Manipulating matter at the nanoscale
jet skis, just as a start. Then ask what it could do to change the way people engage with natural resources and how it could bring life to where previously there was none.
“Nanoscale technology forms the inner space in which all disciplines of science, engineering and technology find innovation,” says Professor Shivani Bhardwaj Mishra of Unisa’s Nanotechnology and Water Sustainability Unit at the College of Science, Engineering and Technology. “It allows scientists and engineers to share ideas within this space and innovate to develop materials with the finest properties and efficiencies. As of today, the materials in nanometre size have done wonders for industrial and commercial products and applications.”
One of the simplest and most easily recognised applications of nanotechnology is the water filter bottle. The filter inside the bottle likely contains carbon materials nanometres in size, which have been developed specifically to ensure water is kept clean and pure. In fact, water applications form the strong arm of the nanotechnology body and could potentially go a long way towards alleviating serious water shortages and challenges around access to clean water.
“The availability of clean water is a global challenge,” adds Mishra. “There are numerous technologies available to clean water and allow for its re-use, but many of these systems are too expensive for the lower income groups. Researchers in different universities are working towards the development of technologies that use low-cost nanomaterials, and industries are setting up pilot plants to gain a deeper understanding of the requirements of nanotechnology to combat the challenge of wastewater discharge into the environment, or re-using it so as to cut down on water usage in production.”
“In South Africa, we are currently facing a two-fold water crisis — water scarcity and deteriorating water quality,” says Gumbi. “Nanotechnology is being used for the development of materials that will not only effectively remove the contaminants that are responsible for deteriorating water quality, but reduce the number of steps involved in a conventional water treatment setup. It is also being used to develop materials with selfcleaning properties, such as carbon nanotubes incorporated in membrane filters.”
Methods that nanotechnologies use as they work with water include membranes, adsorption (adhesion of tiny particles to a surface), ion exchange, coagulation (where liquids become more solid), flocculation (where particles in a liquid clump together), photocatalysis (where nanomaterials work together with light to cause chemical reactions). All these methods have been exploited in improving the decontamination of water.
There is ongoing research into finding ways of converting “new water” sources such as wastewater, brackish groundwater and seawater into potable water of high quality. Nanotechnology-based membranes or nanofiltration membrane filters with nanomaterials have extremely small pore sizes and work well in removing tiny contaminants or salt particles. They also work to destroy bacteria and can handle water filtration at high pressure. The potential to create low-cost, effective solutions that assure all members of society have access to clean drinking water is evident, and one which the government has not ignored.
According to a Nanotechnology Public Engagement Programme report, the department of science and technology has invested more than R170-million into various arenas of nanotechnology research and development. These funds have been spread across several universities, industries and nanotechnology centres in South Africa.
“A lot is being initiated by government and the private sector,” says Mishra. “The mutual efforts of academic institutes and the involvement of the corporate sector and government bodies have given us a platform on which we can develop skills and commercialise opportunities. There are still plenty of innovations that need to be discovered and new ideas needed to improvise on existing systems via nanotechnology, and industry participation will definitely help us to achieve sustainable solutions.”
South Africa is paying attention to the value of nanotechnology and its potential for the future. The list of institutions and organisations that have invested time and money into its applications is impressive. PST Sensors found applications in sensors, Comar Chemicals manufactures catalysts for the production of rubber, and Nanotech Water Solutions makes water and nanotechnology its business. Even Eskom has climbed aboard the nanotechnology bandwagon, alongside the University of the Witwatersrand, University of Pretoria, University of Cape Town, University of Free State, Mintek and the South African Nanotechnology Research Initiative. The particles may be small, but the interest in their capabilities most certainly is not.
The areas of research being explored span a variety of industries and sectors other than water, including rubber and healthcare. There are some extraordinary developments in medicine using nanotechnology, and many of these have the potential to change the course of diseases such as cancer or tuberculosis.
“Nanotechnology materials can be used to deliver drugs that cure certain ailments such as TB and cancer,” explains Dr Vuyo Mavumengwana, medical biochemist at the University of Johannesburg. “It isn’t quite yet the answer to every problem, but indications so far show that these nanotechnology solutions have some interesting applications and potential.”
Gumbi adds: “We can look forward to interesting developments in the health sector around nanorobots or nanobots, which can be loaded with cancer-curing drugs and used to deliver them directly to the affected area.”
Many modern medicines, vaccines and supplements are made up from nanosize formulations to ensure their delivery is more effective. In addition, biosensors, such as those used to measure blood sugar or cholesterol, are now designed using nanomaterials to ensure more accurate responses. Nanotechnology has also played a significant role in the development of space and aircrafts.
However, as with all scientific exploration there should be that all-important caveat: “Although advances made from nanotechnology are promising to improve the quality of life and make the world a better place to live in, we also need to ensure that the ethical dimensions of some of the discoveries are carefully considered,” concludes Gumbi.