Preparation of conductive PDDA/(PEDOT:PSS) multilayer thin film: Influence of polyelectrolyte solution composition

• Published in: Journal of colloid and interface science 2014-10, Vol.431 (431), p.64-70
• Main Authors: Jurin, F.E., Buron, C.C., Martin, N., Filiâtre, C.
• Format: Article
• Language: English
• Subjects: Acoustics; Applied sciences; Electrical conductivity; Engineering Sciences; Exact sciences and technology; Forms of application and semi-finished materials; Materials; Micro and nanotechnologies; Microelectronics; Miscellaneous; Multilayer; Optical reflectometry; PEDOT:PSS; Polymer industry, paints, wood; Technology of polymers
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2014.06.005

[Display omitted] •Build-up of multilayer film using PEDOT:PSS as an anionic conductive polyelectrolyte.•Increase in the adsorbed amount when divalent cations were used as electrolyte.•No decomplexation of PEDOT was recorded after film preparation.•Electrical conductivity of PDDA/PEDOT:PSS multilayer films was around 0.31Sm−1. Self-assembled multilayer films made of PEDOT:PSS poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) and PDDA poly(diallyldimethylammonium chloride) were prepared using layer-by-layer method. In order to modify the growth regime of the multilayer, to fabricate an electrical conductive film and to control its thickness, the effects of pH, type of electrolyte, ionic strength and polyelectrolyte concentration were investigated. Optical reflectometry measurements show that the pH of the solutions has no effect on the film growth while the adsorbed amount increases more rapidly when BaCl2 is used instead of NaCl as electrolyte. An increase in the ionic strength (with NaCl) induces a change in the growth regime from a linear to an exponential one at low polyelectrolyte concentration. As UV–vis measurements indicate, no decomplexation of PEDOT was recorded after film preparation. With polyelectrolyte concentration below 1gL−1, no conductive films were obtained even if 50 bilayers were deposited. A conductive film was prepared with a polyelectrolyte concentration of 1gL−1 and the measured conductivity was 0.3Sm−1. A slight increase in conductivity was recorded when BaCl2 was used probably due to a modification of the film structure.