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An NSF-sponsored center for nanoscale science and engineering Description: The

An NSF-sponsored center for nanoscale science and engineering Description: The instructor introduces a product with unique properties called Magic Sand. Students explore its properties in a hands-on activity. They learn why it was initially developed, and they learn about some of its practical applications. Prerequisites: Student should have an introductory knowledge of nanotechnology that can be provided by Kits 1 and 2. Instruction Time: Approximately 25-30 minutes Audience: Middle or high school students Lesson Objective: Students will explore and understand the properties of Magic Sand. They will know why it was first developed and they will know some practical uses of Magic Sand. National Science Education Standards: Content Standard A: Understandings about Scientific Inquiry. Content Standard B: Properties and Changes of Properties in Matter. Content Standard E: Understandings about Science and Technology. llinois State Learning Standards: 11.A.3b. Conduct scientific experiments that control all but one variable. 12.C.5b Analyze the properties of materials (e.g., mass, boiling point, melting point, hardness) in relation to their physical and/or chemical structures. 13.B.5b. Analyze and describe the processes and effects of scientific and technological breakthroughs. Magic Sand Materials: • 1 evaluation and 30 assessments • Power Point presentation and documents on CD • overhead transparencies of slides • 1 pound of magic sand • 1 pound of regular sand • 60 tiny plastic cups • 60 plastic drinking cups Teacher provides: LCD or overhead projector and tap water Preparation: Fill each yellow dispenser ¼ full of water. Prepare 30 plates that each are holding 1 knife, 2 spoons, 2 tiny cups (one 1/3 full of Magic Sand and the other 1/3 full of regular sand), 2 drinking cups, and the filled yellow dispenser. Prepare the sieve and the container for water. Background Information: Sand is made up of particles of silica. Silica is composed of three- dimensional network of silicon and oxygen atoms. On the surface of the grains, the oxygen atoms bond covalently to hydrogen atoms. When you put beach sand in water, the partially positive and partially negative ends of the silica and water are attracted to each other. So the sand “likes” water and is “hydrophilic.” Magic Sand is also made of silica, but it has been treated with methyl (CH3) groups. Magic Sand is an example of how nanoscale changes can affect the properties of a substance dramatically. Ordinary sand is hydrophilic (water-loving or water-absorbing). When nanoscale-sized methyl groups are attached, the properties of the sand change completely. Now the sand repels water; it is hydrophobic. This learning kit was made possible through a generous gift from Motorola, Inc., and through support from the National Science Foundation. To order more kits from this series, please see our website: http://www.nano-cemms.uiuc.edu • 30 paper plates • 60 plastic spoons • 30 plastic knives • 30 plastic yellow dispensers • 1 sieve • 1 Tupperware container • 1 coffee filter Instructional Method: The instructor uses a PowerPoint presentation to introduce Magic Sand in a guided exploration. Students explore Magic Sand in a hands-on activity and compare its properties to those of regular sand. The instructor explains the reason why Magic Sand was developed and some ways in which it is useful. Copyright © 2012 Board of Trustees, University of Illinois. All rights reserved. Safety: Involvement in this activity poses minimal safety issues. Presentation Details: Slide 1 (Magic Sand): Today we are going to be exploring a fascinating substance called magic sand. Slide 2 (Objective): The goal is for you to explore and understand the properties of magic sand. Another objective is to understand the reason why magic sand was developed originally and other uses it has. Slide 3 (Properties of Matter): Everything around us has properties that we just know exist. Let’s take beach sand, for example. It is fine and it absorbs water. Beach sand sinks when placed on the surface of water because it is denser than water. Today we will experiment with sand that has quite different properties. Slide 4 (Properties of Matter): Before we begin our experiments, let’s review a few vocabulary words. What do we call substances that absorb water? (Answer: