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Enabling simultaneous reprocessability and fire protection via incorporation of phosphine oxide monomer in epoxy vitrimer

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Journal of Materials science & technology 2024年第29期196卷 224-236页

作者： Zhenyu Huang Wenyu Wu Klingler Daniele Roncucci Carolina Polisi Valentin Rougier Sandro Lehner Milijana Jovic Daniel Rentsch Sithiprumnea Dul Karin Brändli Hedlund Véronique Michaud Zhengzhou Wang Sabyasachi Gaan Department of Polymeric Materials School of Materials Science and EngineeringTongji UniversityShanghai201804China Laboratory for Advanced Fibers Empa Swiss Federal Laboratories for Materials Science and TechnologyLerchenfeldstrasse 5St.Gallen9014Switzerland Laboratory for Processing of Advanced Composites(LPAC) Ecole Polytechnique Fédérale de Lausanne(EPFL)1015 LausanneSwitzerland Laboratory for Functional Polymers Empa Swiss Federal Laboratories for Materials Science and TechnologyÜberlandstrasse 1298600 DübendorfSwitzerland Institute for Materials technology and plastics processing OST-Eastern Switzerland University of Applied Sciences8640 RapperswilSwitzerland Key Laboratory of Advanced Civil Engineering Materials Tongji UniversityShanghai201804China

The conception of epoxy thermosets with both reprocessability and flame retardancy delineates a new horizon in polymer science,offering a material solution that is not only superior in fire safety but is also environment ***,a flame-retardant epoxy vitrimer(EV)was prepared using partially bio-based IADPPO(diphenylphosphine oxide itaconic anhydride)and citric acid as curing reagents via a solvent-free *** incorporation created covalent adaptable networks(CANs)in the matrix which promote reprocessability and *** EV exhibits excellent thermal stability with high initial decomposition temperature(T_(- 5wt%)∼308℃)and high glass transition temperature(T_(g)∼107℃),similar to the blank EV(115℃).The flame retardancy,mechanical properties,transesterification-based reprocessability,and flame-retardant mechanism were *** EV containing 3 wt%phosphorus(EV IADPPO 3P)achieved UL-94 V0 classification with a limiting oxygen index(LOI)of 27%,while the virgin sample Blank EV(without phosphorus)burned ***,increased flexural strength of 79%was observed for EV IADPPO 3P compared to Blank ***,the flame-retardant EV showed high malleability and reparability that could be thermomechanically reprocessed without sacrificing the thermal,mechanical,and flame-retardant ***,the newly developed epoxy vitrimer is not only fire-safe but fulfills the sustainability goals of today’s society.

关键词： Epoxy vitrimer Covalent adaptable networks Flame retardancy Reparable and reprocessable Bio-based thermoset

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Efficient hydrogen peroxide production enabled by exploring layered metal telluride as two electron oxygen reduction reaction electrocatalyst

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Journal of Energy Chemistry 2023年第12期87卷 247-255,I0007页

作者： Yingming Wang Hongyuan Yang Zhiwei Liu Kui Yin Zhaowu Wang Hui Huang Yang Liu Zhenhui Kang Ziliang Chen Institute of Functional Nano and Soft Materials(FUNSOM) Jiangsu Key Laboratory for Carbon-based Functional Materials and DevicesJoint International Research Laboratory of Carbon-Based Functional Materials and DevicesSoochow UniversitySuzhou 215123JiangsuChina School of Physics and Engineering Longmen Laboratory Henan University of Science and TechnologyLuoyang 471023HenanChina Macao Institute of Materials Science and Engineering(MIMSE) MUST-SUDA Joint Research Center for Advanced Functional MaterialsMacao University of Science and TechnologyTaipa 999078MacaoChina Suzhou Weimu Intelligent System Co. Ltd.Suzhou 215123JiangsuChina

