Incorporating Nanotechnology Concepts in a High School Classroom

1. Incorporating Nanotechnology Concepts in a High School Classroom - Ritu Linhart

2. Oxygen-Sensing Nanofiber Scaffolds for Tissue Engineering Applications How in the world do you translate this to a high school classroom lesson !

3. Why Nanofibers ? • high surface area • small pore size • high pore volume

4. Jan 2010Science Editor • Polymer nanofibers are being investigated to harness the power of movement. • Now we could possibly convert energy 20 percent more efficiently than possible until now. • The clothes we wear will store all our released energy, even during sleep and we could use that energy to power up wireless sensors or portable electronics.

5. Surface Area to Volume Ratio • The smaller something is, the larger its surface area is compared to its volume. This high surface-to-volume ratio is a very important characteristic of nanoparticles.

6. Total Surface Area Increases while Total Volume Stays Constant

7. Melon Cubes with Sugar !

8. Increased Reactivity ! • When something has more surface area, there are more places for other chemicals to bind or react with it. • Catalysts, e.g. • Think of crushed ice vs. cubed ice • Nanoscale particles maximize surface area, and therefore maximize possible reactivity!

9. What is Nanofiber Technology? • Used for Tissue Engineering Applications • To design scaffolds from biocompatible materials, which encourage living cells to repair and restore damaged tissues

10. Nanofiber Production Electrospinning Nanofibers

11. ElectrospinningApparatus

12. Syringe Pump High voltage power supply collector

13. The Electrospinning Process • a high voltage power supply is used to supply the necessary voltage to a conical metal reservoir filled with the desired polymer solution. • When the electrostatic repulsive forces become sufficient to overcome the surface tension of the polymeric solution, a “Taylor cone” is formed, and the fluid jet is ejected. • As the polymeric solution jet travels further from the tip of the metal reservoir, it becomes more destabilized, creating what is known as a bending instability. • The combination of electrostatic and mechanical forces pulling the polymer solution from the metal reservoir to the grounded collector result in stretching of the polymer fiber, which leads to the collection of fibers with submicron (<1 μm) or nanometer diameters: nanofibers.

14. A Oh No !What Happened to My Nanofibers!

15. Competition Between the Forces ! • Surface Tension forces caused the polymer solution to form beads during the electrospinning process • Process parameters needed to be optimized • Research does not follow YOUR time schedule!

16. Hydrophilic vs. Hydrophobic • Make your own Magic Sand ! • It’s silicon dioxide coated with Scotchgard fabric protector. • When Magic Sand is added to water, it appears to bond to itself, forming interesting shapes. • But when the water is decanted, the sand is dry, and the shapes disappear.

17. Where Did Magic Sand Come From? • It was used initially to purify water systems from oily contaminants. • It resembles the fumed silicon dioxide used for optical clarity in products such as coatings, adhesives, cosmetics, inks, plastics, and rubbers. • It is also used as an anti-caking agent to promote the free flow of dry powders.

18. Seeing is Believing ! • Optical properties of nanofibers are different from those of macrofibers • My PCL polymer solution was clear, but the nanofibers were white • Use food coloring and almond essence to demonstrate the absence of color in a solution that has been diluted down to one billionth of the original concentration. • Discuss how particles at nanoscale are present even though they can’t be seen!

19. Optical Properties of Nanomaterials • Sunscreen is usually white • It has white ZnO macro-particles that absorb ultraviolet light and protect our skin against sunburn • ZnO nanoparticles, however, are clear and scatter away all visible light, yet absorbing uv light still

20. http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10/http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10/ There are 200-r400 billion suns in our galaxy alone Our whole solar system is a single dot on this picture

21. The Milky Way • Our Milky Way is spiral and rotating at a speed of 370 miles/second • It takes our sun 230 million years to make just 1 revolution • Albert Einstein was the first person to realize that empty space is not nothing. • The matter we see is only 5% of total matter; rest is dark matter

22. Other Relevant Topics • Strength of polymer nanofiber scaffolds for bone tissue applications • Electrical conductivity and magnetic properties of the nanofibers • Biological compatibility of the nanofibers

23. Medical Applications of Nanofibers • detection and treatment of tumors • therapies and drug delivery to damaged tissue • As bandage for burn victims

24. Negative Implications of Nanotechnology ! • nanomaterials can move with great speeds through aquifers and soil • nanomaterials provide a large and active surface for absorbing smaller contaminants, such as cadmium and organics.

25. Toxicity! • Sunscreens • Cosmetics • Moisturizers • Facial Soaps/washes • Presence of nanoparticles produces reactive oxygen species (ROS) when entering a punctured skin membrane • which are basically cancer causing free radicals

26. What Did I Gain From My RET Experience? • Knowledge and hands-on experience with cutting edge technology • Valuable Research Skills • Modern Lab Techniques & Instrumentation use, e.g. charge gun and SEM training • The Reality of Actual Research (it’s not as glitzy as it sounds!)

27. By-Products of my RET Experience ! • Published abstracts, papers, and/or posters • Self-confidence and Excitement • Added Respect from Students • Pride in being a high school teacher • Increased Morale/Motivation • Attending various Conferences and Presenting the Research

28. Personal Long-Term Goal • Develop a nanotechnology course to be taught at the high school level • Introduce this course at my school and later to the rest of the state