Greening up the blue dye in jeans, police uniforms and the red, white and blue

Apr 04, 2012

Efforts are underway to develop a more environmentally friendly process for dyeing denim with indigo, the storied "king of dyes," used to the tune of 50,000 tons annually to color cotton blue jeans and hundreds of other products. That effort is the topic of an article in the current edition of Chemical & Engineering News (C&EN). C&EN is the weekly newsmagazine of the American Chemical Society (ACS), the world's largest scientific society.

In the article, C&EN Assistant Managing Editor Michael McCoy notes that concerns about the environmental effects of indigo represent a modern concern about an ancient product. Indigo produces a rainbow of hues, ranging from deep navy to pale pastels. For centuries, the primary source of indigo was branches of a bush native to India. In 1878, German chemist and Nobel laureate Adolf von Baeyer made the first synthetic indigo, but the process was too expensive. It took chemical manufacturer BASF years to find a practical process for making the dye, and that happened only because of a lucky accident in which a lab worker broke a mercury thermometer, and the mercury catalyzed a reaction to make the dye.

The story describes how a partnership between the dye manufacturer DyStar and Swiss startup RedElec Technologie may be the beginning of a new revolution in indigo dyeing that will improve its environmental profile. To get indigo dye to attach to denim and other fabrics requires chemical reactions before and after the impregnates the cotton fibers. Even with modern improvements to the technique, the process produces large amounts of waste. The article highlights a new approach designed to achieve a long-standing goal of eliminating the need for sodium hydrosulfite in the dyeing process. Doing so would green up the indigo dyeing process and stop a water pollution problem at its source.

Explore further: Video: This town has been on fire for 50 years

More information: Into the Blue - cen.acs.org/articles/90/i14/Blue.html

Related Stories

Indigo ointment may help treat patients with psoriasis

Nov 17, 2008

An ointment made from indigo naturalis, a dark blue plant-based powder used in traditional Chinese medicine, appears effective in treating plaque-type psoriasis, according to a report in the November issue of Archives of ...

Ancient Mayans Inspire Modern Fade Proof Dye

Jul 30, 2010

Physicists have created a dye that promises to last for a thousand years. The secret to this extraordinary durability? Its formula is based on a Mayan pigment, a brilliant blue color that survives to this ...

Recommended for you

Video: This town has been on fire for 50 years

11 hours ago

In 1962, an underground fire started in the coal-mining town of Centralia, Pennsylvania. Fifty-three years later, that fire still burns. In this week's episode of Reactions, we explain the history and science ...

Genetic switch detects TNT

13 hours ago

Cleaning-up post-war explosive chemicals could get cheaper and easier, using a new genetic 'switch' device, being developed by scientists at the University of Exeter to detect damaging contaminants, such ...

Why Matisse's bright yellow pigments fade to beige

14 hours ago

An international team of scientists led by Jennifer Mass, Winterthur Museum's senior scientist and an affiliated University of Delaware faculty member, has announced new findings on why a bright yellow pigment ...

Killer sea snail a target for new drugs

Jul 06, 2015

University of Queensland pain treatment researchers have discovered thousands of new peptide toxins hidden deep within the venom of just one type of Queensland cone snail.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.