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Toward understanding the cross-linking from molecular chains to aggregates by engineering terminals of supramolecular hyperbranched polysiloxane

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Aggregate

Aggregate 2024年第1期5卷 228-235页

作者： Yuanbo Zhang Junshan Yuan Jingzhi Hu Zhixuan Tian Weixu Feng Hongxia Yan Shaanxi key laboratory of macromolecular Science and technology Xi’an Key Laboratory of Hybrid Lumines-cent Materials and Photonic DeviceSchool of Chemistry and Chemical engineeringNorthwestern Polytechnical UniversityXi’anChina

Crosslinking thermosets with hyperbranched polymers confers them superior comprehensive ***,it still remains a further understanding of polymer crosslinking from the molecular chains to the role of *** this study,three hyperbranched polysiloxane structures(HBPSi-R)are synthesized as model macromolecules,each featuring distinct terminal groups(R denotes amino,epoxy,and vinyl groups)while similar molecular backbone(Si-O-C).These structures were subsequently copolymerized with epoxy monomers to construct interpenetrating HBPSi-R/epoxy/anhydride co-polymer *** spatial molecular configuration and flexible Si-O-C branches of HBPSi-R endow them with remarkable reinforcement and toughening ***,an optimum impact strength of 28.9 kJ mol^(−1) is achieved with a mere 3%loading of HBPSi-V,nearly three times that of the native epoxy(12.9 kJ mol^(−1)).By contrasting the terminal effects,the aggregation states and crosslinking modes were proposed,thus clarifying the supramolecular-dominant aggregation mechanism and covalent-dominant dispersion mechanism,which influences the resulting material *** work underscores the significance of aggregate science in comprehending polymer crosslinking and provides theoretical insights for tailoring material properties at a refined molecular level in the field of polymer science.

关键词： aggregates crosslinking hyperbranched polymers

Semiconductor fibers for textile integrated electronic systems

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National Science Review 2024年第6期11卷 100-101页

作者： Yuanyuan Zheng Zhen Wang Peining Chen Huisheng Peng State key laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceInstitute of Fiber Materials and Devices and Laboratory of Advanced Materials Fudan University

Over 5000 years of development, the functions of clothing have been mainly limited in warmth and modesty. With the development of smart fibers, fabrics are anticipated to revolutionize multidisciplinary applications, ... 详细信息

关键词： Fibers

Chemoselective epoxidation of electron-deficient olefins with molecular oxygen via conjugated olefins epoxidation and BHT hydroxylation

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Science China Chemistry 2024年第9期67卷 3012-3018页

作者： Jia Nie Huanfeng Jiang Chuanle Zhu School of Chemistry and Chemical Engineering Key Lab of Functional Molecular Engineering of Guangdong ProvinceSouth China University of TechnologyGuangzhou 510640China Guangdong Provincial key laboratory of Technique and Equipment for macromolecular Advanced Manufacturing South China University of TechnologyGuangzhou 510640China

The chemoselective epoxidation of electron-deficient olefins in the presence of electron-rich alkene moieties is *** chemoselective epoxidation strategy undergoes a conjugated olefin epoxidation and BHT hydroxylation process to give various useful oxiranes in high yields,especially for the 2-substituted ***,this protocol features mild conditions,is transition-metal free,operationally simple,and gram-scalable,and tolerates diverse functional *** candidate HSD-16 is synthesized smoothly by this *** studies indicate molecular oxygen is the terminal oxidant and the O-source of the oxiranes.

关键词： chemoselective epoxidation alkene fluorine molecular oxygen

Upconverting and downshifting circularly polarized luminescence in a superstructural helix

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Science China Chemistry 2024年第8期67卷 2571-2577页

作者： Honghan Ji Bin Wu Enquan Tian Chao Ren Xue Jin Liangliang Zhu Pengfei Duan CAS key laboratory of Nanosystem and Hierarchical Fabrication National Center for Nanoscience and Technology(NCNST)Beijing 100190China State key laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai 200438China University of Chinese Academy of Sciences Beijing 101408China

