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 (

Global Warming Greenhouse gases (especially CO 2 ) Natural cycle or human caused? –Can we wait? Image from stock.xchng (

Pollution Challenges! Ozone Acid rain Drinking water Chesapeake Bay Image from stock.xchng (

Landfills! Take space Produce methane gas (global warming) Add to water pollution Image from stock.xchng (

Nonrenewable Resources Oil and Natural Gas Imports Mining for coal and mineral deposits Making electricity Image from stock.xchng (

Buildings Waste and Pollute! 43% of CO 2 40% of Landfills 40% of Electricity Image from stock.xchng (

What Can We Do? Live in caves or tents? Ignore the challenges? Practice the three “R’s”? Innovate and Invent new solutions? Image from

Can Nanotechnology Help? Different Approach to Science and Engineering –Building blocks invisible to human eye Not new to Nature OR bright idea potential disaster

What is Nanotechnology? 1.1 item (usually 2 to 3) is 1 – 100 nm in size. 2.Substances behave differently at the nanoscale! 3.Control or manipulate at the nano scale.

How Small is Small!? Comparing one hundred nanometers to the size of a soccerball is like comparing a soccerball to the size of the earth! 100 nm u/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 Video Clip Photos from stock.xchng (

Everything is Sticky Internal Forces Dominate Over Gravity Image from stock.xchng (

Appearances May Deceive Optical properties vary at the nanoscale. Image source:

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).

Wings are Colorful and Hydrophobic! The butterfly’s wing in the picture isn’t getting wet. The butterfly can thank its nanoscales. Water droplet Look, Mom, I’m dry!

“Like Water Off of a Duck’s Back… As the Saying Goes… 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 nanoscopic view of a butterfly wing is 1 µm. The white bar on this picture of a butterfly wing is 1mm long. Or a Butterfly’s Wing!

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 onSpray or paint on –AerogelAerogel –Window FilmWindow Film Printed with permission

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

Atomic Level

LED’s Today

ACTIVITY VS

Safety Avoid placing incandescent bulbs against flammable surfaces.

Procedures Turn off room lights. Measure temperature ( o C) and illuminations (lumens). Lights off. Measure temperature ( o C) and illuminations (lumens). Lights on. Record “raw data” (first part of data sheet)

INCANDESCENT VS LED ILLUMINATION

INCANDESCENT VS LED TEMPERATURE RANGE

RELATIVE EFFICIENCY (lumens/temp range)

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 (

Steel and Concrete (and Wood?) zig zag, chiral and armchair carbon nanotubes 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

Thank You