Tie dying chemistry fun

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  • 1. FLINN SCIENTIFIC INC. ((11 J J [, JJ :Jour Ja~ersource ~orscience JUpp ie» P.O. BOX 219 • BATAVIA, ILLINOIS 60510 • 800/452-1261 Vol. 93-4 CHElIISTRYEDITION ©1993 Flinn Scientific, Inc. Tie-Dyeing ~Chemistry Fun Penney Sconzo dye cellulose, a reactive dye must combine • Reactive Dyes Westminster School with the hydroxyl groups in the fiber. Place a small amount of cold water in a Atlanta, Georgia Tie dyeing is one of the oldest methods of beaker and add 4 to 6 teaspoons (12-18 The art of dyeing probably originated in printing designs on fabrics. Typically, parts grams) of the reactive dye you have India or China no later than 2500 BC. Most of the fabric are bunched together in a selected. Mix until lumps are removed natural dyes came from parts of plants such design and knotted or tied together with and all dye is moistened. Add urea solu- as the bark, berries, flowers, leaves, and string. Tied sections are protected from tion (as described above) to make a total roots. Because these dyes did not have a absorbing the dye and patterns are created. of one liter of dye solution.o strong attraction for the fibers being dyed, a process known as mordantinq was used to improve colorfastness. To react with acidic Related Chemical Concepts: Dyes, chrornophores, affinity (hydropho- The amount of reactive dye is not specific as it depends on how strong you want the colors to be. Colors like yellow will need more dye. Remember some of the dye dyes, fibers were treated with basic or bic/hydrophilic). covalent bonding vs. metallic mordants which might include adsorbtion, electrolyte concentration, equi- will wash out when the T-shirt is washed solutions of aluminum, copper, iron, or librium, kinetics, reaction rates (tempera- in hot water, so make the color darker chromium salts. Compounds formed by the ture effects, concentration effects), pH than you want as an end product dye and the mordant, called lakes, pre- Each student will require about one cup vented the colors from washing out and Materials Needed and Preparation of dye solution. For a class of 30 stu- made the color longer lasting. Such natural Instructions dents, prepare a total of 2 liters <5freac- . dyes became less and less important as syn- • T-shirts, 100% cotton, PFD (prepared for tive dye solution for each color you want thetic dyes that produced brighter colors dyeing) to use. were developed. Today, Iogwood black is the Reactive dyes should be stored at room only natural dye widely used. If you buy T-shirts that are not prepared temperature. for dyeing, they must be pre-washed in In 1856, William Henry Perkin began the hot water with 2 tablespoons of a mild If kept dry, reactive dyes have a shelf life synthetic organic chemical industry by detergent like Joy®, Dawn", Ivory", etc. of two years. accidentally discovering the purple dye, Do not use a detergent with phosphates • Plastic bucket mauveine, when he tried to produce quinine or chlorines. Dry shirts on the hot cycle • Plastic drop cloth from aniline. The synthetic dyes were known to remove spinning lubricants or other as coal tar dyes because the six-membered (Continued on page 2) surface additives. ring structures of carbon atoms were all de- rived from coal tar. Congo Red was the first • Sodium carbonate activator solution dye discovered with so great an affinity for For a class of 30 students you will need cellulose that a mordant was not required. approximately 8 liters of sodium carbon- ate activator solution. To prepare this About 100 years after Perkins first discov- solution, mix 250 grams of sodium car- ery, fiber-reactive dyes capable of forming bonate anhydrous into 8 liters of distilled covalent linkages with the fiber were dis- water and stir. covered. A fiber-reactive dye is washfast. During dyeing, dye molecules must diffuse • Urea solution from the aqueous solution and into the For a class of 30 students you will needo fibers. Fibers such as cotton absorb water readily and are said to be hydrophilic, while fibers such as polyester absorb water with approximately 8 liters of Urea solution. To prepare this solution, mix 650 grams of urea into 8 liters of water and stir. difficulty and are described as hydrophobic. This solution can be stored if it is not Dyeability is influenced if a fiber can some- mixed with the reactive dye. Urea how carry an ionic charge and better inter- increases the solubility of the heavy act with oppositely charged colored ions. To shades of reactive dyes.
