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Nanotechnology applications that benefit the environment
Introduction
What is Nanotechnology?
According to Center For Responsible Nanotechnology (C.R.N) Nanotechnology refers to the engineering functional systems at the molecular scale.This covers more both current work and concepts that are more advanced.
In its original sense, 'nanotechnology' refrs to the projected ability to construct items from the buttom up, using techniques and tools being developed today to make complete, high performance products.
When K. Eric Drexler popularized the word 'nanotechnology' in the 1980's, he was talking about building machines on the scale of molecules, a few nano-meters wide—motors, robot arms, and even whole computers, far smaller than a cell. Drexler spent the next ten years describing and analyzing these incredible devices, and responding to accusations of science fiction. Meanwhile, mundane technology was developing the ability to build simple structures on a molecular scale. As nanotechnology became an accepted concept, the meaning of the word shifted to encompass the simpler kinds of nano-meter-scale technology. The U.S. National Nanotechnology Initiative was created to fund this kind of nano-tech: their definition includes anything smaller than 100 nano-meters with novel properties.
Much of the work being done today that carries the name 'nanotechnology' is not nanotechnology in the original meaning of the word. Nanotechnology, in its traditional sense, means building things from the bottom up, with atomic precision. This theoretical capability was envisioned as early as 1959 by the renowned physicist Richard Feynman.
With 15,342 atoms, this parallel-shaft speed reducer gear is one of the largest nano-mechanical devices ever modeled in atomic detail.
Nanotechnology utilizes the unique properties of nano-materials which has at least one dimensional size of a material between 1 nm to 100 nm to produce nano-scale devices, components, and systems. Applications utilizing nanotechnology includes manufacturing various products, measuring, imaging and manipulating matter on the nano-scale. Nanotechnology is of considerable interest by scientists in the fields of nano-composites, bio-composites, optical, bio-medical, and electronic manufacturing.
Nano-scale materials can be different in properties compared to bulk materials for two reasons:
- Nano-scaled particles have relatively larger surface area per unit mass which is the critical factor to increase mechanical modulus and other physical and chemical properties.
- Basic material properties are changed at nano-scale due to the dominance of quantum effects and lesser imperfections.
In general, nanotechnology devices consume less energy, reduce material wastes, and help in monitoring. Nanotechnology can also be used to reduce and prevent the toxicity of nano-particles in environment more efficiently.
Method
Cognitive interviewing methodology was used for data collection. Fellow computer science/Engineering students and several I.T specialists were interviewed moreover books helped helped in data collection and further analysis in this report.A draft screening measure was developed by literature reviewing and consultation of professionals.
Rising prices for raw materials and energy, coupled with the increasing environmental awareness of consumers, are responsible for a flood of products on the market that promise certain advantages for environmental and climate protection. Nano-materials exhibit special physical and chemical properties that make them interesting for novel, environmentally friendly products.
Examples of materials developed with nanotechnology include the following engineered nano-materials:
- Carbon buckyballs or fullerenes;
- Carbon nano-tubes;
- Metal oxide nano-particles (e.g., titanium dioxide); and
- Quantum dots, which are nano-scale semiconductor materials (e.g., cadmium selenide).
In trying to help our ailing environment, nanotechnology researchers and developers are pursuing the following avenues:
Generating less pollution during the manufacture of materials.
One example of this is how researchers have demonstrated that the use of silver nano-clusters as catalysts can significantly reduce the polluting byproducts generated in the process used to manufacture propylene oxide. Propylene oxide is used to produce common materials such as plastics, paint, detergents and brake fluid.
Producing solar cells that generate electricity at a competitive cost.
Researcher have demonstrated that an array of silicon nano-wires embedded in a polymer results in low cost but high efficiency solar cells. This, or other efforts using nanotechnology to improve solar cells, may result in solar cells that generate electricity as cost effectively as coal or oil.
Increasing the electricity generated by windmills.
Epoxy containing carbon nano-tubes is being used to make windmill blades. The resulting blades are stronger and lower weight and therefore the amount of electricity generated by each windmill is greater.
Cleaning up organic chemicals polluting groundwater.
Researchers have shown that iron nano-particles can be effective in cleaning up organic solvents that are polluting groundwater. The iron nano-particles disperse throughout the body of water and decompose the organic solvent in place. This method can be more effective and cost significantly less than treatment methods that require the water to be pumped out of the ground.
Cleaning up oil spills.
Using photocatalytic copper tungsten oxide nano-particles to break down oil into biodegradable compounds. The nano-particles are in a grid that provides high surface area for the reaction, is activated by sunlight and can work in water, making them useful for cleaning up oil spills.
Capturing carbon dioxide in power plant exhaust.
Researchers are developing nano-structured membranes designed to capture carbon dioxide in the exhaust stacks of power plants instead of releasing it into the air.
Clearing volatile organic compounds (VOCs) from air.
Researchers have demonstrated a catalyst that breaks down VOCs at room temperature. The catalyst is composed of porous manganese oxide in which gold nano-particles have been embedded.
Reducing the cost of fuel cells.
Changing the spacing of platinum atoms used in a fuel cell increases the catalytic ability of the platinum. This allows the fuel cell to function with about 80% less platinum, significantly reducing the cost of the fuel cell.
Storing hydrogen for fuel cell powered cars.
Using graphene layers to increase the binding energy of hydrogen to the graphene surface in a fuel tank results in a higher amount of hydrogen storage and a lighter weight fuel tank. This could help in the development of practical hydrogen-fueled cars.
Generating less pollution during the manufacture of materials.
