Effects of urea and thiourea on the absorption and fluorescence behaviours of the dye safranine T in micellar medium

✍ Scribed by Kamala R. Acharya; Subhash C. Bhattacharya; Satya P. Moulik

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 480 KB
• Volume: 87
• Category: Article
• ISSN: 0167-7322
• DOI: 10.1016/s0167-7322(00)00130-6

✦ Synopsis

The absorption and fluorescence extents of the dye Safranine T (ST) are influenced by miceUar solution. The critical micellar concentration (CMC), aggregation number and mieeUe-ST binding constant of ionic surfacta~ sodium dodeeylsulphate (SDS) and nonionic surfnctan~ polyoxyethylene (20) sorbitan -monolaurate, -monopaimltate, -monostearate and -monooleate (Tween-20, Tween-40, Tween-60 and Tween-80) respectively have been determined by exploiting the spectral behaviours of ST in presence of urea and thiourea. The CMC and the aggregation number of the micelles have been found to increase and decrease iespectively in presence of the additives urea and thiourea. While thiourea has greater EMC increasing effect than urea, it diminishes tile aggregation number of the micelles efficiently than urea. The dye-micelle binding constant has been found to decrease in presence of urea and thiourea. Thiourea also quenches the fluorescence of ST in aqueous as well as in micellar medium.