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Dielectric Constant Calculation of Poly(vinylidene fluoride)Based on Finite Field and Density Functional Theory

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Chinese Journal of Polymer Science 2024年第5期42卷 655-662,I0009页

作者： Yong-Zhi Lin Lu-Kun Feng Ya-Dong Li Chao-Fan Chang Cai-Zhen Zhu Ming-Liang Wang Jian Xu College of chemistry and Environmental Engineering Shenzhen UniversityShenzhen518055China Chengdu institute of Organic chemistry Chinese Academy of SciencesChengdu610041China

In this study,we proposed a novel method that integrates density functional theory(DFT)with the finite field method to accurately estimate the polarizability and dielectric constant of *** approach effectively accounts for the influence of electronic and geometric conformation changed on the dielectric *** validated our method using polyethylene(PE)and polytetrafluoroethylene(PTFE)as benchmark materials,and found that it reliably predicted their dielectric ***,we explored the impact of conformation variations in poly(vinylidene fluoride)(PVDF)on its dielectric constant and *** resulting dielectric constants ofα-andγ-PVDF(3.0)showed excellent agreement with crystalline PVDF in *** findings illuminate the relationship between PVDF’s structural properties and its electrical behavior,offering valuable insights for material design and applications.

关键词： Dielectric constant PVDF Finite field DFT

Diatomic Fe-Co catalysts synergistically catalyze oxygen evolution reaction

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Nano Research 2024年第5期17卷 3794-3800页

作者： Tianmi Tang Jingyi Han Zhenlu Wang Xiaodi Niu Jingqi Guan institute of Physical chemistry College of ChemistryJilin UniversityChangchun 130021China College of Food Science and Engineering Jilin UniversityChangchun 130062China

The design of diatomic catalysts with uniformly dispersed metal atoms is expected to improve catalytic performance,which is conducive to the intensive comprehending of the synergistic mechanism between dual-metal sites for the oxygen evolution reaction(OER)at the atomic ***,we design a strategy to immobilize bimetallic Fe-Co atoms onto nitrogen-doped graphene to obtain a diatomic catalyst(DA-FC-NG)with FeN_(3)-CoN_(3) *** DA-FC-NG shows excellent OER activity with a low overpotential(η_(10)=268 mV),which is superior to commercial iridium dioxide *** calculations uncover that the excellent activity of DA-FC-NG is due to the interaction between Fe and Co diatoms,which causes charge rearrangement and induces the adsorption of intermediates on the Fe-O-Co bridge structure,thus improving the catalytic OER *** work is of great significance for the design of highly active diatomic catalysts to replace noble metal catalysts for energy-related applications.

关键词： oxygen evolution reaction diatomic catalyst FeN_(3)-CoN_(3) X-ray absorption spectroscopy(XAS)spectrum theoretical calculation

Making topological protein links using enzymatic reactions

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National Science Review 2024年第03期11卷 50-51页

作者： Roger Castells-Graells Todd O.Yeates Department of chemistry and Biochemistry University of California UCLA-DOE institute for Genomics and Proteomics

Proteins are exceedingly complex molecules though, at their heart, they are essentially linear polymers. Pull at their ends and one obtains an extended backbone. While that is true in most cases, some natural proteins... 详细信息

关键词： DESIGN

Introducing urea into tirapazamine derivatives to enhance anticancer therapy

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National Science Review 2024年第4期11卷 245-253页

作者： Yajun Xu Jianlin Lv Chaoying Kong Ya Liu Kun Wang Zhaohui Tang Xuesi Chen Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied ChemistryChinese Academy of Sciences School of Applied chemistry and Engineering University of Science and Technology of China

Tirapazamine（TPZ） has been approved for multiple clinical trials relying on its excellent anticancer ***,as a typical hypoxia-activated prodrug（HAP）,TPZ did not exhibit survival advantages in Phase Ⅲ clinical trials when used in combination therapy due to the insufficient hypoxia levels in patients' *** this study,to improve the therapeutic effects of TPZ,we first introduced urea to synthesize a series of urea-containing derivatives of *** urea-containing TPZ derivatives showed increased hypoxic cytotoxicity（9.51-30.85-fold） compared with TPZ,while maintaining hypoxic ***,one of these derivatives,showed 20-fold higher cytotoxicity than TPZ while maintaining a similar hypoxic cytotoxicity *** highly efficiently deliver TPZP to the tumors and reduce its side effects on healthy tissues,we further prepared TPZP into a nanodrug with fibrin-targeting ability:***4-NPs,a vascular disrupting agent,was used to increase the fibrin level within tumors and exacerbate tumor *** being combined with CA4-NPs,FT11-TPZP-NPs can accumulate in the hypoxia-aggravated tumors and activate sufficiently to kill tumor *** a single-dose treatment,FT11-TPZP-NPs+CA4-NPs showed a high inhibition rate of 98.1% against CT26 tumor models with an initial volume of ～480 mm3and four out of six tumors were completely eliminated;it thereby exerted a significant antitumor *** study provides a new strategy for improving the therapeutic effect of TPZ and other HAPs in anticancer therapy.

