An insight into the mechanism of the cellulose dyeing process, part 2: Simulation of aggregation, solvent and additive effects upon azo-linked aromatics and dyes

Abstract

In order to probe the complex process of dying cellulosic materials with common azo-linked dye systems, the aggregation-disaggregation process has been studied using molecular simulation techniques. In particular, the dynamics of multiple dye species in both gaseous and aqueous environments have been examined by molecular modeling methods, with emphasis upon the effects of urea upon these species in aqueous solutions. Such simulation techniques can demonstrate the natural drive for dye molecules to aggregate in solution and compare well with those results obtained from spectroscopic results. In addition, molecular modeling does predict that urea tends to cause disaggregation, by breaking up dye clusters; this also closely follows literature prediction and practical predictions.