Aggregation-induced sensitization in aqueous solutions of Al³⁺–chrome azurol S complexes and ionic liquids based on 1-alkyl-3-methylimidazolium bromide

详细信息    查看全文

• 作者：Hucheng Zhang ; Kun Li ; Xuxu Zhang ; Liwei Zhang ; Jianji Wang
• 关键词：Sensitization ; Aggregation ; Dye ; Ionic liquid ; Absorption spectrum
• 刊名：Colloids and Surfaces A: Physicochemical and Engineering Aspects
• 出版年：2010
• 出版时间：5 June 2010
• 年：2010
• 卷：362
• 期：1-3
• 页码：77-83
• 全文大小：680 K

文摘

The dependences of the absorption spectra of chrome azurol S (CAS) and Al³⁺–CAS complexes on the concentration of ionic liquids (ILs), 1-alkyl-3-methylimidazolium bromide ([C_nMim]Br, with n = 8, 10, 12), were measured at 298.15 K in aqueous solutions with pH = 5.6. It is found that ILs can induce the significant red-shifts of the wavelength at the absorption maximum (λ_max) of Al³⁺–CAS complex from 545 to 646 nm for [C₈Mim]Br, and to 642 nm for [C₁₂Mim]Br and [C₁₆Mim]Br, respectively. Accompanying the red-shifts, the absorbance at λ_max, and thereby molar absorptivity (), changes markedly with the IL concentration, and consequently the effect of ILs on the absorbance at λ_max is systematically investigated in this work. Along with the experimental results of resonance light scattering, the sensitization mechanism is analyzed from the aggregation of the ILs and the interactions of ILs with CAS and Al³⁺–CAS complexes. It is shown that the hydrophobic interactions of IL subaggregates with CAS in Al³⁺–CAS complex are the crucial factor for the sensitization.