It is of great interest to develop the novel transition metal-based electrocatalysts with high selectivity and activity for two electron oxygen reduction reaction(2e^(-) ORR).Herein,the nickel ditelluride(NiTe_(2)) with layered structure was explored as the 2e^(-) ORR electrocatalyst,which not only showed the highest 2e^(-) selectivity more than 97%,but also delivered a slight activity decay after 5000 cycles in alkaline ***,when NiTe_(2) was assembled as the electrocatalyst in H-type electrolyzer,the on-site yield of H_(2)O_(2) could reach up to 672 mmol h^(-1)g^(-1) under 0.45 V *** in situ Raman spectra,theoretical calculation and post microstructural analysis synergistically unveiled that such a good 2e^(-) ORR performance could be credited to the intrinsic layered crystal structure,the high compositional stability,as well as the electron modulation on the active site Ni atoms by neighboring Te atoms,leading to the exposure of active sites as well as the optimized adsorption free energy of Ni to –*** inspiringly,such telluride electrocatalyst has also been demonstrated to exhibit high activity and selectivity towards 2e^(-) ORR in neutral media.

关键词： Transition metal telluride Oxygen reduction reaction Charge polarization Activity and selectivity Hydrogen peroxide

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Topochemical polymerization of hydrogen-bonded organic framework for supporting ultrafine palladium nanoparticles

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science China Chemistry 2023年第7期66卷 2019-2027页

作者： Xu Ding Bin Han Baoqiu Yu Hailong Wang Jianzhuang Jiang Beijing Advanced Innovation Center for Materials Genome Engineering Beijing Key Laboratory for Science and Application of Functional Molecular and Crystalline MaterialsDepartment of Chemistry and Chemical EngineeringSchool of Chemistry and Biological EngineeringUniversity of Science and Technology BeijingBeijing 100083China

Topochemical polymerization of molecular crystals into porous materials is of significance due to their promising applications in the field of adsorption and catalysis,yet rarely reported due to the synthesis ***,a hydrogen-bonded organic framework(HOF-45)has been fabricated by the crystallization of a cage-like building block containing three alkynyl *** exhibits almost mesoporous structure demonstrated by single crystal X-ray diffraction ***-driven topochemical polymerization of HOF-45 with ethanedithiol covalently links alkynyl groups in HOF-45,generating a hydrogen-bond and covalentbond cross-linked material(HOF-45C).In contrast to HOF-45,cross-linked HOF-45C retains the crystalline nature and displays improved solution resistence according to the powder X-ray diffraction *** particular,HOF-45C is able to support the growth of ultrafine palladium nanoparticles with the average size of ca.1.9 nm for rapidly promoting the degradation of nitrophenol,methyl orange,and congo red with the help of NaBH_(4)as well as Suzuki-Miyaura coupling *** work inputs a new idea on the HOFs application in preparing covalent-linked porous organic materials.

关键词： hydrogen-bonded organic frameworks topochemical polymerization palladium nanoparticles nitrophenol degradation organic dyes degradation Suzuki-Miyaura coupling reaction

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Improved thermal stability and infrared emissivity of high-entropy REMgAl_(11)O_(19)and LaMAl_(11)O_(19)(RE=La,Nd,Gd,Sm,Pr,Dy;M=Mg,Fe,Co,Ni,Zn)

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Journal of Materials science & technology 2022年第9期104卷 131-144页

作者： Haolin Zhu Ling Liu Huimin Xiang Fu-Zhi Dai Xiaohui Wang Zhuang Ma Yanbo Liu Yanchun Zhou School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing 100076China National Key Laboratory of Science and Technology on Materials under Shock and Impact Beijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

