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Building Green in the 21 st Century Engineering with Nanotechnology Why Green? Why Now? What are some challenges? Global Warming? Air and Water Pollution Landfills Nonrenewable Resources Image from stock.xchng (http://www.sxc.hu/) Global Warming Greenhouse gases (especially CO 2 )
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Building Green in the 21st Century Engineering with Nanotechnology
Why Green? Why Now? • What are some challenges? • Global Warming? • Air and Water Pollution • Landfills • Nonrenewable Resources Image from stock.xchng (http://www.sxc.hu/)
Global Warming • Greenhouse gases (especially CO2) • Natural cycle or human caused? • Can we wait? Image from stock.xchng (http://www.sxc.hu/)
Pollution Challenges! • Ozone • Acid rain • Drinking water • Chesapeake Bay Image from stock.xchng (http://www.sxc.hu/)
Landfills! • Take space • Produce methane gas (global warming) • Add to water pollution Image from stock.xchng (http://www.sxc.hu/)
Nonrenewable Resources • Oil and Natural Gas Imports • Mining for coal and mineral deposits • Making electricity Image from stock.xchng (http://www.sxc.hu/)
Buildings Waste and Pollute! • 43% of CO2 • 40% of Landfills • 40% of Electricity Image from stock.xchng (http://www.sxc.hu/)
What Can We Do? • Live in caves or tents? • Ignore the challenges? • Practice the three “R’s”? • Innovate and Invent new solutions? Image from www.stockxpert.com
Can Nanotechnology Help? bright idea potential disaster OR • Different Approach to Science and Engineering • Building blocks invisible to human eye • Not new to Nature
What is Nanotechnology? • 1 item (usually 2 to 3) is 1 – 100 nm in size. • Substances behave differently at the nanoscale! • Control or manipulate at the nano scale.
How Small is Small!? 100 nm Comparing one hundred nanometers to the size of a soccerball is like comparing a soccerball to the size of the earth! http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10/
Let’s Compare! • How small is a human hair (diameter) • Compare this to a nanotube (4nm diameter)
Surface Area/Volume Ratio increases as size decreases Solubility and Reactivity Increase Video Clip Photos from stock.xchng (http://www.sxc.hu/)
Everything is Sticky Internal Forces Dominate Over Gravity Image from stock.xchng (http://www.sxc.hu/)
Appearances May Deceive • Optical properties vary at the nanoscale. Image source: http://mrsec.wisc.edu/Edetc/SlideShow/slides/nanoparticles/Au_nanoshells.html
Mother Nature Mother Nature has used nanotechnology for millions of year.
Living LED’s Butterflies figured out how to emit light 30 million years ago. Fluorescent patches on the wings of some butterflies work much like light emitting diodes (LEDs). http://news.bbc.co.uk/2/hi/science/nature/4443854.stm
Look, Mom, I’m dry! Wings are Colorful and Hydrophobic! Water droplet The butterfly’s wing in the picture isn’t getting wet. The butterfly can thank its nanoscales.
Or a Butterfly’s Wing! This picture shows water droplets on a wood surface treated with "Lotus Spray“, a nanotechnology product modeled after the butterfly wing and lotus leaf, which has made the surface extremely water-repellant (superhydrophobic). The white bar on this picture of a butterfly wing is 1mm long. The white bar on this nanoscopic view of a butterfly wing is 1 µm. As the Saying Goes… “Like Water Off of a Duck’s Back… http://nanotechweb.org/articles/news/1/11/5/1/0611102
Building Green with Nanotechnology • How? • When? • Where?
Heating and Cooling • Use HUGE amount of energy • Insulators trap air
Nanotech Insulators • Trap air better • High Surface Area to Volume Ratio • Examples: • Spray or paint on • Aerogel • Window Film Printed with permission http://www.nansulate.com/
Lighting • Uses almost one-third of energy • 95% wasted as heat • Fluorescent bulbs contain mercury • Light-emitting Diodes (LEDs) safer and more efficient
LED FUNDAMENTALS • Semiconductor material • Electrons flow one direction (diode) • Photons released • Color depends on material/band gap
ACTIVITY VS
Safety • Avoid placing incandescent bulbs against flammable surfaces.
Procedures • Turn off room lights. • Measure temperature (oC) and illuminations (lumens). Lights off. • Measure temperature (oC) and illuminations (lumens). Lights on. • Record “raw data” (first part of data sheet)
LED Efficiency (lumens/watt) LEDs are highly efficient compared to other light sources.
Organic LEDs • Small applications today • Potential to mimic natural light • Flat or curved • Potential to be more efficient and less expensive Photos from stock.xchng (http://www.sxc.hu/)
Steel and Concrete(and Wood?) http://www.indigo.com/models/gphmodel/minit-carbon-nanotubes.html"> zig zag, chiral and armchair carbon nanotubes</a> courtesy of Indigo®; Instruments.
Other Applications • Glass • Plastics • Drywall • Wiring • Roofing Tiles • Sensors
Review • Why Green? Why Now? • What is nanotechnology and how can it help? • How do LEDs work? • Environmental and human health concerns