The term ‘nanomaterials’ encompasses a wide range of materials including nanocrystalline materials, nanocomposites, nanoparticles, carbon nanotubes, and quantum dots. The common link between all these materials is that they all have microstructural features on the nanoscale. By virtue of its structure, nanomaterials exhibit different physical, chemical, electrical and magnetic properties than conventional materials.
Perfectly crystalline materials rarely exist in nature. In actual fact, it is the presence of defects in nanocrystalline materials that lead to its interesting properties. While atoms in perfectly crystalline materials are all periodically arranged, atoms in amorphous materials are disordered. Most materials, however, are somewhere between these two extremes.
Such materials may contain many crystalline regions that are bounded by defects (i.e. grain boundaries) and are said to be ‘polycrystalline’. In conventional polycrystalline materials, the size of these crystal grains is on the order of micrometers. “Nanocrystalline” materials can be engineered by increasing the defect density in a material to a point where the grain size approaches the nanoscale (< 100 nm). The increased density of grain boundaries impedes the migration of defects within a crystal and ultimately makes the material harder. Similarly, other physical, chemical, electrical and magnetic properties are affected by the small grain size and the nature of the grain boundaries.
Carbon nanotubes (CNTs) are another example of a nanomaterial. CNTs are analogous to a sheet of graphite rolled into a tube with each end capped by half of a fullerene (i.e. Buckyball or C60) and they can be either single-walled (SWNT) or multi-walled (MWNT). By virtue of their unique structure they possess exotic physical, optical, and electronic properties - for example, carbon nanotubes are known to be stronger than steel and yet they are highly elastic under load. CNTs could find applications as lightweight fibers for bulletproof vests, tips for scanning electron microscopes, field-effect transistors, and molecular test tubes. Some futurists, and even some scientists and engineers, have proposed that CNTs can be woven into a long, thick cable with one end anchored on an ocean platform and the other end in space. The so-called “Space Elevator” would slowly hoist heavy loads into space, bypassing the need for rockets. While most serious scientists still consider this idea a dream, it serves to show the boundless possibilities of carbon nanotubes.
Within the realm of nanotechnology, the field of nanomaterials stands as the most mature and nanomaterials have already been applied in a wide range of industrial settings. Pioneering research on engineered nanomaterials started in the early 1980s and over two decades of work has led to the development and subsequent commercialization of nanomaterials that outperform conventional materials.
Integran Technologies Inc. is a Toronto-based company well known for their work on nanocrystalline materials. Based in part on the collaborative work of Ontario Hydro, Queen’s University and the University of Toronto, Integran has developed synthesis routes to produce nanocrystalline materials for various advanced applications. In 1993, Integran developed a process for in-situ repair of damaged heat exchangers and steam generators in nuclear power plants. The ElectrosleeveTM process is an electroplating process that deposits a nanocrystalline alloy sleeve protecting the inside of a tube from corrosion. This process was performed at the Pickering Nuclear Power Plant and was the first ever large-scale commercial application of nanocrystalline materials.
Integran’s Grain Boundary EngineeringTM technology produces compounds that are stronger and more resistant to corrosion and fatigue in comparison to conventional materials. Grain Boundary Engineering has been applied in the battery industry as well as the automotive and aerospace industries.
Another company that has found commercial applications for nanomaterials is Oxonica. The three core products of this nanomaterials company really show the diverse impact that nanomaterials are making on the world. Oxonica’s “Environ” nanocatalyst technology is a diesel additive that produces less carbon deposits, reduces harmful emissions, and increases fuel efficiency by up to 12%. Oxonica’s second product, “Optisol” is a nanoparticle additive for sunscreens that absorbs UV radiation. “Optisol” has been carefully engineered to not generate free radicals upon UV absorption while conventional UV absorbing agents do. Free radicals are a highly reactive species and have been known to trigger skin ageing. The company’s third product is a line of precision-engineered quantum dots – “Evidots”. These nanocrystals have a very narrow emission spectrum and thus make them ideal for research or photonics applications. Oxonica is a prime example of the many different possible applications for nanomaterials.
The core curriculum of the Nanoengineering Option in Engineering Science provides a background in materials science with emphasis on the structure, synthesis, and properties of nanostructured materials. In third year, MSE358 discusses the fundamental structure of materials and the techniques employed to characterize these materials. In fourth year, MSE459 focuses on methods to synthesize nanostructured materials and the synthesis-structure relationship. MSE550 completes the picture by describing the advanced physical properties of materials and the relationship between the structure of a material and its properties. These courses are taught by world-class faculty members who are experts in nanomaterials.
While the prospects of commercialization for the other branches of nanotechnology lie at the horizon, nanomaterials are beginning to make an impact on the world right now. The Nanoengineering Option provides students with the knowledge to pursue graduate level research in the field of nanomaterials and to ultimately work in this exciting and expanding industry.
