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Polymer-to-Monomers Chemically Recyclable Poly(imide-imine)Plastics with Extreme-Condition Resistance and Flame Retardancy

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Chinese Journal of Polymer Science 2024年第10期42卷 1525-1535,I0012页

作者： Zhen-Yu Wang Xiao-Kong Liu state key laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun130012China

Polyimides are a family of high-tech plastics that have irreplaceable applications in the fields of aerospace,defense,and opto-electronics,but polyimides are difficult to be reprocessed and recycled at the end of their service life,resulting in a significant waste of ***,it is of great significance to develop recyclable polyimides with comparable properties to the commercial ***,we report a novel polymer-to-monomers chemically recyclable poly(imide-imine)(PtM-CR-PII)plastic,synthesized by cross-linking the amine-terminated aromatic bisimide monomer and the hexa-vanillin terminated cyclophosphazene monomer via dynamic imine *** PtM-CR-PII plastic exhibits comparable mechanical and thermal properties as well as chemical stability to the commercial *** PtM-CR-PII plastic possesses a high Young’s modulus of≈3.2 GPa and a tensile strength as high as≈108 MPa,which also exhibits high thermal stability with a glass transition temperature of≈220℃.Moreover,the PtM-CR-PII plastic exhibits outstanding waterproofness,acid/alkali-resistance,and solvent-resistance,its appearance and mechanical properties can be well maintained after long-term soaking in water,highly concentrated acid and base,and various organic ***,the cyclophosphazene moieties endow the PtM-CR-PII plastic with excellent flame *** PtM-CR-PII plastic exhibits the highest UL-94 flame-retarding rating of V-0 and a limiting oxygen index(LOI)value of 45.5%.Importantly,the PtM-CR-PII plastic can be depolymerized in an organic solvents-acid mixture medium at room temperature,allowing easy separation and recovery of both monomers in high *** recovered pure monomers can be used to regenerate new PtM-CR-PII plastics,enabling sustainable polymer-monomers-polymer circulation.

关键词： Chemical recyclability Polyimides Polyimines Dynamic imine bonds Mechanical properties Chemical stability

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S-scheme heterojunction of crystalline carbon nitride nanosheets and ultrafine WO_(3)nanoparticles for photocatalytic CO_(2)reduction

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Journal of Environmental Sciences 2024年第6期140卷 103-112页

作者： Gongjie Chen Ziruo Zhou Bifang Li Xiahui Lin Can Yang Yuanxing Fang Wei Lin Yidong Hou Guigang Zhang Sibo Wang state key laboratory of Photocatalysis on Energy and Environment College of ChemistryFuzhou UniversityFujian 350116China

Highly crystalline carbon nitride polymers have shown great opportunities in overall water photosplitting;however,their mission in light-driven CO_(2)conversion remains to be *** this work,crystalline carbon nitride(CCN)nanosheets of poly triazine imide(PTI)embedded with melon domains are fabricated by KCl/LiCl-mediated polycondensation of dicyandiamide,the surface of which is subsequently deposited with ultrafine WO_(3)nanoparticles to construct the CCN/WO_(3)heterostructure with a S-scheme *** characterizations have been conducted to reveal the compositions and structures of the S-scheme CCN/WO_(3)hybrid,featuring strengthened optical capture,enhanced CO_(2)adsorption and activation,attractive textural properties,as well as spatial separation and directed movement of light-triggered charge *** mild conditions,the CCN/WO_(3)catalyst with optimized composition displays a high photocatalytic activity for reducing CO_(2)to CO in a rate of 23.0μmol/hr(i.e.,2300μmol/(hr·g)),which is about 7-fold that of pristine CCN,along with a high CO selectivity of 90.6%against ***,it also manifests high stability and fine reusability for the CO_(2)conversion *** CO_(2)adsorption and conversion processes on the catalyst are monitored by in-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS),identifying the crucial intermediates of CO_(2)^(*)-,COOH^(*)and CO^(*),which integrated with the results of performance evaluation proposes the possible CO_(2)reduction mechanism.

