键词： alkaline water electrolysis bifunctional electrocatalyst FeCoNi alloy hydrothermal oxidation in-situ growing

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Manipulating fast Li_(2)S redox via carbon confinement and oxygen defect engineering of In_(2)O_(3)for lithium-sulfur batteries

引用

Nano Research 2024年第6期17卷 5179-5187页

作者： Jinlei Qin Rui Wang Zilong Yuan Pei Xiao Deli Wang key laboratory of material Chemistry for Energy Conversion and Storage Ministry of EducationHubei Key Laboratory of Material Chemistry and Service FailureSchool of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan 430074China

Lithium-sulfur(Li-S)batteries have been considered as promising energy storage systems due to the merits of high energy density and low ***,the lithium polysulfides(LiPSs)diffusion and sluggish redox kinetics hamper the battery *** this work,low-bandgap indium oxide(In_(2)O_(3))with dense oxygen vacancies(In_(2)O_(3−x),0chemical adsorbability to LiPSs,and catalyzes the bidirectional Li_(2)S *** to the structural and chemical cooperativities,the obtained sulfur electrodes exhibit a stable cycling over 550 cycles at 1.0 C and splendid rate capability up to 4.0 *** significantly,when the sulfur-loading reaches as high as 5.5 mg·cm^(−2),the cathodes achieve an areal capacity of 5.12 mAh·cm^(−2)at 0.1 *** strategy of NC confined catalyst with rich defects engineering demonstrates great promise in the development of practical Li-S batteries.

关键词： Li-S batteries nitrogen-doped carbon confinement oxygen vacancies bidirectional Li_(2)S redox

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Unlocking the Potential of Poly(butylene succinate) through Incorporation of Vitrimeric Network Based on Dynamic Imine Bonds

引用

Chinese Journal of Polymer Science 2024年第10期42卷 1414-1424页

作者： Shan-Song Wu Hui-Juan Lu Yi-Dong Li Shui-Dong Zhang Jian-Bing Zeng Chongqing key laboratory of Soft-Matter material Manufacturing School of Chemistry and Chemical Engineering Southwest University school of Mechanical and Automotive engineering South China University of Technology

Poly(butylene succinate)(PBS) exhibits many advantages, such as renewability, biodegradability, and impressive thermal and mechanical properties, but is limited by the low melt viscosity and strength resulted from the linear structure. To address this, vitrimeric network was introduced to synthesize PBS vitrimers(PBSVs) based on dynamic imine bonds through melt polymerization of hydroxyl-terminated PBS with vanillin derived imine containing compound and hexamethylene diisocyanate using trimethylolpropane as a crosslinking monomer. PBSVs with different crosslinking degrees were synthesized through changing the content of the crosslinking monomer. The effect of crosslinking degree on the thermal, theological, mechanical properties, and stress relaxation behavior of the PBSVs was studied in detail. The results demonstrated that the melt viscosity, melt strength, and heat resistance were enhanced substantially without obvious depression in crystallizability, thermal stability, and mechanical properties through increasing crosslinking degree. In addition, the PBSVs exhibit thermal reprocessability with mechanical properties recovered by more than 90% even after processing for three times. Furthermore, PBSV with improved melt properties shows significantly improved foamability compared to commercial PBS. This research contributes to the advancement of polymer technology by successfully developing PBS vitrimers with improved properties, showcasing their potential applications in sustainable and biodegradable materials.

关键词： Foamability Imine bonds Poly(butylene succinate) Vitrimer

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

A Self-Healing Elastomer with Extremely High Toughness Achieved by Acylsemicarbazide Hydrogen Bonding and Cu2+-Neocuproine Coordination Interactions

引用

Chinese Journal of Polymer Science 2024年第10期42卷 1425-1434页

作者： Xiao-Ming An Yi-Ping Wang Tang-Song Zhu Chong Xing Xu-Dong Jia Qiu-Hong Zhang key laboratory of High Performance Polymer material and Technology of MOE Department of Polymer Science and EngineeringSchool of Chemistry and Chemical EngineeringNanjing University State key laboratory of Coordination Chemistry Nanjing University

