4. BioChromes¶

Research¶

This week, we will be dyeing natural textiles using dyes extracted from various natural components Pigments are substances that provide color to materials. Since ancient times, various cultures have used natural pigments extracted from sources such as minerals, plants, insects, and other elements to color textiles, paintings, and artistic objects. For example, the Egyptians used iron oxide pigments for their murals, and the Maya used indigo, a natural blue dye.

Industrial Development of Pigments¶

During the 19th and 20th centuries (1800-1960), the chemical industry experienced a significant boom in the production of synthetic pigments. These industrial pigments, made from chemical compounds derived from petroleum, became the preferred choice due to their low cost, wide range of colors, and ease of mass production. However, many of these pigments contain heavy metals or chemical compounds that can be toxic to both humans and the environment.

Questioning and Activist Movements (1960 onwards) In the 1960s, activist movements began questioning the indiscriminate use of these synthetic pigments. These movements focused on the risks associated with exposure to certain compounds, such as lead and cadmium, which are harmful to health and pollute the environment. This led to a greater emphasis on the regulation and control of chemicals in products.

Revival of Natural Pigments¶

In response to these concerns, there has been a resurgence of interest in natural pigments. These are derived from plant, mineral, or animal sources and do not pose as significant a risk to health or the environment.

References & Inspiration¶

billynou_ Billy Nou🌸 is a natural dyer and slow fashion designer who focuses on sustainable fashion practices. Her work emphasizes the use of eco-friendly materials and natural dyeing techniques, transforming textiles with colors derived from plants and other organic sources. As a slow fashion advocate, she promotes mindful consumption, ethical production, and the preservation of traditional craftsmanship. Her creations often reflect a deep connection to nature, showcasing unique textures and earthy tones that celebrate the beauty of natural materials.

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The article discusses the benefits of using natural colorants in the food industry, as opposed to synthetic dyes, which can pose health risks. It highlights various plant-based pigments, such as anthocyanins, betalains, carotenoids, and chlorophylls, which not only enhance the visual appeal of foods but also offer health benefits like antioxidant and anti-inflammatory properties. The trend toward natural colorants aligns with global efforts to reduce synthetic chemical usage in food production.

Mina Smith page

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Links to reference files, PDF, booklets,

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Extraction and Kinetic Study of the Degradation of Betalains Present in Fuchsia Bougainvillea (Bougainvillea sp).

Process and workflow¶

Our team worked together to create various pigments with different shades and tones. Our guide for the week was María José, a chemical engineer with a master's and doctorate in biochemical engineering. She advised us on the process of generating our wide range of pigments. Each of us worked with two natural elements to produce multiple pigments. In my case, I used bougainvillea flowers and experimented with the indigo blue pigment that Anastasia Pistofidou kindly provided for us to explore.

Fabric preparation¶

First, we had to prepare the fabric by washing it to remove any factory residues. After that, the fabric is mordanted to ensure it absorbs the dye more effectively.

ingredients

4 lt of distilled water
1 balance
Sodium carbonate, at 2% of WOF

In the preparation of the fabric, we also worked as a team. My partner Raúl cut the fabric into squares using a laser cutter, while my colleague Aristarco carried out the washing process, and I assisted him.

Mordanting process¶

The mordanting process involves treating the fabric with a substance that helps the dye bond more effectively to the fibers.

ingredients

Distilled water 4 or 5 l
1 balance
Alumbre 15 % WOF for cotton fabric
Aluminium Sulfate for the wool cloth

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Bougainvillea¶

The bougainvillea, also known as Bougainvillea, is an ornamental plant native to South America, especially Brazil, Peru, and Argentina. It is known for its bright and colorful bracts, which are often mistaken for petals and can come in pink, purple, white, or red. The actual flowers are small and white. In addition to its decorative use, bougainvillea is used in traditional medicine to treat respiratory problems, and its natural pigments, such as betalains, are used for dyeing fabrics and food.

To use bougainvillea for dyeing fabrics, the process involves extracting the pigment from the petals. First, the flowers are heated in water to release the betalain pigments. The mixture is then strained to separate the liquid dye. Fabric is submerged in the dye and heated to help it absorb the color, usually for about 25 minutes. The dye’s color can be influenced by adjusting the pH, using substances like hydrochloric acid or sodium hydroxide, which can intensify or darken the hue.

ingredients

6.8 grams of bougainvillea petals
Distilled water
Water
1 balance
1 beaker
1 mixelectric grill
1 coffee filter
1 collected it in a blue borosilicate jar
1 funnel
1 test tube
Hydrochloric acid (HCl)
Sodium hydroxide (NaOH)
PH strip
1 stainless steel bowl
blanket fabric and wool

"Figure 7. Structure of Betalains. Source: Ecorfan Handbook on Engineering and Technology Sciences."

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Indigo blue¶

Indigo blue pigment is one of the oldest and most iconic dyes in human history. It has a deep and vibrant hue that has been valued across various cultures for millennia. Here’s more about this pigment:

ingredients