Werbowesky R, Chow A
Talanta. 1996 Feb;43(2):263-74. doi: 10.1016/0039-9140(95)01770-4.
The extraction of 12 closely related mono-azo dyes by polyester and polyether-type polyurethane foams was studied to gain more information regarding the mechanism of the extraction of organic compounds. The effects on extraction of solution pH, dye concentration and salt concentration were investigated. It was found that the extraction of the dyes involved a neutral zwitterionic species and is highly dependent on the parameters studied. The dependency of the extraction on these parameters can be explained in a manner consistent with solvent extraction; however, the dual-mode sorption mechanism seems a more likely model. This mechanism involves both absorption related to solvent extraction, and an added component for surface adsorption. While the dual-mode sorption model explains the observed extraction behaviour, the data suggest that surface adsorption plays a much larger role than previously considered.
研究了聚酯和聚醚型聚氨酯泡沫对12种密切相关的单偶氮染料的萃取，以获取更多关于有机化合物萃取机理的信息。研究了溶液pH值、染料浓度和盐浓度对萃取的影响。发现染料的萃取涉及中性两性离子物种，并且高度依赖于所研究的参数。萃取对这些参数的依赖性可以用与溶剂萃取一致的方式来解释；然而，双模式吸附机理似乎是一个更有可能的模型。该机理既涉及与溶剂萃取相关的吸收，也涉及表面吸附的附加成分。虽然双模式吸附模型解释了观察到的萃取行为，但数据表明表面吸附所起的作用比以前认为的要大得多。
