pH Dependence of the Interaction between Rhodamine B and the Water-Soluble Poly(sodium 4-styrenesulfonate)

Abstract

The binding of rhodamine B (RB) to the polyanion containing aromatic groups poly(sodium 4-styrenesulfonate) (PSS) is studied by separation and spectroscopic techniques at pH between 2 and 7. Significant binding is found at pH below 5, together with a red-shift of the RB maximum of absorbance to 564 nm, and RB fluorescence quenching. The dependence of the pH is related with protonation of RB molecules. Fluorescence quenching is a consequence of a more hydrophobic environment and may occur on territorially or site-specifically bound molecules, and/or on self-aggregated molecules in a hydrophobic polymer domain. Remarkably, the basicity of RB is increased by the influence of the polymer.

Binding of Methylene Blue to Polyelectrolytes Containing Sulfonate Groups

“…We have already reported the high ability of this polymer to bind aromatic cations or zwitterions, due to a suitable complementation of short-range electrostatic forces, nonspecific hydrophobic interactions, and ar/ar interactions. [28][29][30][31][32][33] UV-Vis analyses show that in the presence of small amounts of PSS, the aggregation of MB is also induced in the environment of the polymer, as can be seen in Figure 7 by the disappearance of the monomer band. But as the concentration of PSS increases from an equimolar ratio (in sulfonate groups), the band corresponding to the higher aggregates shifts continuously to 616 nm, revealing the continuous formation of smaller aggregates.…”

“…Thus, the luminescent, [28][29][30] redox, [31] acid/base, [29,30,32] and binding properties [29][30][31]33] of various substrates are modified by this method. Ar/ar interactions are one of the principal noncovalent forces governing molecular recognition and biomolecular structure.…”

Photoinduced interaction between xanthene dyes and colloidal CdS nanoparticles

“…These dyes are interesting molecules with spectral luminescence properties that make them useful as a marker, as a probe in studies of biological systems in sensors etc. [16][17][18]. In literature photophysical properties of xanthene dyes is well established [19,20,13].…”

Water‐Soluble Polyelectrolytes with Metal Ion Removal Ability by Using the Liquid Phase Based Retention Technique

“…This method is known as the liquid-phase polymer-based retention (LPR) technique. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] Water-soluble polymers are commercially available or can be synthesized by different routes. Among the most important requirements for technological applications of these polymers are: high solubility in water; an easy, inexpensive synthesis route; an adequate molecular weight and molecular weight distribution; chemical stability; high affinity for one or more metal ions; and selectivity for the metal ion of interest.…”