Today’s modern society thrives on technology. This has created a huge demand for high-strength materials to satisfy our thirst for the latest and best technology. Material scientists around the world have been pooling their resources and brain power to create stiffer, tougher, and stronger materials through extremely complicated chemical and physical processes.
While they have been successful in the performance department, environmental concerns keep scientists searching for new solutions. In particular, there is need for materials that combine the best of both worlds, ones that are both strong and environmentally friendly. And Mother Nature appears to have the answer. I am talking about chitin nano-whiskers, the material that crab and shrimp shells are made of. My research team (Smart and Adaptive Polymer Laboratory at University of Toronto) is using it to create functional high-performance materials.
In order to understand how chitin nano-whiskers are used, you need to understand both what makes a material weak and what nano-materials are.
All substances are made up of atoms, those extremely small spherical particles often pictured in science textbooks. In most everyday materials, the atoms do not line up perfectly. There are numerous voids, displaced atoms, and micro cracks that cannot be seen by the naked eye. These flaws cause materials to fail prematurely. For a material to be be truly strong, it needs to be flawless at the atomic level.
Meanwhile, “nanomaterial” is a name given to a class of materials that are engineered on the nanometer scale. If you imagine the diameter of the Earth as 1 meter in diameter, then a marble would be approximately 1 nanometer in diameter. On such a small scale, truly amazing things can happen. Chitin nano-whiskers are an example of a material that, on a nano-scale, takes the form of a crystal where all of the atoms line up perfectly. By all indications, it is flawless and extremely strong.
You may wonder how cars could be built from such a small material. Granted, tables, chairs, cars, and houses cannot be built from single, flawless chitin nano-whiskers. However, these tiny crystals can be added to everyday materials in order to improve their strength.
Combining two different materials involves the creation of a composite whose material properties are somewhere between those of the two parent materials. For example, when these extremely strong crystals are added to a typical plastic, the plastic becomes lot stronger.
Best of all, when chitin nano-whiskers and bio-plastics are combined, the result is a very strong composite material that is fully biodegradable. It could be used to make cars that are stronger, safer, and more durable, while providing new environmentally-friendly options for dealing with waste.
For more nano-scale analogies go to: http://www.nano.gov/nanotech-101/what/nano-size.