Hydrophilic. “Hydro” means water and “-philic” means loving.) What do we call substances that repel water? (Answer: Hydrophobic. ”Phobic” means fearing.) Slide 5 (Sand): (Pass out plates to students.) On your tray, you have two kinds of sand that are colored so you can tell them apart. One of the samples of sand is just regular sand that has been colored. The other sample is colored, but it has been coated with nano-particles, as well. Slide 6 (Guess!): I would like for you to feel both of the samples and guess which one has been coated with nano-particles. How are they different? What makes you think one is “nano?” Slide 7 (Magic Sand): If you guessed the red sand, you are correct! It feels slightly different from regular sand. It has been covered with nano-particles. This is what makes it “magic sand.” Slide 8 (Coating): Each particle of the magic sand has been coated with a substance made up of carbon and hydrogen (methyl groups or --CH3). You can see from the picture that carbon can make 4 bonds while hydrogen can make 1 bond. --CH3 is a hydrophobic substance. (Oils are composed primarily of carbon and hydrogen and repel water, as we know from experience.) Since the coating is hydrophobic, the sand does not “like” water anymore. Changes at the nanoscale have affected the properties of sand dramatically. Slide 9 (Hydrophobic?): Let’s do some more exploration! Take your water bottle and drop just a few drops of water on each sample. Slosh the water around. Which one do you think is hydrophobic? The red sand—the Magic Sand—is hydrophobic. It repels the water. The yellow sand is hydrophilic. It likes water and absorbs it. Slide 10 (Magic Sand): Now fill each of the large cups one-third full of water. Use one spoon to add a small amount of magic sand to one cup and another spoon to add the regular sand to the other cup. Why does the Magic Sand float on the surface of the water? (Answer: it is repelled by water so it stays on the surface until a great enough mass is added.) Slide 11 (Magic Sand): Now take the knife and slowly push it through the Magic Sand layer and into the water. What happens? (Answer: the sand sticks to the knife as it is lowered.) Now pull the knife out. What do you observe? (Answer: the knife is dry.) Why is the knife dry? (Answer: the sand “coats” the knife and protects it from getting wet. Slide 12 (Magic Sand): Now pour all of the Magic Sand in one cup and the other sand in the other cup. Use separate spoons to mix the sand and the water. Make sure to really mix them up quite a bit! What happens? (Answer: the regular sand and the water form a mixture. The sand gets wet. In the case of Magic Sand, the sand forms clumps and does not absorb the water and get wet.) Slide 13 (Magic Sand): This will be our last exploration with Magic Sand. I will come around with a sieve lined with a coffee filter and you can pour your cup of Magic Sand and water into the filter. Once the water has passed through the filter, feel the sand. What do observe when you touch the Magic Sand? (Answer: It is dry.) Remember, the coating on Magic Sand is hydrophobic and repels water. Slide 14 (What Good Is Magic Sand?): Now we have experienced how fun it is to play with Magic Sand. Can you think of why scientists and engineers thought of developing it in the first place? Why would there be a need for a substance with like Magic Sand? It was developed to clean up oil spills or oil slicks. Magic Sand can be poured over an area that has been contaminated by an oil spill and the sand, since it is hydrophobic, will absorb the oil but not the water. After absorbing the oil, the Magic Sand will sink to the sea floor and it could be dredged from the bottom. However, it is very expensive so new ways of producing Magic Sand must be developed in order for its use to be economically feasible. Slide 15 (Arctic Regions): One way that Magic Sand can be used is in junction boxes in the Arctic regions. In the winter, the land (and the moisture in it) freezes so thoroughly that if there is a problem with one of these boxes, it is extremely difficult to dig it up and repair it. If engineers bury it in Magic Sand, it can be pulled out of the ground much more easily. It has actually been tested for this purpose by utility companies who work in the Arctic! Slide 16 (Houseplants): Magic Sand can also be useful in keeping houseplants healthy. Have any of you ever taken care of uploads/Litterature/ activity-guide.pdf