偶氮染料吸附於金屬有機骨架之螢光猝滅研究：Stern-Volmer圖之探討

Fluorescence quenching study of metal-organic frameworks adsorption of azo-dyes: Analysis of Stern-Volmer Plots.

楊上民(Shang-Min Yang)

指導教授 ： 李世琛

中原大學/理學院/化學研究所/碩士(2014年)

https://doi.org/10.6840/cycu201400568

摘要

本研究主要是探討金屬有機骨架吸附偶氮染料(甲基紅同分異構物與甲基橙)後的螢光強度變化。金屬有機骨架的放光特性，是藉由有機配位基到金屬的電荷轉移所產生的放光。金屬有機骨架吸附染料後，螢光強度會隨著染料濃度增加而減少。藉由分析Stern-Volmer方程式，動態猝滅常數KD以及螢光生命期τ的測量，瞭解染料猝滅金屬有機骨架螢光的能力。研究發現甲基紅異構物，因為取代基COO-立體障礙不同，造成甲基紅吸附在金屬有機骨架的吸附位向不同，所造成的猝滅能力也有所不同。而在不同激發波長研究，發現雖然270nm所激發的螢光較350nm弱，仍可以觀察到螢光隨染料濃度而有猝滅變化。最後為了驗證染料吸附在金屬有機骨架的吸附位向，我們並測量拉曼光譜，發現拉曼光譜的結論和螢光猝滅實驗的結果是一致的。而針對螢光光譜、紫外-可見光光譜、拉曼光譜、時間相關單一光子計數系統實驗數據結果的關聯性，我們將會有詳細的討論。

關鍵字

金屬有機骨架、螢光猝滅

並列摘要

The main objective of this study is to investigate the adsorption of azo dyes (methyl red isomers and methyl orange) on metal-organic frameworks (MOFs) by measuring the variation of fluorescence intensity. Because of the adsorption of dyes by MOFs, the fluorescence intensity is decreased with increasing concentration of the dyes. The fluorescence measurement is further analyzed by using the Stern-Volmer equation. Dynamic quenching constant (KD) and the fluorescence lifetime (τ) are calculated in order to understand the dye fluorescence quenching ability of MOFs. The results revealed that the methyl red molecule, due to the steric hindrance of the carboxylate functional group at different position, has been adsorbed differently on MOFs, therefore the quenching capability is also different. In the excitation wavelength dependence study, though the fluorescence excitation using 270 nm is weaker compared with using 350 nm, we can still observe the fluorescence quenching of dye at 270 nm. Finally, Raman spectroscopy was also performed in order to verify the adsorption orientation of the dye adsorbed on MOFs. We have demonstrated that the results of Raman spectroscopy and fluorescence quenching are consistent. In addition to fluorescence spectroscopy, we have used the UV-visible spectroscopy, Raman spectroscopy, and time-correlated single photon counting system.The results & discussion of these studies are included in this thesis.

並列關鍵字

Fluorescence、Stern-Volmer、 metal-organic frameworks

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