2010-09-292024-05-14https://scholars.lib.ntu.edu.tw/handle/123456789/658032摘要：近年來光電顯示器的技術蓬勃發展，由光電高分子所主導的PLED也越來越受到重視。然而大部分具有光電性質的高分子通常由多苯環等官能基(共軛硬桿段)所組成，溶解性較差並且不易加工，所以研究學者們便在疏溶劑的硬桿段鏈上加上了親溶劑的軟鏈段，來改善光電高分子的溶解性。此類共軛硬桿-柔軟嵌段共聚高分子(conjugated rod-coil block copolymer)之硬桿段會造成特殊之立體作用，影響高分子在溶液中聚集時之構形及堆疊方式。 一般而言，硬桿-柔軟嵌段共聚高分子所形成之聚集體型態必然與柔軟-柔軟嵌段共聚高分子的聚集體型態有很大的不同。更重要的是，共軛硬桿-柔軟嵌段共聚高分子聚集體之光學性質，是由嵌段共聚高分子中的硬桿嵌段所主導。依照其空間排列主要可分為兩大類：一類是硬桿段平行且頭對頭齊平排列、錯位角小的H聚集體，此類聚集體在UV-Vis吸收光譜上較分散相往藍端偏移(Blue shift)；另一類則是硬桿段平行但滑移錯開一定程度，而可明顯看出錯位的J聚集體，此類聚集體的吸收光譜上則較分散相向紅端偏移(Red shift)。 許多因素，都會影響硬桿嵌段在聚集體中的排列方式，如不同的分子結構（線性硬桿-柔軟雙嵌段、線性柔軟-硬桿-柔軟三嵌段或星狀硬桿-柔軟雙嵌段等），不同的硬桿與柔軟段長度比，或是不同的共軛作用強度。本計畫主要是利用介觀尺度的模擬方法：耗散粒子動力學(dissipative particle dynamic)來研究共軛硬桿-柔軟嵌段共聚高分子在溶液中的自組裝行為。此外我們也嘗試利用量子化學的計算，探討硬桿-柔軟嵌段共聚高分子的聚集行為，解釋產生紅移或藍移現象的可能機制。這兩種方法雖耗時，但可提供與實驗比對的訊息。因此我們將以上述的研究方式，系統性地研究共軛硬桿-柔軟嵌段共聚高分子在溶液中的排列行為，及其所對應的光學性質，希望其結果對光電顯示科技產業的發展有所助益。 <br> Abstract: Rod-coil block copolymers with -conjugation have advanced applications in optoelectronic material. The optoelectronic properties of rod-coil block copolymers are greatly affected by their supramolecular organization or morphology. The aggregates in solution exhibit distinct changes in the absorption band compared to the monomeric species. From the spectral shifts, various aggregative patterns have been proposed. The aggregates that exhibit the bathrochromically shifted J-bands (red shift) in their absorption spectrum are called J-aggregates and the aggregates that exhibit the hypsochromically shifted H-bands (blue shift) are called H-aggregates. It is agreed that both H- and J- aggregates are composed of parallel rod blocks however with different degree of slippage. Larger molecular slippage results in a bathrochromic shift and small slippage results in a hypsochromic shift. Therefore, structural control is very important for the semiconducting polymers. The self-assembly of rod-coil block copolymer is fundamentally different from that of coil-coil block copolymers due to the effect of chain topology on conformatonal entropy and molecular packing geometries. As a consequence, the rod block has limited ability to stretch and to accommodate packing within self-assembled structures. On the other hand, the additional interactions occurring between anisotropic rod blocks may bring about the potential for liquid crystalline ordering. In many rod-coil materials, the rod blocks show not only liquid crystalline alignment but also extended chain crystalline phases or high-order smectics, further increasing the complexity of the systems. Possible microphases in rod-coil copolymers include micelles, isotropic, lamellar, nematic, and various smectic phases. We intend to use Dissipative Particle Dynamics to study the self-assembling behavior of the rod-coil block copolymers in dilute solutions. Therefore, the effect of the rod-to-coil ratio, degree of polymerization, conformations of polymers (rod-coil, coil-rod-coil, star, brush), and the strength of the - interactions on the final morphologies of the aggregative micelles will be investigated. We also plan to apply quantum chemistry to study the possible mechanisms for inducing the blue/red shift of the aggregates in the absorption band compared to the monomeric species The result is of great importance to the development of a practical device with enhanced performance in optoelectronic properties.共軛硬桿-柔軟嵌段共聚高分子自組裝行為耗散粒子動力學H/J聚集體吸收光譜紅藍移conjugated rod-coil block copolymersself-assemblydissipative particle dynamicsH/J aggregatesblue/red shift in absorption band