Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, ul. Niezapominajek 8, 30-239 Cracow, Poland.
J Colloid Interface Sci. 2012 Feb 15;368(1):547-51. doi: 10.1016/j.jcis.2011.11.025. Epub 2011 Nov 19.
The paper is focused on the problem of interpretation of the experimental data related to the thermodynamics of metal ions binding by alginate-based biosorbents. When considering the thermodynamic parameters (i.e., changes in the enthalpy and entropy values; ΔH and ΔS, respectively), one can observe large discrepancies between their values even if the considered systems have very similar features. For instance, the binding of copper, cadmium, and lead can be entropy-driven, enthalpy-driven or both entropy- and enthalpy-driven, depending on the considered report. The aim of this paper is to find the reason for this paradox and to discuss the problem of interpretation of the data being usually the base for estimating ΔH and ΔS values. It appears that both numerous "technical" (e.g., pH, ionic strength) and model-related (e.g., monodentate vs. bidentate binding models) parameters can seriously influence the obtained values of thermodynamic parameters. The significance of these two types of factors is discussed in qualitative and quantitative manners. The proposed methods of distinguishing between the "apparent" and the "real" ΔH and ΔS values can be also related to other types of sorption/adsorption systems.
本文主要关注的是解读与海藻酸钠基生物吸附剂对金属离子结合热力学相关的实验数据的问题。在考虑热力学参数（即焓和熵值的变化，分别为ΔH 和 ΔS）时，即使考虑的系统具有非常相似的特征，也会观察到它们的值之间存在很大差异。例如，根据不同的报告，铜、镉和铅的结合可以是熵驱动的、焓驱动的或熵和焓共同驱动的。本文的目的是找出这种悖论的原因，并讨论数据解释的问题，因为这通常是估计 ΔH 和 ΔS 值的基础。似乎有许多“技术”（例如 pH 值、离子强度）和模型相关（例如单齿和双齿结合模型）参数都会严重影响热力学参数的获得值。这两种类型的因素的重要性以定性和定量的方式进行了讨论。提出的区分“表观”和“真实”ΔH 和 ΔS 值的方法也可以与其他类型的吸附/吸收系统相关。
