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The Chemical Educator
ISSN: 1430-4171 (electronic version)
Abstract Volume 13
Issue 6 (2008) pp 344-347
Green Chemical Experiment: Indigo Dyeing
Nobuyoshi Koga*, A.H.A. Oliveira, and Kazuma Sakamoto
Department of Science Education, Graduate School
of Education, Hiroshima University, 1-1-1 Kagamiyama, Higashi-Hiroshima
739-8524,
Japan, nkoga@hiroshima-u.ac.jp
Received March 9, 2007. Accepted July 24, 2008.
Published online: 1 December 2008
Abstract. A possible way to improve the experiment of indigo dyeing using green chemistry is examined. In the preparation of the dyestuff solution, the sulfurous reducing agent for reducing water-insoluble indigo into water-soluble leuco-indigo can be replaced with a reducing sugar by slightly increasing the alkalinity of the reactant solution and by using ultrasonic waves to lower the reduction temperature. The dyeing process is also accelerated by the effect of ultrasonic waves. On the basis of the examination of the practical reaction conditions, a green chemical experiment of indigo dyeing is proposed as a student experiment in chemistry courses at secondary schools and colleges.
Key Words: Laboratories and Demonstrations; general chemistry; green chemistry; teaching materials; indigo dyeing; eco-friendly reducing agent; ultrasonic wave
(*) Corresponding author. (E-mail: nkoga@hiroshima-u.ac.jp)
Article in PDF format (124 KB) HTML format
Issue date: December
1, 2008
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