LaMgAl_(11)O_(19)(LMA),characterized by high melting point,low density and thermal conductivity as well as good infrared emissivity,is regarded as a potential candidate for the thermal protection of hypersonic ***,the unsatisfied phase stability at high temperature results in declining of the emissivity below 6μm,which limits the extensive applications of LaMgAl_(11)O_(19).In order to overcome this obstacle,three dense bulk high-entropy ceramics,(La_(0.2)Nd_(0.2)Gd_(0.2)Sm_(0.2)Pr_(0.2))MgAl_(11)O_(19)(HE LMA-1),(La_(0.2)Nd_(0.2)Gd_(0.2)Sm_(0.2)Dy_(0.2))Mg Al_(11)O_(19)(HE LMA-2)and La(Mg_(0.2)Fe_(0.2)Co_(0.2)Ni_(0.2)Zn_(0.2))Al_(11)O_(19)(HE LMA-3),were designed and successfully prepared through solid state reaction at 1700℃for 4 h in one *** analyses show that the phase compositions of HE LMA-1,HE LMA-2 and HE LMA-3 are single-phase solid solutions with the relative density of 95.61%,95.49%and 94.31%,*** treatment experiments demonstrate that the phase composition of HE LMA-1 remains a single phase after high-temperature heating,while second phase appears in other two *** stability of HE LMA-1 is attributed to small average size differenceδ(~4%)of constitute ***,the average emissivity of HE LMA-1 in the range of 3-6μm reaches 0.9,which is significantly higher than that of LMA and other two HE LMA *** emissivity of all samples remains above 0.95 from 6 to 10μ*** the far infrared region(10-14μm),although the emissivity of these specimens decreases slightly,it still exceeds *** UV-Vis absorption spectra indicate that the formation of many discrete impurity energy levels with small intervals in HE LMA-1 promotes the f electrons to transit between adjacent impurity energy levels and conduction band,which enhances the infrared emission of HE LMA-1 below 6μ*** a word,with improved phase stability and thermal emissivity in infrared range,high-entropy REMgAl_(11)O_(19),especially(La_(0.2)Nd_(0.2)

关键词： High-entropy ceramics LaMgAl_(11)O_(19) Thermal stability Infrared emissivity UV-Vis absorption

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Grain growth behavior and properties of high-entropy pseudobrookite(Mg,Co,Ni,Zn)Ti_(2)O_(5) ceramics

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Journal of advanced Ceramics 2024年第6期13卷 757-768页

作者： Xiaohui Ma Jinyu Wu Lingyi Meng Jinfeng Zhang Heng Chen Liwen Yan Anran Guo Jiachen Liu Key Laboratory of Advanced Ceramics and Machining Technology of Ministry of Education School of Materials Science and EngineeringTianjin UniversityTianjin 300072China Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstitutesChinese Academy of SciencesXiamen 361021China

It is well known that the grain size of high-entropy ceramics is quite small owing to the sluggish diffusion effect. However, abnormal grain growth often occurs in high-entropy pseudobrookite ceramics, ultimately resulting in the formation of many abnormally grown grains with a grain size as large as 50 μm. To study this phenomenon, the grain growth behavior of high-entropy pseudobrookite ceramics was systematically investigated in this paper. The results demonstrate that the starting material powders first react with each other to form a high-entropy intermediate phase and calcined TiO_(2) powders (TiO_(2)-1100 ℃), and then as the sintering temperature increases, the formed high-entropy intermediate phase further reacts with TiO_(2)-1100 ℃ to form high-entropy pseudobrookite ceramics. Thus, in this system, in addition to the sluggish diffusion effect, the grain sizes of the high-entropy intermediate phase and TiO_(2)-1100 ℃ also affect the morphology of high-entropy pseudobrookite. Compared to nanosized TiO_(2), micron-sized TiO_(2) has a lower sintering activity. Therefore, the high-entropy intermediate phases (Mg,Co,Ni,Zn)TiO_(3) and TiO_(2)-1100 ℃ prepared with micron-sized starting materials exhibit lower grain sizes, finally resulting in the formation of high-entropy (Mg,Co,Ni,Zn)Ti_(2)O_(5) with small grain sizes. Moreover, nano-indentation and thermal conductivity tests were carried out on high-entropy (Mg,Co,Ni,Zn)Ti_(2)O_(5) with different morphologies. The results show that the hardness of high-entropy (Mg,Co,Ni,Zn)Ti_(2)O_(5) increases from 6.05 to 9.95 GPa as the grain size increases, whereas the thermal conductivity decreases from 2.091±0.006 to 1.583±0.006 W·m^(−1)·K^(−1). All these results indicate that high-entropy (Mg,Co,Ni,Zn)Ti_(2)O_(5) with a small grain size is a potential material for thermal protection.