关键词： tirapazamine vascular disrupting agent hypoxia-activated prodrug combretastatin A4 urea

Exfoliation,functionalization and antibacterial activity of transition metal dichalcogenides

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Tungsten 2024年第1期6卷 1-16页

作者： Avijit Mondal Mrinmoy De Department of Organic chemistry Indian Institute of ScienceBengaluru 560012India

Due to the growing resistance of available drugs to bacterial infection and the slow development of antibiotics,there is a continuous need to design and develop new antibacterial *** interest to develop transition metal dichalcogenides(TMDs)based antibacterial agents has significantly increased in recent *** research interest is driven by their interesting properties such as metallic and semiconducting nature of different phases,electronic confinement,large surface to volume ratio,the possibility of surface functionalization,and their potential application as a material in biomedical *** synthetic strategies have been developed to synthesize monolayered TMDs and their functionalization with different bioactive *** have given a lot of effort to establish the structure-activity correlation between different TMDs and their antibacterial ***,we have reviewed various exfoliation strategies for TMDs,different methods for their functionalization,and the antibacterial activity of different TMDs.

关键词： Transition metal dichalcogenides(TMD) Functionalization Antibacterial activity Antibacterial mechanism

Mn incorporated RuO2 nanocrystals as an efficient and stable bifunctional electrocatalyst for oxygen evolution reaction and hydrogen evolution reaction in acid and alkaline

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Chinese Chemical Letters 2024年第10期35卷 220-226页

作者： Jing Cao Dezheng Zhang Bianqing Ren Ping Song Weilin Xu State Key Laboratory of Electroanalytical chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences University of Science and Technology of China

The development of efficient and stable bifunctional overall water-splitting is a crucial goal for clean and renewable energy,which is a challenging ***,we report an Mn-incorporated RuO2（MnRuO2） catalyst for highly efficient electrocatalytic oxygen evolution reaction （OER） and hydrogen evolution reaction （HER） in acid and alkaline *** from a more electrochemical active area with the incorporation of Mn,the Mn-RuO2required an overpotential of 200 mV to attain a current density of 10 mA/cm2for OER in *** result indicates that the doping of Mn into RuO2can enhance the OER *** acidic overall water-splitting electrolyzer with good stability constructed by bifunctional Mn-RuO2only requires a cell voltage of 1.50 V to afford 10 m A/cm2and can operate stably for 50 h at50 mA/cm2,which is better than the state-of-the-art Ru-based ***,the Mn-Ru O2exhibits excellent HER and OER activity in alkaline media,and it shows superior activity and durability for overall water-splitting,only needing a cell voltage of 1.49 V to attain 10 m A/*** present work provides an efficient approach to designing and constructing efficient Ru-based electrocatalysts for overall water-splitting.

关键词： Acid and alkaline Hydrogen evolution reaction Overall water splitting Oxygen evolution reaction RuO2-based solid solution electrocatalysts

Pd-catalyzed intermolecular Si–O formation via Si–C activation

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Science China chemistry 2024年第8期67卷 2661-2669页

作者： Shuang Liu Yu-Shu Chen Yichen Wu Peng Wang State Key Laboratory of Organometallic chemistry Shanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesShanghai 200032China School of chemistry and Materials Science Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China College of Material chemistry and Chemical Engineering Key Laboratory of Organosilicon Chemistryand Material Technology of Ministry of EducationHangzhou Normal UniversityHangzhou 311121China

The development of efficient Si–O bond formation reaction with 100% atom-economy, excellent functional group tolerance, and broad scope under mild conditions is highly desired due to the prevalence of silanol, silyl ether, and their derivatives in synthetic chemistry and materials science. Here, we have realized the Pd-catalyzed Si–O formation reaction via a Si–C activation approach with 100% atom-economy by employing silacyclobutanes(SCBs) and various hydroxy-containing substrates, including water,alcohols, phenols, and silanols. This protocol features a broad substrate scope, remarkable functional compatibility and mild conditions, providing a series of silanols, silyl ethers in high efficiency. Notably, this protocol could also be used for selective protection of hydroxy functionalities, and for the access of a class of novel polymers containing Si–O main chain. Preliminary mechanistic studies unveiled that this reaction underwent a Pd-catalyzed concerted ring-opening mechanism.

