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Manipulating the Phase Transition Behavior of Dual Temperature-Responsive Block Copolymers by Adjusting Composition and Sequence

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Chinese Journal of Polymer Science 2024年第2期42卷 176-187,I0006页

作者： Zhi Zou Xiang Xu Hai-Tao Zhao Jian-Nan Cheng Wei-Wei He li-fen zhang Zhen-Ping Cheng Suzhou key Laboratory of Macromolecular Design and Precision Synthesis Jiangsu Key Laboratory of Advanced Functional Polymer Design and ApplicationState and Local Joint Engineering Laboratory for Novel Functional Polymeric MaterialsCollege of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhou215123China State Key Laboratory of Radiation Medicine and Protection School for Radiological and Interdisciplinary Sciences(RAD-X)and Collaborative Innovation Center of Radiation Medicine of JiangsuSoochow UniversitySuzhou215123China

Temperature-responsive polymers have garnered significant attention due to their ability to respond to external *** this work,dual temperature-responsive block copolymers are synthesized via reversible addition-fragmentation chain transfer polymerization(RAFT)polymerization utilizing zwitterionic monomer methacryloyl ethyl sulfobetaine(SBMA) and N-isopropyl acrylamide(NIPAAm) as *** thermal responsive behaviors can be easily modulated by incorporating additional hydrophobic monomer benzyl acrylate(BN) or hydrophilic monomer acrylic acid(AA),adjusting concentration or pH,or varying the degree of polymerization of the block chain *** cloud points of the copolymers are determined by UV-Vis spectrophotometry,and these copolymers exhibit both controlled upper and lower critical solu bility temperatures(LCST and UCST) in aqueous *** study analyzes and summarizes the influencing factors of dual temperature responsive block copolymers by exploring the effects of various conditions on the phase transition temperature of temperature-sensitive polymers to explore the relationship between their properties and environment and structure to make them more selective in terms of temperature application range and regulation *** is very interesting that the introduction of poly-acrylic acid(PAA) segments in the middle of di-block copolymer PSBMA_(55)-b-PNIPAAm_(80) to form PSBMA_(55)-b-PAA_(x)-b-PNIPAAm_(80) results in a reversal of temperature-responsive behaviors from 'U'(LCST UCST) type,while the copolymer PSBMA_(55)-b-P(NIPAAm_(80)-co-AA_(x)) *** work provides a clue for tuning the phase transition behavior of polymers for manufacture of extreme smart materials.

关键词： Temperature responsive polymers High critical solubility temperature(UCST) Low critical solubility temperature(LCST) Block copolymers

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Iron-mediated AGET ATRP of Styrene and Methyl Methacrylate Using Ascorbic Acid Sodium Salt as Reducing Agent

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Chinese Journal of Polymer Science 2014年第8期32卷 1010-1018页

作者： Jin-long Pan Zhen li li-fen zhang 程振平朱秀林 Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application Department of Polymer Science and Engineering College of Chemistry Chemical Engineering and Materials Science Soochow University

Atom transfer radical polymerization of styrene （St） and methyl methacrylate （MMA） in bulk and in different solvents using activators generated by electron transfer （AGET ATRP） were investigated in the presence of a limited amount of air using FeC13-6H2O as the catalyst, ascorbic acid sodium salt （AsAc-Na） as the reducing agent, and a cheap and commercially available tetrabutylammonium bromide （TBABr） as the ligand. It was found that polymerization in THF resulted in shorter induction period than that in bulk and in toluene for AGET ATRP of St, while referring to AGET ATRP of MMA, polymerization in THF showed three advantages compared with that in bulk and toluene：1） shortening the induction period, 2） enhancing the polymerization rate and 3） having better controllability. The living features of the obtained polymers were verified by chain end analysis and chain-extension experiments.

关键词： Atom transfer radical polymerization (ATRP) AGET ATRP Iron catalyst Kinetics (polym.).

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Synthesis of a New β-Mercaptoalcohol

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Chinese Chemical Letters 2001年第7期12卷 569-570页

作者： Jian feng GE li fen zhang Zong Xuan SHEN Ya Wen zhang Department of Chemistry and Chemical Engineering Suzhou UniversitySuzhou 215006 Department of Material and Engineering Suzhou UniversitySuzhou 215006

In this letter, (R)-1,1-diphenyl-2-mercapto-3-methyl-1-butanol was synthesized from L-valine and two synthetic routes have been tried.

关键词： R)-1 1-Diphenyl-2-mercapto-3-methyl-1-butanol asymmetric synthesis L-valine.