The modulation of circularly polarized luminescence(CPL) has become an increasingly prominent area of research. In this study,we propose a unique “one-excitation-to-three-emissions” CPL system through the co-assembly of an upconversion system,incorporating one sensitizer(Pt(II) mesotetraphenyl tetrabenzoporphyrine, Pt TPBP) and two annihilators(R/S-DPA and R/SBDP) within liquid crystals. The chiral nature of the annihilators induces a transformation of the nematic liquid crystal into chiral nematic liquid crystals(N*LC), establishing an excellent chiral matrix. Upon the incorporation of the sensitizer Pt TPBP and subsequent excitation at 635 nm, the system demonstrates two independent triplet–triplet annihilation photon upconversion(TTA-UC) with the emission in blue and yellow, aided by thermally activated triplet–triplet energy transfer(TTET). This is accompanied by the simultaneous generation of upconverting circularly polarized luminescence(UC-CPL) and downshifting near-infrared circularly polarized luminescence(DS-CPL) originating from the residual luminescence of Pt TPBP. Remarkably,fine-tuning the ratio between the two annihilators allows the TTA-UC system to exhibit multicolor CPL emission with an amplified luminescence dissymmetry factor(glum, reaching up to 0.6). Our study unveils a previously unreported “one-excitation-to-three-emissions” system and provides a versatile strategy for modulating CPL emissions, surpassing conventional methodologies.

关键词： circularly polarized luminescence triplet–triplet annihilation upconversion near-infrared emission chiral nematic liquid crystal luminescence dissymmetry factor

Flexible and Robust Functionalized Boron Nitride/Poly(p‑Phenylene Benzobisoxazole)Nanocomposite Paper with High Thermal Conductivity and Outstanding Electrical Insulation

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Nano-Micro Letters 2024年第2期16卷 423-437页

作者： Lin Tang Kunpeng Ruan Xi Liu Yusheng Tang Yali Zhang Junwei Gu Chongqing key laboratory of Green Synthesis and Applications College of ChemistryChongqing Normal UniversityChongqing 401331People’s Republic of China Shaanxi key laboratory of macromolecular Science and technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072People’s Republic of China

With the rapid development of 5G information technology,thermal conductivity/dissipation problems of highly integrated electronic devices and electrical equipment are becoming *** this work,“high-temperature solid-phase&diazonium salt decomposition”method is carried out to prepare benzidine-functionalized boron nitride(m-BN).Subsequently,m-BN/poly(pphenylene benzobisoxazole)nanofiber(PNF)nanocomposite paper with nacremimetic layered structures is prepared via sol–gel film transformation *** obtained m-BN/PNF nanocomposite paper with 50 wt%m-BN presents excellent thermal conductivity,incredible electrical insulation,outstanding mechanical properties and thermal stability,due to the construction of extensive hydrogen bonds andπ–πinteractions between m-BN and PNF,and stable nacre-mimetic layered ***λ∥andλ_(⊥)are 9.68 and 0.84 W m^(-1)K^(-1),and the volume resistivity and breakdown strength are as high as 2.3×10^(15)Ωcm and 324.2 kV mm^(-1),***,it also presents extremely high tensile strength of 193.6 MPa and thermal decomposition temperature of 640°C,showing a broad application prospect in high-end thermal management fields such as electronic devices and electrical equipment.

关键词： Poly(p-phenylene-2,6-benzobisoxazole)nanofiber Boron nitride Thermal conductivity Electrical insulation

Organic interfacial engineering of gold nanowires for selective glycerol electrooxidation

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Chinese Chemical Letters 2024年第3期35卷 502-507页

作者： Zhe Wang Qingling Hong Boqiang Miao Tianjiao Wang Yu Ding Pujun Jin Pei Chen Yu Chen key laboratory of macromolecular Science of Shaanxi Province Key Laboratory of Applied Surface and Colloid Chemistry(Ministry of Education)Shaanxi Key Laboratory for Advanced Energy DevicesSchool of Materials Science and EngineeringShaanxi Normal UniversityXi'an 710062China

The selective electrochemical conversion of glycerol into value-added products is a green and sustainable strategy for the biomass *** this work,Au nanowires(Au-NW)modified with polyethyleneimine(PEI)molecule(Au-NW@PEI)is obtained by an up-bottom post-modification *** characterization,molecular dynamics simulation and density functional theory demonstrate that the loose-packed PEI monolayer firmly and uniformly distribute on the Au-NW surface due to the strong Au-N *** experiments and product analysis display that PEI modification significantly enhance the electro-activity of Au-NW for the glycerol electro-oxidation reaction(GEOR)due to the electronic ***,the steric hindrance and electrostatic effect of PEI layer make the optimizing adsorption of intermediates ***,the selectivity of C3 product glyceric acid over Au-NW@PEI is increased by nearly 20%.The work thus indicates that the rational design of metal-organic interface can effectively elevate the electro-activity and selectivity of Au nanostructures,which may have wide application in biomass development.