Elastomers with high mechanical toughness can guarantee their durability during service life. Self-healing ability, as well as recyclability, can also extend the life of materials and save the consuming cost of the materials. Many efforts have been dedicated to promoting the mechanical toughness as well as the self-healing capability of elastomers at the same time, while it remains a challenge to balance the trade-off between the above properties in one system. Herein we proposed a molecular design driven by dual interactions of acylsemicarbazide hydrogen bonding and Cu2+-neocuproine coordination simultaneously. By introducing the reversible multiple hydrogen bonds and strong coordination bonds, we successfully fabricated an extremely tough and self-healing elastomer. The elastomer can achieve an impressive top-notch toughness of 491 MJ/m3. Furthermore, it boasted rapid elastic restorability within 10 min and outstanding crack tolerance with high fracture energy（152.6kJ/m2）. Benefiting from the combination of dynamic interactions, the material was able to self-repair under 80 ℃ conveniently and could be reprocessed to restore the exceptional mechanical properties.

关键词： Hydrogen bond Metal-ligand coordination Self-healing Ultra-tough elastomer

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Progresses and Prospects of Asymmetrically Coordinated Single Atom Catalysts for Lithium-Sulfur Batteries

引用

Energy & Environmental materials 2024年第4期7卷 48-63页

作者： Rong Zhou Shaonan Gu Meng Guo Shuzheng Xu Guowei Zhou key laboratory of Fine chemicals in Universities of Shandong Jinan Engineering Laboratory for Multi-scale Functional Materials School of Chemistry and Chemical Engineering Qilu University of Technology(Shandong Academy of Sciences)

Lithium-sulfur batteries (LSBs) are widely regarded as promising next-generation batteries due to their high theoretical specific capacity and low material ***,the practical applications of LSBs are limited by the shuttle effect of lithium polysulfides (LiPSs),electronic insulation of charge and discharge products,and slow LiPSs conversion reaction kinetics.

关键词： asymmetrical coordination conversion catalysis Li-S batteries shuttle effect single atom catalysts

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Tuning interface mechanism of FeCo alloy embedded N,S-codoped carbon substrate for rechargeable Zn-air battery

引用

Journal of Energy Chemistry 2024年第6期93卷 400-410,I0010页

作者： Hui Chang Lulu Zhao Shan Zhao Zong-Lin Liu Peng-Fei Wang Ying Xie Ting-Feng Yi school of materials Science and engineering Northeastern UniversityShenyang 110819LiaoningChina key laboratory of functional Inorganic material Chemistry Ministry of EducationSchool of Chemistry and Materials ScienceHeilongjiang UniversityHarbin 150080HeilongjiangChina key laboratory of Dielectric and Electrolyte functional material Hebei Province School of Resources and MaterialsNortheastern University at QinhuangdaoQinhuangdao 066004HebeiChina

The interface mechanism between catalyst and carbon substrate has been the focus of *** this paper,the FeCo alloy embedded N,S co-doped carbon substrate bifunctional catalyst(FeCo/S-NC)is obtained by a simple one-step pyrolysis *** experimental results and density functional theory(DFT)calculation show that the formation of FeCo alloy is conducive to promoting electron transfer,and the introduction of S atom can enhance the interaction between FeCo alloy and carbon substrate,thus inhibiting the migration and agglomeration of particles on the surface of carbon *** FeCo/SNC catalysts show outstanding performance for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).FeCo/S-NC shows a high half-wave potential(E_(1/2)=0.8823 V)for ORR and a low overpotential at 10 mA cm^(-2)(E_(j=10)=299 mV)for *** addition,compared with Pt/C+RuO_(2) assembled Zn-air battery(ZAB),the FeCo/S-NC assembled ZAB exhibits a larger power density(198.8 mW cm^(-2)),a higher specific capacity(786.1 mA h g_(zn)~(-1)),and ultra-stable cycle *** results confirm that the optimized composition and the interfacial interaction between catalyst and carbon substrate synergistically enhance the electrochemical performance.

关键词： FeCo alloy N S co-doped carbon DFT calculation Zn-air batteries Interfacial interaction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：