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Molar Mass Dispersity Control by Iodine-mediated Reversible-deactivation Radical Polymerization

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Chinese Journal of Polymer Science 2021年第9期39卷 1155-1160页

作者： Jin-Ying Wang Yuan-Yuan Ni Jian-Nan Cheng li-fen zhang Zhen-Ping Cheng State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials Suzhou Key Laboratory of Macromolecular Design and Precision SynthesisCollege of Chemistry Chemical Engineering and Materials Science Soochow University

Dispersity(?) of polymers has a great effect on the properties of polymeric materials, and therefore how to control ? is very important but still a huge challenge in polymer synthesis, especially for reversible-deactivation radical polymerization(RDRP) strategy. Herein, we successfully developed a novel strategy to adjust ? of polymers by visible light-controlled reversible complexation mediated living radical polymerization(RCMP) and combination of single-electron transfer-degenerative chain transfer living radical polymerization(SET-DTLRP) at room temperature. In RCMP system, 2-iodo-2-methylpropionitrile(CP-I) and ethyl 2-iodo-2-phenylacetate(EIPA) were used as alkyl iodide initiators, by using methyl methacrylate(MMA) as the model monomer and n-butylacrylate(BA) as the end-capping reagent to regulate ? of polymers. Subsequently, we successfully prepared the block copolymer PMMA-b-PBA with adjustable ? by reactivating the polymer end-chains via SET-DTLRP in the presence of copper wire, fully demonstrating that it is a promising strategy that can keep the "living" feature of polymers while regulating their molar mass dispersities easily.

关键词： Dispersity control Iodine-mediated reversible-deactivation radical polymerization (RDRP) Visible light-controlled polymerization Reversible complexation mediated living radical polymerization (RCMP) Single-electron transfer-degenerative chain transfer living radical polymerization (SET-DTLRP)

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Continuous Synthesis of Main-Chain-type Fluorinated Graft Copolymers via Successive Flow START Polymerization and Cu(0)-Mediated RDRP

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Chinese Journal of Polymer Science 2023年第8期41卷 1155-1161,I0004页

作者： Peng Wang Shuai-Jie Chen Jian-Nan Cheng Wei-Wei He li-fen zhang Zhen-Ping Cheng 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 ScienceSoochowUniversitySuzhou 215123China State Key Laboratory of Radiation Medicine and Protection School of Radiological and Interdisciplinary Sciences(RADX)Soochow UniversityCollaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education InstitutionsSuzhou 215123China

Fluorinated polymers are receiving more and more attention worldwide due to their unique chemical properties,and modified fluorinated polymers with different topologies are persued for enriching and enhancing their performance in a variety of application *** this work,main-chain-type semifluorinated graft copolymers are produced steadily in continuous tube reactors via photocontrolled step transferaddition and radical-termination(START)polymerization and Cu(0)-mediated reversible deactivation radical polymerization(Cu(0)-RDRP)at room temperature for the first ***,semifluorinated alternating copolymer(AB)n B is prepared by START polymerization of 1,6-diiodoperfluorohexane(A)and 1,7-octadiene(B)in the first quartz pipeline under irradiation with purple LED light at 20℃.The(AB)nB with periodic C―I bonds is then flowed into the second copper pipeline directly and acts as the macroinitiators for Cu(0)-RDRP of methyl acrylate(MA)to obtain corresponding graft copolymer(AB)n *** work provides a new strategy for continuous synthesis of fluorinated graft copolymer materials.

关键词： Fluoropolymers Photopolymerization Graft Polymer Cu(O)-mediated RDRP START polymerization

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Influences of the Three Gorges Project on seismic activities in the reservoir area

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Science Bulletin 2017年第15期62卷 1089-1098页

作者： Yun-Sheng Yao Qiu-liang Wang Wu-lin liao li-fen zhang Jun-Hua Chen Jing-Gang li li Yuan Yan-Nan Zhao Key Laboratory of Earthquake Geodesy Institute of Seismology China Earthquake Administration Wuhan 430071 China Hubei Earthquake Administration Wuhan 430071 China Wuhan Institute of Technology Wuhan 430071 China

