Direct coloration of textiles with photochromic dyes. Part 3: dyeing of wool with photochromic acid dyes

Shah Reduwan Billah, Robert M. Christie, Renzo Shamey

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21 Citations (Scopus)


Wool dyed with two isomeric water-soluble spirooxazine-based photochromic acid dyes, which were specifically designed and synthesised for direct application to protein and polyamide substrates, showed reversible change from a pale yellowish colour to blue when exposed to sunlight or UV light. With the first dye, significantly higher photochromic colour change was obtained when the wool was bleached, a feature attributed to a more open fibre structure which may facilitate penetration of the non-planar dye anion and also the photocoloration reaction which requires a change in molecular geometry. Experimentation demonstrated that the optimum conditions for application of this dye to wool was from an aqueous dyebath at neutral pH and a temperature of 60 degrees C. An investigation using HPLC demonstrated that the dye was susceptible to decomposition in aqueous solution at higher temperatures and at lower pH values. The second dye was also applied to wool fabric to give a fabric with similar photochromic properties. The technical performance of the dyed fabrics, in terms of washfastness and photostability, was assessed.

Original languageEnglish
Pages (from-to)488-492
Number of pages5
JournalColoration Technology
Issue number6
Early online date3 Oct 2012
Publication statusPublished - Dec 2012

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