Print Email Facebook Twitter Formation of polyelectrolyte multilayers: Ionic strengths and growth regimes Title Formation of polyelectrolyte multilayers: Ionic strengths and growth regimes Author Tang, K. Besseling, N.A.M. Faculty Applied Sciences Department Chemical Engineering Date 2015-11-03 Abstract This article presents a study of layer-by-layer (LbL) formation of poly-electrolyte multilayers (PEMs). Upon increasing ionic strength LbL growth patterns vary from linear for the lowest salt concentrations ([NaCl] = 0, 0.001, and 0.01 M) to exponential (for [NaCl] = 0.5 and 1 M). The slope of the linear growth at the lowest ionic strengths increases with increasing [NaCl]. During the LbL process at 0.5 M NaCl we observe a cross over from exponential to linear growth for which the slope is orders of magnitude larger than those observed at low salt concentrations. We provide a comprehensive interpretation of these growth behaviors, which are also reported for many other LbL PEM systems, based on the generic features of the phase diagram of aqueous solutions of mixtures of oppositely charged poly-electrolytes. Processes occurring in LbL formation of PEMs can be understood as moving in the direction of equilibrium, while never achieving it. The experimental model system in this study was: polydiallyldimethylammonium chloride/polystyrene sulfonate (PDADMAC/PSS). PEM formation was followed in situ by optical reflectometry in combination with well-controlled transport conditions (impinging jet stagnation point flow). Subject Gold for GoldOpen Access To reference this document use: http://resolver.tudelft.nl/uuid:8df625df-b133-429a-b507-00babfb4d5a0 DOI doi: 10.1039/C5SM02118A Publisher RSC Publishing ISSN 1744-6848 Source Soft Matter, 2016,12, 1032-1040 Part of collection Institutional Repository Document type journal article Rights (c) 2015 RSC Files PDF c5sm02118a.pdf 1.86 MB Close viewer /islandora/object/uuid:8df625df-b133-429a-b507-00babfb4d5a0/datastream/OBJ/view