Reservoir-induced earthquakes related with the construction of the Three Gorges Project have attracted great concerns of the public. Since the first water impoundment on May 25, 2003, a number of earthquakes have occurred during the water storage stages, in which the largest was the Badong M5.1 earthquake on December 16, 2013. In this paper, the relationships between seismic activities, b value, seismic parameters, and reservoir water level fluctuations are studied. In addition, based on the digital seismic waveform data obtained since 2000, the focal depth changes and focal mechanism characteristics before and after the water impoundment are studied as well. These provide us important information to understand the earthquake mechanisms. The results show that these earthquakes are typical reservoir-induced earthquakes, which are closely related to water infiltration, pore pressure, and water level *** majority of the micro and small earthquakes are caused by karst collapse, mine collapse, bank reformation, superficial unloading, and so on. The larger earthquakes are related to the fault structures to some extent. Due to the persistent effects of water impoundment on the seismic and geological environments around the reservoir and water infiltration into the rocks, the influences on the crustal deformation field, gravity field, seepage field, and fault medium-softening action may vary gradually from a higher strength to a weaker one. Therefore, it is possible that small earthquakes and few medium earthquakes(M≤5.5) will occur in the reservoir area in the future.

关键词： Three Gorges Project Earthquake monitoring network Reservoir-induced earthquake Seismic activity b value Focal mechanism

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ZIF-8 modified by isocyanate as a photocatalytic antibacterial agent

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Rare Metals 2024年第6期43卷 2708-2718页

作者： Yi-Ning zhang Zhen Pei Zi-Hao Wang Chong-En Wang fen-fen liang li-Qiao Wei College of Architecture Taiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Interface Science and Engineering in Advanced Materials of Taiyuan University of Technology Ministry of EducationTaiyuan 030024China Department of Materials Science and Engineering Shanxi Institute of TechnologyYangquan 045000China Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering Taiyuan 030000China

Zeolite imidazole skeleton(ZIF-8)is a promising option for self-cleaning of building exterior walls due to its large specific surface area,high antibacterial activity and low ***,it suffers from low antibacterial efficiency and yield under visible light *** address the issues,we developed the photocatalytic materials T-ZIF-8-TDI(thermally treated-ZIF-8-toluene 2,4-diisocyanate)by modifying ZIF-8 with thermal oxygen sensitization and chemical *** results show that the yield of T-ZIF-8-TDI photocatalytic antibacterial agent is increased to 11.5 times of that of T-ZIF-8,while maintaining the crystal structure of T-ZIF-8 and thermal stability up to 60℃.Furthermore,T-ZIF-8-TDI exhibits extended optical response range to the nearinfrared region,significantly narrowed band gap,improved photogenerated elec tron-hole separation efficiency,reduced recombination rate,and excellent photocatalytic *** the concentration of antibacterial agent is 600 mg·L^(-1),the antibacterial rate of Escherichia coli(***)reaches 99.99%irradiated by visible light for30 min,and when the concentration of antibacterial agent is 200 mg·L^(-1),the antibacterial rate of Staphylococcus aureus(***)reaches 99.99%irradiated by visible light for 25 *** also analyzed the reasons in detail from the aspects of bacterial species and antibacterial mechanism,and proposed the antibacterial mechanism of·O_(2)^(-)and h^(+)as the main active *** findings suggest that T-ZIF-8-TDI photocatalytic antibacterial agent has potential for use in self-cleaning of building exterior walls.

关键词： ZIF-8 Hot oxygen sensitization Modified by isocyanate Antimicrobial performance Photocatalytic antibacterial mechanism

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Evaluation and Projection of Extreme High Temperature Indices in Southwestern China Using NEX-GDDP-CMIP6

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Journal of Meteorological Research 2024年第1期38卷 88-107页

作者： fen zhang linxiao WEI Yonghua li Hongyu TANG Tianyu zhang Baogang YANG China Meteorological Administration Key Open Laboratory of Transforming Climate Resource to Economy Chongqing Climate CentreChongqing 401147

