检索结果-内蒙古大学图书馆

Highly active organocatalyst from a trivalent phosphazenium salt for ring-opening copolymerization of epoxides and cyclic anhydrides enhanced by hydrogen bonding interactions

引用

science China chemistry 2024年第9期67卷 3111-3120页

作者： Chunhuan Jiang Junqi Wang Xiaoyu Liu Xiaoxia You Ronglin Zhong Chuanli Ren Zhibo Li Key Laboratory of Biobased Polymer Materials Shandong Provincial Education DepartmentCollege of Polymer Science and EngineeringQingdao University of Science and TechnologyQingdao 266042China College of Chemical Engineering Qingdao University of Science and TechnologyQingdao 266042China Laboratory of Theoretical and Computational Chemistry Institute of Theoretical ChemistryCollege of ChemistryJilin UniversityChangchun 130012China

It is highly desirable to develop simple organocatalysts for the controlled ring-opening alternating copolymerization(ROAC)of epoxides and cyclic anhydrides,leading to high molecular weight ***,a phosphazenium salt,namely tri[tris(dimethylamino)phosphoranylidenamino]phosphonium chloride(P_(4)^(+)Cl^(-)),is developed as a catalyst for the ROAC of epoxides and cyclic ***,the combination of P_(4)^(+)Cl^(-)with a protonic initiator,such as 1,4-benzenedimethanol(BDM)exhibited high efficiency in the copolymerization of propylene oxide(PO)and phthalic anhydride(PA).This led to the production of polyester with an exceptional high molecular weight(M_n)of up to 126 k Da,which represented a rare example of poly(PO-alt-PA)with Mnsurpassing 100 k *** that the core P atom is trivalent status and the tris[tris(dimethylamino)]phosphoranyl group will share one proton in the P_(4)^(+)Cl^(-)*** combined with protonic species,the P_(4)^(+)Cl^(-)will not only serve as a proton acceptor but also as a hydrogen bonding donor for the cyclic ***,it was assumed that the P_(4)^(+)plus proton served dual role in mimic of base/urea pair to effectively catalyze ROAC,which was supported by density functional theory(DFT)calculations.

关键词： ring-opening copolymerization organocatalyst epoxides cyclic anhydrides phosphazenium salt

来源：评论

学校读者我要写书评

暂无评论

Rapid and high-resolution 3D printing via photoacid generator induced cationic RAFT polymerization

引用

science China chemistry 2025年第05期68卷 2010-2016页

作者： Bowen Zhao Jiajia Li Chongyang Yang Xiangqiang Pan Zhengbiao Zhang Jian Zhu State 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 SynthesisDepartment of Polymer Science and EngineeringCollege of ChemistryChemical Engineering and Materials ScienceSoochow University

Vinyl ethers, while being typical monomers for living cationic polymerization, have limited commercial use due to the poor mechanical properties of their polymers at room temperature. We explored the use of photoacid generators to induce cationic reversible addition-fragmentation chain transfer（RAFT） polymerization for the rapid high-resolution three-dimensional（3D） printing of various vinyl ethers. The process demonstrated controlled molecular weights and narrow molecular weight distributions（MWD）, with monomer conversions exceeding 90% in minutes. Incorporating a crosslinker enabled 3D printing at speeds up to 8.46 cm h-1with layer thicknesses as thin as 50 μm. The mechanical properties of the printed objects were tunable by adjusting resin components, allowing for a range of material characteristics from brittle to elastomeric（tensile strength ranging from 13.9 to 31.7 MPa, Young's modulus ranging from 185.6 to 992.7 MPa and elongation at break ranging from 2.8%to 68.3%）. Moreover, polymer welding facilitated the creation of gradient materials, showcasing the potential for engineered applications of poly（vinyl ethers）(PVEs).

关键词： 3D printing cationic RAFT polymerization vat photopolymerization vinyl ether

来源：评论

学校读者我要写书评

暂无评论

Electrocatalysis for sustainable nitrogen management: materials innovation for sensing, removal and upcycling technologies

引用

science China chemistry 2025年第6期68卷 2322-2342页

作者： Mei Yi Hongmei Li Minghao Xie Panpan Li Zhaoyu Jin Guihua Yu Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of China College of Materials Science and Engineering and College of Chemistry Sichuan University Materials Science and Engineering Program and Walker Department of Mechanical Engineering The University of Texas at Austin

