荧光探针技术研究共溶剂对PEO-PPO-PEO嵌段共聚物溶液胶束的形成及内部结构的影响

选择了甲醇、乙醇、正丙醇、乙二醇、乙二胺、乙醇胺及２甲氧基乙醇等七种包括单官能团和双官能团共溶剂、与水组成混合溶剂,并利用荧光探针技术研究了共溶剂对环氧乙烷环氧丙烷环氧乙烷（ＰＥＯＰＰＯＰＥＯ）共聚物水溶液胶束形成及其结构的影响,结果表明,一些共溶剂与水和共聚物ＰＰＯ段都具有较好的混溶性,使形成胶束的ＣＭＴ升高,而其它共溶剂的引入则使得形成胶束的ＣＭＴ降低．从共溶剂对所形成胶束的微结构影响看,能与共聚物链有较强作用的双官能团的共溶剂和有较小分子尺寸的共溶剂有利于使形成的胶束具有较紧密的结构,在此条件下,形成胶束的紧密程度决定了胶束内微极性的大小,而与引入共溶剂的极性大小关系不大．     

荧光探针技术研究共溶剂对PEO—PPO—PEO嵌段共聚物溶液胶束的形成及内 …

选择了甲醇、乙醇,正丙醇,乙二醇、乙二胺、乙醇胺及２－甲氧基乙醇等七种包括单官能团和双官能团共溶剂、与水组成混合溶剂,并利用荧光探针技术研究了共溶剂对环氧乙烷 －环氧丙烷－环氧乙烷共聚物水溶液胶束形成及其结构的影响。     

长软链段对苯二甲酸乙二酯—环氧乙烷多嵌段共聚物的组成…

合成了不同软锻段长度和不同链段含量的系列对苯二甲酸乙二酯－环氧乙烷（ＰＥＴ－ＰＥＯ）多嵌段共聚物，用ＮＭＲ质子谱测定了硬链段一，对部分溶于氯仿的ＰＥＴ－ＰＥＯ多嵌段共聚物进行了分离，并分别测定基氯仿可溶物和不溶物的硬边段一、熔融热谱和热结晶谱，揭示了ＰＥＴ－ＰＥＯ多嵌段共聚物的组成不均一性及其对软段长度和硬链段一的信赖性，进而用ＤＳＣ热谱证明了软链段和硬链段的结晶能力与ＰＥＴ－ＰＥＯ多嵌段共聚物组     

温度对Pluronic嵌段共聚物胶束结构的影响

温度对Ｐｌｕｒｏｎｉｃ嵌段共聚物Ｆ１０８、Ｆ６８、Ｐ９４和Ｌ６４胶束结构影响的研究结果表明,随着温度上升,胶束外壳ＰＥＯ链的水化度急剧减小,胶束趋于形成聚集更为密实、尺寸较均匀的球形结构。在较高温度时,胶束内核基本上以ＰＰＯ链为主构成。     

聚碳酸亚丙亚乙酯的合成和生物降解

由ＣＯ２和环氧丙烷的催化共聚制备了聚碳酸亚雨酯（ＰＰＣ），向ＰＰＣ引入环氧乙烷结构单元得到聚碳酸亚西亚乙酯（ＰＰＥＣ），用１ＨＮＭＲ等进行了结构表征，并用土埋法进行了生物降解性能的测定，结果表明ＰＰＣ仅在分子量很低时才具备显著的生物降解性能；而ＰＰＥＣ的生物降解速度高于分子量相近的ＰＰＣ．此外，土埋三月后共聚物的组成和分子量都保持基本不变，表明实验条件下生物降解主要在聚合物的表面进行．     

聚环氧乙烷/LixMoO3纳米复合材料的制备及表征

介绍了聚环氧乙烷（ＰＥＯ）／ＬｉｍＭｏＯ３纳米复合材料的制备过程。结果表明,ＰＥＯ大分子插入到ＬｉｘＭｏＯ３片层间,使层间距增大了０．７３ｎｍ。ＰＥＯ在ＬｉｘＭｏＯ３层间呈ＰＥＯ－ＨｇＣｌⅠ型构象,其运动能力受到限制。     

含有机硅三元多嵌段共聚物的研究5.含有机硅三元多嵌段共聚物的形态结构

利用ＤＭＡ，ＴＥＭ和ＳＡＸＳ对ＰＳＦ－ＰＤＭＳ－ＰＨＳｎ，ＰＳＦ－ＰＤＭＳ－ＰＨＥｎ，ＰＰＯ－ＰＤＭＳ－ＰＨＳｎ和ＰＨＳ－ＰＤＭＳ－ＰＢＥｎ四种三元多嵌段共聚物的形态结构进行了研究，结果表明，不同三元多嵌段共聚物中三种链段的相互作用情况不同，其动态力学性能和形态结构有很大差异，并与嵌段共聚物微相分离的几种基本形态不同，特别是通过ＴＥＭ在ＰＳＦ－ＰＤＭＳ－ＰＨＳｎ和ＰＰＯ－ＰＤＭＳ－ＰＨＳｎ中观察到清晰的互容界面相。     

