Tamás Szabó: Stability of graphene oxide-based self-assembled multilayers in aqueous solutions

Nizar Alsharif, Alexandr Talyzin, Tamas Szabo TS, NA:  Department of Physical Chemistry and Materials Science, University of Szeged, Aradi vt. 1, H-6720 Szeged, Hungary AT: Department of Physics, Umeå University, SE-901 87 Umeå, Sweden A simple UV-visible spectrophotometric method can be efficiently employed to characterize the structural and chemical stability and adsorption properties of hybrid polyelectrolyte/graphene oxide (GO) films in various aqueous solutions [1]. The immersion stability of GO layer-by-layer (LbL) self-assembled with a polycation into ultrathin multilayered films was studied in water and in concentrated salty, acidic and basic solutions. These films were found to retain both their chemical stability and physical integrity in water, NaCl and HCl solutions with a slight rearrangement of the nanoscale structure as shown by the change in their visible spectrum. However, immersion into NaOH solutions above molar concentration led to the decomposition of the multilayer structure by base-induced deoxygenation of GO. The adsorption of methylene blue on polymer/GO LbL films of various thicknesses revealed that the multilayers are largely impermeable towards this cationic dye. [1] T Szabó, Z Péter, E Illés, L Janovák, A Talyzin; Stability and dye inclusion of graphene oxide/polyelectrolyte layer-by-layer self-assembled films in saline, acidic and basic aqueous solutions. Carbon (2017),111 , 350-357. Tamás Szabó is an Assistant Professor of Chemistry at the University of Szeged, Hungary. His primary interest concerns with the physical chemistry and materials science of graphene oxide. He received both his MSc (2002) and PhD (2006) from University of Szeged, where he was mainly involved with the early research on the chemical and nanostructure of graphite oxide. He spent alltogether 3 years as postdoctoral researcher at the Catholic University of Leuven (Belgium), and at  the University of Geneva (Switzerland). He has then joined the Chemistry Institute in Szeged, where his main teaching roles are related to colloid and interface science. Accordingly, he is active in various fields of research employing aqueous colloidal graphene-based dispersions. He has been awarded the Polányi Prize of the Hungarian Academy of Sciences in 2011.