The global nitrogen cycle holds immense importance due to its crucial role in supporting life, supplying vital nutrients for plant growth, preserving environmental balance, and enabling the proper functioning of ecosystems. However, human activities frequently disrupt this cycle, leading to the accumulation of nitrates and nitrites in water bodies. This accumulation causes environmental pollution and health risks. Traditional methods for treating nitrogen pollution, including biological, physical, and chemical approaches, have inherent limitations. In recent years, electrocatalysis has emerged as a promising and sustainable approach for nitrogen management. This technology offers superior efficiency, high selectivity, and environmental *** not only enables accurate detection of nitrogen pollutants in the environment but also facilitates their conversion into harmless nitrogen gas. Moreover, recent advancements have focused on the upcycling of nitrogen pollutants into valuable compounds,such as ammonia and urea. In this comprehensive review, we showcase the applications of electrocatalysis in sustainable nitrogen management. Specifically, we highlight its use in the sensing, removal, and upcycling of major nitrogen pollutants,including nitrate（NO3-）, nitrite（NO2-）, and nitric oxide（NO）. We discuss the use of catalysts, such as Pd alloys, Cu-based, and Fe-based materials, in electrochemical sensing and catalysis. Additionally, we explore recent advancements in the conversion of nitrogen pollutants into valuable compounds like ammonia and urea. The review also addresses current challenges and future opportunities in the field, including innovations in sensor and catalyst design, as well as large-scale treatment strategies. We anticipate that these perspectives will provide profound insights for effective nitrogen pollution control and sustainable utilization of nitrogen resources.

关键词： electrocatalysis electrochemical sensor nitrogen removal ammonia electrosynthesis C–N coupling

来源：评论

学校读者我要写书评

暂无评论

Dense carbon nanofiber self-supporting electrode fabricated by orientation/compaction strategy for high volumetric lithium storage capacity

引用

Progress in Natural science:Materials International 2025年第1期35卷 229-237页

作者： Haihui Liu Chaoqun Chen Qiang Xu Yan Song Xiangwu Zhang Chang Ma Tianjin Municipal Key Lab of Advanced Fiber and Energy Storage Technology Tiangong University CAS Key Laboratory of Carbon Materials Institute of Coal Chemistry Chinese Academy of Sciences Fiber and Polymer Science Program Department of Textile Engineering Chemistry and Science Wilson College of Textiles North Carolina State University

Low bulk density greatly restricts the large-scale application of electrospun carbon-based fiber membrane as electrode in energy storage devices. To solve the above challenges, herein an orientation-compaction densification strategy is proposed to enhance the bulk density and volumetric capacity of PAN-based carbon nanofiber membranes as self-supporting electrode used in lithium-ion batteries（LIBs）. Specifically, highly-oriented fibers are achieved by high-speed roller collecting during electrospinning, and compaction densification is conducted by hot-pressing treatment. The effects of collecting speed and hot-pressing pressure on the morphology, conductivity,bulk density, tensile strength, and flexibility of the obtained carbon nanofiber membrane are *** to conventional fiber membranes, of which fibers are disorderly stacked, the oriented fiber membrane is much easier to achieve dense stacking by compaction. The obtained dense carbon nanofiber membrane demonstrates a bulk density of 0.566 g cm-3, and shows a significantly-enhanced volumetric capacity(318.3 mA h cm-3), high-rate performance(86.6 mA h cm-3at 5 A g-1), and satisfactory cycling stability when used as selfsupporting electrode of LIBs.

关键词： Bulk density Densification Electrospinning Orientation-compaction Volumetric capacity

来源：评论

学校读者我要写书评

暂无评论

Phenols/Al(C_(6)F_(5))_(3) Initiation Systems for Cationic polymerizations of Isobutylene

引用

Chinese Journal of polymer science 2023年第5期41卷 713-719,I0008页

作者： Ling Cai Qi-Yuan Wang Xin-Li Liu Dong-Mei Cui State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Department of Polymer Science and Engineering University of Science and Technology of ChinaHefei 230026China

We report herein the cationic polymerization of isobutylene(IB)under mild conditions is realized with a new binary initiation system generated by simply mixing a Lewis super acid Al(C_(6)F_(5))_(3) and a substituted phenol(RPhOH).polymers with medium and/or high molecular weights(M_(W)=4.9×10^(4)-27.7×10^(4) g·mol^(-1))can be obtained in toluene and temperatures from-20℃to 0℃.NMR spectrum analysis and DFT sim ulation reveals the in situ generated acidic coordinating complex Ak(C_(6)F_(5))_(3)·RPhOH is the initiating active species,which fu rther tran sformed into the ion-pair[Al(C_(6)F_(5))_(3)ORPh]^(-)[PIB]^(+)of the active intermediates upon growing IB monomers where the counter anion[Al(C_(6)F_(5))_(3)R^(O)Ph]-coordinates to the macrocation via the phenoxy *** catalyst performances are the concert effects of the steric bulkiness and electronics of the counter anion on the coordinating strength to the macrocation,which is significant to the stability of the active species.