关键词： Si–O formation Si–C activation palladium silacyclobutane silanol silyl ether

Suppressing the lattice oxygen diffusion via high-entropy oxide construction towards stabilized acidic water oxidation

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Nano Research 2024年第3期17卷 1107-1113页

作者： Jing Ni Zhaoping Shi Yibo Wang Jiahao Yang Hongxiang Wu Pengbo Wang Kai Li Meiling Xiao Changpeng Liu Wei Xing State Key Laboratory of Electroanalytic chemistry Jilin Province Key Laboratory of Low Carbon Chemistry PowerChangchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied chemistry and Engineering University of Science and Technology of ChinaHefei 230026China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China

The scale-up deployment of ruthenium(Ru)-based oxygen evolution reaction(OER)electrocatalysts in proton exchange membrane water electrolysis(PEMWE)is greatly restricted by the poor *** the lattice-oxygen-mediated mechanism(LOM)has been identified as the major contributor to the fast performance degradation,impeding lattice oxygen diffusion to inhibit lattice oxygen participation is imperative,yet remains challenging due to the lack of efficient ***,we strategically regulate the bonding nature of Ru–O towards suppressed LOM via Ru-based high-entropy oxide(HEO)*** lattice disorder in HEOs is believed to increase migration energy barrier of lattice *** a result,the screened Ti_(23)Nb_(9)Hf_(13)W_(12)Ru_(43)O_(x) exhibits 11.7 times slower lattice oxygen diffusion rate,84%reduction in LOM ratio,and 29 times lifespan extension compared with the state-of-the-art RuO_(2) *** work opens up a feasible avenue to constructing stabilized Ru-based OER catalysts towards scalable application.

关键词： ruthenium-based high-entropy oxide suppressing the lattice oxygen diffusion acidic oxygen evolution reaction

Polyoxometalate-based flexible conductive materials with superionic conductivity

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Science China chemistry 2024年第10期67卷 3299-3309页

作者： Yuxin Wang Shuping Xue Jun Geng Ying Lu Teng Li Xiaozheng Duan Xue Bai Yanli Yang Jingqi Yang Shuxia Liu Key Laboratory of Polyoxometalate and Reticular Material chemistry of Ministry of Education College of ChemistryNortheast Normal UniversityChangchun 130024China State Key Laboratory of Polymer Physics and chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China

Flexible ion-conductive materials exhibit intriguing advantages for applications in flexible electronic ***,the further enhancement of their conductivity within environmental limitations is an urgent demand for the development of flexible electronic devices,yet remains as a great ***,we report a“dual-acid”strategy,via the encapsulation of two acids,H_(3)PW_(12)O_(40)(HPW) and NH_(2)SO_(3)H(SA),with synergistic interaction into poly(vinyl alcohol)-glycerol(PVA-Gly) hydrogel,to achieve polyoxometalate(POM)-based flexible materials with superionic conductivity under various environmental *** a representative example,the prepared PVA-Gly/HPW-SA-20% hydrogel presents an ultrahigh proton conductivity ranging from -30℃(3.33×10^(-2)S cm^(-1)) to room temperature(2.78×10^(-1)S cm^(-1)) under ambient ***,the PVA-Gly/HPW-SA-20% hydrogel exhibits remarkable advantages in anti-freezing,mechanical flexibility and self-adhesiveness,making it a promising multifunctional electrolyte for flexible electronic *** experimental results and molecular dynamics(MD) simulations jointly demonstrate that SA bridges HPW clusters to form a dense proton transport pathway induced by multiple electrostatic and hydrogen bonding interactions between SA and HPW counterparts,which contributes to the high-level proton conductivity of the PVA-Gly/HPW-SA-20% *** work provides new insights into the design of POM-based flexible materials with superionic conductivity.

关键词： polyoxometalates proton conduction dual-acid effect hydrogel molecular dynamics simulation