Formation of Strong Polycation (Poly[(3-allylamino-2-hydroxypropyl)trimethylammonium chloride]) Monolayers on Mica, Silica, and Gold Substrates: Modeling and Experimental Studies
Year: 2019
Journal: J. Phys. Chem. C, Volume 123, AUG 8, page 19022–19032
The formation of poly[(3-allylamino-2-hydroxypropyl)- trimethylammonium chloride] (PAH-GTMAC, a strong polycation) monolayers on various substrates was thoroughly studied. Molecular dynamics simulations and experimental techniques (dynamic light scattering, electrophoresis, streaming potential measurements, and quartz crystal microbalance (QCM-D)) were applied to characterize the system. The density, cross-sectional area, end-to-end length, diffusion coefficient, number of uncompensated charges of the PAH-GTMAC molecules were theoretically evaluated. The QCM-D measurements allowed to determine the PAH-GTMAC adsorption kinetics on these substrates interpreted in terms of a hybrid random sequential adsorption model. The dynamic hydration of the PAH-GTMAC monolayer on these substrates was evaluated for the first time. The results confirmed that the macrocation adsorption is mainly driven by electrostatic interactions. Besides significance to basic science, the results of our studies can be exploited to prepare stable and biocompatible macroion coatings of well-defined coverage and electrokinetic properties.