One example of this is how researchers have demonstrated that the use of silver nano-clusters as catalysts can significantly reduce the polluting byproducts generated in the process used to manufacture propylene oxide. Propylene oxide is used to produce common materials such as plastics, paint, detergents and brake fluid.
Producing solar cells that generate electricity at a competitive cost.
Researcher have demonstrated that an array of silicon nano-wires embedded in a polymer results in low cost but high efficiency solar cells. This, or other efforts using nanotechnology to improve solar cells, may result in solar cells that generate electricity as cost effectively as coal or oil.
Increasing the electricity generated by windmills.
Epoxy containing carbon nano-tubes is being used to make windmill blades. The resulting blades are stronger and lower weight and therefore the amount of electricity generated by each windmill is greater.
Cleaning up organic chemicals polluting groundwater.
Researchers have shown that iron nano-particles can be effective in cleaning up organic solvents that are polluting groundwater. The iron nano-particles disperse throughout the body of water and decompose the organic solvent in place. This method can be more effective and cost significantly less than treatment methods that require the water to be pumped out of the ground.
Cleaning up oil spills.
Using photocatalytic copper tungsten oxide nano-particles to break down oil into biodegradable compounds. The nano-particles are in a grid that provides high surface area for the reaction, is activated by sunlight and can work in water, making them useful for cleaning up oil spills.
Capturing carbon dioxide in power plant exhaust.
Researchers are developing nano-structured membranes designed to capture carbon dioxide in the exhaust stacks of power plants instead of releasing it into the air.
Clearing volatile organic compounds (VOCs) from air.
Researchers have demonstrated a catalyst that breaks down VOCs at room temperature. The catalyst is composed of porous manganese oxide in which gold nano-particles have been embedded.
Reducing the cost of fuel cells.
Changing the spacing of platinum atoms used in a fuel cell increases the catalytic ability of the platinum. This allows the fuel cell to function with about 80% less platinum, significantly reducing the cost of the fuel cell.
Storing hydrogen for fuel cell powered cars.
Using graphene layers to increase the binding energy of hydrogen to the graphene surface in a fuel tank results in a higher amount of hydrogen storage and a lighter weight fuel tank. This could help in the development of practical hydrogen-fueled cars.
Nanotechnology could make battery recycling economically attractive
Many batteries still contain heavy metals such as mercury, lead, cadmium, and nickel, which can contaminate the environment and pose a potential threat to human health when batteries are improperly disposed of. Not only do the billions upon billions of batteries in landfills pose an environmental problem, they also are a complete waste of a potential and cheap raw material. Researchers have managed to recover pure zinc oxide nano-particles from spent Zn-MnO2 batteries alkaline batteries.
Nano-materials for radioactive waste clean-up in water
Scientists are working on nanotechnology solution for radioactive waste cleanup, specifically the use oftitanate nano-fibers as absorbents for the removal of radioactive ions from water. Researchers have also reported that the unique structural properties of titanate, nanotubes and nanofibers make them superior materials for removal of radioactive cesium and iodine ions in water.
Rising prices for raw materials and energy, coupled with the increasing environmental awareness of consumers, are responsible for a flood of products on the market that promise certain advantages for environmental and climate protection. Nano-materials exhibit special physical and chemical properties that make them interesting for novel, environmentally friendly products.
Conclusion
Working on the nano-scale, researchers have shown that an inexpensive and environmentally benign inorganic light harvesting nano-crystal array can be combined with a low-cost electro-catalyst that contains abundant elements to fabricate an inexpensive and stable system for photoelectrochemical hydrogen production.
| Based on their special properties, nano-materials have the potential to make products or production processes more environmentally friendly. The focus lies mostly on energy and resource efficiency. Several consumer products that promise environmental advantages are already available, and certain applications have already been implemented in the industrial sector. Much is currently in the research and development stage, especially in the sectors energy and environmental technology. | |
| The high expectations for potential environmental benefits of nano-technologically optimized products are contrasted by fears that the high consumption of energy and resources in industrial-scale nano-material production will negate any potential advantages. Unfortunately, in most cases no comprehensive life cycle analyses are available to evaluate the actual environmental effects – both the potential advantages as well as the risks – during the entire lifespan of a product. | |
| Manufacturers are therefore called upon to provide the necessary evidence to support claims of environmental advantages or to provide the data required for analyses and evaluations. As in other cases of technological innovation, the focus in nanotechnology is primarily on the intended functions of the respective nanomaterials. Positive environmental effects are rarely the reason for using a nanomaterial, but such an influence is clearly a welcome side effect. Depending on the actual conditions, negative effects or no effects at all can occur. This calls for actively creating conditions under which positive effects can be realized. |
| 1. Bernhardt, Emily, et al., 2010, An Ecological Perspective on Nano-material Impacts in the Environment (pdf), Journal of Environmental Quality 39, 1954-1965. | |||||
| 2. Tiede, Karen, et al., 2008, Detection and characterization of engineered nano-particles in food and the environment, Food Additives and Contaminants 25(7), 795-821. | |||||
| 3. University of Essex, o.J., Measurement Techniques for Nano-particles (pdf), commissioned by: Nano-cap. | |||||
| 4. Von der Kammer, Frank, et al., 2011, Analysis of Engineered Nano-materials in Complex Matrices (Environment and Biota): General Considerations and Conceptual Case Studies,Environmental Toxicology and Chemistry 31(12), 1-18. 5. National Institute of Standards and Technology (NIST), Department of Commerce (DOC). 6. A Nanotechnology Consumer Products Inventory. 7. Center For Responsible Nanotechnology.
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