非离子型表面活性剂对聚硅氧烷阴离子型乳液的耐电解质稳定性的影响

本文研究了非离子型表面活性剂对聚硅氧烷阴离子型乳液的耐电解质稳定性的影响。十二烷基聚氧乙烯醚C_12H_25(OCH_2CH_2)_nOH(n=6.3,C_12E_6.3)能提高乳液的氯化镁临界凝聚浓度。乳液的表面化学性质和乳液粒子表面上表面活性剂的组成表明C_12E_6.3与十二烷基苯磺酸之间存在着协同作用,组成了混合界面膜。根据DLVO理论对C_12E_6.3提高乳液耐电解质凝聚稳定性进行了解释。     

固态单离子聚合物电解质的研究进展

综述了用于锂金属聚合物电池中固态单离子聚合物电解质的研究进展，从均聚、共聚、共混、杂原子链及单阴离子型聚合物电解质等方面对不同体系的组成与性质进行了概述，并对该类电解质的发展趋势进行了分析。     

外加盐对纤维素硫酸半酯钠盐溶液粘度的影响

纤维素硫酸半酯钠盐是一种阴离子型强聚电解质,共水溶液是典型的聚电解质溶液。本文以粘度法研究了多种外加盐对纤维素硫酸半酯钠盐溶液粘度的影响,考察了外加盐浓度、外加盐阳离子和阴离子与大分子形态结构的关系,对高价Al~(+3)离子的桥架效应也作了初步探讨。     

正负离子和表面活性剂对水解聚丙烯酰胺分子线团尺寸的影响及其作用机理

采用动态光散射(DLS)方法,研究了无机电解质正离子与负离子对部分水解聚丙烯酰胺(HPAM)分子线团尺寸的影响,也研究了阴离子型表面活性剂与非离子型表面活性剂对HPAM分子线团尺寸的影响.结果表明,无机电解质负离子对HPAM分子尺寸(分子流体力学直径(Dh))影响较小,而无机电解质正离子对Dh的影响较大,且影响程度随正离子浓度增大而减小.Ca2+、Mg2+、K+和Na+对Dh的作用强弱顺序为Mg2+>Ca2+>Na+>K+.当向聚合物溶液中加入阴离子型表面活性剂时,随表面活性剂浓度增大,Dh先减小,后增大,再减小.此外,由于强烈的静电斥力作用,阴离子型表面活性剂分子在聚合物分子表面吸附较弱,难形成"表面活性剂-聚合物"络合物,而非离子型表面活性剂会以类似于胶束聚集体的形式吸附在聚合物分子链上,形成"表面活性剂-聚合物"络合物,结果造成Dh随表面活性剂浓度增加而逐渐增大.     

偶氮聚电解质的聚集和纳米聚集体

研究了两种具有不同化学结构的阴离子型偶氮聚电解质在四氢呋喃 /水混合溶剂中的聚集行为 .利用紫外 可见光谱和透射电镜等研究了偶氮聚电解质的聚集过程以及相应聚集体的形貌以及介质pH对聚集的影响 .结果表明 ,在四氢呋喃 /水混合溶剂中 ,随着水含量的增加 ,偶氮生色团逐渐聚集 ,其紫外光谱上最大吸收峰位置逐渐蓝移 ,而强度逐渐下降 .在较高浓度条件下 ,形成的聚集体可以用透射电镜直接观察到 ,呈现直径为 80nm左右的球形超分子结构 .与相应的偶氮两亲性小分子相比 ,这两种偶氮聚电解质形成的聚集体具有更高的稳定性 .由于羧酸基团和偶氮生色团相互连接的方式不同 ,溶液pH对这两种聚集体具有完全相反的影响 .偶氮生色团的聚集会严重影响偶氮生色团反式至顺式的异构化效率 .     

硅氧烷乳液聚合过程中大颗粒形成机理的研究Ⅱ．聚硅氧烷乳液的耐酸碱稳定性

研究了阴离子型与阳离子型聚硅氧烷乳液的耐酸碱稳定性。发现阴离子型乳液对酸碱都相当稳定，在乳液制备过程中，酸性催化剂不会引起乳液颗粒的凝聚；而阳离子型乳液的耐酸碱稳定性较差，尤其是引起乳液颗粒慢速凝聚的碱浓度下限值很低，碱是制备阳离子型乳液的催化剂，碱引起乳液颗粒的慢速凝聚是阳离子型乳液中大颗粒形成的主要原因。在乳液聚合过程中所发生的相当部分的乳化剂从水相向有机硅相的转移也是影响阳离子型乳液稳定性的一个重要因素。     

