Quantitative rate constants for radical reactions in the nanopores of cotton.
The understanding of radical reactions in nanostructured materials is important for developing new synthetic procedures and controlling degradation reactions. To develop this area, an easy method for measuring quantitative rate constants of some radical reactions in nanostructures is required. A simple method for measuring the rate constant of dye bleaching, kdye, by organic radicals in such materials is introduced, involving the measurement of microsecond bleaching kinetics by diffuse reflectance spectroscopy, following laser flash creation of the radicals. Using wet and dry cotton as model substrates, we obtained kdye of 2-hydroxy-2-propyl and 1-hydroxy-1-cyclohexyl radicals with reactive red 3 and reactive orange 4 and compared them to solution-phase values. Surprisingly, the reactions in cotton follow simple liquid-phase kinetics and are diffusion-controlled. A cage effect in cotton is also found.
Hunt
Paula
P
Department of Chemistry, University of Technology Loughborough, Leicestershire LE11 3TU, United Kingdom.
Worrall
David R
DR
Wilkinson
Frank
F
Batchelor
Stephen N
SN
D001391:Azo Compounds / Q000737:chemistry; D004396:Coloring Agents / Q000737:chemistry; D003368:Gossypium / Q000737:chemistry*; D007700:Kinetics; D010782:Photolysis
D001391:Azo Compounds; D004396:Coloring Agents