Showing papers by "Guido Viscardi published in 1993"
TL;DR: In this paper, a novel 4-Tert-butyl-1-(4-dimethylaminobenzylideneamino)pyridinium perchlorate (BDPP) is described.
36 citations
TL;DR: In this article, the micellar-enhanced ultrafiltration technique was used for the preconcentration of aniline derivatives present in aqueous solutions containing ionic surfactants.
Abstract: The preconcentration of aniline derivatives present in aqueous solutions containing ionic surfactants was performed using the micellar-enhanced ultrafiltration technique. The efficiency of the analyte recovery in the surfactant-rich retentate was significantly improved by exploiting the electrostatic, hydrophobic and specific interactions between the aggregates and the solute molecules. By working at low pH, in the presence of anionic micelles, the quantitative retention of amines having different substituent groups can be achieved. The enriched sample can be analysed directly using high-performance liquid chromatography.
27 citations
TL;DR: The absorption and fluorescence characteristics of 2(4-aminophenyl)pyrido[3,2-d]oxazole (1), of its thiazole 2 and imidazole 3 analogues, as well as of the corresponding pyrido [3,4-d]-imidazoles 4 have been examined in this article.
23 citations
TL;DR: In this paper, a wide series of electronic spectra of assembled heterocyclic systems (pyridine or quinoline, benzoor pyrido-X-azole), of their quaternary salts and of the related polymethine dyes has been considered in the light of general relationships obtained.
9 citations
TL;DR: In this article, N,N-diethylaminoazo-benzene was tested as a model dye, in quantitative studies on the dyeing of secondary cellulose-acetate rayon, and the effects of surfactant, cosurfactants with tuned HLB values, and long chain alcohols on both the spectral behaviour and the partition of the dye between the bath and the substrate, were investigated.
Abstract: Microemulsions, or their precursors, are assuming increasing importance in dyeing processes. N,N-diethylaminoazo-benzene was tested, as a model dye, in quantitative studies on the dyeing of secondary cellulose-acetate rayon. The effects of surfactant, cosurfactants with tuned HLB values, and long-chain alcohols on both the spectral behaviour and the partition of the dye between the bath and the substrate, were investigated. Taking advantage from quantitative results, technical dyeing tests were carried out on a substituted azobenzene dye possessing very good fastness properties. The tests evidenced the important role of sonication and of the choice of the suitable cosurfactant. The presence of an oil component promoted excellent dye uptake, uniformity of coloration, saving chemicals and related environmental implications.
6 citations