Examples of different fabrics are positioned in one dye bath containing three dyes. Materials emerge colored different tints, illustrating how dyeing requires specific substance interactions between the dye and molecular nature of fibre.
This can be apt to be done as an instructor demonstration, in framework regarding the topic of natural dyestuffs, either as a basic attention-grabber, or later inside topic to stimulate conversation of chemical communications involved in dyeing. If products for the demonstration were fully ready, the demonstration itself should take around 30 minutes. The demonstration is scaled up as needed for larger viewers.
Beakers (400 cm3), 4
Big view eyeglasses or petri meals, 4
Tongs or forceps
Sample pipes, stoppered, 6
Heat resistant pad
String and report videos, crocodile videos or garments pegs (Note 1)
Examples of these materials in white (Note 2):
wool, silk, plastic, cotton fiber, polyester, cellulose acetate (‘triacetate’), polyester/cotton blend.
Top pan stability
Acid blue 40, 0.06 g
Disperse yellow 7, 0.04 g (IRRITANT)
Direct red 23, 0.04 g (IRRITANT)
Hydrochloric acid, 2 M (IRRITANT), tiny amount
Make reference to wellness & Safety and Specialized notes part below for additional information.
Health & protection and Technical notes
Wear attention defense
Acid blue 40, Disperse yellow 7 (IRRITANT) and Direct red 23 (IRRITANT) - see CLEAPSS Hazcard (Dyes, indicators and spots). Bottles is established in a fume cabinet. The dilute solutions are low danger but will stain epidermis and garments. Defensive gloves (ideally nitrile) is worn. Weigh-out into stoppered test pipes, two examples of 0.02 g of every regarding the purple and yellow dyes, and two types of 0.03 g associated with blue dye. Label each sample tube. These dyes are available from Philip Harris Ltd or from - see connect to Dyes for Salters Advanced Chemistry). If the teacher requires the dye bath becoming made prepared before the tutorial, break down 0.02 g of every of red and yellow dyes, and 0.03 g associated with blue dye in 200 cm3 of water in a beaker, add a few falls of dilute hydrochloric acid as well as heat to boiling.
Hydrochloric acid, HCl(aq) (IRRITANT at focus used) - see CLEAPSS Hazcard and CLEAPSS Recipe Book.
1 Ready a ‘clothes line’ using string between laboratory stands, long enough with sufficient ‘pegs’ (crocodile films, report films or miniature clothing pegs) to hold from dyed material samples.
2 About 100 cm2 of every material, or a couple of cm of thread will be enough. As the very least, samples of cotton, either polyester or cellulose acetate, and either wool, silk, or plastic are needed. White plastic, 100per cent, is difficult to acquire also it might essential to take to a second-hand clothes shop. Cut four pieces of every textile (about 4 cm x 4 cm works). Each fabric should-be easily recognizable one way or another, as an example by cutting different shapes.