Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10375060 | Colloids and Surfaces B: Biointerfaces | 2005 | 6 Pages |
Abstract
The aim of this work was to investigate the diffusion of Rhodamine B into bleached, photo bleached and abraded hair, treated or not with an emulsion of ceramide using two different techniques: spectrophotometry and fluorescence optical microscopy with image analysis. This comparison, combined with the Einstein-Smoluchowski equation, allowed validating a methodology that uses the apparent diffusion coefficient of a dye as an index for hair damage. Distinct behaviors of the dye were observed in the cuticle and in the cortex. For a bleached hair sample the apparent diffusion coefficient in the cuticle ranges from 8.2Â ÃÂ 10â11Â cm2Â sâ1 to 10Â ÃÂ 10â11Â cm2Â sâ1, while for the cortex this value drops to 4.0Â ÃÂ 10â11Â cm2Â sâ1 to 4.2ÃÂ 10â11Â cm2Â sâ1. The diffusion is always faster in the cuticle than in the cortex and the apparent diffusion coefficient shows up to a seven-fold decrease when the dye penetrates the cortex. The chemical, photochemical and physical treatments applied to hair significantly change the values of the apparent diffusion coefficients in the cuticle. The data also proved that the penetration of Rhodamine B into hair occurs via an intercellular path.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Colloid and Surface Chemistry
Authors
A.L. dos Santos Silva, I. Joekes,