<p>Indian researchers have successfully developed an eco-friendly method to help silkworms spin naturally fluorescent, coloured silk - by feeding them dyed mulberry leaves.<br /><br /></p>.<p>For some 5,000 years, cultivated silkworms have been spinning luxurious white silk fibres destined for use in the finest clothing.<br /><br />However, current dyeing practices produce wastewater that contains potentially harmful toxins, so scientists are now turning to a new, "greener" dyeing method in which they coax already-coloured fibres from the caterpillars by feeding them dyed leaves.<br /><br />Anuya Nisal, Kanika Trivedy and colleagues from the National Chemical Laboratory in Pune point out that dyeing textile fabrics is one of today's most polluting industries.<br /><br />The process requires huge quantities of water for bleaching, washing and rinsing, and it results in a stream of harmful wastewater that needs to be treated effectively before release into the environment, researchers wrote in the study published in the American Chemical Society (ACS)'s journal Sustainable Chemistry & Engineering.<br /><br />To make the industry greener and more environmentally friendly, researchers have been developing less toxic methods, including feeding dyed leaves to silkworms so they spin coloured - rather than white - cocoons.<br /><br />However, so far, this technique has only been tested with one type of dye, which is too pricey for large-scale production.<br /><br />Thus, the team turned to azo dyes, which are inexpensive and account for more than half of the textile dyes used today.<br /><br />They dipped or sprayed mulberry leaves, the silkworm's food of choice, with azo dyes to see which ones, when consumed, would transfer to the silk.<br /><br />Of the seven dyes they tested, three were incorporated into the caterpillars' silk, and none seemed to affect the worms' growth.<br /><br />Scientists noticed that certain dye traits, such as the ability to dissolve in water, affected how well the dye worked.<br /><br />"These insights are extremely important in development of novel dye molecules that can be successfully used in this green method of producing coloured silk fabrics," scientists said.</p>
<p>Indian researchers have successfully developed an eco-friendly method to help silkworms spin naturally fluorescent, coloured silk - by feeding them dyed mulberry leaves.<br /><br /></p>.<p>For some 5,000 years, cultivated silkworms have been spinning luxurious white silk fibres destined for use in the finest clothing.<br /><br />However, current dyeing practices produce wastewater that contains potentially harmful toxins, so scientists are now turning to a new, "greener" dyeing method in which they coax already-coloured fibres from the caterpillars by feeding them dyed leaves.<br /><br />Anuya Nisal, Kanika Trivedy and colleagues from the National Chemical Laboratory in Pune point out that dyeing textile fabrics is one of today's most polluting industries.<br /><br />The process requires huge quantities of water for bleaching, washing and rinsing, and it results in a stream of harmful wastewater that needs to be treated effectively before release into the environment, researchers wrote in the study published in the American Chemical Society (ACS)'s journal Sustainable Chemistry & Engineering.<br /><br />To make the industry greener and more environmentally friendly, researchers have been developing less toxic methods, including feeding dyed leaves to silkworms so they spin coloured - rather than white - cocoons.<br /><br />However, so far, this technique has only been tested with one type of dye, which is too pricey for large-scale production.<br /><br />Thus, the team turned to azo dyes, which are inexpensive and account for more than half of the textile dyes used today.<br /><br />They dipped or sprayed mulberry leaves, the silkworm's food of choice, with azo dyes to see which ones, when consumed, would transfer to the silk.<br /><br />Of the seven dyes they tested, three were incorporated into the caterpillars' silk, and none seemed to affect the worms' growth.<br /><br />Scientists noticed that certain dye traits, such as the ability to dissolve in water, affected how well the dye worked.<br /><br />"These insights are extremely important in development of novel dye molecules that can be successfully used in this green method of producing coloured silk fabrics," scientists said.</p>