Preparation and applications of novel fluoroalkyl end-capped oligomers/calcium carbonate nanocomposites
Preparation and applications of novel fluoroalkyl end-capped oligomers/calcium carbonate nanocomposites
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DOI：
10.1007/s00396-006-1566-8
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发表时间：
2007-01
影响因子：
2.4
通讯作者：
H. Sawada;Y. Shikauchi;Hiroshi Kakehi;Y. Katoh;M. Miura
中科院分区：
文献类型：
--
作者：
H. Sawada;Y. Shikauchi;Hiroshi Kakehi;Y. Katoh;M. Miura
氯化钙与碳酸钠在由氟烷基封端的丙烯酸、2-甲基丙烯酰氧基乙磺酸、二甲基丙烯酰胺和丙烯酰吗啉低聚物在水溶液中形成的各种自组装分子聚集体的存在下反应，以优异至中等的分离产率提供相应的氟化低聚物/碳酸钙复合物。由此获得的这些氟化碳酸钙复合材料显示出不仅在水中而且在包括氟化溶剂的传统有机介质中具有良好的溶解性。动态光散射测量（DLS），扫描电子显微镜（SEM）和透射电子显微镜（TEM）表明，这些氟化复合材料是纳米尺寸控制的颗粒，并在这些介质中分散良好。在类似的条件下，交联的含氟烷基封端的丙烯酸共聚低聚物也被应用于制备新的交联氟化碳酸钙纳米复合材料。与相应的氟烷基封端的低聚物纳米复合材料相比，发现所获得的交联氟化碳酸钙纳米复合材料在包括氟化溶剂的水性和有机介质中具有极高的溶解度。特别地，证实了这些氟化碳酸钙纳米复合材料适用于聚（甲基丙烯酸甲酯）（PMMA）膜表面上方的分散体。有趣的是，改性PMMA膜的横截面的场发射SEM（FE-SEM）图像显示，分散到这些PMMA膜中的碳酸钙颗粒可以在改性膜表面上方规则地排列。更有趣的是，交联的氟化低聚物聚集体能够为碳酸钙的结晶提供合适的主体部分。
Calcium chloride reacted with sodium carbonate in the presence of a variety of self-assembled molecular aggregates formed by fluoroalkyl end-capped acrylic acid, 2-methacryloyloxyethane sulfonic acid, dimethylacrylamide, and acryloylmorpholine oligomers in aqueous solutions to afford the corresponding fluorinated oligomers/calcium carbonate composites in excellent to moderate isolated yields. These fluorinated calcium carbonate composites thus obtained were shown to have a good dispersibility not only in water but also in traditional organic media including fluorinated solvents. Dynamic light scattering measurements (DLS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that these fluorinated composites are nanometer-size-controlled particles and well dispersed in these media. Cross-linked fluoroalkyl end-capped acrylic acid co-oligomer containing poly(oxyethylene) units was also applied to the preparation of new cross-linked fluorinated calcium carbonate nanocomposites under similar conditions. The obtained cross-linked fluorinated calcium carbonate nanocomposites were found to have an extremely higher dispersibility in aqueous and organic media including fluorinated solvents, compared to that of the corresponding fluoroalkyl end-capped oligomer nanocomposites. In particular, it was verified that these fluorinated calcium carbonate nanocomposites are applicable to the dispersion above poly(methyl methacrylate) (PMMA) film surface. Interestingly, field-emission SEM (FE-SEM) images of the cross-section of the modified PMMA films showed that calcium carbonate particles dispersed into these PMMA films could be arranged regularly above the modified film surface. More interestingly, cross-linked fluorinated oligomeric aggregates were able to provide suitable host moieties for the crystallization of calcium carbonate.