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Tunable Cis-cisoid Helical Conformation of Poly(3,5-disubstibuted phenylacetylene)s Stabilized by Interaction

Chinese Journal of Polymer Science 2020年第7期38卷 685-695,I0005页

作者： Sheng wang Si-Liang Cai Jie Zhang xin-hua wan Beijing National Laboratory for Molecular Sciences Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

A series of novel cis poly(phenylacetylene)s(PPAs)substituted at meta-position(s)by two alkoxycarbonyl pendants,Le.,sP-Me-C8/rP-Me-C8,P-Me-C12,sP-Et-C4,sP-2C4 and sP-Oct-C4,were synthesized under the catalysis of[Rh(nbd)Cl]2(nbd=norbornadiene).The dependence of elongation,screw sense,and stimuli response of helical polyene backbone on the structure of pendant,solvent,and temperature was systematically investigated in both solution and solid *** of n→π*interaction between vicinal carbonyl groups,sP-Me-C8/rP-Me-C8 could adopt contracted cis-cisoid helix in THF,toluene,CH2Cl2,and *** an intramolecular interaction was sensitive to the hydrogen bond donating ability of solvent and temperature,but insensitive to the dielectric constant and polarity of *** poly(3-methoxycarbonyl-5-alkoxycarbonylphenylacetylene),the longer the chiral alkyl chain was,the easier the stable cis-cisoid helix could be ***,when the methoxycarbonyl was changed to ethoxycarbonyl,sec-butyloxycarbonyl,and octyloxycarbonyl pendant groups,only cistransoid helix was obtained at room temperature due to the increased steric ***,lowering temperature was found to facilitate the stabilization of n→π*interactions,and reversible temperature-dependent stereomutations were achieved in sP-Me-C8 and sP-Et-C4depending on the solvent where they were *** results suggested that the long alkyl chain,small pendant size,and lower temperature favored the stabilization of intramolecular n→π*interactions and the formation of contracted,cis-cisoid helices for poly(3,5-diestersubstituted phenylacetylene)s.

关键词： Polyphenylacetylenes Cis-cisoid,Cis-transoid n→π*Interactions,Helical conformation

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A Luminescent Thermometer Based on Linearly Thermo-responsive Copolymer and Polyoxometalates

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Chinese Journal of Polymer Science 2019年第11期37卷 1113-1118页

作者： Jin-Long Zhang Jun-Yan Tan xin-hua wan Jie Zhang Beijing National Laboratory for Molecular Sciences Key Laboratory of Polymer Chemistry and Physics of Ministry of Education Center for Soft Matter Science and Engineering College of Chemistry and Molecular Engineering Peking University

A novel switchable luminescent thermometer based on thermo-responsive triblock copolymer poly(ethylene glycol)-bpoly(acrylamide-co-acrylonitrile-co-dimethylaminoethylmethacrylate)(PEO113-b-P(AAm264-co-AN112-co-DMA8)) and Eu-containing polyoxometalate (Eu-POM) was successfully *** copolymer synthesized by RAFT exhibited a linear response to temperature variations in aqueous media,which was quite different from the uncharged copolymer P(AAm-co-AN) having a specific upper critical solution temperature (UCST).Eu-POM was surrounded around thermo-responsive blocks through electrostatic interactions,and its luminescence could be finely tuned due to the sensitivity of copolymer to the temperature *** cold water,POMs were trapped in highly hydrophobic cores,exhibiting an intense *** the upraising of temperature,the emission intensity presented a gradual decrease and showed a linear correlation with *** the complex solution cooled down,the luminescence could also be perfectly *** temperature-luminescence correlation could be held for numerous trials,showing a potential application in thermometer.

关键词： Luminescent thermometer Block copolymer Polyoxometalate UCST

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Wave-shaped microfluidic chip assisted point-of-care testing for accurate and rapid diagnosis of infections

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Military Medical Research 2022年第5期9卷 553-564页

作者： Bin-Feng Yin xin-hua wan Ming-Zhu Yang Chang-Cheng Qian A.S.M.Muhtasim Fuad Sohan School of Mechanical Engineering Yangzhou UniversityYangzhou 225127JiangsuChina Department of Biochemistry Institute of Basic Medical SciencesChinese Academy of Medical Sciences(CAMS)and Peking Union Medical CollegeBeijing 100005China

