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Conformational Disorder Within the Crystalline Region of Silica-Filled Polydimethylsiloxane:A Solid-State NMR Study

Chinese Journal of polymer science 2024年第11期42卷 1780-1792,I0012页

作者： Yu-Qi Xiong Chang-Lin Li Ai Lu Liang-Bin Li Wei Chen National Synchrotron Radiation Laboratory Anhui Provincial Engineering Laboratory of Advanced Functional Polymer FilmCAS Key Laboratory of Soft Matter ChemistryUniversity of Science and Technology of ChinaHefei230026China Department of Accelerator Science and Engineering Physics School of Nuclear Science and TechnologyUniversity of Science and Technology of ChinaHefei230026China Institute of Chemical Materials China Academy of Engineering PhysicsMianyang621900China

The crystallization behavior of silica-filled polydimethylsiloxane(PDMS)was investigated in detail by^(1)H solid-state nuclear magnetic resonance(^(1)H SS-NMR)in combination with synchrotron radiation wide-angle X-ray scattering(WAXS),and temperature-modulated differential scanning calorimetry(TMDSC)*** neat PDMS,no apparent difference is observed for the crystallinity characterized by^(1)H SS-NMR and WAXS at low-temperature ***,upon filler addition,a 15%-35%lower difference in crystallinity is observed measured by^(1)H SS-NMR compared to *** origin of such mismatch was explored through multi-component structural,dynamics,and chain-order analysis of PDMS samples with different filler *** 1D integrated WAXS results of PDMS with different filler fractions at different temperatures show that the packing structure as well as crystal size basically remain unchanged,but as the filler fraction increases from 0 phr to 60 phr,the rigid component’s dynamics order parameter S_(r)obtained by^(1)H SS-NMR decreases from 0.70 to *** filler fraction-dependent crystallinity calculated based on S_(r)was compared with experimental values,revealing a behavior of decreasing order in the crystalline *** with the results of accelerated chain dynamics in crystalline region as reflected by T_(2)values,the molecular origin is attributed to the formation of CONDIS crystals,whose conformational order is lost but the position and orientation orders are *** hypothesis is further supported by the TMDSC results,where,as the filler fraction increases from 0 phr to 60 phr,the melting range widens from 8.77 K to 14.56 K,representing a growth of166%.In addition to previous reports related to the condition for forming CONDIS mesophase,i.e.,temperature,pressure,and stretching,the nano-sized filler could also introduce the local conformational disorder for chain packing.

关键词： Solid state NMR polymer nanocomposite CONDIS crystal Local chain order PDMS crystallization

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In-situ forming ultra-mechanically sensitive materials for high-sensitivity stretchable fiber strain sensors

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National science Review 2024年第6期11卷 254-263页

作者： Rouhui Yu Changxian Wang Xiangheng Du Xiaowen Bai Yongzhong Tong Huifang Chen Xuemei Sun Jing Yang Naoji Matsuhisa Huisheng Peng Meifang Zhu Shaowu Pan State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and Engineering Donghua University MOE Key Lab of Disaster Forecast and Control in Engineering School of Mechanics and Construction Engineering Jinan University State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular Science and Institute of Fiber Materials and Devices Fudan University Department of Cardiology Shanghai Xuhui Central HospitalZhongshan-Xuhui Hospital Fudan University Research Center for Advanced Science and Technology and Institute of Industrial Science The University of Tokyo

Fiber electronics with flexible and weavable features can be easily integrated into textiles for wearable applications. However, due to small sizes and curved surfaces of fiber materials, it remains challenging to load robust active layers, thus hindering production of high-sensitivity fiber strain sensors. Herein, functional sensing materials are firmly anchored on the fiber surface in-situ through a hydrolytic condensation *** anchoring sensing layer with robust interfacial adhesion is ultra-mechanically sensitive, which significantly improves the sensitivity of strain sensors due to the easy generation of microcracks during stretching. The resulting stretchable fiber sensors simultaneously possess an ultra-low strain detection limit of 0.05%, a high stretchability of 100%, and a high gauge factor of 433.6, giving 254-folds enhancement in sensitivity. Additionally, these fiber sensors are soft and lightweight, enabling them to be attached onto skin or woven into clothes for recording physiological signals, e.g. pulse wave velocity has been effectively obtained by them. As a demonstration, a fiber sensor-based wearable smart healthcare system is designed to monitor and transmit health status for timely intervention. This work presents an effective strategy for developing high-performance fiber strain sensors as well as other stretchable electronic devices.

