Effect of Laponite and a nonionic polymer on the absorption character of cationic dye solutions

Koray Yurekli; Emily Conley; Ramanan Krishnamoorti

doi:10.1021/la047540k

Effect of Laponite and a nonionic polymer on the absorption character of cationic dye solutions

Langmuir. 2005 Jun 21;21(13):5825-30. doi: 10.1021/la047540k.

Authors

Koray Yurekli¹, Emily Conley, Ramanan Krishnamoorti

Affiliation

¹ Department of Chemical Engineering, University of Houston, Houston, Texas 77204-4004, USA.

PMID: 15952829
DOI: 10.1021/la047540k

Abstract

The effect of Laponite and an amphiphilic triblock copolymer of poly(ethylene oxide) (PEO)-poly(propylene oxide) (PPO)-poly(ethylene oxide) (PEO) (PEO(99)-PPO(65)-PEO(99), and labeled F127) on the absorption character of two cationic dyes, methylene blue and toluidine blue O, was studied and interpreted in terms of the changing state of aggregation of the dye molecules. The combined effect of the polymer and Laponite on dye absorption was significantly different from their individual influences. Specifically, the presence of Laponite resulted in an increase in monomer population by dispersing the dye on the silicate surface. The presence of F127 also resulted in an increase in the dye monomer population, although to a smaller extent. The combined effect of the polymer and Laponite was an increase in the dimer or aggregate populations attributed to the competition of F127 with the dye molecules for the silicate surface.