C60 molecules have an intriguing ball-shaped structure that suggests several interesting possibilities for motion on surfaces. Indeed, researchers have found that the passage of electrons through a bucky ball in a transistor is correlated to the spinning of the ball around its center of mass. Moreover, since bucky balls look like molecular ball bearings, it has been thought that they may be useful as lubricants for use in automobile brakes. Now a team of researchers at the University of Bologna (Italy) and the University of Liverpool (UK) have carried out detailed molecular dynamics simulations to understand the motion of bucky balls on metal surfaces.
Francesco Zerbetto and Gilberto Teobaldi have found that C60 molecules exhibit a wide range of molecular motions on surfaces. The bucky balls spin and bounce on the surface and also show an intercage rattling motion that Zerbetto says is similar to that of billiard balls in a partly filled roll-a-rack triangle. The simulations have been carried out as a function of temperature and model the movement of several bucky ball molecules over times ranging up to one nanosecond. There is some transfer of charge from the gold surface to the bucky ball that helps in the adsorption of these molecules at the surface. The researchers have found that with increasing temperature the cages move away from the gold surfaces resulting in a lower frequency of bouncing. The bouncing frequencies obtained by simulation match very nicely with experimental measurements of single-molecule bucky-ball transistors, corroborating the validity of the simulations.
The researchers have found that the bouncing of the cage on the surface and the intercage rattling govern the friction-related properties of the bucky balls on a surface. "The strong van der Waals interactions of the bucky balls with neighboring atoms makes the friction far too high for lubrication", said Zerbetto, but he is hopeful that doping or chemical modification can be used to separate the bucky balls to get them to act more like ball bearings.
Original publication: Francesco Zerbetto et al.;"C60 on Gold: Adsorption, Motion, and Viscosity"; Small 2007, 3, No. 10, 1694-1698.
Chemical hydrogen storage system
Hydrogen is a highly attractive, but also highly explosive energy carrier, which requires safe, lightweight and cheap storage as well as transportation systems. Scientists at the Weizmann Institute of Science, Israel, have now developed a chemical storage system based on simple and abundant ... more
Magnetic resonance imaging (MRI) has emerged as one of the most powerful clinical imaging tools because of its superb spatial resolution and soft tissue contrast, especially when using contrast agents. In the European Journal of Inorganic Chemistry, scientists have presented a new kind of n ... more
Coupled oxygen transfer and electron transfer reactions that use cofactors are enzymatic reactions of crucial significance to all lifeforms from bacteria to vertebrates. In the European Journal of Inorganic Chemistry, scientists have introduced a model for the enzyme sulfite oxidase. It is ... more
Wiley-VCH Verlag GmbH & Co. KGaA
Wiley-VCH publishes monographs, textbooks, major references works and journals in print or online. Wiley-VCH can look back on over 80 years of publishing in chemistry, materials sciences, physics and the life sciences. more
New AI tool accelerates discovery of truly new materials
Researchers at the University of Liverpool have created a collaborative artificial intelligence tool that reduces the time and effort required to discover truly new materials. Reported in the journal Nature Communications, the new tool has already led to the discovery of four new materials ... more
Researchers discover a new inorganic material with lowest thermal conductivity ever reported
A collaborative research team, led by the University of Liverpool, has discovered a new inorganic material with the lowest thermal conductivity ever reported. This discovery paves the way for the development of new thermoelectric materials that will be critical for a sustainable society. Re ... more
Searching for lead materials with specific properties, researchers have developed a workflow that incorporates artificial intelligence to guide discovery of a new ceramic structure with particularly low thermal conductivity. As they explain in the journal Angewandte Chemie, the material has ... more
Can diamonds originate methane?
Turning one of the world's finest gems - diamonds – into one of the worst greenhouse gases – methane - does not seem a great idea. Yet this happened through the work of a group of researchers from the Universities of Bologna and Edinburgh (UK), the Centre National de la Recherche Scientifiq ... more
Smog-eating graphene composite reduces atmospheric pollution
Graphene Flagship partners the University of Bologna, Politecnico di Milano, CNR, NEST, Italcementi HeidelbergCement Group, the Israel Institute of Technology, Eindhoven University of Technology, and the University of Cambridge have developed a graphene-titania photocatalyst that degrades u ... more
Organizing dumbbells for nanotech devices
A team of chemists from France, Italy, Spain, the UK, and the US are working together to bridge the gap between nanoscience and nanotechnology. They have now devised a method that could allow them to organize tiny molecular machines on a surface and so build devices that pack in thousands o ... more