关键词： fiber strain sensor stretchable wearable healthcare

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Synthesis of Long-Chain Oligomeric Donor and Acceptors via Direct Arylation for Organic Solar Cells

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Chinese Journal of Chemistry 2024年第5期42卷 523-532页

作者： Yu Wu Xin-Yu He Xu-Min Huang Ling-Jun Yang Peng Liu Na Chen Chang-Zhi Li Shi-Yong Liu Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry College of MaterialsMetallurgical and ChemistryJiangxi University of Science and TechnologyGanzhouJiangxi341000 China Department of Polymer Science and Engineering Zhejiang UniversityHangzhouZhejiang310027 China

The rapid synthesis of structurally complicated electron donors&acceptors still remains a major challenge in organic solar cells(OSC).In this work,we developed a highly efficient strategy to access long-chain oligomeric donor and acceptors for OSC applications.A series of cyclopentadithiophene(CPDT)and benzothiadiazole(BT)-basedπ-conjugated oligomers,i.e.,three oligomeric acceptors(BTDT)n-IC(n=1—3)and one long-chain oligomeric donor(BTDT)4-RD,are facilely synthesized by an atom-and step-economical,and labor-saving direct C—H arylation(DACH)reaction(i.e.,C—H/C—Br cross coupling).Note that(BTDT)4-RD involving five CPDT,four BT and two rhodamine(RD)building blocks is the longest oligomeric donor in the fullerene-free OSC devices ever *** dependence of the structure-property-performance correlation of(BTDT)n-IC(n=1—3)and(BTDT)4-RD on theπ-conjugation lengths is thoroughly investigated by opto-electrochemical measurements,bulk heterojunction(BHJ)OSC devices and ***(BTDT)1-IC:PBDB-T and(BTDT)4-RD:Y6 BHJs achieve power conversion efficiencies of 9.14%and 4.51%,*** findings demonstrate that DACH reaction is a powerful tool to tune the opto-electronic properties and device performances by regulating the lengths ofπ-conjugated oligomers with varied numbers of repeating units.

关键词： Long-chainπ-conjugated oligomer Organic solar cells Direct arylation Atom-economical synthesis Cyclopentadithiophene Benzothiadiazole C—H activation Conjugation Oligomers

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Hydrophilic polyanionic hydrogel electrolyte for anti-freezing and bending resistant zinc-ion hybrid supercapacitors

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Journal of Materiomics 2024年第6期10卷 1299-1307页

作者： Xuejuan Wan Hangqi Song Zejia Zhao Zuocai Zhang Jingwei Wang Junye Cheng Shenzhen Key Laboratory of Polymer Science and Technology Guangdong Research Center for Interfacial Engineering of Functional MaterialsCollege of Materials Science and EngineeringShenzhen UniversityShenzhen518060China Department of Materials Science Shenzhen MSU-BIT UniversityShenzhen517182China Institute of Semiconductor Manufacturing Research College of Mechatronics and Control EngineeringShenzhen UniversityShenzhen518060China

Zinc-ion hybrid supercapacitors(ZHSCs)have been widely considered as promising candidates for flexible electrochemical energy storage *** key challenge is to develop hydrogel electrolytes with high hydrophilicity,anti-freezing,bending resistance,and stable interface with *** study reported a hydrogel electrolyte system that can meet the above functions,in which the zincophilic and negatively charged SO_(3)^(−),migratable Na^(+),abundant hydrophilic functional groups,gum xanthan,and porous architecture could effectively promote the electrochemical performance of *** with such hydrogel electrolytes not only exhibited good low-temperature performance but also showed excellent bending resistance ability.A high specific capacitance could be kept after a long air-working lifespan over 10,000 cycles under a wide operation voltage of 1.85 V at−10℃.Furthermore,flexible ZHSCs could maintain the capacitance retention of 93.18%even after continuous 500 bends at an angle of 180°.The designed hydrogel electrolytes could be also used for other electrochemical energy storage devices with anti-freezing and bending resistance by changing electrolyte salt.

