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Dr Wynand Steyn |
Effect of bitumen ageing as observed using an atomic force microscope [View enlarged version] |
Although nanotechnology has traditionally been used in the areas of micro-electronics, medicine and materials science, it has potential for application in transportation engineering.
Nanotechnology and transportation engineering structures operate on hugely different dimensions. When looking at the potential application of nanotechnology in the transportation engineering field, the biggest challenge is to scale up nanotechnology to ensure the benefits gained through working in the nano-sphere are realistic in the macro-sphere - the application level.
But why look at nanotechnology application in this area? "Materials form the building blocks of any transportation infrastructure and it is therefore prudent to evaluate the potential effects of nanotechnology developments on transportation engineering," explains Wynand Steyn of the CSIR. "Our current research looks at the development of improved materials for the construction of transportation facilities, the characterisation of traditional materials used in transportation facilities and the application of techniques and knowledge developed in the broader transportation engineering field to understand and characterise processes in nanotechnology."
The specific areas within transportation engineering where nanotechnology could find application are safety, durability, economy and sustainability.
Safety
Safe transportation facilities are probably the overriding requirement from the general public regarding transportation engineering. "Research in this area includes the use of nanoscale silicon carbide into tyre manufacturing to improve the wet skid resistance and decrease the abrasion of the tyre by up to 50%," comments Steyn.
Durability
Nanotechnology can be used to improve materials, either through improving existing materials or developing novel materials. The main requirement is that the material should be able to operate under applied stresses and strains. According to Steyn, current research focuses on improving the shear strength of concrete through applying various nano-sized particles. Increases of up to 50% in the strength of concrete have been reported.
Economy
The provision of transportation facilities is done in the most economic way possible, with both initial construction and maintenance costs being evaluated. It is anticipated that nanotechnology could find application in appropriate maintenance. The main area would be the extension of the life span of facilities, not the replacement of these.
Various types of nanocomposites coatings that can be applied to concrete surfaces are an example of how nanotechnology could prolong the life span of facilities.
Sustainability
The focus here is again on the modification of existing materials. The efficient re-use of materials is also investigated. Materials could be modified to enable construction at lower temperatures to reduce the energy requirements for the construction process.
Looking ahead, the main challenges and limitations of using nanotechnology in transportation engineering are considered to be:
- Dimension: Large volumes of materials are needed. When nanomaterials are combined with bulk aggregates and binders, one should evaluate whether the benefits of nanomaterials are still applicable and cost and energy-efficient at such big scales.
- Upscaling of fabrication: Current efforts look at the fabrication, characterisation and use of nanomaterials at a nanoscale. This is typically far removed from the kind of quantities needed for transportation infrastructure. A potential solution is to use nanomaterials as a catalyst, which will reduce the amount needed substantially.
- Costs: Nano materials and equipment are relatively expensive due to the novelty of the technology and the complexity of the equipment used to prepare and characterise materials. Current opinion is that in special cases, nanomaterials will enable unique solutions to complicated problems, which cause them to be cost-effective.
- Environmental and health issues: The effect of various nanomaterials on the environment is the topic of hot debate in nanotechnology and environmental research circles. One of the main reasons for using nanomaterials is the difference in performance of material on nanoscale, as well as the effect it has on the environment when used on nanoscale. In cases such as improved methods for purifying water, the different effect on potentially deadly microbes in the water is specifically the reason why nanomaterials are being used. A clear distinction is required between controlled and positive effects on the environment and uncontrolled and unexpected effects.
"We recommend that focused research is done to ensure the potential benefits of nanotechnology in transport infrastructure can be obtained to provide more economical infrastructure and to prolong its life span," Steyn concludes.
Enquiries: CSIR Communication
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