Based on the recently released NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP)Coupled Model Intercomparison Project Phase 6(CMIP6) dataset and the gridded observational daily dataset CN05.1, this study evaluates the performance of 26 CMIP6 models in simulating extreme high temperature(EHT) indices in southwestern China and estimates future changes in the EHT indices under the Shared Socioeconomic Pathways(SSPs) SSP1-2.6, SSP2-4.5, and SSP5-8.5 using 11 optimal CMIP6 models. Five EHT indices are employed:annual maximum value of daily maximum temperature(TXX), high temperature days(T35), warm days(TX90P),heat wave frequency(HWF), and heat wave days(HWD). The main results are as follows.(1) NEX-GDDP-CMIP6 is highly capable of simulating the spatial patterns of TXX and T35 in southwestern China but it presents a weaker ability to simulate the spatial patterns of TX90P, HWF, and HWD.(2) The simulated time series of T35, TX90P, HWF,and HWD in southwestern China exhibit consistent upward trends with the observations. The linear trends of increase in TX90P and HWD are much greater than those of increase in TXX, T35, and HWF.(3) The estimated increases in TXX and T35 in southwestern China are significantly greater in Chongqing and the adjacent areas of Sichuan than in the other regions. Spatial distributions of the increases in TX90P, HWF, and HWD generally show higher values in the west and lower values in the east.(4) In the three different scenarios, the projected future TXX,T35, TX90P, and HWD in southwestern China all display a continuous increase with time and radiative forcing levels, whereas HWF initially increases but then decreases under the SSP5-8.5 scenario. By the end of the 21st century, under the SSP5-8.5 scenario, TXX and T35 are projected to increase by 6.0℃ and 45.0 days, respectively. The duration of individual heat waves is also expected to increase.

关键词： NEX-GDDP-CMIP6 extreme high temperature(EHT) southwestern China evaluation projection

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High-efficiently doping nitrogen in kapok fiber-derived hard carbon used as anode materials for boosting rate performance of sodium-ion batteries

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Journal of Energy Chemistry 2024年第9期96卷 472-482页

作者： Tianyun zhang Tian zhang Fujuan Wang fen Ran School of Mechanical and Electronical Engineering Lanzhou University of TechnologyLanzhou 730050GansuChina State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals School of Materials Science and EngineeringLanzhou University of TechnologyLanzhou 730500GansuChina

The engineering of plant-based precursor for nitrogen doping has become one of the most promising strategies to enhance rate capability of hard carbon materials for sodium-ion batteries;however,the poor rate performance is mainly caused by lack of pyridine nitrogen,which often tends to escape because of high temperature in preparation process of hard *** this paper,a high-rate kapok fiber-derived hard carbon is fabricated by cross-linking carboxyl group in 2,6-pyridinedicarboxylic acid with the exposed hydroxyl group on alkalized kapok with assistance of zinc ***,a high nitrogen doping content of 4.24%is achieved,most of which are pyridine nitrogen;this is crucial for improving the defect sites and electronic conductivity of hard *** optimized carbon with feature of high nitrogen content,abundant functional groups,degree of disorder,and large layer spacing exhibits high capacity of 401.7 mAh g^(−1)at a current density of 0.05 A g^(−1),and more importantly,good rate performance,for example,even at the current density of 2 A g^(−1),a specific capacity of 159.5 mAh g^(−1)can be *** findings make plant-based hard carbon a promising candidate for commercial application of sodium-ion batteries,achieving high-rate performance with the enhanced pre-cross-linking interaction between plant precursors and dopants to optimize aromatization process by auxiliary pyrolysis.

关键词： Kapok fiber Hard carbon Electrode materials Rate performance Sodium-ion batteries

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Recent Progress in Improving Rate Performance of Cellulose-Derived Carbon Materials for Sodium-Ion Batteries

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Nano-Micro Letters 2024年第8期16卷 102-147页

作者： Fujuan Wang Tianyun zhang Tian zhang Tianqi He fen Ran State Key Laboratory of Advanced Processing and Recycling of Non‑Ferrous Metals Lanzhou University of TechnologyLanzhou 730050People’s Republic of China School of Materials Science and Engineering Lanzhou University of TechnologyLanzhou 730050People’s Republic of China School of Mechanical and Electronical Engineering Lanzhou University of TechnologyLanzhou 730050People’s Republic of China

Cellulose-derived carbon is regarded as one of the most promising candidates for high-performance anode materials in sodium-ion batteries;however,its poor rate performance at higher current density remains a challenge to achieve high power density sodium-ion *** present review comprehensively elucidates the structural characteristics of cellulose-based materials and cellulose-derived carbon materials,explores the limitations in enhancing rate performance arising from ion diffusion and electronic transfer at the level of cellulose-derived carbon materials,and proposes corresponding strategies to improve rate performance targeted at various precursors of cellulose-based *** review also presents an update on recent progress in cellulose-based materials and cellulose-derived carbon materials,with particular focuses on their molecular,crystalline,and aggregation ***,the relationship between storage sodium and rate performance the carbon materials is elucidated through theoretical calculations and characterization ***,future perspectives regarding challenges and opportunities in the research field of cellulose-derived carbon anodes are briefly highlighted.

关键词： Cellulose Hard carbon Anode materials Rate performance Sodium-ion batteries

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