Filippova NL
Russian Branch RTD Corporation, Moscow, 111538, Russia
J Colloid Interface Sci. 1998 Oct 15;206(2):592-602. doi: 10.1006/jcis.1998.5771.
The adsorption and desorption kinetics of water-soluble associative polymers with different molecular weights on the silicon wafers were studied by ellipsometry. The parameters characterizing the adsorption and desorption processes such as (a) the maximum amount of adsorbate adsorbed, Gammainfinity, (b) the equilibrium constant, K(p), (c) the activation energy of adsorption, (-DeltaH), (d) the rate constants for adsorption and desorption processes, Kad, Kdes, (e) the coefficient of diffusion, D0, (f) the activation energy of the effective diffusion, Q, and (g) the time needed to attain the equilibrium states for the adsorption and desorption processes were calculated from the experimental ellipsometric data. It is shown that the adsorption kinetics for mixtures over a wide range of concentrations is governed by: (I) the kinetic adsorption at the interface, (II) the kinetic adsorption at the interfaces as well as simultaneous diffusion, and/or (III) diffusion. The existence of regimes (I), (II), and (III) for adsorption and desorption kinetics are justified by using the experimental data for the adsorption and desorption kinetics of water-soluble associative polymers with different molecular weights of 12, 62, and 120 kg/mol. Copyright 1998 Academic Press.
采用椭偏仪研究了不同分子量的水溶性缔合聚合物在硅片上的吸附和解吸动力学。根据实验椭偏数据计算了表征吸附和解吸过程的参数，如：(a) 吸附质的最大吸附量，Γ∞；(b) 平衡常数，K(p)；(c) 吸附活化能，(-ΔH)；(d) 吸附和解吸过程的速率常数，Kad、Kdes；(e) 扩散系数，D0；(f) 有效扩散活化能，Q；(g) 吸附和解吸过程达到平衡态所需的时间。结果表明，在很宽的浓度范围内，混合物的吸附动力学受以下因素控制：(I) 界面处的动力学吸附；(II) 界面处的动力学吸附以及同时进行的扩散；和/或(III) 扩散。利用分子量分别为12、62和120 kg/mol的不同水溶性缔合聚合物的吸附和解吸动力学实验数据，证明了吸附和解吸动力学中(I)、(II)和(III)三种情况的存在。版权所有1998年学术出版社。
