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

• Published in: Macromolecular chemistry and physics 2019-08, Vol.220 (15), p.n/a
• Main Authors: Herrera, Santiago E., Agazzi, Maximiliano L., Cortez, M. Lorena, Marmisollé, Waldemar A., Bilderling, Catalina, Azzaroni, Omar
• Format: Article
• Language: English
• Subjects: Aqueous solutions; Bromophenol blue; Construction materials; Controlled release; Crosslinking; Deposition; hybrid films; layer‐by‐layer assembly; loading capacity; Multilayers; Polyamines; Polyelectrolytes; supramolecular colloids; Thin films
• ISSN: 1022-1352; 1521-3935
• 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. Polyamine‐salt aggregates based on poly(allylamine) and phosphate ions are used as building blocks in the preparation of layer‐by‐layer (LbL) films. This strategy facilitates the rapid fabrication of thick polymeric films through LbL assembly. These films exhibit high loading efficiency of an anionic dye probe with potential practical applications for controlled release.