关键词： Crystalline carbon nitride Photocatalysis CO_(2)reduction S-scheme WO_(3)

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Interparticle energy transfer between NaNdF_(4) and NaYbF_(4) in self-assembled nanostructures

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Journal of Rare Earths 2024年第6期42卷 1029-1035,I0001页

作者： Xinyu Chen Haoze Yang Yuyang Gu Chenqing Wen Yishuo Sun Jiaming Ke Wei Feng Department of chemistry and state key laboratory of Molecular Engineering of Polymers Fudan University Shanghai200433China

Forster resonance energy transfer(FRET)is a widely used spectroscopic *** development of donor-acceptor combinations is essential to advance this *** make the energy transfer efficiency independent of the external environment,we explored the potential of constructing donor—acceptor combinations with lanthanide ion-doped nanoparticles(LNPs),in which the 4f electrons of the lanthanide ions are shielded by the 5s and 6p ***-radiative energy transfer between LNPs was demonstrated in self-assembled nanostructures and core-shell structure of LNPs was used to control the distance between donor and acceptor in self-assembled *** emission intensity ratio of donor and acceptor illustrates that the energy transfer efficiency decreases significantly with increasing distance and the effective energy transfer distance is 8.5 nm,showing the potential of using LNPs as donor-acceptor pairs in the construction of distance-dependent energy transfer system.

关键词： Lanthanide nanoparticles Self-assembly Energy transfer Distance Epitaxialgrowth Rare earths

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Post-treatment of Ti-MWW zeolite with potassium fluoride for propylene epoxidation

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Frontiers of Chemical Science and Engineering 2024年第8期18卷 37-47页

作者： Xintong Li Xianchen Gong Jilong Wang Shengbo Jin Hao Xu Peng Wu state key laboratory of Petroleum Molecular&Process Engineering Shanghai Key Laboratory of Green Chemistry and Chemical ProcessesSchool of Chemistry and Molecular EngineeringEast China Normal UniversityShanghai 200062China

Epoxidation of propylene to propylene oxide(PO)with hydrogen peroxide(HPPO)is an environmentally friendly and cost-efficient process in which titanosilicates are used as ***-MWW is a potential industrial catalyst for this process,which involves the addition of HPPO to *** silanol groups generated during secondary crystallization unavoidably result in ring-opening of PO and inefficient decomposition of HPPO,which diminish the PO selectivity and the lifespan of *** address this issue,we conducted post-treatment modifications of the structured Bf-Ti-MWW catalyst with potassium fluoride aqueous *** quenching the silanol groups with potassium fluoride and implanting electron-withdrawing fluoride groups into the Ti-MWW framework,both the catalytic activity and HPPO utilization efficiency were ***,the ring opening reaction of PO was *** a continuous fixed-bed liquid-phase propylene epoxidation reaction,the KF-treated structured Ti-MWW catalyst displayed an exceptionally long lifespan of 2700 h,with a PO yield of 590 g·kg^(-1)·h^(-1).

关键词： titanosilicates Ti-MWW propylene epoxidation structured catalyst KF modification

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Ru(Ⅱ)-Catalyzed Selective C-H Alkynylation of Isoquinolones,Quinazolones and Phthalazinones with Bromoalkynes

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Chinese Journal of chemistry 2024年第15期42卷 1686-1690页

作者： Quan-Jian Luo Han-Chi Wang Jing Zhang Jin-Heng Li Bo Sun state key laboratory Base of Eco-Chemical Engineering College of Chemical EngineeringQingdao University of Science and TechnologyQingdaoShandong 266042China state key laboratory of Applied organic chemistry Lanzhou UniversityLanzhouGansu 730000China School of chemistry and Chemical Engineering Henan Normal UniversityXinxiangHenan 453007China

A new,selective Ru(Ⅱ)-catalyzed alkynylation reaction of isoquinolones,quinazolones and phthalazinones with readily available bromoalkynes has been *** reaction enables the selective construction of a new C(sp^(2))-C(sp)bond through C-H activation and C-Br functionalization,and offers an effective and selective route to synthesizing highly valuable alkynylated isoquinolone,quinazolone and phthalazinonederivatives with a wide substrate scope and highselectivity.

关键词： Ru(Ⅱ) Alkynylation Isoquinolones Bromoalkynes Heterocyclic compounds C-H activation C-C coupling Synthetic methods

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New strategies for asymmetric photocatalysis: asymmetric organocatalytic/photoredox relay catalysis for efficient synthesis of polycyclic compounds containing vicinal amino alcohols

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Science China chemistry 2024年第3期67卷 945-952页

作者： Jia-Lu Zhang Wen-Bo He Xiu-Qin Hu Peng-Fei Xu state key laboratory of Applied organic chemistry College of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou 730000China state key laboratory of Veterinary Etiological biology College of Veterinary MedicineLanzhou UniversityLanzhou Veterinary Research InstituteChinese Academy of Agricultural SciencesLanzhou 730000China MOE Frontiers Science Center for Rare Isotopes Lanzhou UniversityLanzhou 730000China

