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Abstract：
The impact of solvents on the efficiency of cationic dye adsorption from a solution onto protonated Faujasite-type zeolite (FAU-Y) was investigated in the prospect of supporting potential applications in wastewater treatment or in the preparation of building blocks for optical devices. The adsorption isotherms were experimentally determined for methylene blue (MB) and auramine O (AO) from single-component solutions in water and in ethanol. The limiting dye uptake (saturation capacity) was evaluated for each adsorption system, and it decreased in the order of MB-water > AO-water > AO-ethanol > MB-ethanol. The mutual distances and orientations of the adsorbed dye species, and their interactions with the oxygen sites of the FAU-Y framework, with the solvent molecules, and among themselves were inferred from Monte Carlo simulations and subsequently utilized to rationalize the observed differences in the saturation capacity. The dye-solvent competition and the propensity of the dyes to form compact pi-stacked dimers were shown to play an important role in establishing a non-uniform distribution of the adsorbed species throughout the porous space. The two effects appeared particularly strong in the case of the MB-water system. The necessity of including solvent effects in modeling studies is emphasized.
摘要：
研究了溶剂对阳离子染料从溶液中吸附到质子化八面沸石（FAU-Y）上的效率的影响，以支持在废水处理或制备光学器件的结构单元中的潜在应用。实验确定了水和乙醇中单组分溶液中亚甲蓝（MB）和金胺O（AO）的吸附等温线。对每个吸附系统的极限染料吸收(饱和容量)进行评估,按MB-水>AO-水>AO-乙醇>MB-乙醇的顺序降低。吸附的染料种类的相互距离和方向，以及它们与FAU-Y框架的氧位点的相互作用，溶剂分子，并从蒙特卡洛模拟中推断出来，随后用于合理化观察到的饱和容量差异。染料-溶剂竞争和染料形成紧密的pi堆叠二聚体的倾向被证明在整个多孔空间中建立吸附物种的不均匀分布中起着重要作用。在MB-水系统的情况下,这两种效应显得特别强。强调了在建模研究中包括溶剂效应的必要性。
