IS PLASTIC ALWAYS FANTASTIC?:

EXPLORING PLASTICS ON THE NANO SCALE LESSON PLAN

Authors: W. Haynes, H. Taylor, and C. Wolfe

Course: Science

Grades: 8

Lesson: Exploring Plastics on the Nanoscale

ALCOS2015:
3.) Construct explanations based on evidence from investigations to differentiate among compounds, mixtures, and solutions.

a. Collect and analyze information to illustrate how synthetic materials (e.g., medicine, food additives, alternative fuels, and plastics) are derived from natural resources and how they impact society. (8th grade)

NGSS:

MS-PS1-3.

Gather and make sense of information to describe that synthetic materials come from natural resources and impact society.

[Clarification Statement: Emphasis is on natural resources that undergo a chemical process to form the synthetic material. Examples of new materials could include new medicine, foods, and alternative fuels.]

[Assessment Boundary: Assessment is limited to qualitative information.]

Goals:

  • To differentiate between compounds, mixtures, and solutions and explain their distinguishing qualities.
  • To explain how some plastics are made.
  • To determine that nanoparticles can be added to plastics to alter their properties and make the plastics stronger, more durable, or lightweight.

Context:

  • This unit on plastics will relate to the students’ everyday lives by applying real life, everyday examples of compounds, mixtures, and solutions that the students use. As we go into synthetics, this will be heavily applied to the students’ lives by bringing in examples of the plastics they use every day.

Objectives:

  • Given the explanation and demonstration of compounds, mixtures, and solutions, students will be able to compare and contrast compounds, mixtures, and solutions and produce two examples of each.
  • Given the information in the lesson on how plastics are made, students will be able to explain how plastic is made, including where plastic originally comes from and how it ends up as plastic.
  • Given the information in the lesson on recycling, students will be able to describe why recycling is important.
  • Given the information from the lesson and the students own knowledge, students will able to identify a material they wouldadd to plastic and explain how they hoped it would alter the properties of the plastic and explainhow they would use the transformed plastic.

Approximate Duration of Lesson

  • 3 consecutive class periods (greater than 120 minutes)

Materials:

  • Computer
  • Exploring Plastics on the Nanoscale PowerPoint
  • Projector or SmartBoard
  • Pens/Pencils
  • Vegetable oil (1 cup will be enough for the Compounds, Mixtures, and Solutions Demonstration)
  • Dirt(1 cup will be enough for the Compounds, Mixtures, and Solutions Demonstration)
  • Salt (1 cup will be enough for the Compounds, Mixtures, and Solutions Demonstration)
  • Water (4 cups total) (3 cups are to be used for the Compounds, Mixtures, and Solutions Demonstration and 1 cup is to be used in the Sand Demonstration)
  • Sand (1 package is to be used for the Sand Demonstration)
  • Hydrophobic Sand (2 packages are to be used for the Sand Demonstration)
  • Styrofoam bowls (1 package of 50)
  • Paper towels (2 rolls)
  • Whole milk (2 gallons per 25/30 students)
  • White vinegar (3/4 cup per every half gallon of whole milk)
  • Hot plates (2 of these are needed to heat the milk on)
  • Pots/Pans (2 of these are needed to heat the milk in)
  • Fine mesh strainers (2 of these are needed to drain out the extraneous liquid after heating the milk)
  • Bucket/Sink (1 of these is needed to drain out the extraneous liquid into)
  • *Optional* Food coloring(1 package is needed for students to add color to their milk plastic)
  • Iron filings (1 container is needed to add to students milk plastic to represent nanotechnology changing the properties of plastic) (*note: these iron filings are not nano in size, but are a symbol of nanotechnology)
  • Magnets (1 packet of 4)

Safetyprecautions:

  • Students should not eat or drink any materials or products of the lab or demonstrations.
  • Proper clothing and closed-toe shoes should be worn.
  • For general lab safety, no food or drink should be allowed in lab.
  • The students and teacher should be extremely careful with the hotplates and pans or the slow cookers. It would be best for teachers to handle the hot materials.

Lesson Procedures:

