The electrostatically driven self-assembly of a novel polyelectrolyte multilayer (PEM) film was investigated in real-time using dual-beam polarization interferometry (DPI) and quartz crystal microgravimetry with dissipation monitoring (QCM-D). Multilayer assemblies of the water-soluble polycation poly[(9,9-di(3,3'-N,N'-trimethyl-ammonium) propyl fluorenyl-2,7-diyl)-alt-co-(1,4-phenylene) diiodide salt] (PFN-B-I) and polyanion poly[2-(3-thienyl)ethyloxy-4-butylsulfonate sodium salt] (PTE-BS) were constructed on anionic functionalized substrates using a layer-by-layer self-assembly method. DPI and QCM-d measurements indicate linear mass build-up over ten bilayer depositions with film density asymptotically approaching 1.20 g/cm<sup>3</sup> and water content approaching 60 wt%. Real-time measurements allow for the resolution of mechanistic aspects of polyelectrolyte deposition. PFN-BI quickly saturates binding sites while PTE-BS deposition leads to both rigid and loosely bound polymer. Loosely bound polymer is rinsed off prior to subsequent polyelectrolyte deposition and dissipation changes remained less than 3 ppm throughout assembly. Films constructed under atmosphere and characterized by UV-vis and ellipsometry showed a kink in film build-up due to the substrate effect. Thin films with two conjugated moieties and their optical tunability makes these systems highly applicable for optical sensing applications.

Self-assembly and characterization of a novel conjugated polyelectrolyte multilayer film

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.