The Effects of Oil Spills on Birds: why do feathers float on water but not oil? GEMS April 22, 2017
Today we are going to investigate how water interacts with different substances. Discussion: As a group, write down at least 3 things that repel water and 3 things that attract or absorb water. Think about things you use everyday. Things that attract water Things that repel water Have a volunteer go up to the board and write down your list of examples.
Group Discussion Describe a situation when you would want something attract or absorb water? What makes certain chemicals attract water? Describe a situation when you would want something to repel water. What makes certain chemicals repel water? Write your answers on the white boards.
Activity 1: How will water behave on different surfaces? You have water and several surfaces. Place 1-2 drops of water on each surface. Use the terms hydrophobic (repels water) and hydrophilic (attracts or absorbs water) to classify the substances. Surface Hydrophobic or Hydrophilic? Why do you think it is hydrophobic or hydrophilic?
Why do animals have feathers? What animals have feathers? Do you think feathers will attract or repel water? Why? What are feathers made of?
Activity 2: Oil Spills and Birds During oil spills, one of the biggest concerns is for birds. We are going to try to understand why this is such a problem for birds. 1) Feel the feather. How does it feel? 2) Now put the feather in water and swirl it around like a bird swimming in the ocean. How does it feel? How easy it is to dry with a paper towel? 3) Now put the feather in the oil spill solution and swirl it around like a bird swimming through an oil spill How does if feel now? How easy it is to dry with a paper towel? 4) Why are oil spills dangerous for birds?
How would the following functions of feathers be impacted from an oil spill? Role of feather Impact from oil spill Flying Temperature regulation Protection from environment Protection from Predators Swimming/ diving Feeling Hearing Communication (sound and visual) Keeping clean Digestion Camouflage
5) Now put the feather back in the clean water and swirl it around How does it feel? Can the bird clean their feathers by just getting into clean water? 6) Why do you think the water did not remove the oil? 7) What does this tell you about using water to remove oil? 8) To remove the oils we will need a different type of chemical called a surfactant. If you could design a molecule that would attract both water and oil what would it look like?
What surfactants look like Copyright 2010 Samuel Dupont and Ryan Cates. STARS-University of South Florida Copyright 2010 Samuel Dupont and Ryan Cates. STARS-University of South Florida
Activity 3: Surfactants in Action To see how surfactants can interact with both hydrophobic and hydrophilic we are going to look at the interaction of milk(hydrophobic) and food coloring (hydrophilic) 1) Put one drop of food coloring in the milk. Do not stir or agitate it. What do you notice? 2) Now take a q-tip, dip it into the soapy water, and then touch it to the food coloring in the milk. What happened?
Bird Feathers 1) Take the bird feather and wash it in soapy water. Make sure to also rinse it with water. 2) Does it feel the same as before you washed it? 3) After the birds have been washed with soapy water, they are not ready to fly yet. Why do you think this is?
Activity 4: Make Your Own Shampoo! Unlike birds we frequently use soap to get dirt and oils off of our skin and hair. What do you think you need to make a good shampoo? Which ingredients in the recipe below are hydrophobic and which are hydrophilic? Recipe Dr. Bronner s castile soap: about 0.9 fl oz Water: about 0.9 fl oz Glycerin (optional): 6-10 drops Your favorite essential oil: 1-2 drops Fill the container to the half way point with water. Add the castile soap up the line. Add 8-12 drops of glycerin (optional). The glycerin is important because this is what makes the shampoo sudsy. If you like to play with bubbles in the tub, that s where the glycerin comes in. Add 1-2 drops of your favorite fragrance/essential oil. A little goes a long way! You want to be clean, not smell like a bottle of perfume. Place the cap on your shampoo bottle and make sure it is sealed. Gently swirl the contents of the container to mix the water, soap, and oil. (You may find it helpful to invert the container several times to make sure all the contents mix.) (Note shaking vigorously will give you a bottle of suds.) Now it s time to decorate your shampoo bottle!