关键词： Zn-ion hybrid supercapacitors Polyanionic Anti-freezing Bending resistance Porous architecture

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Ordered Mesoporous Magnetic Ceramics from Single-Source Self-Assembled Ferrocene-Functionalized Giant Molecules

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CCS Chemistry 2025年第2期7卷 460-469页

作者： Qing-Yun Guo Xing-Han Li Yuean Wu Xiao-Yun Yan Yuchu Liu Di Han Bo-xing Zhang Xian-You Liu Huanyu Lei Zebin Su Jiahao Huang Wei Zhang GengXin Liu Hao Liu Xueyan Feng Stephen Z.D.Cheng South China Advanced Institute of Soft Matter Science and Technology School of Emergent Soft MatterSouth China University of TechnologyGuangzhou 510640 Department of Polymer Science School of Polymer Science and Polymer EngineeringThe University of AkronAkronOhio 44325-3909 Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices Guangdong Basic Research Center of Excellence for Energy and Information Polymer MaterialsSouth China University of TechnologyGuangzhou 510640 College of Polymer Science and Engineering State Key Laboratory of Polymer Materials and EngineeringSichuan UniversityChengdu 610065 Department of Pharmaceutical Science School of PharmacyUniversity of PittsburghPittsburghPennsyl-vania 15261 State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Center for Advanced Low-dimensional MaterialsCollege of Materials Science and EngineeringDonghua UniversityShanghai 201620 State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai 200438

Ordered mesoporous materials have demonstrated con-siderable potential in various fields,such as catalysis,separation,and biomedical *** such materials has garnered extensive ***-ever,current investigations of mesoporous materials predominantly focus on high porosity and related appli-cations,often neglecting the development of mesopor-ous materials possessing additional ***,we report the fabrication of ordered mesoporous magnetic ceramics by pyrolyzing single-source self-assembled giant molecules,constructed by dihydroxyl-functiona-lized polyhedral oligomeric silsequioxane,polystyrene,and *** ordered magnetic ceramics with high surface areas and uniform pore sizes were obtained after the *** measure-ments revealed the ferromagnetic nature of the ceramic *** magnetic ceramic monoliths and magnetic ceramic thin films can be fabricated by pro-cessing the precursor giant ***,the mesoporous magnetic ceramics exhibit exceptional adsorption capacity and facile separability,making them suitable for water pollutant removal applications.

关键词： mesoporous materials self-assembly giant molecules polyhedral oligomeric silsequioxane ferrocene

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Entropy-modulated and interlayer-doped transition metal layered oxides enable high-energy-density sodium-ion capacitors

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Nano Research 2024年第10期17卷 8785-8793页

作者： Tiansheng Wang Yadong Li Zhengyuan Chen Qingshan Liu Jian Lang Langyuan Wu Wendi Dong Zhengyu Ju Hongsen Li Xiaogang Zhang Guihua Yu College of Physics Qingdao UniversityQingdao 266071China Jiangsu Key Laboratory of Materials and Technologies for Energy Storage College of Materials Science and TechnologyNanjing University of Aeronautics and AstronauticsNanjing 210016China Materials Science and Engineering Program and Walker Department of Mechanical Engineering The University of Texas at AustinAustin 78712USA

In recent years,sodium-ion capacitors have attracted attention due to their cost-effectiveness,high power density and similar manufacturing process to lithium-ion ***,the utilization of oxide electrodes in traditional sodium-ion capacitors restricts their further advancement due to the inherent low operating voltage and electrolyte consumption based on their energy storage *** address these challenges,we incorporated Zn,Cu,Ti,and other elements into Na_(0.67)Ni_(0.33)Mn_(0.67)O_(2) to synthesize P2-type Na_(0.7)Ni_(0.28)Mn_(0.6)Zn_(0.05)Cu_(0.02)Ti_(0.05)O_(2) with a modulated entropy and pillaring *** the synergistic interplay between the interlayer pillar and the entropy modulation within the layers,the material exhibits exceptional toughness,effectively shielding it from detrimental phase transitions at elevated voltage *** a result,the material showcases outstanding kinetic properties and long-term cycling stability across the voltage *** integrating these materials with hierarchical porous carbon nanospheres to form a"rocking chair"sodium-ion capacitor,the hybrid full device delivers a high energy density(171 Wh·kg^(-1))and high power density(5245 W·kg^(-1)),as well as outstanding cycling stability(77% capacity retention after 3000 cycles).This work provides an effective material development route to realize simultaneously high energy and power for next-generation sodium-ion capacitors.