PP／LDPE共混体系的辐射效

研究了在多官能团单体－三烯丙基异氰脲酸酯存在下ＰＰ／ＬＤＰＥ共混体系接受γ－辐射的效果。用溶解度参数和ＴＥＭ技术评估了共 体系的相容性与多官能团单体在共混体系中的分布，并用ＳＥＭ、ＤＣＳ、动态力学等方法对共混体系相容性进行了表征。     

聚环氧乙烷为支链的两亲共聚物的表征及性能

用端基带有甲基丙烯酸酯的聚环氧乙烷大分子单体（ＰＥＯ—ＭＡ）分别与小分子单体苯乙烯（Ｓ）、甲基丙烯酸甲酯（ＭＭＡ）、丙烯酸甲酯（ＭＡ）溶液自由基共聚合得到了三种具有不同主链结构的以聚环氧乙烷（ＰＥＯ）为支链的两亲接枝嵌段共聚物（分别简写为：ＰＳ─ｇ─ＰＥＯ，ＰＭＭＡ─ｇ─ＰＥＯ，ＰＭＡ─ｇ─ＰＥＯ）．用ＧＰＣ、ＩＲ、１Ｈ─ＮＭＲ、ＷＡＸＤ和ＤＳＣ对其结构进行了表征．研究了接校共聚物的结晶性能、乳化性能以及在Ｗｉｌｌｉａｍｓｏｎ反应中相转移催化作用．结果表明，不同主链结构有不同的结晶度，并随支链ＰＥＯ含量的增加，分子量的增大而提高；其乳化体积和相转移催化反应的转化率均随着共聚物浓度的增加、支链ＰＥＯ含量的增人而增大，随支链ＰＥＯ分子量的提高而减小．     

CYCLOPROPANATION OF ENAMINE AND ETHYL DIAZOACETATE CATALYZED BY COPPER COMPLEX

ＣＹＣＬＯＰＲＯＰＡＮＡＴＩＯＮＯＦＥＮＡＭＩＮＥＡＮＤＥＴＨＹＬＤＩＡＺＯＡＣＥＴＡＴＥＣＡＴＡＬＹＺＥＤＢＹＣＯＰＰＥＲＣＯＭＰＬＥＸ￥ＭＩｎＷＡＮＧ，ＭｉｎｇＡｎＷＡＮＧ，ＢｉｎｇＦａｎｇＨＵ（ＤｅｐａｒｔｍｅｎｔｏｆＡｐｐｌｉｅｄＣｈａｍｉｓ...     

两亲嵌段共聚物溶液内胶束形成的温度效应

合成了一系列具有两亲嵌段结构的聚（乙二醇）（PEO）一聚（丙二醇）（PPO）共聚物．利用荧光探针及示差量热法测定了共聚物水溶液的临界胶束形成温度（CMT）值．发现二嵌段共聚物（PEO－PPO）和三嵌段共聚物（PEO－PPO－PEO）有着类似的变化规律，即随共聚物分子中疏水链（PPO）长度的增大，其CMT值降低．但三嵌段共聚（PPO－PEO－PPO）则因疏水链段处于共聚物分子的两端，因而在溶液中有可能形成立体网状交联结构．此外，利用探针分子在不同极性溶剂中荧光峰值波长发生位移的现象可以对形成胶束内核的组织程度、极性大小进行估测．     

荧光探针法研究新型Gemini表面活性剂在水溶液中的聚集行为

以芘为荧光探针、二苯酮为猝灭剂,用稳态荧光探针法测定了新型Gemini表面活性剂的临界胶团浓度(CMC)、胶团聚集数(N_agg)及胶团微极性.研究了Gemini表面活性剂结构和氯化钠浓度对CMC、N_agg、胶团微极性的影响.结果表明,新型Gemini表面活性剂的CMC比常规表面活性剂的CMC低1—2个数量级.当疏水基碳原子数增加时,CMC依次降低,N_agg增大,胶团微极性减小.当氯化钠浓度增大时,N_agg增大,胶团微极性减小.     

