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Chinese Journal of polymer Science 2024年第10期42卷 1545-1556页

作者： Miao Xie Xiao-Rong Wang Zhan-Hua Wang He-Sheng Xia State Key Laboratory of polymer materials Engineering Polymer Research InstituteSichuan University school of Petrochemical Engineering Liaoning Petrochemical University

Covalent adaptive networks (CANs) are capable of undergoing segment rearrangement after being heated, which endows the materials with excellent self-healing and reprocessing performance, providing an efficient solution to the environment pollution caused by the plastic wastes. The main challenge remains in developing CANs with both excellent reprocessing performance and creep-resistance property. In this study, a series of CANs containing dynamic covalent benzopyrazole-urea bonds were developed based on the addition reaction between benzopyrazole and isocyanate groups. DFT calculation confirmed that relatively low dissociation energy is obtained through undergoing a five-member ring transition state, confirming excellent dynamic property of the benzopyrazole-urea bonds. As verified by the FTIR results, this nice dynamic property can be well maintained after incorporating the benzopyrazole-urea bonds into polymer networks. Excellent self-healing and reprocessing performance is observed by the 3-ABP/PDMS elastomers owing to the dynamic benzopyrazole-urea bonds. Phase separation induced by the aggregation of the hard segments locked the benzopyrazole-urea bonds, which also makes the elastomers display excellent creep-resistance performance. This hard phase locking strategy provides an efficient approach to design CANs materials with both excellent reprocessing and creep-resistance performance.

关键词： Covalent adaptive networks Dynamic covalent bond Self-healing polymer

Recent Advances in Asymmetric Structural Composites for Excellent Electromagnetic Interference Shielding: A Review

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Chinese Journal of polymer Science 2024年第6期42卷 693-710页

作者： Ying Zhou Bai Xue Lan Xie Chang-Mei Wu Qiang Zheng Department of polymer materials and Engineering College of Materials and Metallurgy Guizhou University National Engineering research Center for Compounding and Modification of polymer materials National and Local Joint Engineering Research Center for Functional Polymer Membrane Materials and Membrane Processes State Key Laboratory of Public Big Data Guizhou University Department of polymer Science and Engineering Zhejiang University

Since electromagnetic pollution is detrimental to human health and the environment, numerous efforts have been successively made to achieve excellent electromagnetic interference shielding effectiveness(EMI SE) via designing the hierarchical structures for electromagnetic interference(EMI) shielding polymer composites. Among the plentiful structures, the asymmetric structures are currently a hot spot, principally categorizing into multi-layered, porous, fibrous, and segregated asymmetric structures, which endows the high EMI shielding performance for polymer composites incorporated with magnetic, conductive, and/or dielectric micro/nano-fillers, due to the “absorption-reflection-reabsorption” shielding mechanism. Therefore, this review provides the retrospection and summary of the efforts with respect to abundant asymmetric structures and multifunctional micro/nano-fillers for enhancing EMI shielding properties, which is conducive to the booming development of polymeric EMI shielding materials for the promising prospect in modern electronics and 5-generation(5G) technology.

关键词： Asymmetric structure Microano functional filler polymer composite Electromagnetic interference shielding

3D printing encouraging desired in-situ polypyrrole seed-polymerization for ultra-high energy density supercapacitors

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Journal of Energy Chemistry 2024年第8期95卷 117-125,I0004页

作者： Tiantian Zhou Shangwen Ling Shuxian Sun Ruoxin Yuan Ziqin Wu Mengyuan Fu Hanna He Xiaolong Li Chuhong Zhang State Key Laboratory of polymer materials Engineering Polymer Research InstituteSichuan UniversityChengdu 610065SichuanChina

