最新刊期
      卷 ， 期 10 ， 2009

        Feature Articles

      • ZHANG Yiheng,WANG Zhiqiang,ZHANG Xi
        Issue 10, Pages: 973-979(2009) DOI: 10.3724/SP.J.1105.2009.00973
        摘要：Atomic force spectroscopy(AFM)based singlemolecule force spectroscopy(SMFS) can serve as an important tool for studying intramolecular and intermolecular interactions at single-molecule level.On the basis of our recent work,this feature article is aimed to introduce how to combine the delicate SMFS with elegant self-assembly for direct measurements of different intermolecular intera ctions,including π-π interaction,multivalency and intercalation interaction.To realize the force measurement of singlemolecule rupture,one of the interacting components needs to be covalently attached to AFM tip through a flexible polyethylene glycol(PEG) spacer,and the other component to the substrate surface.By the movement of piezo tube,the force-extension curve can be obtained.The introduction of PEG as a spacer provides a means for differentiating the force signal based on the extension length as well as for avoiding the disturbance of the non-specific interaction between the AFM tip and the substrate.In addition,with dynamic force spectroscopy,details about the kinetic of the unbinding and information concerning the length scale of the interaction can be extracted.Therefore,SMFS can investigate not only the intermolecular interactions directly,but also physical insight of the interactions,thus guiding molecular selfassem bly.  
          
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        发布时间：2021-03-19

        Reviews

      • WANG Lixiang,JING Xiabin,WANG Fosong
        Issue 10, Pages: 980-991(2009) DOI: 10.3724/SP.J.1105.2009.00980
        摘要：Developments in the studies of white electroluminescence from singlepolymer systems were reviewed according to single-polymer systems with simultaneous two-color or threecolor emission,because white-light emission requires the mixing of two complementary colors or three primary colors(red,green and blue colors).In these single-polymer WPLED systems,selection of highly efficient and suitable blue-,green-,and red-emitting components and their attachment ways to polymer backbones are important for stable and efficient white-light emission.Either singlet or triplet species can be choses as the multiple emission components in single-polymer WPLED systems.Based on the recent progress in single-polymer systems for white light-emitting diodes,the future of the research in this field is envisaged.  
          
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      • FANG Yong,MIAO Ruiying,WANG Tongtao,WANG Xindong,FANG Shibi
        Issue 10, Pages: 992-1006(2009) DOI: 10.3724/SP.J.1105.2009.00992
        摘要：The structure,properties and latest developments of varios kinds of polymer proton exchange membranes,such as membranes of perfluorinated sulfonic acid polymers,part-fluorinated sulfonic acid polymers,non-fluorinated sulfonic acid polymers and inorganic/organic nanohybrids etc. are reviewed.In the various DMFCs membranes,the nonfluorinated polymer membranes,including sulfonated poly(ether ether ketone),sulfonated polyimide,polybenzimidazole and sulfonated polyphosphazene membranes,seem to have a promising future for DMFCs.Finally,the problems and perspectives in these fields are also discussed.  
          
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        发布时间：2021-03-19

        Research Article

      • HOU Jiqiang,QIAO Lijun,WEI Jun,HU Yuxi,WANG Xianhong,ZHAO Xiaojiang,WANG Fosong
        Issue 10, Pages: 1007-1011(2009) DOI: 10.3724/SP.J.1105.2009.01007
        摘要：To explore the non-petroleum route for carbon dioxide copolymers,furfuryl glycidyl ether oxirane with 99.7% purity was prepared from furfuryl alcohol and epichlorohydrin employing sodium hydroxide and tert-butylammonium sulfate as catalysts,where furfuryl alcohol was a hydrogenation product of furfural from pentoserich agricultural residues like rice hulls,bagasse,corn cob, et al.,and epichlorohydrin could be produced from glycerine which was a byproduct in biodiesel production.Copolymerization of carbon dioxide and furfuryl glycidyl ether was carried out in a 500 mL autoclave with carbon dioxide pressure of 4 MPa at elevated temperatures,using Y(CCl3COO)3glycerine ZnEt2 coordination catalyst and 1,4-dioxane as solvent.Aliphatic polycarbonate with pendant furfuryl methyl ether was obtained with number average molecular weight as high as 13.0×104.The glass transition temperature (Tg) of the resultant copolymer was around -30℃,which was 65℃ lower than that of poly(propylene carbonate) (PPC),providing possibility for solving the brittleness of PPC,and the application window of PPC was therefore enlarged to lower temperature range.Compared with common PPC,this new polycarbonate showed significant improvement in thermal stability,the onset thermal degradation temperature (Td) of the copolymer was 231℃,approximately 60℃ higher than that of PPC.  
          
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        发布时间：2021-03-19
      • LI Deli,CHEN Wenping,FAN Xinghe,CHENG Yanhua,WAN Liying,ZHAO Xiaodong,XU Yiding,SHEN Zhihao,ZHU Meifang,ZHOU Qifeng
        Issue 10, Pages: 1012-1017(2009) DOI: 10.3724/SP.J.1105.2009.01012
        摘要：The shape memory effect of poly{2,5-bis［(4-butoxyphenyl)oxycarbonyl］-styrenes} (PBPCS),one of the classical mesogen jacketed liquid crystal polymers (MJLCPs),fiber was studied by dynamic mechanical analysis (DMA). According to the results,the outstanding shape recovery ability of PBPCS fiber was found.The reversion rate of PBPCS fiber was improved with the increase of temperature apparently when it was above Tg(106.7℃).Especially when temperature above 145℃,the rate of shape recovery was the best.The time of recovery from 400% draw ratio to origin length was about 9 min.The repeatability of shape memory was good in 5 repeated times.2-Dimensional wide angle X-ray diffraction(2D WAXD) experiments showed the diameter of helical cylindrical blocks changed from 2.5 nm to 2.4 nm after deformation.This result indicated that the helical main-chain of PBPCS was in a more straight conformation.So,there would be a certain inner stress in the molecular chain,namely the shape memory force(Fsm).It was about 1.6 MPa.There was no stable and memory phase structure of traditional shape memory polymers(SMP) in PBPCS because it was an amorphous polymer.The reason of PBPCS fiber with the shape memory effect is its special helical molecular chain structure just as a spring,say,the flexible polystyrene main chain makes PBPCS fiber present a good strain reversion ability,and the mesogenic effect of side chains makes the fiber keep its original dimension.  
          
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        发布时间：2021-03-19
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