关键词： grain size sluggish diffusion effect two-step solid phase process high-entropy intermediate phase high-entropy pseudobrookite ceramic

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Dislocation evolution and induced precipitation on corrosion resistance of a novel Al-Mg-Zn-Er-Zr alloy during hot compression

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Rare Metals 2023年第7期42卷 2371-2380页

作者： Da Xue Wu Wei Wei Shi Xiao-Rong Zhou Sheng-Ping Wen Xiao-Lan Wu Kun-Yuan Gao Li Rong Peng Qi Hui Huang Zuo-Ren Nie Key Laboratory of Advanced Functional Materials Education Ministry of ChinaBeijing University of TechnologyBeijing100124China Institute of Corrosion Science and Technology Guangzhou510530China Department of Materials The University of ManchesterManchesterM139PLUK

Al-Mg-Zn-Er-Zr alloy was compressed in temperature range from 300 to 500℃to investigate the microstructure *** dynamics simulations were used to study the mechanical behavior and dislocation *** results showed that mobile dislocations are widely distributed in alloys and make important contributions to coordinate compressive *** sessile dislocations hinder the deformation,and the content is about 1/20 of that of mobile *** dynamic recrystallization(CDRX)is considered to be the main recrystallization *** accumulation of dislocations can provide element diffusion channels and driving force forτ(Mg_(32)[Al,Zn]_(49))phase precipitation,resulting in the forced precipitation of discontinuousτphase to replace the continuousβphase(Al_(3)Mg_(2)),which reduces the corrosion potential,resulting in increased corrosion resistance.

关键词： Al-Mg-Zn-Er-Zr alloy Dislocation Corrosion Mg_(32)(AlZn)_(49)phase Molecular dynamics

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All-fiber and self-starting Yb-doped Mamyshev oscillator based on nonlinear polarization evolution

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Chinese Optics Letters 2024年第12期22卷 74-79页

作者： Zecong Li Kai Wang Zinan Huang Qianqian Huang YanlüLin Weixi Li Zhichao Luo Chengbo Mou Key Laboratory of Specialty Fiber Optics and Optical Access Networks Shanghai Institute for Advanced Communication and Data ScienceJoint International Research Laboratory of Specialty Fiber Optics and Advanced CommunicationShanghai UniversityShanghai 200444China Key Laboratory of Space Active Opto-Electronics Technology Shanghai Institute of Technical PhysicsChinese Academy of SciencesShanghai 200083China Laboratory of Nanophotonic Functional Materials and Devices School of Information and Optoelectronic Science and EngineeringSouth China Normal UniversityGuangzhou 510006China

We experimentally demonstrate a Yb-doped all-fiber mode-locked laser based on the Mamyshev *** entire experimental setup operates only by injecting pump powers and adjusting polarization controllers(PCs),which realizes *** types of pulse patterns are observed at different pump powers and polarization states,including single pulses and up to eight-pulse bound-state *** operating wavelength of single-pulse mode-locking switching between 1072.3and 1043.1 nm can be realized by increasing the pump power while keeping the PCs in a fixed *** design can provide an attractive experimental model for all-fiber and self-starting Mamyshev oscillators.

关键词： Mamyshev oscillator Yb-doped fiber laser pulse dynamic pattern nonlinear polarization evolution

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Rechargeable Metasurfaces for Dynamic Color Display Based on a Compositional and Mechanical Dual-Altered Mechanism

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Research 2023年第1期2022卷 367-377页

作者： Le Yang Xiaorong Hong Jiafang Li Chang-Yin Ji Yu Han Shanshan Chen Hanqing Jiang Wei-Li Song Hao-Sen Chen Daining Fang Beijing Key Laboratory of Lightweight Multi-Functional Composite Materials and Structures Institute of Advanced Structure TechnologyBeijing Institute of TechnologyBeijing 100081China Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement(Ministry of Education) Beijing Key Lab of Nanophotonics e Ultrafine Optoelectronic SystemsSchool of PhysicsBeijing Institute of TechnologyBeijing 100081China School of Engineering Westlake UniversityHangzhou 310024China

