A friend’s son dropped some methyl orange solution on a light-grey carpet. Naive attempts by the parent to remove it using “Vanish” (a domestic carpet cleaning product) merely resulted in it changing colour from orange to yellow. I am no chemist, but here I search for a stain-removal method.
Web-search seems to indicate that:
- Methyl Orange is a traditional form of dye.
- Also it is a ph indicator, a water solution of it is orange in its own weakly acidic state, becoming yellower with increasing alkali. I guess “Vanish” is alkaline then…
- It is also toxic and could potentially be carcinogenic, e.g. if the powder is inhaled.
- It breaks down in daylight?
- In that case maybe all my friend needs to do is hang it ouside in the sunshine?
- Or does this only happen in the context of specially-treated fibres?
- ???
Web Research:
- http://www.scribd.com/doc/47832345/A-level-Chemistry-Investigation-Methyl-Orange
- Long paper describing experiments for its production and measurement.
- http://bsclarified.wordpress.com/2012/01/23/how-to-clean-your-clothes-without-water/
- researchers have developed a new self-cleaning cotton fabric that just requires visible light, which would be a more efficient use of the sunlight available [2]. Deyong Wu, from the School of Chemical and Environmental Engineering at Hubei University for Nationalities in China, and his colleague made the new material by treating the cotton fibres with a combination of nitrogen-doped titanium dioxide (N-TiO2) and silver-iodide (AgI).The team evaluated the self-cleaning properties of the new cotton fibres based on the removal of methyl orange, a dye commonly used in textiles. The dye breaks down with exposure to visible light by a process known as photocatalytic degradation. With just two hours of exposure to visible light, about 70% of the dye was removed from the cotton fibres.
- http://www.cleapss.org.uk/attachments/article/0/SSS70.pdf?Secondary/Science/Student%20Safety%20Sheets/
- Wash off skin with soap and plenty of water
- Rinse contaminated clothing.