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Lessons from the past
OPINION
Lessons from the past
| Sumitra Rajagopalan
Colloidal chemistry, as envisioned by Wilhelm Ostwald, can show us how to link fragmented nanoscience courses into a cohesive whole. Sumitra Rajagopalan | McGill University and École Polytéchnique, Montreal, Canada | [email protected]
With clouds of fumes bursting from her pot and steam puffs screeching out of her ears, a witch stirs her poisonous brew. After a few seconds, a caption appears: ‘Making Materials: The Old Way’. Next slide: a submicroscopic image of a self-assembled material with tiny clusters perfectly arranged along the surface. Nearby, a neatly-attired chemist tinkers with a sophisticated probe ready to pattern biomolecules onto the surface. The caption: ‘Making Materials: The New Way’. Thus begins my introductory lecture in nanoscience. Nanotechnologies have caught the imagination of scientists worldwide for their mind-boggling potential to create a new generation of materials and structures. But lost in the hype and hoopla surrounding the technology and its market potential is the teaching of nanoscience in universities. This is a shame, for nanotechnology, taught properly, can offer a comprehensive lesson in natural science by bringing together seemingly disparate disciplines into a cohesive whole. This would help students immensely, as university course offerings in the field are often highly fragmented and piecemeal with students unable to connect the dots on their own. Many credit Richard Feynman for having sown the first seed of nanotechnology in 1959 with his ‘Plenty of room at the bottom’ talk. In fact, the start gun was fired nearly four decades earlier. Born in Latvia, Wilhelm Ostwald was a chemist and Nobel Laureate credited with numerous discoveries in catalysis and synthetic chemistry. Even while steeped in his main scientific activities, he would often reflect on what he termed the ‘neglected dimension’: the colloidal state. Ostwald waxed eloquently on this state that lies somewhere between single molecules and bulk matter, with particles of 1 nm to 1 µm dispersed in solution. In this twilight zone, such materials display
64
unusual mechanical, electrical, and optical properties. Even back then he proposed many interesting applications for these colloidal systems ranging from responsive soft materials, flocculants, and dispersants, to better pigments and drug-release systems, foreshadowing some of the nanotechnology applications widely touted today. Seven decades on, colloidal chemistry continues to hold pride of place in chemistry programs in Russian and German universities. As an undergraduate student in St. Petersburg, we studied the properties of nano- and microparticles in solution, their peculiar light-scattering properties, unusual electrokinetic behavior, and viscous properties. This led to the study of surface phenomena and micelle formation, as well as adsorption of charged particles at interfaces. As we covered the coagulation and coacervation of these particles, sols gave way to gels, which in turn provided insights into the behavior of macromolecules in nature. As Ostwald himself noted, “I know no other branch of present science which touches upon so many different spheres of knowledge as does colloidal chemistry…” Nanoscience, is really an extension of colloidal chemistry, especially in its ability to straddle various disciplines. Yet, colloids and nanoscience remain the neglected dimension in university curricula. A cursory examination of nanotechnology-related courses across North America reveals these shortcomings. Ironically for a discipline that starts at the bottom, there is a paucity of courses dealing with the basics. For the most part, they are rich in techniques, sparse in theory. The result is that we have legions of scientists trained in state-of-the-art techniques, such as lithography, scanning probe microscopy, microfluidics – you name it – but with little appreciation of the underlying science.
NOVEMBER 2006 | VOLUME 9 | NUMBER 11
There is no question: nanotechnology promises to be a hotbed of materials innovation for decades to come. Yet, students cannot hope to master the intricacies of nanotechnology without the basics of colloidal, interface, and nanoscale sciences. Rather than institute standalone degree programs in nanotechnology, it would make more sense to introduce the ‘neglected dimensions’ within existing undergraduate degree programs. These could become comprehensive courses in nanoscience that would cover colloidal sciences, supramolecular chemistry, surfaces, and interfaces. And let’s not forget the best nanoengineer of them all: nature. As part of a course in biomedical engineering, I give a lecture on design in nature that covers the complex hierarchical structure of bone, the molecular motors in muscle, and the liquidcrystalline nature of cartilage that gives it its soft, yet tough compressive properties. Thereafter, with little prompting, these hard-core mechanical engineering students connect the dots. The template synthesis that characterizes tough bone and teeth are back-engineered to make more durable hardtissue implants; they deconstruct the powerful ioninduced actuation of contractile proteins to design molecular motors; and the intricate folding patterns of tree leaves are modeled to build self-expanding cardiovascular stents. This might be the best thing about nanotechnology: not only will it be the backbone of materials science in the 21st century, it will also offer a unique lens through which we can study biological structures anew. With this new paradigm, we could finally move away from the old, witchcraft-like techniques of making materials to new and elegant methods using design from the bottom-up, just like Mother Nature.
