Release Time:2019-03-09  Hits:

Indexed by: Journal Article

Date of Publication: 2011-12-01

Journal: DYES AND PIGMENTS

Included Journals: EI、SCIE、Scopus

Volume: 91

Issue: 3

Page Number: 389-395

ISSN: 0143-7208

Key Words: Anthraquinone dyes; Dye/amphiphile system; Solvatochromism; Binary solvent mixture; Solvent polarity; Solvation state

Abstract: The absorption spectra of novel dye/amphiphile systems, in which the dye is a 1,5-bis-(R-phenylamino) anthraquinone [R = o-methoxy, o-ethoxy, H] and the solvents are either organic or H(2)O/organic solvent mixtures, have been investigated. It was found that an abrupt lambda(max) shift of more than 80 nm occurred for the system containing dye having R = o-methoxy and the amphiphile (poly-bis-(2,2'-dimethyl-5,5'-disulphonate)naphthylmethane disodium salt) in pure solvents with a specific E(T)(30) value or in H(2)O/DMF (N,N-dimethylformamide) mixtures containing at least 38% water. This type lambda(max) shift was not observed when solvent mixtures containing the other two dyes were studied. The origin of the pronounced lambda(max) shift is discussed in detail. It is believed that this shift arises mainly from changes in the solvation state of hydrophobic dye having R = o-methoxy when water is introduced in the presence of a dispersing agent. In this regard, dye is converted from the monomolecular state to dispersed particles. (C) 2011 Elsevier Ltd. All rights reserved.