Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Bujdák, J. Articles by Iyi, N. Search for Related Content GeoRef GeoRef Citation

VISIBLE SPECTROSCOPY OF CATIONIC DYES IN DISPERSIONS WITH REDUCED-CHARGE MONTMORILLONITES

¹ Institute of Inorganic Chemistry, Slovak Academy of Sciences, SK-842 36 Bratislava, Slovakia
² National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan

^* E-mail address of corresponding author: uachjuro{at}savba.sk

The aggregation behavior of one azine and three triphenylmethane cationic dyes in dispersions of reduced-charge montmorillonites (RCMs) was investigated. The extent and types of dye aggregation were monitored using visible spectroscopy. Similar relationships between dye aggregation and layer charge were observed, independent of the structure of the dye cations. High charge-density surfaces induced the formation of H-aggregates, with a face-to-face association between the dye cations that then absorb light at relatively lower wavelengths. Moderate reductions in layer charge were reflected in the lowering of the H-aggregation in favor of monomers, dimers and less densely-packed J-aggregates, absorbing light at higher wavelengths. Dye spectra in the presence of the lowest-charge RCMs resembled those of dilute dye solutions, indicating the absence of dye aggregation of any type in this case. The relationship between dye spectral changes and layer-charge densities of smectites is a general phenomenon which can potentially be used to estimate the layer charge of smectites. However, applying this method to triphenylmethane dyes, which have structurally more complicated cations, may reduce the sensitivity of the probe.

Key Words: Cationic Dyes • Dye Aggregates • Layer-Charge Density • Montmorillonite

This article has been cited by other articles:

				Y. Suzuki, S. Hirakawa, Y. Sakamoto, J. Kawamata, K. Kamada, and K. Ohta HYBRID FILMS CONSISTING OF A CLAY AND A DIACETYLENIC, TWO-PHOTON ABSORPTIVE DYE Clays and Clay Minerals, October 1, 2008; 56(5): 487 - 493. [Abstract] [Full Text] [PDF]

				P. Komadel, J. Madejova, and J. Bujdak PREPARATION AND PROPERTIES OF REDUCED-CHARGE SMECTITES - A REVIEW Clays and Clay Minerals, August 1, 2005; 53(4): 313 - 334. [Abstract] [Full Text] [PDF]