本研究使用螢光光譜技術,探討偶氮染料(甲基橙與甲基紅同分異構物)對金屬有機骨架所產生的猝滅影響,再利用等溫吸附曲線模式(Langmuir、Frenudlich、修飾Langmuir),探討偶氮染料於金屬有機骨架的吸附行為。金屬有機骨架的螢光來自於本身結構中的有機配位基吸收激發光,藉由配位基至金屬的電荷轉移能量到金屬有機骨架中心金屬導致螢光放光。利用此放光特性,加入偶氮染料後,隨著染料濃度的增加,金屬有機骨架的螢光訊號下降,這是因為染料分子與金屬有機骨架之間的作用力,使染料分子猝滅了金屬有機骨架的放光,而不同濃度的偶氮染料對於金屬有機骨架的猝滅效果也不相同。將螢光訊號轉換成吸附量,發現染料濃度對於金屬有機骨架的吸附程度具有符合某些特定等溫吸附曲線模式的關係存在。有關染料於金屬有機骨架的吸附程度以及他們之間的作用力,我們將會有詳細的討論。
The fluorescence spectroscopy was used in this study to investigate the quenching effect of azo dye (methyl orange and methyl red isomers) on metal-organic frameworks. The adsorption isotherm models (Langmuir, Frenudlich, modified Langmuir) were used to investigate the adsorption behavior of azo dye in metal-organic frameworks. The fluorescence of metal-organic frameworks originated from the ligand in the structure absorbing excitation energy, then via ligand-to-metal charge-transfer energy to the central metal of metal-organic frameworks, resulted in fluorescence emission. Based on this light emission characteristic, the fluorescence signal of metal-organic frameworks declined as the concentration of azo dye increased. This is because the interaction between the dye molecules and metal-organic frameworks makes the dye molecules quench the light emission of metal-organic frameworks. The azo dyes at different concentrations have different quenching effects on metal-organic frameworks. The fluorescence signal was converted into adsorption capacity, and it was found that there is specific azo dye concentration-dependence of adsorption isotherms with different types of metal-organic frameworks. Finally, we have detailed discussions about the adsorption capacity and interaction between metal-organic frameworks and dyes.