关键词： Glycerol electrooxidation reaction Organic interface engineering Gold-based nanomaterials Electrocatalysis Selectivity

Special Issue: Functional Polymer Materials

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Chinese Journal of Polymer Science 2024年第7期42卷 895-896,I0004页

作者： Jun-Wei Gu Du-Jin Wang Shaanxi key laboratory of macromolecular Science and technology School of Chemistry and Chemical Engineering Northwestern Polytechnical University Xi’an 710072 China Beijing National laboratory for Molecular Sciences CAS Key Laboratory of Engineering Plastics Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China

The rapid development of science has led to a significant role for polymer materials in multitude fields,including industry,medicine,energy,and the environment,*** a leading academic journal in the field of polymer,Chinese Journal of Polymer Science has been dedicated to fostering the advancement and utilization of polymer science.

关键词： polymer Polymer Functional

Sub-nanosized vanadate hybrid clusters maintain glucose homeostasis and restore treatment response in inflammatory disease in obese mice

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Nano Research 2024年第3期17卷 1818-1826页

作者： Kun Chen Shengqiu Liu Yujun Wei South China Advanced Institute for Soft Matter Science and technology School of Emergent Soft MatterSouth China University of TechnologyGuangzhou 510641China Guangdong Provincial key laboratory of Technique and Equipment for macromolecular Advanced Manufacturing South China University of TechnologyGuangzhou 510641China Guangdong Provincial key laboratory of Functional and Intelligent Hybrid Materials and Devices South China University of TechnologyGuangzhou 510641China

Obesity is closely related with insulin resistance and chronic ***,we report that unsaturated lipid-modified polyoxovanadates(ULPOVs)can restrict weight gain of diet-induced obese mice and improve their glycemic control and obesity-associated *** administration of the sub-nanosized ULPOVs at a low dosage for 7 weeks reduces the body weight and almost normalizes the blood glucose levels of obese mice fed on a high-fat *** treatment increases the activity of the nuclear receptor peroxisome proliferator-activated receptorγ(PPARγ)and reduces intestinal caloric intake,which may be the main reason for blood sugar and body weight *** addition to insulin-sensitizing,PPARγactivation induced by ULPOV treatment in obese mice with atopic dermatitis(AD)promotes the type 2 T helper(TH_(2))cell selective responses and therapeutic effects on immune dysregulation caused by *** data suggest sub-nanosized polyoxovanadate clusters as a class of potential candidates to relieve symptoms accompanied by diet-induced obesity.

关键词： polyoxovanadates lipid modification glucose homeostasis obesity inflammatory disease peroxisome proliferator-activated receptorγ(PPARγ)

Cyclic Pulsating Pressure Enhanced Segregating Structuration of Ultra-High Molecular Weight Polyethylene/Graphene Composites as High-performance Light-Weight EMI Shields

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Chinese Journal of Polymer Science 2024年第7期42卷 958-967,I0008页

作者： Yun-Zhi Huang Xiao-Xiao Liu Lan-Wei Li Guang-Ming Huang Zhao-Xia Huang Jin-Ping Qu National Engineering Research Center of Novel Equipment for Polymer Processing Key Laboratory of Polymer Processing EngineeringMinistry of EducationGuangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced ManufacturingSchool of Mechanical and Automotive EngineeringSouth China University of TechnologyGuangzhou 510641China School of Advanced Manufacturing technology Guangdong Mechanical&Electrical PolytechnicGuangzhou 510550China

Currently,the enhancement in electromagnetic interference(EMI)performance of polymeric composite generally relies on either improving electrical conductivity(σ)for stronger electromagnetic(EM)reflections or tailoring structure for higher EM ***,we proposed a novel technique called cyclic pulsating pressure enhanced segregating structuration(CPP-SS),which can reinforce these two factors *** structural information was supplied by optical microscopy(OM)and scanning electron microscopy(SEM),both of which confirmed the formation and evolution of segregate structured ultra-high molecular weight polyethylene(UHMWPE)/graphene ***,the result showed that CPP-SS can significantly improve theσof ***,advanced specific EMI shielding efficiency of 31.1 d B/mm was achieved for UHMWPE/graphene composite at 1-mm thickness and a low graphene loading of 5 wt%.Meanwhile,it also confirmed that the intrinsic disadvantage of poor mechanical properties of conventional segregated structure composites can be *** work is believed to provide a fundamental understanding of the structural and performance evolutions of segregated structured composites prepared under CPPSS,and to bring us a simple and efficient approach for fabricating high-performance,strong and light-weight polymeric EMI shields.

关键词： Cyclic pulsating pressure Segregated structure Ultra-high molecular weight polyethylene Graphene Electromagnetic interface