“Nano,” derived from the Greek word for dwarf, is the prefix that means one billionth.
A nanometer is a billionth of a metre, or one millionth of a millimetre.
How small is that on a practical scale?
Well the head of a pin would be a million nanometers, a red blood cell flowing through our circulatory system is about 2,500 nanometers and carbon “nanotubes” are about two nanometers wide.
This miniscule size imparts some elements with amazing properties, for example gold changes colour on this scale, zinc oxide appears clear, boiling temperatures change, gravitational forces disappear, and electromagnetic forces dominate.
Nano particles make materials more durable and resilient, biological and chemical reactions more responsive and metal ions and enzymes can be attached for more effective distribution.
Work with nanomaterial includes strengthening common items with carbon; treating sewage and enhancing photovoltaic panel’s materials of manufacture and power production.
Nano-scale coatings of gold applied to the graphite anode of microbial electrochemical cells will enhance electrical power production on the order of twenty times.
It works by using bacteria from biowaste, basically sewage, which when placed in an anode chamber forms a biofilm that consumes nutrients and grows. In the process, electrons are released and this forms the basis for an electric current to flow. This bodes very well for future sewage treatment as a source of energy.
There is also related technology that enhances hydrogen gas production from bio waste.
The resulting hydrogen could be used to run fuels cells and produce electricity, again producing energy from waste water and turning an energy using technology into an energy producing technology.
Nano silver has been used to increase the power output of polymer solar cells by helping the polymer absorb a larger range of the suns wavelengths of light than the polymer can by itself.
This technology can also be adapted to conventional photovoltaic cells to increase their power output. Like adding salt to a meal, nanomaterial’s miniscule pieces of elements can be used to enhance energy production.
Research in to nanoparticles is making huge inroads into environmental technology. New uses include the removal of PCBs and arsenic to make sources of water clean and safe again.
It does not stop there — nanomaterials are being developed for, and are in use in, the food industry, medical treatments, filtration, as well as the production of resilient materials.
For all the advantages that nanomaterial provides, there are some major shortcomings that require more study.
Carbon nanotubes cause lung damage in lab rats, copper nanoparticles cause gill damage in zebra fish, and silver nanoparticles cause liver damage in rats.
Nano particles can be inhaled and enter the brain through the nasal neurons and the particles may translocate to other organs in the body.
These side effects are not well understood and their dangers are not totally defined.
As with most technologies, for all the advantages that are provided, there are always trade-offs. If we can mitigate or eliminate the dangers posed, the advantages provided can be phenomenal.
Lorne Oja is an energy consultant, power engineer and a partner in a company that installs solar panels, wind turbines and energy control products in Central Alberta. He built his first off-grid home in 2003. His column appears every second Friday in the Advocate. Contact him at: lorne@solartechnical.ca.