Background:Early diagnosis and classification of infections increase the cure rate while decreasing complications,which is significant for severe infections,especially for war ***,traditional methods rely on laborious operations and bulky *** the other hand,point-of-care(POC)methods suffer from limited robustness and ***,it is of urgent demand to develop POC devices for rapid and accurate diagnosis of infections to fulfill on-site militarized ***:We developed a wave-shaped microfluidic chip(WMC)assisted multiplexed detection platform(WMC-MDP).WMC-MDP reduces detection time and improves repeatability through premixing of the samples and reaction of the *** further combined the detection platform with the streptavidin–biotin(SA-B)amplified system to enhance the sensitivity while using chemiluminescence(CL)intensity as signal *** realized simultaneous detection of C-reactive protein(CRP),procalcitonin(PCT),and interleukin-6(IL-6)on the detection platform and evaluated the sensitivity,linear range,selectivity,and ***,we finished detecting 15 samples from volunteers and compared the results with commercial ELISA ***:Detection of CRP,PCT,and IL-6 exhibited good linear relationships between CL intensities and concentrations in the range of 1.25–40μg/ml,0.4–12.8 ng/ml,and 50–1600 pg/ml,*** limit of detection of CRP,PCT,and IL-6 were 0.54μg/ml,0.11 ng/ml,and 16.25 pg/ml,***-MDP is capable of good adequate selectivity and *** whole detection procedure takes only 22 min that meets the requirements of a POC *** of 15 samples from volunteers were consistent with the results detected by commercial ELISA ***:WMC-MDP allows simultaneous,rapid,and sensitive detection of CRP,PCT,and IL-6 with satisfactory selectivity and repeatability,requiring minimal ***,WMC-MDP takes advantage of being a microfluidic device sh

关键词： Point-of-care testing(POCT) Infection markers Wave-shaped microfluidic chip Chemiluminescence Multiplex detection

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“沮丧”Lewis酸碱对(FLP)催化序列可控高分子合成:能否再次打开“潘多拉魔盒”

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高分子学报 2020年第6期51卷 569-572,I0002页

作者：宛新华北京分子科学国家研究中心高分子化学与物理教育部重点实验室北京大学化学与分子工程学院北京100871

序列可控高分子合成被称为高分子合成领域的"圣杯"和终极目标之一.由于其合成难度极大,被科学家比喻成无法再次被打开的"潘多拉魔盒".最近,吉林大学的张越涛课题组利用"沮丧"Lewis酸碱对(FLP)活性聚合体系在序列可控高分子合成方面取得... 详细信息

序列可控高分子合成被称为高分子合成领域的"圣杯"和终极目标之一.由于其合成难度极大,被科学家比喻成无法再次被打开的"潘多拉魔盒".最近,吉林大学的张越涛课题组利用"沮丧"Lewis酸碱对(FLP)活性聚合体系在序列可控高分子合成方面取得了突破.他们通过有机超强膦碱和含铝的Lewis酸组成的FLP体系,可以快速并且大量地将4种甲基丙烯酸酯类单体合成为一个53嵌段的聚合物,不仅把以前的记录足足提高了大约2.5倍,而且每一段的聚合度(dpn)高达50,也是以前的5倍.该合成方法条件温和,过程简单,无需额外补加催化剂或是引发剂,每一段聚合只需要添加相应单体就可以快速进行,53嵌段聚合物仅需30 min就可以合成得到.该FLP体系极具工业化应用前景,让科学家们看到了打开"潘多拉魔盒"的希望.

关键词：序列可控高分子 “沮丧”Lewis酸碱对活性聚合有机膦碱潘多拉魔盒

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高分子催化剂:值得挖掘的催化剂富矿

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高分子学报 2022年第8期53卷 873-875页

作者：宛新华北京分子科学国家研究中心高分子化学与物理教育部重点实验室北京大学化学与分子工程学院北京100871

高分子合成化学家通常采用“试错法”构筑聚合反应催化剂,即先确定一个能够催化单体聚合的母体结构,然后再逐步优化.尽管这一策略取得了巨大成功,但受困于规律性缺乏,优化过程耗时耗力.最近中国科学院长春应用化学研究所的王献红团队通... 详细信息

高分子合成化学家通常采用“试错法”构筑聚合反应催化剂,即先确定一个能够催化单体聚合的母体结构,然后再逐步优化.尽管这一策略取得了巨大成功,但受困于规律性缺乏,优化过程耗时耗力.最近中国科学院长春应用化学研究所的王献红团队通过可聚合卟啉铝与助催化剂的共聚合,将不同活性基团构建在一个高分子链中,成功用于二氧化碳与环氧化物的共聚反应,解决了单分子卟啉铝催化效率和选择性较低的问题.这种高分子催化剂设计策略可实现高分子内多重协同效应的调控,从而提高催化剂设计的“容错率”.得益于多种单体的适应性和高分子结构调控的高选择性,高分子催化剂有望成为高分子合成化学领域值得深入发掘的一个富矿,为高分子科学的知识宝库添砖加瓦.

关键词：高分子催化剂分子内协同效应卟啉铝二氧化碳二氧化碳共聚物

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A DSC STUDY OF PHOTOPOLYMERIZATION OF POLYESTERS CONTAINING CONJUGATED DIACETYLENES

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Chinese Journal of Polymer Science 2000年第4期18卷 351-356页

作者： Yao-wen Bai Xiao-fang Chen Dong Zhang xin-hua wan Qi-feng Zhou Department of Polymer Science and Engineering, College of Chemistry, Peking University, Beijing 100871, China Peking Univ Coll Chem Dept Polymer Sci & Engn Beijing 100871 Peoples R China

The photopolymerization of two kinds of prepolyesters containing conjugated diacetylene (PDA-6 and PDA-12) was investigated using DSC. By measuring the endothermic enthalpy of the prepolymers after different UV-irradiation times, the polymerizations were found to follow the first-order rate law which agreed with the results of other investigators using a different method. The endothermic enthalpy measurements of PDA-6 and PDA-12 before UV-irradiation precluded the possibility that the decrease of endothermic enthalpy was caused by thermal polymerization.

