Extension Activity: Using the product to separate an oil and water mixture, simulating oil spill clean-up.
Author: Laura Ruttig
Source: This material is based upon work supported by the National Science Foundation under Grant No. EEC- 1542358. This lesson is original, but here are some great lessons that are related to this topic:
The development of shape memory polymers has applications in aerospace (for example, Mars exploration), medicine, robotics, and even everyday items such as eyeglasses. In this activity, students will be able to make a shape memory polymer using only 2 ingredients: silicone-1 caulk and polyethylene glycol (widely available as MiraLAX).
They will compare the shape memory polymer that they’ve made to the more common “oogoo” – a mixture of silicone-1 caulk and corn starch – in order to investigate how the properties of the mixture change based on the ingredients.
In the extension activity, students make an additional mixture of MiraLAX and silicone-1 with a higher concentration of MiraLAX. This higher ratio allows the MiraLAX to be easily removed after the polymer has set, simply by soaking in water overnight. Once the MiraLAX is removed, a sponge made out of silicone can be observed. This sponge is used to simulate an oil spill clean-up, using a mixture of vegetable oil and water.
What should students know as a result of this lesson?
What should the students be able to do as a result of this lesson?
Lab Part 1: Making the Two Samples
Lab Part 2: Testing the Samples for Shape Memory
Lab Part 3: Exentsion Activity - Separating Mixtures
Twist up a piece of shape memory wire and a paperclip. Ask students to make observations about the appearances of the two. Ask what will happen when you drop the paperclip into hot water. Drop the paperclip into the hot water (heated in beaker on a hot plate). Remove. Then drop the shape memory wire into the hot water. Discuss.
Sample questions: What are some of the properties of metals? What is an alloy? Has anyone ever heard of "shape memory"? What do you think that might mean? How do you think it might work? Can you think of any applications for this (possible prompts: items we might use every day, in space exploration – i.e. Mars Rover, or in medicine)?
Optional: If unable to do the demo or if you would like to extend the discussion, this 5-minute video introduces the concept of Shape Memory Alloys and shows an example: https://www.youtube.com/watch?v=s62PL5vmfNw
Students perform part 1 of the lab, making a sample of corn starch & silicone and a sample of MiraLAX and silicone to test. Samples will need to setup 30-120 minutes before being ready to proceed to part 2 of the lab. Best practice: have students complete the accompanying webquest with any remaining class time, and then start part 2 of the lab the next class period.
Extension Activity: If you would like to incorporate the oil spill clean-up activity (part 3 of the lab), make sure you are using the lab with the extension activity directions included. In part 1, students need to make a second MiraLAX and silicone sample with a different concentration. Also in part 2 of the lab, there is an additional step included, as students prepare their sample for testing in part 3.
Have students complete the Material Science Webquest: Alloys, Polymers, and Shape Memory. Optional: show the video from Science 101: What are Polymers? (2 minutes): https://www.youtube.com/watch?v=bJi8x7bKHqQ to help them get started.
Extension Activity: Have students complete the additional worksheet, Extension Activity: Oil Spills and Mixture Separation Webquest, on separating mixtures and oil spill clean-up techniques.
Students perform part 2 of the lab, testing their previously prepared samples to see if they display any shape memory properties.
Extension Activity: Oil Spill Clean-up and Mixture Separation Techniques
Before starting this lesson, students should have some knowledge of the periodic table, intramolecular bonding, and intermolecular forces.
Students explore how the molecules in a mixture affect the properties of that mixture, incorporating a knowledge of bond types, intermolecular forces, the shape of molecules, and the changes in structure between phases of matter. In addition, students learn about the field of material science, as well as some of the real-world applications for polymers, alloys, and shape memory.
Safety glasses or goggles are recommended during all of the lab portions.
Gloves are recommended for day 1 when preparing the samples to test. The caulk has a very strong smell of acetic acid while drying. Recommend having students measure out the caulk in a fume hood with the fan running, if possible. Having windows open and/or fan running may also help with reducing the smell.
Use caution on day 2 when using the hot plates. Hot plates may cause burns.
Shape memory has applications in cutting edge materials for aerospace, such as those used on NASA's Mars Rover. Eyeglasses are sometimes currently made of a shape memory material with superelasticity. Robotics is another field utilizing shape memory; for example, "muscle wire" contracts when an electrical field is applied, and it can be used in artificial limbs.
The webquest(s), pre- and post-lab questions can be used to assess students’ progress on reaching the lesson objectives.
Lab - Student Documents: