含螢光基團之 多胜肽 PBLG 聚合物的合成與自組裝 性質研究

Synthesis and Self-assembly Properties of Polymers of Polypeptide PBLG Containing Rhodamine B Fluorophore

林合耕

指導教授 ： 劉英麟

國立清華大學/工學院/化學工程學系/碩士(2013年)

摘要

在本研究中，以Polyhedral oligomeric silsesquioxane (POSS) 及胜肽benzyl-L-glutamte (BLG)，經由α-amino acid N-carboxyanhydrides (NCA)開環聚合法製備嵌段共聚物，並接著將此嵌段共聚物之末端氨基接枝上Rhodamine B (RhB)，製備出含有螢光性質的高分子POSS-PBLG-RhB。由於POSS-PBLG在toluene中會自組裝成奈米緞帶(naroribbon)，在接上RhB染色後，於Acetone、Chloroform與Toluene三種溶液中觀察其自組裝的行為。
此研究以傅立葉轉換紅外線光譜分析儀(FTIR)、氫核磁共振光譜(H1NMR)鑑定高分子的化學結構。由於PBLG會在四氫呋喃(THF)相中的凝膠滲透儀(GPC)產生聚集，導致分子量不正確。所以我們也利用氫核磁共振光譜(H1NMR)來計算嵌段共聚物中PBLG段的分子量。並由穿透式電子顯微鏡(TEM)觀察高分子在不同溶液下自組裝的行為，POSS-PBLG-RhB嵌段共聚物於Actone中會自組裝成蠕蟲狀，於Chloroform中會自組裝行成環狀，於Toluene中會自組裝形成球狀與橢圓狀微胞，以及橢圓囊狀。附有多胜肽PBLG的嵌段共聚物可以擁有良好的生物可分解性以及生物相容性，適合應用於生醫材料。

關鍵字

多胜肽 ； 自組裝 ； 螢光

並列摘要

The secondary structure of poly(γ-benzyl L-glutamate) (PBLG) with degrees of polymerization over 18 is dominated by α-helical conformation. POSS-end-capped PBLG polymer has been reported to exhibit nanoribbon self-assembly structure. In this work, we introduce Rhodamine B (RhB) fluorophore to the end of POSS-PBLG-RhB to form a doubly end-capped POSS-PBLG-RhB polymer. The effect of the hydrophilic RhB fluorophore at the chain end to the intramolecular hydrogen bonds of α-helical PBLG block are observed by self-assembling POSS-PBLG-RhB in three chosen solvents including acetone, chloroform and toluene. α-Helical structure of PBLG block can be maintained in chloroform and toluene, but is transformed into mixtures ofα-helical and β-sheet conformations in acetone, which are verified with the measurements of Fourier Transform Infrared spectroscopy (FT-IR). Under the excitation at 365 nm and 532 nm, POSS-PBLG-RhB nanoparticles exhibits two-band emission in three solutions, but the emission from aggregation of POSS-PBLG blocks are not strong enough to decrease the yellow light from RhB. The self-assembly structures of of POSS-PBLG-RhB in the three solvents in different time are also observed by Transmission Electron Microscopy (TEM). The relationship between the solvents properties and the observed self-assembly structures are discussed.

並列關鍵字

PBLG ； RhB ； sel-assembly

參考文獻

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