Li Hongbo, Liu Qingtao, Qin Lidong, Xu Miao, Lin Xiankun, Yin Shengyan, Wu Lixin, Su Zhongmin, Shen Jiacong
Key Laboratory for Supramolecular Structure and Materials of Ministry of Education, Jilin University, Changchun 130012, People's Republic of China.
J Colloid Interface Sci. 2005 Sep 15;289(2):488-97. doi: 10.1016/j.jcis.2005.03.052.
This paper examines the influences of solvent evaporation and atmosphere humidity on self-assembling structures and thin-film microscopic morphologies of amphiphilic rod-coil block oligomers (EOnOPV) containing conjugated oligo(phenylene vinylene) dimer (OPV) coupled to poly(ethylene oxide) (PEO; n, the average number of ethylene oxides, is 16, 12, 7, and 3, respectively) on hydrophilic substrates. Atomic force microscopy (AFM), UV-vis absorption, and small angle X-ray diffraction are employed to investigate the thin-film morphology and structure. Solvent evaporation and atmosphere humidity are found to exert a strong influence on thin-film morphology and structure. Under the condition of quick evaporation and dry atmosphere, all EOnOPV oligomers form the monolayer islands. Increasing the solute volume, both EO16OPV and EO12OPV oligomers can form the polar lamellas with a head-to-tail packing arrangement. Under the condition of slow evaporation and humid atmosphere, EO16OPV and EO12OPV may self-assembly into curvy nanoribbons with well-defined width and curvature radii on mica, while EO7OPV and EO3OPV with the shorter PEO coils do not form. A symmetric bilayer structure for the ribbons is proposed. Plausible reasons for the variation in thin-film morphology are discussed, based on the results obtained from investigation of PEO coil length, solvent evaporation, and atmosphere humidity effects.
本文研究了溶剂蒸发和大气湿度对两亲性棒-线圈嵌段低聚物（EOnOPV）在亲水性基底上自组装结构和薄膜微观形态的影响，该低聚物包含与聚环氧乙烷（PEO；环氧乙烷的平均数量n分别为16、12、7和3）偶联的共轭寡聚（亚苯基亚乙烯基）二聚体（OPV）。采用原子力显微镜（AFM）、紫外-可见吸收光谱和小角X射线衍射来研究薄膜的形态和结构。发现溶剂蒸发和大气湿度对薄膜的形态和结构有强烈影响。在快速蒸发和干燥大气条件下，所有EOnOPV低聚物均形成单层岛状结构。增加溶质体积，EO16OPV和EO12OPV低聚物均可形成头对头排列的极性片层。在缓慢蒸发和潮湿大气条件下，EO16OPV和EO12OPV可能在云母上自组装成具有明确宽度和曲率半径的弯曲纳米带，而具有较短PEO线圈的EO7OPV和EO3OPV则不会形成。提出了纳米带的对称双层结构。基于对PEO线圈长度、溶剂蒸发和大气湿度影响的研究结果，讨论了薄膜形态变化的合理原因。