The tireless pursuit of supercapacitors with high energy density entails the parallel advancement of wellsuited electrode materials and elaborately engineered ***(PPy)emerges as an exceedingly conductive polymer and a prospective pseudocapacitive materials for supercapacitors,yet the inferior cyclic stability and unpredictable polymerization patterns severely impede its real-world ***,for the first time,an innovative seed-induced in-situ polymerization assisted 3D printing strategy is proposed to fabricate PPy-reduced graphene oxide/poly(vinylidene difluoride-cohexafluoropropylene)(PVDF-HFP)(PPy-rGO/PH)electrodes with controllable polymerization behavior and exceptional areal mass *** preferred active sites uniformly pre-planted on the 3D-printed graphene substrates serve as reliable seeds to induce efficient polypyrrole deposition,achieving an impressive mass loading of 185.6 mg cm^(-2)(particularly 79.2 mg cm^(-2)for polypyrrole)and a superior areal capacitance of 25.2 F cm^(-2)at 2 mA cm^(-2)for a 12-layer *** agreement with theses appealing features,an unprecedented areal energy density of 1.47 mW h cm^(-2)for a symmetrical device is registered,a rarely achieved value for other PPy/rGO-based *** work highlights a promising route to preparing high energy density energy storage modules for real-world applications.

关键词： 3D printing Seed-induced polymerization Supercapacitor Polypyrrole High energy density

Preparation of Self-limiting Heating Cables with Excellent Processability, Mechanical Properties and PTC Effect via Thermal and Electrical Treatments

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Chinese Journal of polymer Science 2024年第4期42卷 511-520页

作者： Tian-Hao Yang Tong Wu Qiang Fu State Key Laboratory of polymer materials Engineering College of Polymer Science and EngineeringSichuan UniversityChengdu610065China State Key Laboratory of polymer materials Engineering Polymer Research Institute of Sichuan UniversityChengdu610065China

polymer/conductive filler composites have been widely used for the preparation of self-limiting heating cables with the positive temperature coefficient (PTC) effect. The control of conductive filler distribution and network in polymer matrix is the most critical for performance of PTC materials. In order to compensate for the destruction of the filler network structure caused by strong shearing during processing, an excessive conductive filler content is usually added into the polymer matrix, which in turn sacrifices its processability and mechanical properties. In this work, a facile post-treatment of the as-extruded cable, including thermal and electrical treatment to produce high-density polyethylene (HDPE)/carbon black (CB) cable with excellent PTC effect, is developed. It is found for the as-extruded sample, the strong shearing makes the CB particles disperse uniformly in HDPE matrix, and 25 wt% CB is needed for the formation of conductive paths. For the thermal-treated sample, a gradually aggregated CB filler structure is observed, which leads to the improvement of PTC effect and the notable reduction of CB content to 20 wt%. It is very interesting to see that for the sample with combined thermal and electrical treatment, CB particles are agglomerated and oriented along the electric field direction to create substantial conductive paths, which leads to a further decrease of CB content down to 15 wt%. In this way, self-limiting heating cables with excellent processability, mechanical properties and PTC effect have simultaneously been achieved.

关键词： Self-limiting heating cables Positive temperature coefficient Thermal treatment Electrical treatment

Hybrid assembly of conducting nanofiber network for ultra-stretchable and highly sensitive conductive hydrogels

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Journal of materials Science & Technology 2024年第2期169卷 1-10页

作者： Yalei Wang Shulong Zeng Shaohong Shi Yuheng Jiang Zhiwei Du Bingzhen Wang Xiurong Li State Key Laboratory of Featured Metal materials and Life-cycle Safety for Composite Structures School of ResourcesEnvironment and MaterialsGuangxi UniversityNanning 530004China State Key Laboratory of polymer materials Engineering Polymer Research Institute of Sichuan UniversitySichuan UniversityChengdu 610065China

Conductive hydrogels have attracted extensive attention owing to their promising application prospects in flexible and wearable ***,achieving both high sensitivity and mechanical robustness remains ***,a novel and versatile conductive hydrogel based on the hybrid assem-bly of conductive cellulose nanofiber(CNF)networks has been designed and *** by the templating effect of CNFs and stabilizing effect of negatively charged poly(styrene sulfonate)(PSS),conducting polymer poly(3,4-ethylenedioxythiophene)(PEDOT)was self-organized into three-dimensional nanostructures which constructed a robust conductive network after in-situ oxidative *** unique structure derived from CNF bio-template endowed polyacrylamide(PAM)hydrogels with improved electrical conductivity and excellent mechanical *** a result,the as-fabricated CNF/PEDOT:PSS/PAM hydrogel exhibited an ultimate tensile strain of 1881%and toughness of 3.72 MJ/m^(3),which were 4.07 and 8.27 times higher than the CNF-free hydrogel,*** significantly,the resultant hydrogel sensor showed highly desirable sensing properties,including remarkable sensing range(1100%),high gauge factor(GF=5.16),fast response time(185 ms),and commendable durability,as well as good ***,the hydrogel sensor was able to distinguish subtle physiological activities including phonation and facial expression,and monitor large human body motions such as finger flexion and elbow ***,it was feasible to integrate the strain sensor on the joints of robots to recognize complicated machine motion signals,showing potential in advanced human-machine interactions.