Dynamic color display can be realized by tunable optical metasurfaces based on the compositional or structural ***,it is still a challenge to realize the efficient modulation by a single-field ***,we report a novel compositional and mechanical dual-altered rechargeable metasurface for reversible and broadband optical reconfiguration in both visible and near-infrared wavelength *** employing a simple fabrication and integration strategy,the continuous optical reconfiguration is manipulated through an electro-chemo-mechanical coupled process in a lithium ion battery,where lithiation and delithiation processes occur dynamically under a low electric voltage(<1.5 V).By controlling the phase transformation from Si to Li,Si,both structural morphology and optical scattering could be rapidly and dramatically tailored within 30s,exhibiting high-contrast colorization and decolorization in a large-area nanofilm and showing long cyclic *** wide-angle reconfiguration of high-resolution structural colors in bowtie metasurfaces is demonstrated from anomalous *** results provide a multifield mechanism for reconfigurable photonic devices,and the new platform can be introduced to the multidimensional information encryption and storage.

关键词： scattering figuration Dynamic

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C2-phenyl-substituted benzimidazolium-based covalent organic framework as efficient catalyst for CO_(2) conversion without solvents,metals,and cocatalysts

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science China Chemistry 2024年第2期67卷 551-557页

作者： Zhenzhen Wu Jing Wang Lili Liu Shang Guo Juan Li Xianming Zhang Shanxi Institute for Functional Food Shanxi Agricultural UniversityTaiyuan030031China Institute of Crystalline Materials Shanxi UniversityTaiyuan030006China Key Laboratory of Interface Science and Engineering in Advanced Materials College of ChemistryTaiyuan University of TechnologyTaiyuan030024China

Covalent organic frameworks(COFs) are a potential platform for carbon dioxide(CO_(2)) conversion owing to their periodic permanent porosity,adjustable structure,and chemical *** good catalytic performance in CO_(2) conversion,collaborative multifunctions should be strategically integrated into the catalytic system design and *** this study,a four-in-one high-efficiency catalyst was synthesized and tested for CO_(2) cycloaddition to form cyclic *** obtained Tp-MPB-BrCOF had a high nitrogen content,which enhanced its CO_(2) affinity through substantial Lewis acid-base or dipole-quadrupole interactions;moreover,the acid(protons transferring from oxygen(–OH) to nitrogen(–NH)),hydrogen bond donor(hydroxyl group),and Br-(nucleophile group) served as three active sites,further improving the catalyst *** results provide a basis for designing efficient and stable CO_(2)-conversion catalysts.

关键词： covalent organic framework C2-phenyl-substituted benzimidazolium CO_(2)conversion four-in-one catalyst

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Atomistic Investigation of the Influence of Hydrogen on Mechanical Response during Nanoindentation in Pure Iron

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Acta Metallurgica Sinica(English Letters) 2023年第7期36卷 1179-1192页

作者： Wenjing Lou Lin Cheng Runsheng Wang Chengyang Hu Kaiming Wu The State Key Laboratory of Refractories and Metallurgy Hubei Province Key Laboratory of Systems Science on Metallurgical ProcessingInternational Research Institute for Steel TechnologyCollaborative Center on Advanced SteelsWuhan University of Science and TechnologyWuhan430081China Metals Valley and Band(Foshan)Metallic Composite Materials Co. Ltd.Foshan528000China

The effects of hydrogen on the mechanical response of pure iron with randomly distributed hydrogen atoms under nanoindentation were systematically investigated by molecular dynamics simulations with the aim to further understand hydrogen embrittlement mechanism in the *** simulations results revealed that,for the three models with[001],[110]and[111]surface normal,hydrogen reduced the critical load of the pop-in event,promoted the dislocation slipping and reduced the plastic region size and dislocation density around the indenter compared to the hydrogen free ***,the different mechanical responses of the three models with different surface normal were further explained in the perspective of Schmid factor.

关键词： Hydrogen embrittlement Dislocations Nanoindentation Molecular dynamics

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