Adsorption of a Cationic Laser Dye onto Polymer/Surfactant Complex Film Fabricated by Layer-by-Layer Electrostatic Self-Assembly Technique

TL;DR

This study demonstrates the successful incorporation and aggregation behavior of a cationic dye within polymer/surfactant films fabricated by layer-by-layer assembly, revealing insights into dye aggregation and film properties.

Contribution

It introduces a novel method of embedding Rhodamine 6G into polyelectrolyte/surfactant films using electrostatic self-assembly, analyzing dye aggregation states and film characteristics.

Findings

R6G forms H-type aggregates in solution and both H- and J-type in films.

The aggregation ratio in films is independent of SDS concentration.

AFM confirms dye aggregation within the films.

Abstract

Fabrication of complex molecular films of organic materials is one of the most important issues in modern nanoscience and nanotechnology. Soft materials with flexible properties have been given much attention and can be obtained through bottom up processing from functional molecules, where self-assembly based on supramolecular chemistry and designed assembly have become crucial processes and technologies. In this short communication, we report the successful incorporation of cationic laser dye Rhodamine 6G abbreviated as R6G into the pre-assembled polyelectrolyte/Surfactant complex film onto quartz substrate by electrostatic adsorption technique. Poly(allylamine hydrochloride) (PAH) was used as polycation and Sodium dodecyl sulphate(SDS) was used as anionic surfactant. UV-Vis absorption spectroscopic characterization reveals the formation of only H-type aggregates of R6G in their aqueous solution and both H and J-type aggregates in PAH/SDS/R6G complex LbL films as well as the kinetics of adsorption of R6G onto the complex films. The ratio of the absorbance intensity of two aggregated bands in PAH/SDS/R6G complex films is merely independent of the concentration range of the SDS solution used to fabricate PAH/SDS complex self-assembled films. Atomic Force Microscopy reveals the formation of R6G aggregates in PAH/SDS/R6G complex films.