Unprecedented diverse nanostructures formed by amphiphilic graft copolymer bearing PEO side chains synthesized by ATNRC

A series of well‐defined amphiphilic graft copolymers bearing hydrophilic poly(ethylene oxide) (PEO) side chains with tunable grafting densities were synthesized by atom transfer nitroxide radical coupling (ATNRC) reaction using CuBr/PMDETA as catalytic system via the grafting‐onto strategy. PEO side chains were linked to α‐C of carbonyl of polyacrylate‐based backbone, not to the ester side groups as usual, so that every repeating unit of the backbone possessed a pendant steric bulky tert‐butyl group. The critical micelle concentrations of the obtained amphiphilic graft copolymers in aqueous media determined by fluorescence probe technique using pyrene as probe increased with the raising of molecular weights. These amphiphilic graft copolymers with novel chemical structure showed unprecedented diverse nanostructures visualized by transmission electron microscopy in aqueous media and micellar morphologies varied with the changing of experiment parameters. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Micellization phenomena of biodegradable amphiphilic triblock copolymers consisting of poly(beta-hydroxyalkanoic acid) and poly(ethylene oxide)

This paper reports the studies on micelle formation of new biodegradable amphiphilic poly(ethylene oxide)-poly[(R)-3-hydroxybutyrate]-poly(ethylene oxide) (PEO-PHB-PEO) triblock copolymer with various PHB and PEO block lengths in aqueous solution. Transmission electron microscopy showed that the micelles took an approximately spherical shape with the surrounding diffuse outer shell formed by hydrophilic PEO blocks. The size distribution of the micelles formed by one triblock copolymer was demonstrated by dynamic light scattering technique. The critical micellization phenomena of the copolymers were extensively studied using the pyrene fluorescence dye absorption technique, and the (0,0) band changes of pyrene excitation spectra were used as a probe for the studies. For the copolymers studied in this report, the critical micelle concentrations ranged from 1.3 x 10(-5) to 1.1 x 10(-3) g/mL. For the same PEO block length of 5000, the critical micelle concentrations decreased with an increase in PHB block length, and the change was more significant in the short PHB range. It was found that the micelle formation of the biodegradable amphiphilic triblock copolymers consisting of poly(beta-hydroxyalkanoic acid) and PEO was relatively temperature-insensitive, which is quite different from their counterparts consisting of poly(alpha-hydroxyalkanoic acid) and PEO.     

水溶液中的分子内扭转电荷转移──阴阳离子胶束中对二甲基氨基苯甲酸分子内扭转电荷转移的比较研究

在阳离子表面活性剂CTMAB水溶液中,对二甲氨基苯甲酸(DMABOA)的分子内扭转电荷转移(TICT)荧光带随着胶束的形成而显着蓝移,同时伴随着TICT荧光带与正常荧光带强度比I_a/I_b和总荧光强度I_f的增大;而阴离子表面活性剂SLS胶束的形成并未引起TICT荧光带位置和I_a/I_b的变化,仅使I_f提高(较在CTMAB胶束中的小).实验发现在胶束疏水核中的TICT行为与纯有机溶剂中不同,DMABOA与CTMAB胶束的疏水相互作用和静电作用是协同的。     

Effect of cosolvents on the binding interaction between poly(ethylene oxide) and sodium dodecyl sulfate

The micellization of sodium dodecyl sulfate (SDS) in different glycol-water solvent mixtures was studied using the isothermal titration calorimetric (ITC) technique. At the same time, microcalorimetric titrations were also carried out to monitor the binding interaction of SDS and poly(ethylene oxide) (PEO) in the presence of different cosolvents. The demicellization of SDS in mixtures of water and cosolvents is different from that in water due to the reduction in solvent polarity and charge interaction of surfactants. The critical micelle concentration (cmc) first decreases with the addition of a small amount of cosolvents and then increases at higher cosolvent concentrations. The thermodynamics of surfactant micellization can be analyzed using the solubility parameters of solvent mixtures. For the binding interaction between SDS and PEO in different solvent mixtures, the dehydration process at low SDS concentrations is replaced by the chain solubilization process with decreasing solvent polarity. With further reduction in the solvent polarity, the binding interaction between SDS and PEO becomes weak and no aggregates can be formed beyond a certain glycol concentration. The binding interaction between SDS and PEO in different solvent mixtures was analyzed and ascribed to the effects of PEO solubility and hydrophobicity of SDS.     

Electrospinning of Gelatin/PEO Blends: Influence of Process Parameters in the Nanofiber Properties

Summary: Results of electrospinning of gelatin/PEO blends from aqueous solutions are presented. The effects of applied electric field (15–25 kV), flow rate (0.25–0.75 mL/h) and gelatin concentration in the final fiber diameter were studied. It was observed that the resulting fiber system presented high polydispersity, where fiber diameters ranged from 150 nm to 1.3 µm. In some cases an adequate fibrous system were not obtained. It was observed that the average diameter decreased mainly when the flow rate and gelatin concentration decreased.     

环糊精诱导胶束形成的TICT荧光探针法研究

环糊精与表面活性剂的相互作用研究已有诸多报导，但主要涉及环糊精与表面活性剂的包络物的稳定常数和其中主客体的化学剂量比［１，２］，至于环糊精对表面活性剂胶束化性质的影响则少见涉猎，这或许与研究方法有关，分子内扭转电荷转移激发态涉及到一个完整的电荷转移，具有很高的极性，其荧光特性显示出显著的介质性质敏感性［３］，因此将ＴＩＣＴ荧光探针法用于环糊精－表面活性剂相互作用研究可能会提供一些新的信息，本文的结