Maroni Plinio, Montes Ruiz-Cabello Francisco Javier, Cardoso Catia, Tiraferri Alberto
†Department of Inorganic and Analytical Chemistry, University of Geneva, Sciences II, Quai Ernest-Ansermet 30, 1205 Geneva, Switzerland.
‡Biocolloid and Fluid Physics Group, Applied Physics Department, Faculty of Sciences, University of Granada, Fuente Nueva s/n, 18071 Granada, Spain.
Langmuir. 2015 Jun 9;31(22):6045-54. doi: 10.1021/acs.langmuir.5b01103. Epub 2015 May 28.
The adsorbed mass of polymers on surfaces with different chemistry is presented, and the related adsorption mechanism is discussed. Strong and weak polyelectrolytes of negative and positive charge are studied, as well as an uncharged polymer. Self-assembled monolayers of alkanethiols on gold are used in reflectometry and quartz crystal microbalance (QCM-D) experiments as adsorbing substrates bearing different terminal moieties, namely, methyl, hydroxyl, carboxyl, and amine groups. The various polymer-surface combinations allow the systematic investigation of the role of surface chemistry and polymer charge on adsorbed amount. Interactions of different nature and range drive polymer adsorption: the measured adsorbed amounts reveal information about their relative contribution. When electrostatic chain-surface attraction is present, the largest adsorbed masses are observed. However, significant mass is measured even when an electrostatic barrier to adsorption is present, suggesting the importance of forces of nonelectrostatic origin, which include both hydrophobic interactions and specific forces acting at short distances. This mechanism results in large adsorbed amounts for the adsorption of weak polyelectrolytes, and it is apparent especially in the adsorption behavior of a neutral polymer.
本文展示了聚合物在具有不同化学性质的表面上的吸附质量，并讨论了相关的吸附机制。研究了带负电荷和正电荷的强、弱聚电解质以及一种不带电的聚合物。在反射测量和石英晶体微天平（QCM-D）实验中，将金表面的烷硫醇自组装单分子层用作带有不同末端基团（即甲基、羟基、羧基和胺基）的吸附底物。各种聚合物 - 表面组合使得能够系统地研究表面化学和聚合物电荷对吸附量的作用。不同性质和范围的相互作用驱动聚合物吸附：测量得到的吸附量揭示了它们相对贡献的信息。当存在静电链 - 表面吸引力时，观察到最大的吸附质量。然而，即使存在吸附的静电屏障，也能测量到显著的质量，这表明非静电起源的力的重要性，其中包括疏水相互作用和在短距离起作用的特定力。这种机制导致弱聚电解质吸附时吸附量很大，并且在中性聚合物的吸附行为中尤为明显。