硅氧烷乳液聚合过程中大颗粒形成机理的研究：Ⅱ.聚硅氧烷乳液的耐酸碱…

研究了阴离子型与阳离子型聚硅氧烷乳液的耐酸碱稳定性，发现阴离子型乳液对酸碱都相当稳定，在乳液制备过程中，酸性催化剂不会引起乳液颗粒的凝聚；而阳离子型乳液的耐酸三稳定性性差，尤其是引起乳液颗粒慢速凝聚的碱浓度下限值很低，碱是制备阳离子型乳液的化剂，碱引起乳液颗粒的慢速凝聚是阳离子型乳液中大颗粒形成的主要原因，在乳液聚合过程中所发生的相当部分的乳化剂从水相向有机硅相的转移也是影响阳离子型乳液稳定性的一     

锂离子电池凝胶聚合物电解质改性的研究现状

从目前凝胶聚合物电解质的研究现状及问题出发,重点介绍了两种改性凝胶聚合物电解质的方法。无机纳米粒子复合凝胶聚合物电解质能够降低结晶型聚合物的结晶度,提高其离子电导率,改善其力学性能和稳定性;多孔凝胶聚合物电解质能够实现在较宽的温度范围内能保持较高的离子电导率和较好的机械强度及尺寸稳定性。最后,对凝胶聚合物电解质的改性研究方向作出了展望。     

卤化物固态电解质研究进展

全固态电池因其高能量密度和高安全性而成为具有发展前景的下一代储能技术。开发具有高室温离子电导率、优异化学/电化学稳定性、良好正/负极兼容性的固态电解质是实现全固态电池实用化的关键。卤化物固态电解质因其优异的电化学窗口、高正极稳定性、可接受的室温锂离子电导率等优势,受到了广泛的关注。本文通过对近年来卤化物电解质的相关研究进行总结,综述了该类电解质的组成、结构、离子传导路径及制备方法,并分析了金属卤化物电解质的电导率、稳定性特点,归纳了近年来该电解质在全固态电池中具有代表性的应用,并基于以上总结和分析,指出了卤化物固态电解质的研究难点及发展方向。     

AM/DMC/C11AM疏水缔合聚两性电解质的合成、表征与溶液性质

通过Ritter反应合成弱阴离子型疏水单体丙烯酰胺基十一烷基酸(C11AM). 以丙烯酰胺(AM)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)和丙烯酰胺基十一烷基酸(C11AM)为原料, 在水介质中合成新型疏水缔合聚两性电解质AM/DMC/C11AM. 利用1H NMR确证了疏水单体和共聚产物的分子结构. 流变性和芘荧光探针的研究结果表明, AM/DMC/C11AM系列疏水缔合聚两性电解质由于兼具疏水缔合性质和反聚电解质效应, 使其具有较好的耐盐性能.     

The effect of polyoxyethylene glycol monoethers ofn-hexadecanol on the stability of a polystyrene latex dispersion

The influence of nonionic surface active agents, a series of polyoxyethylene glycol monoethers ofn-hexadecanol, on the stability of dispersions of 2m diameter polystyrene latices has been investigated.Adsorption and microelectrophoretic studies showed the presence of looped monolayers of surface active agent at plateau adsorption.Examination of sedimentation volumes and redispersibility, correlated with potential energy calculations, showed that the stability of the dispersions depended on the characteristics of the adsorbed layer and on added electrolyte.     

Cationic latex formation by ionic modification

Stable cationic latices were prepared by charge inversion of anionic styrene-acrylic copolymer latices upon binding Al3+ and Fe3+ ions. This is achieved by stabilizing the latices with a high-HLB (hydrophile-lypophile balance) nonionic surfactant that imparts strong steric stability to the latex, even in the presence of high concentrations of multivalent counterions while these are bound to the latex anionic sites. The cationic latices thus prepared have good stability properties, and the same procedure should be applicable to essentially any latex-carrying anionic sites. Analytical ESI-TEM images show that particle-bound iron is concentrated at the particle borders, but it is also found in the particle bulk.     