An asymmetric catalytic strategy in photocatalysis utilizing a chirality-induced approach through an organocatalytic/photoredox relay catalysis strategy is successfully achieved for the rapid construction of polycyclic compounds containing vicinal amino alcohols in a one-pot protocol. This methodology facilitates the efficient synthesis of diverse substituted polycyclic tetrahydroquinoline and benzofuran-derived vicinal amino alcohols, each containing five consecutive chiral centers, with high yields,excellent diastereoselectivities and enantioselectivities(up to 95% yield, >20:1 dr and 98% ee), under mild reaction conditions driven by sequential bifunctional squaramide organocatalyst-catalyzed [4+2] annulation and photocatalyst-catalyzed ketyl radical addition cyclization reaction process. Furthermore, investigations into the stereoselectivity mechanism and high-resolution mass spectrometry(HRMS) experiments on free radical trapping have provided evidence for elucidating the detailed mechanism of chirality-induced processes and chiral intermediate conversions in this procedure.

关键词： enantioselective photocatalysis asymmetric organocatalytic/photocatalysis relay catalysis five consecutive chiral centers chirality-induced strategy chirality vicinal amino alcohols

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Nature-inspired design of droplet-synthesized polymeric nanoelectrode for photoelectrochemical microRNA sensing within single cells

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Science Bulletin 2024年第2期69卷 159-162页

作者： Si-Yuan Yu Yi-Li Liu Zheng Li Dechen Jiang Jing-Juan Xu Hong-Yuan Chen Wei-Wei Zhao state key laboratory of Analytical chemistry for Life Science School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China

Nanoelectrodes have been shown to be powerful tools for nanoscopic research on single entities,deepening the understanding of heterogeneity and stochastics for single molecules,nanoparticles and cells[1–3].However,despite their importance,current nanoelectrode preparations are highly restrained to flame/electrochemical etching,metal sputtering,electrochemical deposition,etc.[3],resulting in a limited range of materials(mainly gold,platinum and carbon)for potential-resolved detection of redox-active species(Table S1 online).The enrichment of preparation methods to introduce novel materials and mechanisms should prove significant for the development of nanoelectrodes.

关键词： electrode deepening restrained

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Dealloyed TiCuMn efficiently catalyze the NO reduction and Zn-NO batteries

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Frontiers of Chemical Science and Engineering 2024年第9期18卷 51-59页

作者： Lang Zhang Tong Hou Weijia Liu Yeyu Wu Tianran Wei Junyang Ding Qian Liu Jun Luo Xijun Liu state key laboratory of Featured Metal Materials and Life-Cycle Safety for Composite Structures MOE Key Laboratory of New Processing Technology for Nonferrous Metals and MaterialsSchool of ResourcesEnvironment and MaterialsGuangxi UniversityNanning 530004China Education Department of Guangxi Zhuang Autonomous Region Key Laboratory of Applied Analytical ChemistryGuangxi Collaborative Innovation Center for Chemistry and Engineering of Forest ProductsGuangxi Key Laboratory of Chemistry and Engineering of Forest ProductsKey Laboratory of Chemistry and Engineering of Forest ProductsState Ethnic Affairs CommissionSchool of Chemistry and Chemical EngineeringGuangxi Minzu UniversityNanning 530006China Institute for New Energy Materials&Low-Carbon Technologies School of Materials Science and EngineeringTianjin University of TechnologyTianjin 300384China Institute for Advanced Study Chengdu UniversityChengdu 610106China ShenSi Lab Shenzhen Institute for Advanced StudyUniversity of Electronic Science and Technology of ChinaShenzhen 518110China

Electrocatalytic NO reduction reaction offers a sustainable route to achieving environmental protection and NH3 production targets as *** this work,a class of dealloyed Ti_(60)Cu_(33)Mn_(7)ribbons with enough nanoparticles for the high-efficient NO reduction reaction to NH_(3)is fabricated,reaching an excellent Faradaic efficiency of 93.2%at–0.5 V vs reversible hydrogen electrode and a high NH3 synthesis rate of 717.4μmol·h^(-1)·mgcat.-1 at–0.6 V vs reversible hydrogen *** formed nanoparticles on the surface of the catalyst could facilitate the exposure of active sites and the transportation of various reactive ions and ***,the Mn content in the TiCuMn ribbons modulates the chemical and physical properties of its surface,such as modifying the electronic structure of the Cu species,optimizing the adsorption energy of N^(*)atoms,decreasing the strength of the NO adsorption,and eliminating the thermodynamic energy barrier,thus improving the NO reduction reaction catalytic ***,a Zn-NO battery was fabricated using the catalyst and Zn plates,generating an NH3 yield of 129.1µmol·h^(-1)·cm^(-2)while offering a peak power density of 1.45 mW·cm^(-2).