关键词： Strain sensor Cellulose nanofibers PEDOT:PSS Conductive hydrogel Templating method

Regulating photothermal properties of near-infrared croconaine dyes by supramolecular assembly

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Nano research 2024年第9期17卷 8560-8570页

作者： Yangge Ren Yue Lu Juanjuan Gao Yi Ding Bo Zhu Xinyu Hou Lin Jia Department of polymer materials School of Materials Science and EngineeringShanghai UniversityShanghai 200444China Department of Electronic Information materials School of Materials Science and EngineeringShanghai UniversityShanghai 200444China

The photochemical and photophysical properties of near-infrared(NIR)dyes are significantly influenced by their aggregation state and mesoscopic ***,beyond chemical synthesis,the regulation mechanisms for the properties of NIR dyes,particularly with respect to photothermal properties of the aggregates,are not yet fully ***,we investigate the photothermal behaviors of croconaine-based(CroA)NIR dyes containing dipeptide or amino acids *** introduction of hydrogen bonding promotesπ-πstacking of croconaine center,which can efficiently regulate aggregation states and assembly structures in *** laser irradiation,CroA aggregates undergo aggregation-dissociation transition,the in-situ monomer generation process regulates two parameters of photothermal performance:heating rates and plateau photothermal *** study reveals the regulation effect of non-covalent bonding interactions on CroA aggregates,highlighting supramolecular assembly strategy not only facilitates to construct of photothermal nanomaterials with well-defined structures,but also provides an alternative and effective method for regulating photothermal performance of NIR dyes.

关键词： croconaine dye hydrogen bonding photothermal performance supramolecular assembly chirality

Highly Stretchable and Tunable Thermo-fluorochromic polymer Elastomer through Eu3+ Dynamic Coordination Cross-linking

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Chinese Journal of polymer Science 2024年第10期42卷 1449-1458页

作者： Qiu-Li Tan Kai Gou Jing-Zhi Tang Ming-Hui Wei Chong Wang Yi-Jing Nie Geng-Sheng Weng school of materials Science and Chemical Engineering State Key Laboratory Base of Novel Functional Materials and Preparation Science Ningbo University Institute of polymer materials School of Materials Science and Engineering Jiangsu University

Thermochromic polymers with tunable thermochromism, high stretchability and mechanical strength are of interests for optical information storage and encryption. In this work, we demonstrate a new design of thermo-fluorochromic carboxylated nitrile butadiene rubber(XNBR) elastomer cross-linked by Eu3+-COOH dynamic coordination with deprotonated imidazole (DPIm) as the ancillary ligand. The presence of DPIm not only improves the mechanical strength and stretchability, but also dramatically intensifies the fluorescence emission and lifetime of the Eu-containing elastomer. The elastomer behaves reversible thermo-fluorochromism with easily tunable transition temperature and emission intensity by the simple change of the deprotonation degree of imidazole. The facile tunable thermo-fluorochromism, exceptional mechanical strength, and high stretchability (up to about 5000%) enable the Eu-containing XNBR elastomer with potential applications in soft electronics where optical information storage and encryption are required.

