title: Photo-induced decolorization of dimethylmethylene blue with selenious acid: a novel method to examine selective monomer-dimer distribution of the dye in micelle.
abstract: In this report, selenious acid (H2SeO3) has been exploited to study the decolorization of a cationic dye, dimethylmethylene blue (DMMB) with UV-light. Micelles have effectively been employed as organized media to promote the rate of decolorization of the dye molecules. Micellar catalysis has been explained as a consequence of electrostatic, hydrophobic and charge transfer interactions. It has also been shown that strong charge transfer and electrostatic interaction lead to an appreciable enhancement of the reaction rate in micelle, whereas, weak hydrophobic interaction is of marginal importance. Existence of monomer-dimer equilibrium for the dye molecules under certain selective environments has been identified spectrophotometrically. Then the shift of dimer-monomer equilibrium of the dye has been successfully studied in aqueous and micellar environments exploiting photodecolorization process for the dye in solution. 'Salting-in' and 'salting-out' agents were introduced into the reaction mixture to examine the viability of the dye decolorization process for dye contaminated water samples.
authors.affiliation: Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India.
authors.forename: Sudip
authors.initials: S
authors.lastname: Nath
authors.forename: Sujit Kumar
authors.initials: SK
authors.lastname: Ghosh
authors.forename: Sudipa
authors.initials: S
authors.lastname: Panigrahi
authors.forename: Tarasankar
authors.initials: T
authors.lastname: Pal
mesh_terms: D003116:Color; D004396:Coloring Agents / Q000737:chemistry*; D019281:Dimerization; D057927:Hydrophobic and Hydrophilic Interactions; D008027:Light; D008751:Methylene Blue / Q000031:analogs & derivatives* / Q000737:chemistry / Q000528:radiation effects; D008823:Micelles; D010777:Photochemistry; D020887:Selenious Acid / Q000737:chemistry*; D013053:Spectrophotometry; D055672:Static Electricity; D014867:Water / Q000737:chemistry
chemical_list: D004396:Coloring Agents; D008823:Micelles; C435946:dimethylmethylene blue; D014867:Water; D020887:Selenious Acid; D008751:Methylene Blue