关键词： nitric oxide reduction NH3 electrosynthesis TiCuMn alloy Mn modulation Zn-NO battery

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Photoinduced copper-catalyzed alkoxyl radical-triggered ring-expansion/aminocarbonylation cascade

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Chinese Chemical Letters 2024年第6期35卷 331-336页

作者： Jing-Qi Tao Shuai Liu Tian-Yu Zhang Hong Xin Xu Yang Xin-Hua Duan Li-Na Guo Department of chemistry School of ChemistryXi’an Key Laboratory of Sustainable Energy Material Chemistry and Engineering Research Center of Energy Storage Materials and DevicesMinistry of EducationXi’an Jiaotong UniversityXi’an 710049China School of Electrical Engineering Xi’an Jiaotong UniversityXi’an 710049China state key laboratory of Applied organic chemistry Lanzhou UniversityLanzhou 730000China

A photoinduced copper-catalyzed alkoxyl triggered C-C bond cleavage/aminocarbonylation cascade is *** adjusting the structure of alkoxyl radical precursors,functionalized lactones and ketoamides were synthesized with good yields and excellent functional group tolerance under redox-neutral ***,this protocol enables the integration of lactone fragments with many amine drugs and drug fragments.

关键词： Copper catalysis Ring-expansion Aminocarbonylatioin Macrolactones Keto-amides

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New sustainable polymers with on-demand depolymerization property

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Science China chemistry 2024年第9期67卷 2803-2841页

作者： Yangyang Sun Zesheng An Yanshan Gao Rongrong Hu Ye Liu Hua Lu Xiao-Bing Lu Xuan Pang Anjun Qin Yong Shen Youhua Tao Yu-Zhong Wang Junpeng Wang Gang Wu Guang-Peng Wu Tie-Qi Xu Xing-Hong Zhang Yuetao Zhang Zhenbiao Zhang Jian-Bo Zhu Miao Hong Zhibo Li state key laboratory of Organometallic chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China state key laboratory Base of Eco-Chemical Engineering College of Chemical EngineeringQingdao University of Science and TechnologyQingdao266042China state key laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun 130012China state key laboratory of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou 510640China state key laboratory of Fine Chemicals Frontiers Science Center for Smart MaterialsDalian University of TechnologyDalian 116024China Beijing National laboratory for Molecular Sciences Center for Soft Matter Science and EngineeringKey Laboratory of Polymer Chemistry and Physics of Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China key laboratory of Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials(MoE) National Engineering Laboratory of Eco-Friendly Polymeric Materials(Sichuan)College of ChemistryState Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610064China School of Polymer Science and Polymer Engineering the University of AkronAkronOH 44325USA MOE key laboratory of Macromolecular Synthesis and Functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou 310027China state and Local Joint Engineering laboratory for Novel Functional Polymeric Materials Jiangsu Key Laboratory of Advanced Functional Polymer Design and ApplicationSuzhou Key Laboratory of Macromolecular Design and Precision SynthesisCollege of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhou 215123China

To combat the crisis of today's synthetic polymers arising from unsustainable production and disposal,it is essential for the synthetic polymer community to reshape the current polymer industry with sustainable *** an emerging class of sustainable polymers,the development of chemically depolymerizable polymers(CDPs),which can undergo closed-loop depolymerization/repolymerization cycles to reproduce virgin polymers without the loss of properties from recovered monomers,offers an ideal solution to preserve finite natural resources,provides a feasible solution to the end-of-life issue of polymer waste,and thereby establishes a circular materials ***,two grand key challenges have been encountered in the establishment of practically useful CDPs:how to balance polymerization and depolymerization ability and how to unify conflicted depolymerizability and physical ***,this critical review article presents our vision for summarizing feasible strategies to overcome the above two significant challenges and the design principles for constructing an ideal CDP by highlighting selected major progress made in this rapidly expanding field.

关键词： chemically depolymerizable polymers sustainable polymers depolymerization monomer recovery degradation plastics

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