Polyelectrolytes-assisted layer-by-layer assemblies of graphene oxide and dye on glass substrate

Abstract

Pyronin Y (PyY) and graphene oxide (GO) were assembled on a glass substrate by the electrostatic layer-bylayer (LbL) method with the assistance of polyelectrolytes. Firstly, the glass surface was modified with the successive adsorption of positively charged PEI (polyethylenimine) and negatively charged PSS (poly(sodium-p-styrenesulfonate)) to enhance the loading of PyY molecules and GO sheets. Secondly, PyY molecules and GO sheets were loaded on the glass substrate depending on their charges after the successive adsorption of polyelectrolyte layers via a procedure of {PEI/GO/PEI/PSS/PyY/PSS} n . Thus, the LbL thin films containing PyY molecules and GO sheets, which remained stable for months, were homogeneously coated on the glass substrate. The photophysical and morphological features of the LbL films were examined. The spectroscopic data of the LbL films based on PyY revealed that H-aggregate and monomers structures of the dye molecules in the LbL films were formed by a function of the number of layers. Furthermore, the effect of immersion time on the molecular interaction of PyY molecules with the other components were studied in detail. SEM (scanning electron microscope) was used to examine the morphologies of as-prepared LbL thin films. SEM images revealed that the morphologies of LbL thin films were changed by the immersion time and the number of layers. Tel: +904422314410 † Electronic supplementary information (ESI) available: Normalized UV-vis absorption spectra of {PEI/GO/PEI/PSS/PyY/PSS} n multilayer lm at various layers and SEM image of {PEI/GO} 1 multilayer lm. See

The interaction of fluorescent Pyronin Y molecules with monodisperse silver nanoparticles in chloroform

“…It is not easy that two phenomenon are mostly recognized. Dye aggregation processes and their spectroscopic characterizations have been reported for many dyes in the presence of some additives such as polyelectrolytes [23], polymer [14] and colloidal particles [5,6,22] as well as clay particles [6,13,15]. The absorption spectrum of PyY (1.0x10 -5 M) in chloroform had two absorption bands appeared at 553 nm (monomer) and at 540 nm (H-dimer) (Figure 2).…”