Have you visited America on Wheels, an over-the-road transportation museum located in Allentown, Lehigh County, Pennsylvania in the United States? Do you know that America and rest of the world have a long history of engineering the environmental risk of the wheels? By the 1950s traffic in California had become so heavy that smog posed a significant risk to the residents. Today, China’s cities have now reached a similar stage, and are increasingly following American and European regulators in imposing limits on emissions by new cars of nitrogen oxides (NOX), hydrocarbons and fine soot particles. Other countries are also getting more concerned about global warming and pollution, and have started to require manufacturers steadily to reduce the carbon dioxide (CO2) emissions of the vehicles they make. Having been depicted as environmental villains since the 1950s, cars and their makers may soon be able to move out of the spotlight with the help of nanotechnology.
A car is a complex combination of various components that can be converted to a greener vehicle in various ways. These may include invention of non fossil fuel energy for these vehicles such as hydrogen fuel cells, reduction in the consumption of fossil fuels by using nanocomposites, for tire innovation as nanomaterials combined with rubber. Here are a few examples:
* Nanotechnology constitutes a certain percentage of a final product whose key functions hinge on exploiting the size-dependent phenomena of nanotechnology. Green cars are complex products which incorporate green nanotechnology in several different ways, being present in the tires, in the chassis, in the windscreen, etc.
* Green nano-electronic manufacturing enables components of the green car, and its production through the use of sensors to reduce energy wastage and to monitor and reduce emissions.
* Electric cars using nanotechnology-enabled batteries. The battery material (LiFePO4), the component electrode and the system as a whole (the battery) are all based on nanotechnology, so the final product (green car) is nano-enabled through its batteries i.e. its performance is enhanced by the use of nanotechnology.
Potential fields of improvement include increased car and truck fuel efficiency and tyre durability and reduced greenhouse gas emissions and tire weight. The tire industry faces many challenges – from the on-going supply of raw materials in the face of massive predicted growth in demand for vehicles over the coming decades, to implementing innovations that will improve the sustainability of cars, e.g. through the reduction of CO2 emissions, while still delivering a high-quality product with a critical role in vehicle safety. Nanotechnology helps improve safety and sustainability by:
* A nanotechnology-enabled tread compound helps the tires grip the road. This tire is intended to provide higher performance than conventional tires.
* A nanoparticle enables tires last longer, have a better grip, reduce resistance, and thus save fuel. Here, nanoprene particles of rubber compound in the tire provide anchor points to attach to a silica filler.
Tires thus represent a good case study through which to analyze and identify safety, technical, socio-economic and policy issues relating to the use of green nanotechnology.
Some of the most promising nanomaterials for tires include nanosilica, organoclay and Carbon
Nano Tubes (CNTs) used as fillers, substituting for traditional fillers like carbon black and silica.
Composites reinforced with CNTs have been shown to have dramatically improved tensile strength, tear strength and hardness compared with more conventional materials. Silicon carbide has been used to produce tires with improved skid resistance and reduced abrasion. Nanoparticles of clay can be mixed with plastic and synthetic rubber to seal the inside of tires, creating an airtight surface and allowing the amount of rubber required to be reduced. CNT-based materials have great potential to improve the energy use of the transport sector including cars, trucks and trains.
High-strength, ultra-light nanomaterials being used for lower-weight cellular manufacturing of vehicles are making an important contribution to higher energy and resource efficiency and substantial amounts of fuel saving, enabling America on Wheels – safe and green.
drjohnxwang 