Nanocrystalline Materials
Perfectly crystalline materials rarely exist in nature. In actual fact, it is the presence of defects in nanocrystalline materials that lead to its interesting properties. While atoms in perfectly crystalline materials are all periodically arranged, atoms in amorphous materials are disordered. Most materials, however, are somewhere between these two extremes.
Such materials may contain many crystalline regions that are bounded by defects (i.e. grain boundaries) and are said to be ‘polycrystalline’. In conventional polycrystalline materials, the size of these crystal grains is on the order of micrometers. “Nanocrystalline” materials can be engineered by increasing the defect density in a material to a point where the grain size approaches the nanoscale (< 100 nm). The increased density of grain boundaries impedes the migration of defects within a crystal and ultimately makes the material harder. Similarly, other physical, chemical, electrical and magnetic properties are affected by the small grain size and the nature of the grain boundaries.
Carbon Nanotubes
Carbon nanotubes (CNTs) are another example of a nanomaterial. CNTs are analogous to a sheet of graphite rolled into a tube with each end capped by half of a fullerene (i.e. Buckyball or C60) and they can be either single-walled (SWNT) or multi-walled (MWNT). By virtue of their unique structure they possess exotic physical, optical, and electronic properties - for example, carbon nanotubes are known to be stronger than steel and yet they are highly elastic under load. CNTs could find applications as lightweight fibers for bulletproof vests, tips for scanning electron microscopes, field-effect transistors, and molecular test tubes. Some futurists, and even some scientists and engineers, have proposed that CNTs can be woven into a long, thick cable with one end anchored on an ocean platform and the other end in space. The so-called “Space Elevator” would slowly hoist heavy loads into space, bypassing the need for rockets. While most serious scientists still consider this idea a dream, it serves to show the boundless possibilities of carbon nanotubes.
Nanomaterials In the Market
Within the realm of nanotechnology, the field of nanomaterials stands as the most mature and nanomaterials have already been applied in a wide range of industrial settings. Pioneering research on engineered nanomaterials started in the early 1980s and over two decades of work has led to the development and subsequent commercialization of nanomaterials that outperform conventional materials.
Integran Technologies Inc. is a Toronto-based company well known for their work on nanocrystalline materials. Based in part on the collaborative work of Ontario Hydro, Queen’s University and the University of Toronto, Integran has developed synthesis routes to produce nanocrystalline materials for various advanced applications. In 1993, Integran developed a process for in-situ repair of damaged heat exchangers and steam generators in nuclear power plants. The ElectrosleeveTM process is an electroplating process that deposits a nanocrystalline alloy sleeve protecting the inside of a tube from corrosion. This process was performed at the Pickering Nuclear Power Plant and was the first ever large-scale commercial application of nanocrystalline materials.
Integran’s Grain Boundary EngineeringTM technology produces compounds that are stronger and more resistant to corrosion and fatigue in comparison to conventional materials. Grain Boundary Engineering has been applied in the battery industry as well as the automotive and aerospace industries.
Another company that has found commercial applications for nanomaterials is Oxonica. The three core products of this nanomaterials company really show the diverse impact that nanomaterials are making on the world. Oxonica’s “Environ” nanocatalyst technology is a diesel additive that produces less carbon deposits, reduces harmful emissions, and increases fuel efficiency by up to 12%. Oxonica’s second product, “Optisol” is a nanoparticle additive for sunscreens that absorbs UV radiation. “Optisol” has been carefully engineered to not generate free radicals upon UV absorption while conventional UV absorbing agents do. Free radicals are a highly reactive species and have been known to trigger skin ageing. The company’s third product is a line of precision-engineered quantum dots – “Evidots”. These nanocrystals have a very narrow emission spectrum and thus make them ideal for research or photonics applications. Oxonica is a prime example of the many different possible applications for nanomaterials.
Nanomaterials in the Classroom
The core curriculum of the Nanoengineering Option in Engineering Science provides a background in materials science with emphasis on the structure, synthesis, and properties of nanostructured materials. In third year, MSE358 discusses the fundamental structure of materials and the techniques employed to characterize these materials. In fourth year, MSE459 focuses on methods to synthesize nanostructured materials and the synthesis-structure relationship. MSE550 completes the picture by describing the advanced physical properties of materials and the relationship between the structure of a material and its properties. These courses are taught by world-class faculty members who are experts in nanomaterials.
While the prospects of commercialization for the other branches of nanotechnology lie at the horizon, nanomaterials are beginning to make an impact on the world right now. The Nanoengineering Option provides students with the knowledge to pursue graduate level research in the field of nanomaterials and to ultimately work in this exciting and expanding industry.