  • Before the lesson teacher should:
  • Prep the Compounds, Mixtures, and Solutions demonstration by pouring water into 3 different cups and adding salt to one cup, dirt to another, and oil to the third cup.
  • Prep the Sand demonstration by having the hydrophobic sand and the regular sand in different bowls for the students to observe.
  • If using a slow cooker, the milk needs to be warmed for about 40 minutes prior to the lesson.
  • Lesson:
  • Have the students complete the Pre-Test.
  • Go through each slide of the PowerPoint with students
  • At slide 3 there is a demonstration on compounds, mixtures, and solutions which is described below:
  • Compounds, Mixtures, Water filtration activity:
  • Set up three glasses of water.
  • Add pebbles of sand to the first glass. Stir the water. Ask students whether this is a mixture or a solution. (Answer: It is a mixture because the sand and the water stay separate. The sand does not disappear in the water.)
  • Ask the students what salt is (Answer: It is a compound) Ask students which two elements make up salt? (Answer: Sodium and Chlorine) Add a teaspoon of salt to the second glass. Stir the water until the salt disappears. Ask students if this is a mixture or a solution. (Answer: It is a solution because the salt dissolves, or disappears, in the liquid.)
  • Next, ask students if two liquids will form a mixture or a solution.
  • Add some vegetable oil to the third glass and stir. Ask students if the glass contains a mixture or a solution. (Answer: The oil and water form a mixture because they do not mix. The oil does not disappear or dissolve.)
  • Ask the students if you separate mixtures and solutions back into their original components. (Answer: Yes you can. Sometimes you can separate out the parts of a mixture using something as easy as a filter or screen.)
  • At slide 7 there is a demonstration for the students to compare and contrast sand and hydrophobic sand which transitions into introducing the students to the nano world. This demonstration is described below:
  • Sand demonstration:
  • Have each group of students have access to one bowl of sand and one bowl of hydrophobic sand. Allow the students to look at the two different types of sand.
  • Ask the students if they can you tell a big difference in how they feel.
  • Put a little bit of water on both types of sand and have the students observe what happens.
  • Ask the students if they can tell a difference between the two types of sand now.
  • Have the students play around with the hydrophobic sand and see how it interacts with water.
  • The students can even pour some of the sand into the water and scoop it out with your spoon. If they did this ask them if the sand got wet.
  • Ask the students if they can keep their finger dry by sprinkling some sand on top of the water and gently poking their finger in it.
  • On slide 10, watch the Nano video to better the students' understanding of nano and go through the interactive nanoscale graphic with the link provided on the slide to show students how small nano really is. At this time, you could go through the nano handout as well.
  • Slide 11 has another video that talks about nanotechnology and why the students should care about it.
  • Slide 16 has a video that shows students how plastics are made and the slide discusses further what was described in the video.
  • Slide 17 has a video on the importance of recycling and why students should care about recycling.
  • Slide 23 has a video that shows the crash test between a 1959 Chevrolet and a 2009 Chevrolet to show students how plastics are revolutionizing our world and keeping us safe.
  • At slide 25teachers will complete the milk lab with their students. This is described in greater detail below.
  • Milk Lab:
  • The teacher will heat up the whole milk on a hot plate until it is hot, but not boiling. If using a slow cooker, it will take about 40 minutes to heat up, so that needs to be done the period before you plan to do the lab. It might be easier, given the volume of whole milk, to use two hot plates and two pots. If using a hot plate or burner and a large pot, it takes less than ten minutes to reach desired temperature.
  • Before adding the vinegar, ask the students what they think will happen. Teacher will add ¾ cup of vinegar per half gallon of whole milk. Teacher can have students come up in small groups to observe. Students can write down their observations on their lab paper. Ask them again what they think is happening once they saw the reaction between the whole milk and vinegar.
  • After pouring in the vinegar, gently and slowly stir the mixture. If it is stirred too vigorously, the clumps will become too small and will not mold together well. The whole milk will begin to clump up. Once it has fully clumped and is not clumping any more, strain the clumps out of the liquid into a sink or bucket using a fine mesh strainer.
  • Tell the students to line their bowls with paper towels and ask them to come up and get a handful of the clumps from you.
  • Once they get their material, tell them to dry it off with paper towels the best they can, then start kneading it and rolling it into a ball until it starts to stick together (This may take some time. It will not stick together if it is too wet, so make sure they have dried it enough with paper towels beforehand).
  • Teacher will come around with iron filings for the students to knead into their plastic. This iron will represent nano particles and how they can change properties of plastic at the nanoscale. The iron itself is not nano, this is just a representation. The plastic will be magnetic once it is dry.
  • Teacher can also come around with food coloring if the students would like to add colors. This is best done by a teacher, students tend to use too much (2-3 drops is enough). Students will knead this into their plastic as well. This will get on their hands, but it will wash off with soap and water.
  • The students’ milk plastic will need a few days to dry. When they are finished, place their molded plastic in their clean and dried bowls and place out of the way so they can dry.
  • While they are molding their plastic go through slide 28 and explain how the whole milk is turned into plastic.
  • Closure:
  • In conclusion, this week we have learned all about plastics, synthetics, and different compounds, mixtures, and solutions. We learned that nanoscale particles can cause materials to have unexpected properties. We learned that adding nanoscale particles to plastic can cause plastic to be more heat resistant, be magnetic, conduct electricity, be more durable, etc. We learned that biodegradable plastics are being developed and made now. Nanoscale particles can be added to these biodegradable plastics to make them just as strong as their non-biodegradable counterparts.
  • If the teacher would like he or she could do an exit activity, but there is a post test at the end of the lesson. Additionally, the student milk lab worksheet and the guided notes can also be used as forms of assessment if the teacher wishes to do so.
  • Suggestions for an exit activity if desired:
  • Students write open ended questions on index cards. A few students are selected to come forward. The first student draws a question card and poses the question to the class. After the class discusses the question and answers with their partner - the second student draws a student name card to respond to the question, etc.
  • 3-2-1 Exit Ticket: Students write down three things they learned, two things they still are not sure about, and one thing they still do not know, or would like to know more about.

Assessment:

  • Pre-Test and Post Test
  • Options for Assessment: Student Worksheet/Guided Notes and the Milk Lab Worksheet can also be used as assessment tools.

Resources:

  • Standard
  • Compounds, Mixtures, and Solutions Demonstration
  • 87 in PDF)
  • Sand Demonstration
  • Do you know what nano means?
  • Cell Size and Scale graphic
  • Intro to Nano
  • Nanotechnology, big things from a tiny world Publication
  • From Oil to Plastic
  • Scientist in Residence Program, Science Unit: Plastics
  • What really happens to the plastic you throw away - Emma Bryce
  • Ojijo, V., & Ray, S. S. (2013). Processing strategies in bio-nanocomposites. Progress in Polymer Science,38(10), 1543-1589.
  • National Nanotechnology Initiative Benefits and Applications
  • Crash Test 1959 Chevrolet Bel Air VS. 2009 Chevrolet Malibu (Frontal Offset) IIHS 50th Anniversary
  • Plastic Milk experiment - Making polymers in the kitchen
  • Science Buddies: Turn Milk into Plastic!