Self Organization into Bilayer of Fluorocarbon Amphiphiles in Aromatic and Aliphatic Solvent

在这个项目中，我们将自组织双层形成的概念从水体系扩展到非水体系，并建立了组成两亲分子的分子设计。含有两条氟碳链作为疏溶剂单元和柔性油链作为亲溶剂单元的新型两亲性化合物在碳氢化合物分子膜中具有与在水介质中相似的自组装行为。电子显微镜显示了它们不同的形态。这些两亲分子通常含有促进分子间吸引的酰胺连接体。红外光谱表明，在氯环己烷中，酰胺键移动到一个较短的波数，在那里形成了双层。在差示扫描量热法(DSC)测定的相变温度以上，这种转变消失了。红外光谱数据还表明，氟碳链在15ﾟC时呈螺旋构象，在40ﾟC时呈锯齿形构象，这种构象变化与双分子层的形成有关。在空气-氯环己烷界面处观察到单分子膜的形成。分子截面与氟碳链的截面一致，表明存在一个缩合的单分子膜。表面吸附的热力学变化与DSC测定的分散双分子膜的热力学变化一致。因此，分散双分子膜的相变必须发生在单体分散体和双分子膜之间，而不是双水分子膜。总之，非水双分子膜的分子设计需要基于长的碳氟链、有效的分子间相互作用，如氢键和偶极吸引，以及增强的亲溶剂性。

In this project, we extended the concept of self-organizing bilayer formation from aqueous systems to non-aqueous systems, and established the molecular design of the component amphiphile. Novel amphiphilic compounds which contain two fluorocarbon chains as solvophobic unit and flexible oleyl chain as solvophilic unit underwent self-organization in hydrocarbon meflia to bilayer assemblies similar to those in aqueous media. Electron microscopy displayed their varied morphologies. These amphiphiles commonly contained the amide connector that promoted intermolecular attraction. Infrared spectroscopy showed that the amide bond shifted to a shorter wavenumbers in chlorocyclohexane in which the bilayer was formed. This shift was lost above the phase transition temperature as determined by differentialscanning calorimetry (DSC). The IR data also showed that the fluorocarbon chain assumed a helical conformation at 15ﾟC and a zig-zag conformation at 40ﾟC. This conformational change was associated with the bilayer formation. The monolayer formation was observed at the air-chlorocyplohexane interface. The molecular cross-section agreed with that of the fluorocarbon chain, indicating the presence of a condensed monolayer. The thermodynamic changes of the surface adsorption agreed with those obtained for the dispersed bilayer by DSC. Therefore, the phase transition of the dispersed bilayer must occur between the monomeric dispersion and the bilayer, unlike those of aqueous bilayers. In conclusion, molecular design of non-aqueous bilayers needs to be based on long fluorocarbon chains, effective intermolecular interactions such as hydrogen bonding and dipolar attraction, and enhanced solvophilicity.