Methods and apparatus for the production of carbon-containing materials

The present invention provides various methods and apparatus for the production of fullerenes and other carbon-containing materials. In some aspects, the invention provides an arc chamber comprising a graphite element Support, wherein the Support comprises a rotatable frame adapted for moving each graphite element towards and away from an arc discharge position. In other aspects, the invention provides a collection chamber for collecting carbon-containing materials produced in an arc chamber, wherein the collection chamber comprises an inlet and a rotatable element arranged to direct the carbon containing material to a wall of the collection chamber, wherein the sectional area occupied by the rotatable element increases with distance from the inlet. In other aspects, the invention provides a collection chamber comprising means for isolating the collection chamber from an arc discharge apparatus and an inlet for the introduction of solvent into the collection chamber

Hierarchical Self-Assembly of Water-Soluble Fullerene Derivatives into Supramolecular Hydrogels

Controlling the self-assembly of nanoparticle building blocks into macroscale soft matter structures is an open question and of fundamental importance to fields as diverse as nanomedicine and next-generation energy storage. Within the vast library of nanoparticles, the fullerenes—a family of quasi-spherical carbon allotropes—are not explored beyond the most common, C60. Herein, a facile one-pot method is demonstrated for functionalizing fullerenes of different sizes (C60, C70, C84, and C90–92), yielding derivatives that self-assemble in aqueous solution into supramolecular hydrogels with distinct hierarchical structures. It is shown that the mechanical properties of these resultant structures vary drastically depending on the starting material. This work opens new avenues in the search for control of macroscale soft matter structures through tuning of nanoscale building blocks.</p

Keeping perfect time with caged atoms

For Fridtjof Nansen, 13 April 1895 started well. Six days earlier, the Norwegian explorer had set a new record for the closest approach to the North Pole, and now he was moving quickly over unbroken sea ice toward Cape Fligely and home. But then came a sickening realization: In his eagerness to break camp, he had forgotten to wind the chronometers. He had lost track of precise time, and thus the ability to track his longitude. Although Nansen couldn't have lost his position by more than a few minutes, it forced him to take a circuitously conservative route to avoid being swept into the North Atlantic. His expedition thus had to endure a hungry winter, camped on an unknown shore. Not until June the following year did he encounter other explorers and learn his true position-on Cape Felder, in Franz Josef Land

Hierarchical Self-Assembly of Water-Soluble Fullerene Derivatives into Supramolecular Hydrogels

Controlling the self-assembly of nanoparticle building blocks into macroscale soft matter structures is an open question and of fundamental importance to fields as diverse as nanomedicine and next-generation energy storage. Within the vast library of nanoparticles, the fullerenes—a family of quasi-spherical carbon allotropes—are not explored beyond the most common, C60. Herein, a facile one-pot method is demonstrated for functionalizing fullerenes of different sizes (C60, C70, C84, and C90–92), yielding derivatives that self-assemble in aqueous solution into supramolecular hydrogels with distinct hierarchical structures. It is shown that the mechanical properties of these resultant structures vary drastically depending on the starting material. This work opens new avenues in the search for control of macroscale soft matter structures through tuning of nanoscale building blocks.</p

Probing the Interior Environment of Carbon Nano-test-tubes

We report the filling of single walled carbon nanotubes with an electron spin-active fullerene species where a nitroxide radical is functionalized on the fullerene cage. High resolution transmission electron microscopy (HRTEM), optical absorption and electron spin resonance (ESR) are used to determine the rotational behavior of the encapsulated molecules and determine the polar nature of the nanotube interior

The application of the surface energy based solubility parameter theory for the rational design of polymer-functionalized MWCNTs

The surface energy based solubility parameters theory was applied to model the degree of polystyrene-functionalisation of MWCNTs in six different organic solvents. The experimental characterization of the polymer-functionalized MWCNTs is consistent with the predictions of this model providing a breakthrough towards the rational design of functionalized MWCNTs based on thermodynamic parameters

Synthesis and EPR studies of the first water-soluble N@C60 derivative

The first water-soluble derivative of the paramagnetic endohedral fullerene N@C60 has been prepared through the covalent attachment of a single addend containing two permethylated βcyclodextrin units to the surface of the carbon cage. The line width of the derivatives EPR signal is highly sensitive to both the nature of the solvent and the presence of Cu(II) ions in solution

A porphyrin-centred fullerene tetramer containing an N@C60 substituent

An N@C60-containing C60 tetramer was synthesized by quadruple 1,3-dipolar cycloaddition (Prato) reaction. This molecule demonstrates the N@C60 qubit’s ability to form covalently linked arrays. Furthermore, it provides a promising scaffold with which to measure multiple qubit–qubit interactions; which must be well characterized for a functioning quantum information processing architecture

Switchable ErSc2N rotor within a C80 fullerene cage: An EPR and photoluminescence excitation study

Systems exhibiting both spin and orbital degrees of freedom, of which Er3+ is one, can offer mechanisms for manipulating and measuring spin states via optical excitations. Motivated by the possibility of observing photoluminescence and electron paramagnetic resonance from the same species located within a fullerene molecule, we initiated an EPR study of Er3+ in ErSc2N@C80. Two orientations of the ErSc2N rotor within the C80 fullerene are observed in EPR, consistent with earlier studies using photoluminescence excitation (PLE) spectroscopy. For some crystal field orientations, electron spin relaxation is driven by an Orbach process via the first excited electronic state of the 4I_15/2 multiplet. We observe a change in the relative populations of the two ErSc2N configurations upon the application of 532 nm illuminations, and are thus able to switch the majority cage symmetry. This photoisomerisation, observable by both EPR and PLE, is metastable, lasting many hours at 20 K.Comment: 4 pages, 4 figure

Electron paramagnetic resonance study of ErSc2NC80

We present an electron paramagnetic resonance (EPR) study of ErSc2N@C80 fullerene in which there are two Er3+ sites corresponding to two different configurations of the ErSc2N cluster inside the C80 cage. For each configuration, the EPR spectrum is characterized by a strong anisotropy of the g factors (gx,y = 2.9, gz = 13.0 and gx,y = 5.3, gz = 10.9). Illumination within the cage absorption range (<600 nm) induces a rearrangement of the ErSc2N cluster inside the cage. We follow the temporal dependence of this rearrangement phenomenologically under various conditions.Comment: 7 pages, 7 figure