关键词： Dynamic coordination Elastomer Europium Highly stretchable Thermochromism

A Strong, Tough, and Self-Healing Strengthening Thioctic Acid-based Elastomer for Highly Reliable Flexible Strain Sensor

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Chinese Journal of polymer Science 2024年第10期42卷 1610-1618页

作者： Xin-Yu Chen Yu-Bing Fu Xue-Ling Yan Lan Liu school of materials Science and Engineering Key Lab of Guangdong Province for High Property and Functional Polymer Materials South China University ofTechnology

Elastomers with high strength and toughness, excellent self-healing properties, and biocompatibility have broad application prospects in wearable electronics and other fields, but preparing it remains a challenge. In this work, we propose a highly adaptable strategy by introducing the small molecule crosslinking agent of triethanolamine (TEA) to the poly(thioctic acid)(PTA) chains and preparing the PAx Ey elastomers using a simple synthesis step. This strategy stabilizes the PTA chains by constructing multiple non-covalent cross-linked dynamic networks, endowing materials with excellent strength and toughness (tensile strength of 288 kPa, toughness of 278.2 kJ/m3), admirable self-healing properties (self-healing efficiency of 121.6%within 7 h at 70°C), and good biocompatibility. The PAx Ey elastomers can also be combined with MWNTs to become flexible strain sensors, which can be used to monitor human joint movements with high sensitivity, repeatable responses, and stability.

关键词： Flexible strain sensor Ion clusters Multiple dynamic networks Self-healing strengthening Thioctic acid

In situ protonation in a locally flexible porous coordination polymer for enhancing proton-carrier loading and proton conductivity

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Science China Chemistry 2024年第10期67卷 3432-3437页

作者： Xianzhe Wei Jincheng Liu Yan Su Weitao Wang Guixiang Wang Gen Zhang Ping Wang Cheng Gu State Key Laboratory of Luminescent materials and Devices Institute of Polymer Optoelectronic Materials and DevicesSouth China University of Technology College of polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan University Key Laboratory for Soft Chemistry and Functional materials of Ministry of Education School of Chemistry and Chemical EngineeringNanjing University of Science and Technology

Designing efficient proton-conductive materials is crucial in fuel cells. Yet, it remains a substantial challenge because of the issues in proton mobility, proton-carrier amount, and orientation of proton host materials. Herein, we report an in-situ protonation strategy to produce a locally flexible porous coordination polymer(PCP) to enhance the proton-carrier loading and proton conductivity. The local dipole flipping of the ligand allows effective proton exchange with low activation energy, promoting interpore proton transport through the pore apertures and pore walls. The protonation induces substantial charges to the frameworks and enhances the interaction with proton carriers, thereby increasing the loading of the proton carriers. By this design strategy, the resulting PCP exhibits enhanced phosphoric acid loading and extraordinary proton conductivities under both aqueous and anhydrous conditions compared to its isoreticular analog that features rigidity without proton-exchange *** work provides a new avenue for designing proton-conductive materials that combine structural dynamics with performance merits.

关键词： porous coordination polymers in-situ protonation local flexibility proton-exchange mechanism proton conduction

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On-surface synthesis and characterization of polyynic carbon chains

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National Science Review 2024年第3期11卷 192-199页

作者： Wenze Gao Wei Zheng Luye Sun Faming Kang Zheng Zhou Wei Xu Interdisciplinary materials research Center School of Materials Science and Engineering Tongji University

Carbyne, an elusive sp-hybridized linear carbon allotrope, has fascinated chemists and physicists for decades. Due to its high chemical reactivity and extreme instability, carbyne was much less explored in contrast to the sp2-hybridized carbon allotropes such as graphene. Herein, we report the on-surface synthesis of polyynic carbon chains by demetallization of organometallic polyynes on the Au（111） surface;the longest one observed consists of ～60 alkyne units（120 carbon atoms）. The polyynic structure of carbon chains with alternating triple and single bonds was unambiguously revealed by bond-resolved atomic force microscopy. Moreover, an atomically precise polyyne, C14, was successfully produced via tip-induced dehalogenation and ring-opening of the decachloroanthracene molecule(C14Cl10) on a bilayer NaCl/Au（111） surface at 4.7 K, and a band gap of 5.8 eV was measured by scanning tunnelling spectroscopy,in a good agreement with the theoretical HOMO–LUMO gap（5.48 eV）.

关键词： polyyne scanning probe microscopy carbon allotrope on-surface synthesis organometallic polyyne