合成及鑑定全共軛雙親性嵌段共聚高分子及其有機/無機奈米混成系統之研究

Abstract

近年來，共軛高分子與無機奈米粒子的混成材料已被廣泛應用在光電元件上。然而兩者材料混摻最常發生的問題在於因為共軛高分子與無機奈米粒子相容性不佳而產生較嚴重的聚集現象，因此我們需要發展全新高品質的共軛高分子混成系統來有效結合高分子與無機金屬鹽類。在本研究中，我們透過格林鈉反應成功合成出新穎性全共軛段雙親性嵌段共聚物PPP-b-P3EEET。而透過雙親性嵌段共聚物本質上兩端及極性上的差異和控制親油親水兩端的分子量組成比例，可以在不同溶劑下得到微胞或是層狀等奈米自組裝結構。同時可以從溶液顏色與UV吸收範圍的變化等觀察出形態上的改變造成的影響。而像PPP-b-P3EEET這類含有烷氧醚基側鏈的新型材料有幾個特別的現象，例如烷氧基側鏈的氧原子可提供多個螯合位置供金屬離子鍵結且同時這些鍵結的螯合離子剛好可以扮演將原本不容易結晶的P3EEET柔軟彎曲的側鏈拉直而誘發出不同於原本的PPP結晶相而是新的P3EEET非等向性結晶相。這些結晶行為可以透過TEM觀察物質的微結構及GIWAXS/GISAXS的計算高分子晶格大小來做分析。另外，此種雙親性嵌段共聚物可做為合成奈米無機晶體材料原位混成反應系統的基板。我們相信此種新穎性材料在未來探討金屬鹽類誘發結晶用提升載子傳遞速率反應機制的研究及開發高效能光電元件上都有很大的潛力。

In recent years, hybrid materials composed of conjugated polymers and inorganic nanoparticles have been widely used for photovoltaic applications. However, these hybrids often suffered from serious morphology uniformity issues due to the easy aggregation problem of inorganic nanocrystals during blending of hydrophobic conjugated polymers and hydrophilic inorganic nanoparticles. Therefore, the development of a new conjugated polymer system that can efficiently incorporate inorganic nanoparticles to fabricate high quality hybrids is greatly required. In this study, we report on the synthesis of a novel amphiphilic rod-rod all-conjugated diblock copolymer poly (2,5-dihexyoxy-p-phenylene)-b-poly (3-[2-(2-ethoxy ethoxy)ethoxy] thiophene) (PPP-P3EEET) via Grignard metathesis method. By varying the intrinsic difference in the amphiphilic between the two constituting blocks and controlling their chain lengths, it can found that these amphiphilic block copolymers self-assemble into various nanostructured including micelles or lamellae upon solvent drying. In addition, the crystalline, morphological, thermal and optical properties of these novel materials including WAXS, SAXS, TEM, DSC, TGA, and UV-VIS absorption measurements are also investigated.The P3EEET block with ethylene oxide side chains of the block copolymers could also be used as chelating sites for metal ions. The morphological transitions of these hybrid materials with different zinc ion loadings were also investigated. In addition, the amphiphilic all-conjugated diblock copolymers could serve as a nanoreactor system to in situ synthesize zinc oxide nanocrystals within the polymer matrix. We believe that this novel material shows potential to be used in future optoelectronic applications.