Reversibility and irreversibility of adsorption of surfactants and proteins at liquid interfaces
Reversibility and irreversibility of adsorption of surfactants and proteins at liquid interfaces
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DOI：
10.1016/j.cis.2006.05.023
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发表时间：
2006-11-16
影响因子：
15.6
通讯作者：
Michel, M.
中科院分区：
文献类型：
--
作者：
Fainennan, V. B.;Miller, R.;Michel, M.
实验表明，癸基硫酸钠从液体/空气界面的解吸是纯粹的扩散控制，而较高表面活性的表面活性剂如非离子表面活性剂Triton X-100和十三烷基二甲基氧化膦的解吸遵循混合机制。然而，β-乳球蛋白 (BLG) 和 p-酪蛋白的解吸动力学是由屏障机制决定的。通过分析不同温度下的 BLG 和 P-酪蛋白解吸动力学，计算解吸的活化能。获得的值相当接近吸附自由能。解吸动力学的理论模型预测，如果吸附活化能较低，这两个能量参数相似。这就解释了为什么吸附活性较高的物质解吸率较低。在有和没有强制对流的情况下，β-酪蛋白的吸附动力学研究显示出相同的平衡表面张力值。由此得出的结论是，液体界面上的蛋白质吸附在热力学上是可逆的，尽管缓慢的解吸动力学可以假设它是一个不可逆的过程。 (c) 2006 Elsevier B.V. 保留所有权利。
It is shown experimentally that the desorption of sodium decyl sulphate from the liquid/air interface is purely diffusion controlled, while the desorption of higher surface active surfactants such as the non-ionic surfactants Triton X-100 and tridecyl dimethyl phosphine oxide obeys a mixed mechanism. The desorption kinetics of beta-lactoglobulin (BLG) and p-casein is, however, determined by a barrier mechanism. From the analysis of the BLG and P-casein desorption kinetics at different temperatures the activation energy of desorption is calculated. The values obtained are rather close to the free energy of adsorption. The theoretical model of desorption kinetics predicts that these two energetic parameters are similar if the adsorption activation energy is low. This explains why substances with a higher adsorption activity have a lower desorption rate. Adsorption kinetics studies for beta-casein with and without forced convection show the same equilibrium surface tension values. This leads to the conclusion that the protein adsorption at liquid interfaces is thermodynamically reversible, although the slow desorption kinetics would allow to assume it to be an irreversible process. (c) 2006 Elsevier B.V. All rights reserved.