关键词： Cationic polymerization Phenols Lewis super acid Polyisobutylene

来源：评论

学校读者我要写书评

暂无评论

Tandem Olefin Metathesis polymerization to Access Degradable and Recyclable Thermosets,Thermoplastics,and Elastomers

引用

CCS chemistry 2025年第3期7卷 883-892页

作者： Guifu Si Zihao Wang Chen Zou Changle Chen Key Laboratory of Precision and Intelligent Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026

The development of degradable polymers represents an appealing strategy to address ever-growing concerns for treating waste *** metathesis polymerization has been extensively explored for the synthesis of various degradable ***–acyclic monomers metathesis polymerization(CAMMP)has recently been reported to produce degradable polymers via copolymerization of cyclic monomers with acyclic diene ***,this strategy suffers from poor product material properties,especially at high contents of diene *** address this issue,we have designed a tandem olefin metathesis polymerization(TOMP)system that combines olefin ringclosing metathesis(RCM)of diene comonomers,followed by ring-opening metathesis copolymerization(ROMCP)with cyclic olefin monomers(dicyclopentadiene,cyclooctene,or alkyl-substituted cyclooctene).This strategy overcame the intrinsic limitations of diene-induced chain-transfer reactions during olefin metathesis,leading to degradable polymers with high molecular weights and excellent material *** selection of different cyclic olefin monomers provided access to degradable and recyclable cross-linked thermosets,linear thermoplastics,and ***,this one-pot,two-step process was highly efficient and required the addition of only one metathesis catalyst.

关键词： tandem olefin metathesis polymerization ring-closing metathesis diene comonomers degradable polymers one-pot process

来源：评论

学校读者我要写书评

暂无评论

Study on the Radiation Synthesis Mechanism and the Electrochemical Property of Polyaniline

引用

Chinese Journal of polymer science 2025年第2期43卷 328-340页

作者： Shuo Yan Zi-Fang Guo Zhi-Qing Ge Bao-Ying Zhang Ya-Ru Zhang Yi-Shao Li Mo-Zhen Wang Xue-Wu Ge State Key Laboratory of Precision and Intelligent Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei230026China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei230026China

As a highly promising conductive polymer material,the synthesis method,structure regulation,and performance improvement of polyaniline(PANI)are hot research *** this work,the radiation-induced polymerization of aniline in HNO_(3)solution was successfully achieved at room temperature without the use of chemical *** the analysis of the radiation chemical reactions of inorganic acids and nitrate salt solutions,the characterization of the intermediate free radicals in the irradiated systems,and the influence of the pH of the solutions on the polymerization activity and product morphologies,the radiation-induced polymerization mechanism of aniline is discussed in detail and *** at a condition of[HNO_(3)]>[aniline],i.e.,pH<2.5,PANI can be successfully obtained underγ-ray *** polymerization begins with the oxidation of aniline cations to aniline cation radicals by·NO_(3)generated by radiolysis reactions,and undergoes repeated three steps of monomer free radical recombination,deprotonation,and oxidation reaction of·NO_(3),thus forming a PANI *** addition to the polymerization reaction,the aniline units are protonated and oxidized because of the strongly acidity and oxidation of the reaction system under γ-ray irradiation,which means that the molecular chain structure of the radiation-synthesized PANI can be regulated by pH,nitrate concentration,and irradiation ***-synthesized PANI has a moderate protonation and oxidation state,which can be used for the preparation of PANI supercapacitors with better electrochemical properties than those prepared by chemical oxidation under the same *** work presents a new radiation-synthesis method and polymerization mechanism of PANI,which not only expands the application of radiation technique in the field of polymer synthesis,but also provides a new idea for the structural regulation and electrochemical property optimization of PANI.

关键词： Aniline Radiation-induced polymerization Polyaniline Electrochemical property

来源：评论

学校读者我要写书评

暂无评论

Furan-modified thiadiazolo quinoxaline as an electron acceptor for constructing second near-infrared aggregation-induced emission fluorophores for beyond 1300 nm fluorescence/photoacoustic imaging and photothermal therapy

Aggregate

引用

Aggregate 2024年第2期5卷 345-356页

作者： Mengke Liang Luyu Liu Ying Sun Jia Li Ling’e Zhang Xiqun Jiang Wei Wu Department of Polymer Science&Engineering State Key Laboratory of Analytical Chemistry for Life ScienceCollege of Chemistry&Chemical EngineeringNanjing UniversityNanjingP.R.China

