Photophysical and association properties of a diazo dye (acid blue 113) in the presence of a structure breaking additive (urea) and Ag nanoparticles (AgNPs) were investigated at different dye and additive concentrations (0–3 mol·L −1 urea and 0.1 mmol·L −1 AgNPs). The ionic dye, with strong hydrophilic character, has an aromatic diazo skeleton and two sulfide functional groups. The dye concentrations ranging from 1 × 10 −6 to 5 × 10 −4 mol·L −1 were chosen and studied, to avoid formation of the higher-order aggregates. The dye spectra were analyzed using linear and nonlinear decomposition algorithms. Using the least squares fitting approach, the dimerization constant K d and individual monomer and dimer spectra were determined. A reduction of the dimerization constant for AB 113 in aqueous solutions containing additives was observed. The spectral parameters, structure of the dimeric species and the interaction energy between the monomers in the dye solution were estimated based on the molecular exciton theory.

中文翻译：

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酸性蓝 113 在尿素水溶液和水溶液以及银纳米粒子胶体中的光谱和聚集特性

研究了在不同染料和添加剂浓度（0-3 mol·L -1 尿素和 0.1 mmol·L -1 AgNPs)。离子染料亲水性强，具有芳香族重氮骨架和两个硫化物官能团。选择并研究了范围从1×10 -6 到5×10 -4 mol·L -1 的染料浓度，以避免形成高阶聚集体。使用线性和非线性分解算法分析染料光谱。使用最小二乘拟合方法，确定了二聚化常数 K d 和单个单体和二聚体光谱。观察到AB 113 在含有添加剂的水溶液中的二聚常数降低。