  • 2. VoL93-4 CHEMISTRY EDITION TieDyeing-Continued • Rubber bands! size 33 (3 1I2"L x 1/8"W) etc. This makes a great lab to do before .Jumbo, Beral-type pipets, 15 ml bulb the Christmas holidays. Students can capacity . make personalized gifts that are afford- able. Use this activity as a fund raiser for • Beakers, 1000 ml the science club at your school. • Oven racks or sturdy plastic coat hangers interlocked between slats of wood Safety Precautions: • Rubber gloves Students should wear old clothes and shoes. Reactive dyes are "wash fast." Once • Ziplocksbags or small trash bags the reactive dye makes contact with clothes • Newspaper it will not wash out. Figure 2 Procedure: Do not let the students get sloppy. Hint This should be done in an area sep- Students should not squirt each other with 1. Fill the plastic bucket with 8 liters of arate from the dyeing area to prevent sodium carbonate activator solution. filled pipets of reactive dye solution. shirts frompickingup dye by mistake. Soak the T-shirts in the sodium carbon- Students should wear appropriate protec- ate activator solution for a minimum of 3. Dyeing can be done on oven racks placed tive clothing, e.g., chemical splash goggles, 20 minutes. The ionization of cellulose over sinks or on racks with newspaper disposable plastic gloves and chemical- increases with increasing alkalinity of underneath to absorb excess dye. After a resistant aprons. the solution and above pH 8 there is an shirt is placed on a clean rack, dyes can Hands may become stained from the reac- adequate number of ionized hydroxyl be applied using jumbo Beral-type pipets. Apply the dye to one side of the tive dye. It is not easily washed off and will groups in the fiber for most dyeing pur- take about two days for the dye to wear off poses. Soaking the T-shirts for 2 hours shirt by slowly squirting the reactive dye your hands, will maximize the number of possible solution onto each section of the shirt. A bonding sites. After the T-shirt has beautiful design can be made by dyeing Sodium carbonate activator solution is soaked, wring the T-shirt out over the each section of the shirt a .different very basic. Be sure to wear rubber or plastic plastic bucket. color. Once you are done dyeing one side gloves when placing the T-shirts in solution of the shirt, turn the shirt over and and when the shirt is wrung out at the end The sodium carbonate activator solution of the activation period. repeat the dyeing process. Shirts should is very basic so be sure to wear rubber drain for 15 minutes if possible. gloves when placing shirts in the solu- Disposal: Students tend to use a lot of dye and tion and when the shirt is wrung out at All of the chemical solutions and reactive there is a lot of dripping so be prepared. the end of the activation period. dyes may be disposed of according to Flinn Hint: Fewer beakers of dye and more Suggested Disposal Method #26b. Consult pipets work best. Too many beakers take your current Flinn Chemical Catalog/ too long to clean up and reorganize Reference Manual. between classes. Shirts can pick up some dye by mistake, but students will be Literature Cited: applying so much dye that it probably American Association of Textile Chemists will not matter. Clean work areas will and Colorists (MTCC). Dyeing Primer. A minimize problems. series of short papers on the Fundamentals 4. Place shirts in a plastic Ziplock" bag or of Dyeing. P.O. Box 12215, Research small trash bag and close to keep the Triangle Park, NC 27709. shirt moist. Drying will prevent the reac- Vickerstaff, T. "Theoretical Principles of tive dyes from fully reacting. Most colors Dyeing with Reactive Dyes." Procion will have completely reacted after 4 Dyestuffin Textile Dyeing, 1962, pp. 17-40. hours but less reactive colors such as Special thanks to Gerald Blackstone,2. Shirts are now ready to fold and tie. A green and turquoise will take as long as Eastchester High School, Eastchester, NY spiral pattern is created by laying the 24 hours. Be patient. Let the dyes react and Elenore Grow, Horizon High School, shirt flat on a surface protected by a completely. Brighton, CO for showing me how to tie-dye. clean dropcloth. The shirt is held with 5. At home, rinse the shirt in warm water Ordering information for Flinns Tie- the thumb and fingers at the point where (75-900F) in order to remove the unre- Dyeing-Chemistry Fun Kit is listed on the center of the spiral will be located. acted dye and the sodium carbonate acti- page 7 of this Flinn Fax. Individual tie- Use a twisting motion to coil the shirt vator. Change the water and continue to dyeing supplies may be found below. and use your other hand to bring the rinse. Repeat until the water remains loose ends of the shirt into the circle (see clear and the shirt does not feel slippery. Figure 1). Take four rubber bands and Set the washing machine on the HOT AP8701Z Pipets, Jumbo, Beral-type $ 9.50 slide them around the shirt so they inter- 15 ml capacity, pkgJ120 sect at the center where the twist began water setting and wash as many as 10 shirts at one time in 2 tablespoons of the AP8702Z Urea, 650 g 8.45 (see Figure 2). You now have what appears to look like a "pie" cut into eight pre-wash, such as Joy® or Dawn" dish- AP8703Z Sodium carbonate, 250 g 5.40 pieces. The bound shirt can be turned soap. Dry shirts on the hottest dryer set- AP8704Z Reactive Dye, Yellow, 8.50 over and dyed on both sides. We selected ting. The reactive dye is washfast so it is 45 grams this type of folding pattern because it is now safe to wash with other clothes using AP8705Z Reactive Dye, Red, 8.25 the easiest to do and the entire tie-dye- normal detergents. The reactive center on 45 grams ing process can be completed in a 50- the dyes is a dichloro-triazinyl group so Reactive Dye, Blue, 10.10 AP8706Z minute lab period. Students also like this do not use bleaches on the shirt. 45 grams pattern the best. 6. Now be creative! Try other patterns for AP8707Z Reactive Dye, Green, 11.25 folding. Dye labcoats, socks, tennis shoes, 45 grams