【作者】 李红波；

【导师】 沈家骢； 吴立新；

【作者基本信息】 吉林大学 ， 高分子化学与物理， 2005， 博士

【摘要】 由刚性硬棒和柔性线嵌段共价连接而成的棒-线嵌段齐聚物可以形成多种多样的超分子结构。由于所形成微区的尺寸以及分子的取向排列可以在纳米尺度上得到有效的控制,因而,棒-线嵌段齐聚物已经成为理想的制备纳米结构的工具。本论文以构筑具有确定结构和形状的超分子建筑为出发点,以两亲性棒-线嵌段齐聚物为研究对象,开展了超分子界面自组织方面的研究。主要进行了以下几个方面的工作:1. 设计并合成了一系列两亲性的具有不同线长的齐聚苯撑乙烯-聚氧乙烯 棒-线嵌段齐聚物。2. 利用简单浇铸方法,通过控制溶质的量、溶剂的挥发速度以及空气湿度, 成功构筑了具有不同形状或结构的纳米自组织体,如纳米岛、单层、极 性的多层以及对称双层的线条结构等。并且,从能量的观点讨论了这些 纳米结构的形成机理。3. 研究了这些棒-线嵌段齐聚物在气-水界面上的单层行为,并且利用棒-线 嵌段齐聚物与简单脂肪酸的微相分离以及对两相混合比例的调控,实现 了对其中一个棒-线嵌段齐聚物所形成棒状聚集体的长度控制。我们阐述 了可控长度的棒状聚集体的可能形成机理和取向排列的自组织过程。同 时也讨论了共轭棒之间的相互作用,以及柔性线的长度对棒-线嵌段分子 在气-水界面上自组织行为和结构的影响。4. 利用液相的原位AFM,成功地观察了两亲性棒-线齐聚物在液-固界面上 的二维聚集形貌,并且研究了固体基底的表面性质、溶液浓度以及棒-线 嵌段分子结构对其在界面上吸附和聚集性质的影响更多还原

【Abstract】 Rod-coil block molecules are a well self-assembling system to constructsupramolecular structures. Through the phase separation of the rod block and thecoil block, rod-coil block molecules can self-assembly into various nanostructures,where the rod block can align and orient orderly. As a matter of fact, the functionsof self-assembling structures formed by rod-coil block molecules are, to a largeextend, dependent of the molecular alignment and orientation on solid substrates.Especially when organic conjugated groups are incorporated into the rod-coilblock molecules as the rod block, utilizing the ordered alignment and orientationof the organic conjugated groups, they will present some special properties in themicroelectronic field, such as the field-effect transistors, nanowires, polarizedlight-emitting diodes and so on. Recent studies have confirmed that the thin-filmself-assembling structures and microscopic morphologies of rod-coil blockmolecules are not only related to the molecular structure and composition but alsorelated to the interfacial conditions. However, a comprehensive understanding ofthe self–assembling behaviors of rod–coil block molecules on solid substrates,such as their morphologies, structures, and molecular alignments, is still lacking.It is therefore crucial to explore the relationship of the thin–film morphologies andself–assembling structures of rod–coil block molecules on substrates withinterfacial conditions, which will provide experimental and theoreticalfoundations for self-assembling behaviors of rod-coil block molecules atinterfaces and further have important directed meaning and application values forfunctional materials. On the basis of the self-assembly idea, in this thesis, we synthesized a series ofamphiphlic rod-coil diblock oligomers (EOnOPV, n, the ethylene oxide unitnumber, = 3, 7, 12 and 16) containing the conjugated oligo(phenylene vinylene)(OPV) dimer as the rod segment and poly(ethylene oxide) (PEO) as the coilsegment and firstly studied their self-assembling behaviors and structures at theair-solid interface, the air-water interface, and the liquid-solid interface, as well asthe influence of the interfacial conditions on their self-assembling behaviors andstructures. At the air-solid interface, we investigated the influences of the interfacialconditions such as solvent evaporation and atmosphere humidy on the thin-filmmicroscopic morphologies and self-assembling structures of EOnOPV oligomerswith different PEO segments on hydrophilic substrates. It is found that the coillength, solvent evaporation and atmosphere humidity can exert an importantinfluence on the thin-film microscopic morphologies and self-assemblingstructures of EOnOPV oligomers. Under the condition of quick evaporation anddry atmosphere, utilizing the simply casting method, we obtained surfacecoverage-controlled monolayer structures on hydrophilic substrates. Increasingthe cast solute volume, EO12OPV and EO16OPV oligomers with the longer coilsegment can form polar lamellar structure packed in the head-to-tail fashion. But,under the condition of the slow evaporation and humid atmosphere, EO12OPVand EO16OPV oligomers can form the curved and long ribbon-like aggregateswith the symmetric bilayer structure. In all these structures, the OPV segmentscan align shoulder to shoulder through the π-πstacking interaction. We believethat at the air-solid interface, changing the interfacial conditions can adjust themicro-equilibrium among the interactions between the rod segments, the rod andcoil segment with the substrate and the atmosphere, which may lead to theformation of various self-assembling nanostructures. We also study the self-assembly of EOnOPV oligmers with different PEOsegments at the air-water interface. EO3OPV oligomers with the shortest PEOsegment can present a well Langmuir film property and form the close-packedmonolayer film. EO12OPV and EO16OPV oligomers with the longer PEO segmentcannot form closely packed monolayers but form the irregular-shaped aggregates.However, EO7OPV oligomer presents a well Langmuir film property and mayform aggregates with the regular shape and uniform size. Interestingly, utilizing the phase separation of the mixed Langmuir-Blodgett(LB) monolayer of EO7OPV and palmitic acid (PA), the rod-like aggregatesconsisting of EO7OPV with regular shape and uniform size can form. Adjustingthe EO7OPV/PA mixing molar ratio, we can obtain a series of EO7OPV rod-likeaggregates with different lengths. The length of the rod-like aggregates can becontrolled in a large range. We think that the formation of the rod-like aggregatesof EO7OPV originates from the long-range molecular oriented order driven by theπ-πstacking interaction between the OPV segments. In addition, these rod-likeaggregates can align along the K+ ions arrangement with the 6-folded symmetryon the crystalline surface of the mica during the transfer of the Langmuir film. Wepropose a two-step forming processes of the oriented rod-like aggregates on micasubstrates. For the mixed LB film of EO3OPV and PA, the elongated aggregates更多还原