Lessons from the past
| Sumitra Rajagopalan
Colloidal chemistry, as envisioned by Wilhelm Ostwald, can show us how to link fragmented nanoscience courses into a cohesive whole. Sumitra Rajagopalan | McGill University and École Polytéchnique, Montreal, Canada | [email protected]
With clouds of fumes bursting from her pot and steam puffs screeching out of her ears, a witch stirs her poisonous brew. After a few seconds, a caption appears: ‘Making Materials: The Old Way’. Next slide: a submicroscopic image of a self-assembled material with tiny clusters perfectly arranged along the surface. Nearby, a neatly-attired chemist tinkers with a sophisticated probe ready to pattern biomolecules onto the surface. The caption: ‘Making Materials: The New Way’. Thus begins my introductory lecture in nanoscience. Nanotechnologies have caught the imagination of scientists worldwide for their mind-boggling potential to create a new generation of materials and structures. But lost in the hype and hoopla surrounding the technology and its market potential is the teaching of nanoscience in universities. This is a shame, for nanotechnology, taught properly, can offer a comprehensive lesson in natural science by bringing together seemingly disparate disciplines into a cohesive whole. This would help students immensely, as university course offerings in the field are often highly fragmented and piecemeal with students unable to connect the dots on their own. Many credit Richard Feynman for having sown the first seed of nanotechnology in 1959 with his ‘Plenty of room at the bottom’ talk. In fact, the start gun was fired nearly four decades earlier. Born in Latvia, Wilhelm Ostwald was a chemist and Nobel Laureate credited with numerous discoveries in catalysis and synthetic chemistry. Even while steeped in his main scientific activities, he would often reflect on what he termed the ‘neglected dimension’: the colloidal state. Ostwald waxed eloquently on this state that lies somewhere between single molecules and bulk matter, with particles of 1 nm to 1 µm dispersed in solution. In this twilight zone, such materials display
64
unusual mechanical, electrical, and optical properties. Even back then he proposed many interesting applications for these colloidal systems ranging from responsive soft materials, flocculants, and dispersants, to better pigments and drug-release systems, foreshadowing some of the nanotechnology applications widely touted today. Seven decades on, colloidal chemistry continues to hold pride of place in chemistry programs in Russian and German universities. As an undergraduate student in St. Petersburg, we studied the properties of nano- and microparticles in solution, their peculiar light-scattering properties, unusual electrokinetic behavior, and viscous properties. This led to the study of surface phenomena and micelle formation, as well as adsorption of charged particles at interfaces. As we covered the coagulation and coacervation of these particles, sols gave way to gels, which in turn provided insights into the behavior of macromolecules in nature. As Ostwald himself noted, “I know no other branch of present science which touches upon so many different spheres of knowledge as does colloidal chemistry…” Nanoscience, is really an extension of colloidal chemistry, especially in its ability to straddle various disciplines. Yet, colloids and nanoscience remain the neglected dimension in university curricula. A cursory examination of nanotechnology-related courses across North America reveals these shortcomings. Ironically for a discipline that starts at the bottom, there is a paucity of courses dealing with the basics. For the most part, they are rich in techniques, sparse in theory. The result is that we have legions of scientists trained in state-of-the-art techniques, such as lithography, scanning probe microscopy, microfluidics – you name it – but with little appreciation of the underlying science.
NOVEMBER 2006 | VOLUME 9 | NUMBER 11
There is no question: nanotechnology promises to be a hotbed of materials innovation for decades to come. Yet, students cannot hope to master the intricacies of nanotechnology without the basics of colloidal, interface, and nanoscale sciences. Rather than institute standalone degree programs in nanotechnology, it would make more sense to introduce the ‘neglected dimensions’ within existing undergraduate degree programs. These could become comprehensive courses in nanoscience that would cover colloidal sciences, supramolecular chemistry, surfaces, and interfaces. And let’s not forget the best nanoengineer of them all: nature. As part of a course in biomedical engineering, I give a lecture on design in nature that covers the complex hierarchical structure of bone, the molecular motors in muscle, and the liquidcrystalline nature of cartilage that gives it its soft, yet tough compressive properties. Thereafter, with little prompting, these hard-core mechanical engineering students connect the dots. The template synthesis that characterizes tough bone and teeth are back-engineered to make more durable hardtissue implants; they deconstruct the powerful ioninduced actuation of contractile proteins to design molecular motors; and the intricate folding patterns of tree leaves are modeled to build self-expanding cardiovascular stents. This might be the best thing about nanotechnology: not only will it be the backbone of materials science in the 21st century, it will also offer a unique lens through which we can study biological structures anew. With this new paradigm, we could finally move away from the old, witchcraft-like techniques of making materials to new and elegant methods using design from the bottom-up, just like Mother Nature.