Diffusion into hair intercellular

For large metal complex dyes (>650Da), Feeder et al. [62] have demonstrated that intercellular diffusion of these materials occurs into wool fiber. Certain alcohols, such as butanols, are considered nonswelling solvents and have been shown by Jurdana and Leaver [63] not to penetrate into the cortex of wool but to penetrate readily into the cortex of human hair via the intercellular regions. 

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