关键词： diacetylene-containing polyesters DSC enthalpy

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SYNTHESIS OF NOVEL LIQUID CRYSTALLINE POLY(METH)ACRYLATES CONTAINING SILOXANE SPACER AND TERPHENYLENE MESOGENIC UNIT

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Chinese Journal of Polymer Science 2000年第2期18卷 101-107页

作者： Zhi-qian Zang Yu-fei Luo Dong Zhang xin-hua wan Qi-feng Zhou Department of Polymer Science & Engineering, College of Chemistry, Peking University, Beijing 100871, China Peking Univ Coll Chem Dept Polymer Sci & Engn Beijing 100871 Peoples R China

Novel side-chain liquid-crystalline poly(meth)acrylates were synthesized using 1-(3-hydroxyl-propyl)-3-[(4 '-cyano-p-terphenyloxycarbonyl)alkyl]-1,1,3,3-tetramethyldisiloxane as the key intermediate. The polymers used a disiloxane moiety as decoupling spacer with cyano-p-terphenyl as mesogenic unit. The products were characterized by NMR, GPC, DSC and polarizing optical microscopy. All the polymers with cyano-p-terphenyl mesogens formed a stable mesophase. However, if the mesogenic unit is replaced by cyano-p-biphenyl, the liquid crystalline character will be lost. The results also showed that the decoupling is incomplete even if a complex and very flexible decoupling spacer is deliberately incorporated to obtain the highest possible decoupling effect.

关键词： liquid crystalline polymers polyacrylates 4 ''-cyano-p-terphenyl

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SYNTHESIS AND PROPERTIES OF LIQUID CRYSTAL POLYSILOXANES WITH MESOGENIC STILBENE SIDE GROUPS

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Chinese Journal of Polymer Science 2000年第2期18卷 95-99页

作者： Dong Zhang Yan-tao Zhu Da-hui Zhao xin-hua wan Qi-feng Zhou Department of Polymer Science & Engineering, College of Chemistry, Peking University, Beijing 100871, China Peking Univ Coll Chem Dept Polymer Sci & Engn Beijing 100871 Peoples R China

A variety of mesomorphic side-chain polysiloxanes were synthesized by using hydrosilylation reaction with dicyclopentadienylplatinum(II) (DPPC) as the catalyst. The mesogenic groups are derivatives of stilbene with cyano or nitro tail groups. The products were characterized by DSC, X-ray diffraction and polarizing optical microscopy (POM). All the polymers were found to have relatively low T-g and can form a smectic liquid crystal phase.

关键词： liquid crystal polymer polysiloxane

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Uncertain State of nature and Contract in the Principal-Agent Relationship

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Systems Science and Systems Engineering 1999年第3期9卷 351-355页

作者： XU xin\ \ QIU wan\|hua School of Management, Beijing University of Aeronautics & Astronautics, Beijing 100083 China

This paper points out that the principal and agent may have different prior probability to the uncertain state of the world, and the influence of the state to the agent′s effort cost should be considered in the analysis of a principal\|agent relationship. Taking this opinion into a simple principal\|agent model, we get some conclusion with new meaning.

关键词： principal\|agent the state of the world effort cost

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SYNTHESIS AND PROPERTIES OF A NEW AZOBENZENE SIDE-CHAIN POLYMER CONTAINING A TEMPO RADICAL

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Chinese Journal of Polymer Science 2002年第4期20卷 285-290页

作者： Yong Zhang Ze-da Xu xing-he Fan Xiao-fang Chen xin-hua wan Qi-feng Zhou Department of Polymer Science and Engineering College of Chemistry and Molecular Engineering Peking University, Beijing 100871, China Peking Univ Coll Chem & Mol Engn Dept Polymer Sci & Engn Beijing 100871 Peoples R China

To allow anisotropies of optical properties in a magnetic field, nitroxide radical is introduced into the ortho-position of the phenylene ring in the side chain. A new azobenzene side-chain polymer (TEMPO-PAZ) containing TEMPO radical was synthesized. The polymer has a good solubility in organic solvents. The ESR spectrum of the polymer indicated three absorption lines characteristic of TEMPO radical. The optical phase conjugated responses (I-4) of the polymer films were investigated by degenerate four-wave mixing (DFWM). The experimental results showed that optical phase conjugated response of the TEMPO-PAZ could be easily controlled by choosing the appropriate direction of magnetic field presumably due to the nitroxide radical in the TEMPO-PAZ molecular structure. For the polymer investigated here, the nitroxide radical was introduced to increase optical phase conjugated response intensity in a magnetic field, aiming originally at searching for a new photo-active organic magnetic multifunctional materials.

关键词： azobenzene nitroxide radical polymer photo-active organic magnetic materials optical phase conjugated responses

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