Reactive surfactants in heterophase polymerization for high performance polymers

 A variety of nonionic reactive surfactants have been prepared from block copolymer precursors. These precursors are formed from a commercially available polyoxyethylene glycol monomethylether as the hydrophilic sequence of the surfactant; this product is used as initiator of ring opening anionic polymerization of butylene oxide. Finally the reactive surfactants are obtained after proper functionalization of the precursor. The reactive surfactants are an inisurf with an asymmetric azo compound, a transurf with a thiol group, and a few surfmers with acrylic, methacrylic, styrenic and α-methyl styrenic reactive groups. These compounds have been engaged in styrene emulsion or dispersion polymerization. Several of them have been found to be useful for preparing stable latices. Received: 22 July 1997 Accepted: 11 December 1997     

QSPR方法预测阴离子表面活性剂亲水亲油平衡值

首次使用量子化学描述符, 建立了两种阴离子表面活性剂亲水亲油平衡(HLB)值的定量结构性质关系模型(QSPR). 最佳模型1包括四类不同结构的烷基硫酸盐和烷基磺酸盐46种阴离子表面活性剂, 复相关系数R²＝1.000. 又建立了包含聚氧乙烯、乙酸、丙酸和碳氟等特殊类型不同结构的73种阴离子表面活性剂的最佳模型2, 复相关系数 R²＝0.993.     

硅氧烷乳液聚合过程中大颗粒形成机理研究Ⅰ．阳离子型乳液的耐电解质稳定性

探讨了二甲基聚硅氧烷阳离子型乳液耐电解质稳定性的影响因素。结果表明,加入少量的非离子型表面活性剂与阳离子型乳化剂并用进行乳液聚合,可以保护乳液粒子,防止由于电解质引起的乳液粒子的相互凝聚而形成大颗粒。     

Cross-linking copolymers of acrylates’ gel electrolytes with high conductivity for lithium-ion batteries

The cross-linking gel copolymer electrolytes containing alkyl acrylates, triethylene glycol dimethacrylate, and liquid electrolyte were prepared by in situ thermal polymerization. The gel polymer electrolytes containing 15 wt% polymer content and 85 wt% liquid electrolyte content with sufficient mechanical strength showed the high ionic conductivity around 5?×?10^?3 Scm^?1 at room temperature. The gel electrolytes containing different polymer matrices were prepared, and their physical observation and conductivity were discussed carefully. The cross-linking copolymer gel electrolytes of alkyl acrylates with other monomers were designed and synthesized. The results showed that copolymerization can improve the mechanical properties and ionic conductivities of the gel electrolytes. The polymer matrices of gels had excellent thermal stability and electrochemical stability. The scanning electron microscope analysis showed the gel electrolyte was the homogeneous structure, and the cross-linking polymer host was the porous three-dimensional network structure, which demonstrated the high conductivity of the gel electrolytes. The gel polymer Li-ion battery was prepared by this in situ thermal polymerization. The cell exhibited high charge-discharge efficiency at 0.1 C. The results of LiFePO4-PEA-Li cell and graphite-PEA-Li cell showed that gel polymer electrolytes have good compatibility with the battery electrodes materials.     

Nonionic latices in aqueous media

Nonionic latices in aqueous media prepared using methoxy polyethylene glycol methacrylate as a comonomer/stabiliser and ascorbic acid/hydrogen peroxide as the initiator have been examined for stability in the presence of the 21 electrolyte, barium chloride. These latices were found to be stable up to the concentrations of barium chloride examined, 0.75 mol dm^–3. Charge stabilised latices, on the other hand, were coagulated in 2.1×10^–2 mol dm^–3 barium chloride. The high stability of the nonionic latices was attributed to the grafting, during polymerisation, of methoxy polyethylene glycol chains to the surface of the core particle of polystyrene. The nonionic latices on concentration to high volume fraction gave highly ordered packing of the particles even in the presence of 0.1 mol dm^–3 sodium chloride.     

Nonionic latices in aqueous media part 1. Preparation and characterization of polystyrene latices

A series of non-ionic polystyrene latices in aqueous media containing particles with a narrow size distribution have been prepared using a nonyl phenol poly(ehylene glycol) condensate as the surfactant, methoxy poly(ethylene glycol methacrylate) as the comonomer/stabilizer, and ascorbic acid/hydrogen peroxide as the initiator system. As a control synthesis for comparison with the above latex, a charge stabilized polystyrene latex was prepared, using an anionic surfactant and potassium persulphate as the initiator. Latices employing a combination of charge plus steric stabilization mechanisms were also prepared, in order to investigate the effect of the non-ionic surfactant and the comonomer/stabilizer. The particle size of the latices was measured by transmission electron microscopy, the surface charge density by conductimetric titration and the glass transition temperature of the polymer by differential scanning calorimetry. The latex prepared using non-ionic ingredients, showed no titratable charge and exhibited a profound lowering of the glass transition temperature, with respect to the charge stabilized latex. On the basis of these results, schematic models for the polymerization mechanism and the morphology of the latex particles are proposed.