Semiconducting cotton fabrics
doi:10.1038/nindia.2016.13 Published online 27 January 2016
Researchers have synthesized novel semiconducting cotton fabrics by coating the surface of cotton fibres with a carbohydrate-based gel1. These semiconducting fabrics are potentially useful for developing protective layers that can absorb harmful electromagnetic radiation and prevent damage to electronic devices caused by static electricity.
Fabrics that are currently used to wrap various electronic devices are electrical insulators. However, these fabrics build up static electricity, which is harmful to devices and even to humans.
To devise a safe conducting fabric, the researchers synthesized a colourless transparent gel using a carbohydrate-based compound decorated with diacetylene groups, which can self-assemble in non-polar solvents. When exposed to ultraviolet light, the colourless gel turned pink, indicating that diacetylenes had converted into polydiacetylenes. The band gap of this polydiacetylene gel is in the range of that of semiconducting materials.
To probe whether this gel can be used to make semiconducting fabrics, the scientists coated a cotton cloth with a thin layer of the gel by dipping the cloth in a hot solution of the colourless gel and then cooling it to room temperature.
When exposed to ultraviolet light for 2 days, the colourless coating on the cotton changed to pink, indicating the formation of a semiconducting fabric. This cotton cloth could be washed multiple times without leaching the semiconducting material.
“Since it doesn’t use any catalysts or generate any toxic by-products, this method of producing semiconducting fabrics is ecofriendly,” says lead researcher Kana Sureshan.
1. Krishnan, B. P. et al. Semiconducting fabrics by in situ topochemical synthesis of polydiacetylene: a new dimension to the use of organogels. Angew. Chem. Int. Ed. 54, 1–6 (2015)