Dye fabrics with radish, cabbage and onion scraps

They extracted and separated dyes for wool, cotton and linen from plant matrices, essentially agricultural waste, such as radishes, red cabbage, artichokes, red onion and golden onion. And they won the first prize of the 'InvFactor - you are a genius too!', organized by the Institute for Research on Population and Social Policies of the National Research Council (Irpps-Cnr) and by the Representation in Italy of the European Commission. I'm the boys of the Iti 'Cannizzaro' of Catania ', with the professor Angela Percolla that tells their winning proposal is: 'Let's dress in the colors of nature '.

1) How did the idea of ​​natural dyes come about?

During a summer internship at the Chemical laboratory of the customs office in Palermo, the students ofITI Cannizzaro of Catania, Chemistry address (IV A) have been able to see how in colored fabrics there are often toxic substances for humans. We therefore asked ourselves: can natural dyes be a valid alternative to synthetic dyes today?

Imported products from some countries are sometimes treated with non-compliant chemicals. Azo dyes, often present in Chinese fabrics, carried by sweat, are absorbed by the skin. These dyes, due to the action of enzymes, are subsequently transformed into free aromatic amines, harmful to human health.

2) What novelties do you propose?

The element of great innovation was the study of the healthiness of dyes, as well as the environmental impact assessment resulting from their use. Another aspect of the project, of fundamental importance from a technical-application point of view, was the study of the natural color, of instrumental techniques for reading and managing color, well known and used for synthetic dyes at dyeing and industrial level.

At the end of the extraction of the natural dyes, spectrophotometric analyzes were performed in our laboratories as well as by method for the synthetic dyes.

3) What kind of awareness was there among young people on the subject at the beginning and at the end of the project?

The issue of environmental sustainability and issues relating to "Green Chemistry" were always addressed in the classroom. Last year the same class won the 3rd INVFACTOR National Award with the work “Fruit Solvents - Eco-friendly solvents from Sicilian citrus fruits”. I believe that young people today are aware of issues concerning environmental sustainability.

4) What problems arose in carrying out the work and what possible solutions?

No particular problem: the work was carried out in the school laboratories where the students worked both individually and in groups. At the end of the laboratory activity, they created a sample of fabrics colored with natural dyes.

5) What did the boys do?

After choosing the raw materials, that is agricultural waste products such as red cabbage, radishes, red onion and golden onion, the students extracted the dyes in both water and alcohol. Then it moved on to a real one dyeing workshop: natural fabrics such as wool and cotton, after a phase of etching, have been immersed in the color bath. Subsequently, color stability tests were performed in light and washing and a series of spectrophotometric analyzes.

6) Apart from the competition you are participating in, what other initiatives on green issues exist in your school?

Every year I propose a topic on Green Chemistry that differs according to the type of students. In the two-year period I deal with topics such as waste disposal, separate collection, the production of compost, in the three-year period we move on to issues that are well linked to ministerial programs: production and analysis of biodiesel from fried oil, environmentally friendly solvents, bio-plastics, and today dyes natural.

7) Let's hear the kids: how do you perceive the problem of environmental sustainability for your future? What does the school do? And the institutions?

The issue of environmental sustainability is one of the crucial points of economic and social development policy. It is clear that the planet seems to suffer from irreversible environmental degradation, the causes of which are quite clear. The technological domination of the environment is leading to slow and uncontrolled ecological damage. At school, many teachers deal with topics such as environmental pollution, energy resources, climate change, waste reduction and therefore we students have perceived the importance of these issues.

Unfortunately, institutions are not very sensitive to some issues: in Catania, for example, separate waste collection is struggling to take off and car traffic still shows non-existent sustainable mobility.

INV Factor: Timpano pupils Daniele and Di Nanno Michela. Prof. Percolla Angela and Palermo Maria

Interview byMarta Abbà

Video: How to turn unwanted food scraps into stunning natural dye (October 2020).