Tie-dying is always a great year-end experiment and as chemists. A real bonding experience is fun to guess which student will end up with the most dye on their arms. Students also have an opportunity to incorporate chemistry in a meaningful way while creating a nice keepsake.

First, you’ll want to purchase reactive dyes since they are very brilliant and colourfast. They actually bond with the fabric, making the colour on the shirt last longer and the chemistry more interesting. Despite student protest that this is “just supposed to be fun”, tie-dying is an opportunity to review concepts of concentration, absorbance and transmittance. With a PASCO Wireless Spectrometer (PS-2600), you can explore the absorbance of the different coloured dyes before you start the process of colouring your shirts.

To really engage students in the technique of dying and in engineering process skills, the experiment can be opened up to student inquiry. Some things they could investigate as they try to create more vibrant colors include:

• Comparison of reactive dyes, union dyes and acid dyes
• Preparation and use of natural dyes
• Comparison of synthetic and natural fabrics
• Dying conditions like temperature, time and pH

To explore natural dyes create a yellow dye using turmeric, a red dye using beets, a purple dye using blackberries and a blue dye using red cabbage. It is possible to change the red cabbage blue by adjusting the pH of the solution. The results on the fabric are mixed, but because of the real-world application of science and engineering practices, the student learning is very real.  And if nothing else, everyone gets to take home a really cool shirt.

More labs with spectrometer

With the Wireless Spectrometer you can also perform these labs:

• Emission spectra of light
• Absorbance and transmittance spectra
• Beer’s Law: concentration and absorbance
• Kinetics
• Fluorescence

Pasco Wireless Spectrometer

Watch the video below about Quick Start with PASCO Wireless Spectrometer (PS-2600).

Read more about PASCO Wireless Spectrometer in STE.education Product Catalogue.

To purchase, send an email to: ask@ste(.)education. (Brackets must be removed from the email address before sending.)