Layer‐by‐Layer Formation of Polyamine‐Salt Aggregate/Polyelectrolyte Multilayers. Loading and Controlled Release of Probe Molecules from Self‐Assembled Supramolecular Networks

Publication year: 2019
Authors: Herrera S.E. 1, Agazzi M.L. 1, Cortez M.L. 1, Marmisollé W.A. 1, von Bildering C. 1,2, Azzaroni O. 1

1 - Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas, Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata–CONICET, Sucursal 4, Casilla de Correo 16, 1900 La Plata, Argentina
2 - Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1428EHA Buenos Aires, Argentina

Published in: Macromolecular Chemistry and Physics, 2019
doi: 10.1002/macp.201900094

The use of soft materials as building blocks in layer‐by‐layer (LbL) assemblies represent a very appealing and useful approach to enhance the loading capacity of thin films. Here, the capacity of positively charged polyamine‐salt aggregates (PSAs) based on ionically crosslinked poly(allylamine hydrochloride) (PAH) with phosphate anions (Pi) is explored to act as building blocks in construction of multilayers by alternated deposition with poly(sodium 4‐styrenesulfonate). Hybrid thin films are successfully prepared by the LbL technique with a highly regular growth and a material deposition rate higher than the traditional full polyelectrolyte LbL. The loading of bromophenol blue (BPB) is evaluated by integration into PSAs followed by LbL deposition and monitored with UV–vis spectroscopy. Finally, the release of the dye molecules is carried out by exposing the film to different aqueous solutions. It is shown that a fully controlled release can be achieved by simply varying the media pH obtaining total BPB release over periods between minutes and months. The data obtained reveal that this new LbL construction strategy using ionically crosslinked PAH/Pi colloids allows to obtain nanoarchitectures with high loading capacity and remarkable properties for controlled release.

MP-SPR keywords: layer-by-layer (LbL), loading capacity, material science, polyelectrolyte, soft materials, thin film