Creation of new fluorophores is important for understanding the structure-property relationship,by which the required optical properties are likely to be ***,through theory calculation,it is found that furan-modified thiadiazolo quinoxaline acting as an electron acceptor can endow donor-acceptor-donor(D-A-D)type second near-infrared(NIR-Ⅱ)fluorophores with longer emission wavelength than the other thiadiazolo quinoxaline-based acceptors containing pyridine,pyrrole,thiophene,and phenyl groups,*** the basis of this theoretical prediction,a D-A-D type NIR-Ⅱ fluorophore with 6,7-di(furan-2-yl)-[1,2,5]thiadiazolo[3,4-g]quinoxaline(DFTQ)as the acceptor and dithieno[3,2-b:2′,3′-d]pyrrole(DTP)as the donor is designed and synthesized,and the aggregation-induced emission(AIE)function is further achieved by introducing the AIE units of tetraphenylethylene(TPE)and triphenylamine(TPA),respectively,totally forming three NIR-Ⅱ fluorophores DFTQ-DTP,DFTQ-DTPE,and *** biological applications,the fluorophores are encapsulated by amphiphilic DSPE-PEG2000 to generate water-dispersible nanoparticles(NPs).Almost the whole emission of each of the NPs falls into the NIR-Ⅱ spectral range,with part emission beyond 1300 *** using DFTQ-DTPA NPs as the contrast and photothermal therapy(PTT)agent,high-resolution in vivo fluorescence imaging is achieved in the greater than 1300 nm window,and their good performance in photoacoustic imaging and high tumor PTT efficacy in tumor-bearing mice are also *** together,this work mainly provides a strong electron acceptor for constructing longemitting fluorophores,and by using the electron acceptor,a AIE fluorophore with desirable quantum yield(QY)and photothermal conversion efficienciy(PCE)is synthesized and demonstrated to be promising in fluorescence/photoacoustic imaging and PTT.

关键词： aggregation-induced emission fluorescence imaging photoacoustic imaging photothermal therapy second near-infrared fluorophores

来源：评论

学校读者我要写书评

暂无评论

Dynamics of Charged Ring polymers under Gel Confinement

引用

Chinese Journal of polymer science 2025年第3期43卷 399-405页

作者： Lu-Jie Huo Kai-Ru Qu Zhen-Zhong Yang Di Jia State Key Laboratory of Polymer Physics and Chemistry Beijing National Laboratory for Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Institute of Polymer Science and Engineering Department of Chemical EngineeringTsinghua UniversityBeijing 100084China

Ring polymers are ubiquitous in various fields including biomaterials,drug release and gene *** of these applications involve the dynamics and diffusion process of ring polymers in a confined *** using dynamic light scattering(DLS),we discovered a dynamical transition for charged ring polymers with increasing ring concentration in the gel matrix from a diffusive state to a non-diffusive topological frustrated state with a more compact *** the ring polymer size is smaller than the mesh size of the gel matrix,the rings are diffusive at low concentration of 5 g/*** ring diffusion coefficient in the gel matrix is an order of magnitude smaller than that of rings in solution,obeying the Ogston's *** high ring concentration of 40 g/L,the collective dynamical behavior of the charged rings exhibits a topologically frustrated non-diffusive state,which may originate from the inter-ring threading with the external confinement from the gel *** on our previous theoretical work,we also conjectured that in such a non-diffusive state,the ring polymers might adopt a more compact conformation with the overall size exponentν=1/3.

关键词： Charged ring polymer Dynamics under confinement Non-diffusive topologically frustrated dynamics Dynamic light scattering Collective diffusion coefficient

来源：评论

学校读者我要写书评

暂无评论

Facile Synthesis of Polyisothioureas via Alternating Copolymerization of Aziridines and Isothiocayanates

引用

Chinese Journal of polymer science 2024年第3期42卷 292-298,I0005页

作者： Hao-Tian Zhang Ming-Xin Niu Qi Zhang Chen-Yang Hu Xuan Pang Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Department of Materials Science and Engineering Jilin UniversityChangchun 130025China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China

Isothiourea is an important class of sulfur-containing molecules showing unique catalytic and biological activities. As such,polyisothiourea is envisioned to be an interesting type of polymer that potentially exhibits a number of interesting properties. However, there is no access to synthesizing well-defined polyisothiourea, and currently isothiourea-containing polymers are mainly prepared by immobilizing onto other polymer's side chain. Herein, we report the first facile synthesis of polyisothioureas via alternating copolymerization of aziridines and isothiocayanates. Mediated by the catalytic system of phosphazene superbases/alcohol, a broad scope of aziridines and isothiocayanates could be transformed into polyisothioureas with adjustable substitutions(11 examples). The structures of obtained polyisothioureas were fully characterized with ^(1)H-NMR, ^(13)C-NMR, and ^(1)H-^(13)C HMBC NMR. Moreover, the polyisothioureas show tunable thermal properties depending on substitutions on the isothiourea linkages. The novel structure of these polyisothioureas will enable a powerful platform for the discovery of nextgeneration functional plastics.

关键词： Polyisothioureas Alternative copolymer Aziridines Isothiocayanates

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：