关键词： sodium-ion capacitors entropy modulation high power density long-term cycling layered oxide

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A topological polymer network with Cu(Ⅱ)-coordinated reversible imidazole-urea locked unit constructs an ultra-strong self-healing elastomer

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science China Chemistry 2023年第3期66卷 853-862页

作者： Lei Yang Zenghe Liu Rasoul Esmaeely Neisiany Jiaming Lou Yifan Guo Luzhi Zhang Huijie Liu Shuo Chen Shijia Gu Zhengwei You State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Institute of Functional MaterialsCollege of Materials Science and EngineeringDonghua UniversityShanghai 201620China Department of Materials and Polymer Engineering Faculty of EngineeringHakim Sabzevari UniversitySabzevar ***Iran Key Laboratory of Textile Science&Technology Ministry of EducationCollege of TextilesDonghua UniversityShanghai 201620China

It is exceedingly desired, but difficult to construct self-healing materials with both excellent mechanical properties and healing efficiency, which are usually realized by using mutually exclusive methods. Here, we reconcile this contradiction by utilizing copper-bis-(imidazole-2-yl)-methane-urea(Cu-BIMU) locked units based on novel designed dynamic imidazole-urea bonds with coupled multiple noncovalent bonds(coordination bonds, π-π stacking bonds, and hydrogen bonds). The coordination of Cu(II) greatly reduces the electron-cloud density of imidazole, which lowers the free energy barrier of imidazole-urea bonds and promotes their reversible dissociation, as demonstrated by the density functional theory and small-molecule model reaction. The topological design of Cu-BIMU polyurethane(Cu-BIMU-PU), which concentrates multiple crosslinking-in-one locked unit to avoid the formation of excessive crosslinking sites to ensure high chain mobility, facilitates self-healing. Accumulative extensive intermolecular interactions endowed excellent mechanical properties to the resulting Cu-BIMU-PU elastomer with a tensile strength of 65.3 MPa, among the highest ever-reported value. This work provides a novel molecular design principle for fabricating high-performance dynamic polymers.

关键词： topological polymer network self-healing elastomer urea bonds

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Unveiling the size effect of nitrogen-doped carbon-supported copper-based catalysts on nitrate-to-ammonia electroreduction

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Nano Research 2024年第4期17卷 2438-2443页

作者： Ran Li Taotao Gao Wenxi Qiu Minghao Xie Zhaoyu Jin Panpan Li College of Materials Science and Engineering Sichuan UniversityChengdu 610065China Institute for Advanced Study Chengdu UniversityChengdu 610106China Materials Science and Engineering Program and Walker Department of Mechanical Engineering The University of Texas at AustinAustinTexas 78712USA Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054China

The electrocatalytic nitrate reduction reaction(NitRR)represents a promising approach toward achieving economically and environmentally sustainable ***,it remains a challenge to regulate the size effect of electrocatalysts to optimize the catalytic activity and ammonia ***,the Cu-based catalysts were tailored at the atomic level to exhibit a size gradient ranging from single-atom catalysts(SACs,0.15–0.35 nm)to single-cluster catalysts(SCCs,1.0–2.8 nm)and nanoparticles(NPs,20–30 nm),with the aim of studying the size effect for the NO_(3)^(-)-to-NH_(3) reduction ***,the Cu SCCs exhibit enhanced metal–substrate and metal–metal interactions by taking advantageous features of Cu SACs and Cu ***,Cu SCCs achieve exceptional electrocatalytic performance for the NitRR with a maximum Faradaic efficiency of ca.96%NH_(3)and the largest yield rate of ca.1.99 mg·h^(-1)·cm^(-2) at-0.5 V *** hydrogen electrode(RHE).The theoretical calculation further reveals the size effect and coordination environment on the high catalytic activity and selectivity for the *** work provides a promising various size-controlled design strategy for aerogel-based catalysts effectively applied in various electrocatalytic reactions.

