奈米粒子與奈米柱在超分子共聚物中的空間分布探討

Abstract

本實驗利用不同分子量的超分子共聚物PS-b-P4VP(PDP)與奈米粒子混摻，對分子量大小造成奈米粒子不同的空間分布結果進行探討，實驗發現在分子量較小的超分子共聚物中，奈米粒子在P4VP(PDP)區間的分布會隨PDP的多寡而有顯著的影響；但對於大分子量的超分子共聚物而言，奈米粒子並不會隨著PDP的增加而有不同的分布，而是會在靠近P4VP(PDP)區間中間位置均勻分散。且奈米粒子會傾向存在於界面彎曲的區域當中。此外，我們將奈米柱加入超分子系統當中，發現PDP增加而產生的結晶會迫使奈米柱形成特殊的堆疊，此堆疊在超分子共聚物當中會使奈米柱以垂直PS-b-P4VP所形成的層狀方向排列而存在於P4VP(PDP)相當中。若PDP比例更高時，則會形成溶液中特有的液胞型態，且奈米粒子及奈米柱在此狀況下亦能選擇性地分散在P4VP(PDP)區間。 小分子扮演在此系統中扮演多重角色，不僅僅為奈米粒子及團聯式共聚物的混摻的媒介，亦可改變團聯式共聚物兩鏈段的體積分率而使超分子共聚物的型態改變，且在小分子比例很高時，小分子可扮演類似選擇性溶劑的角色而膨潤其中一鏈段，進而形成溶液中特有的液胞結構。這些多重的可調性功能使此系統具有廣泛的應用發展性。

It is confirmed that the incorporation of nanoparticles and nanorods into block copolymer-based supramolecules of poly(styrene-b-4-vinylpyridine) (PS-b-P4VP) possess well selective spatial distribution into P4VP(PDP) microdomain. In this study, we investigate the effect of molecular weight of block copolymer on the spatial distribution of nanoparticles controlled by small molecules. With small molecular weight block copolymer, the spatial distribution of nanoparticles varies with different amount of PDP. However, with large molecular weight block copolymer, nanoparticles disperse around the center of P4VP(PDP) domain regardless of the amount of PDP. Favorable incorporation of nanoparticles into bended lamella is observed. Moreover, Nanorods tend to orientate perpendicular to the lamella of PS-b-P4VP when forming special aggregations of nanorods in the presence of excess free PDP in P4VP(PDP) microdomain. Small molecules not only tailor the incorporation of various nanoparticles into supramolecular assembly by favorable mixing properties, but direct the supramolecular assembly to various morphologies. Besides, small molecules with excess amount can swell the P4VP(PDP) domain in similar to the effect of selective solvent toward P4VP.