Materials List: Designing a Color-Changing Paint Using pH

Part 1 (Day 1)

Each student needs:

Teacher Demonstration needs:

  • two 250 mL beakers
  • hot plate
  • tap water
  • pH indicator litmus paper, or a pH probe (if accessible) with buffers
  • dish towel
  • strainer
  • rubber mallet, food chopper, or mortar and pestle
  • scale, electronic or triple beam balance
  • vegetables, fruits, spices and beans, or flowers for demonstration (vegetables - beets, onion peels, red cabbage, spinach; fruits - berries, cherries; spices and beans - turmeric, coffee, tea; flowers - marigolds, dandelions, zinnia;) as an example, one pint of strawberries or blueberries for color extraction works well

Part 2 (Day 2-4)

Each student needs:

Each group needs:

  • three different types of organic materials from Day 1 (students can select these)
  • three 250 mL beakers
  • strainer
  • tap water
  • hot plate
  • rubber mallet, mortar and pestle, or food chopper
  • safety goggles
  • three 1-gallon Ziploc bags
  • dish towels
  • three stir rods
  • paint brushes
  • three to six pieces of copy paper or watercolor paper per dye. Suggest strips 0.00581m2 (1/16 ft2) in size.  (tested with: Strathmore Paint Pad, 100 Series https://www.strathmoreartist.com/kids/strathmore-100-seriesyouth-paint-pad.html
  • 100 mL beakers or test tubes of the three test solutions: white vinegar 5%, lemon juice, red cabbage water, baking soda solution
  • several droppers (plastic, 1 mL)
  • hair dryer or fan
  • pH paper (provide lots of pieces for experimentation!) or a pH probe with buffers
  • scale, electronic balance or triple beam balance
  • three Organic Chemist Recording Guide for Applying Dyes

Part 3 (Day 5-6)

Each student needs:

Each group needs:

To share with the entire class (if using verbal presentations):

  • computer with projector
  • easel
https://www.teachengineering.org/activities/view/uod-2271-color-change-paint-ph-engineering-design-challenge