关键词： nitrate electroreduction ammonia electrosynthesis size effect single-cluster catalyst

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Understanding the Thermal Impedance of Silicone Rubber/Hexagonal Boron Nitride Composites as Thermal Interface materials

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Chinese Journal of polymer science 2024年第3期42卷 352-363,I0008页

作者： Yuan Ji Shi-Da Han Hong Wu Shao-Yun Guo Feng-Shun Zhang Jian-Hui Qiu The State Key Laboratory of Polymer Materials Engineering Sichuan Provincial Engineering Laboratory of Plastic/Rubber Complex Processing TechnologyPolymer Research InstituteSichuan UniversityChengdu 610065China Institute of Chemical Materials China Academy of Engineering PhysicsMianyang 621900China Department of Mechanical Engineering Faculty of Systems Science and TechnologyAkita Prefectural UniversityAkita 015-0055Japan

Silicone rubber(SR) composites are most widely used as thermal interface materials(TIMs) for electronics heat dissipation. Thermal impedance as the main bottleneck limiting the performance of TIMs is usually neglected. Herein, the thermal impedance of SR composites loaded with different levels of hexagonal boron nitride(h-BN) as TIMs was elaborated for the first time by the ASTM D 5470 standard test and finite element analysis. It was found that elastic modulus and surface roughness of SR composites increased with the increase of h-BN content, indicating that the conformity was reduced. When the assembly pressure was 0.69 MPa, there existed an optimal h-BN content at which the contact resistance was minimum(0.39 K·cm^(2)·W^(-1)). Although the decreased bond line thickness(BLT) by increasing the assembly pressure was beneficial to reduce the thermal impedance, the proper assembly pressure should be selected to prevent the warpage of the contact surfaces and the increase in contact resistance, according to the compression properties of the SR composites. This study provides valuable insights into fabrication of high-performance TIMs for modern electronic device applications.

关键词： Thermal interface materials Hexagonal boron nitride Thermal impedance Surfaces

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Electromagnetic wave absorption performance and rheological behavior of rubber composites with low mass filling rate carbon nanofiber aerogel

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Journal of Materiomics 2024年第4期10卷 928-936页

作者： Zhiyi Zhang Bicheng Zhou Lan Jia Wenwen Yu Qiang Zheng College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan030024China Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering Taiyuan030000China rd Research Institute of China Electronics Technology Group Corporation Taiyuan030032China Department of Polymer Science&Engineering Zhejiang UniversityHangzhou310027China

With the development of electronic information science and technology,electromagnetic information security and electromagnetic pollution become more and more *** wave absorption(EMWA)rubber based on the absorbent of carbon with low density and good corrosion resistance is a kind of good EMWA materials for solving electromagnetic information security and electromagnetic *** this article,three-dimensional network structure carbon nanofiber aerogels(3DNSCAs)are prepared by vacuum annealing of three-dimensional network structure agarose/zinc acetate obtained by freeze-drying of agarose/zinc acetate *** EMWA rubber composites with 2.2%(in mass)3DNSCAs have almost the same density as silicone rubber(PDMS),and the dispersity of 3DNSCAs in PDMS is studied by rheological *** effective absorption bandwidth(EAB,frequency for reflection loss<–10 dB)of the 2 mm thick PDMS/C-800 is 4 GHz,and the minimum value of reflection loss(RL_(min))is−52 dB with the thickness of 3.5 *** PDMS/C-1000 with the thickness of 3.5 mm has an EAB up to 4.8 *** cross section(RCS)reduction of PDMS/C-800 can achieve 20 dB⋅m^(2) at the frequency of 6 GHz.

关键词： Electromagnetic wave absorption Rubber composite Carbon aerogel Rheological behavior Power loss density

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