Probing the charging mechanisms of carbon nanomaterial polyelectrolytes

Chemical charging of single-walled carbon nanotubes (SWCNTs) and graphenes to generate soluble salts shows great promise as a processing route for electronic applications, but raises fundamental questions. The reduction potentials of highly-charged nanocarbon polyelectrolyte ions were investigated by considering their chemical reactivity towards metal salts/complexes in forming metal nanoparticles. The redox activity, degree of functionalisation and charge utilisation were quantified via the relative metal nanoparticle content, established using thermogravimetric analysis (TGA), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and X-ray photoelectron spectroscopy (XPS). The fundamental relationship between the intrinsic nanocarbon electronic density of states and Coulombic effects during charging is highlighted as an important area for future research

Carbon nanotube anions for the preparation of gold nanoparticle–nanocarbon hybrids

Gold nanoparticles (AuNPs) can be evenly deposited on single-walled carbon nanotubes (SWCNTs) via the reduction of the highly stable complex, chloro(triphenylphosphine) gold(I), with SWCNT anions (‘nanotubides’). This methodology highlights the unusual chemistry of nanotubides and provides a blueprint for the generation of many other hybrid nanomaterials

Continuous transformations of cubic minimal surfaces

Although the primitive (P), diamond (D) and gyroid (G) minimal surfaces form the structural basis for a multitude of self-assembling phases, such as the bicontinuous cubics, relatively little is known regarding their geometrical transformations, beyond the existence of the Bonnet isometry. Here their highest symmetry deformation modes, the rhombohedral and tetragonal distortions, are fully elucidated to provide a unified description of these simplest minimal surface families, with all quantities expressed in terms of complete elliptic integrals. The rhombohedral distortions of the gyroid are found to merge continuously with those which bridge the P and D surfaces, furnishing direct transformations between all three cubics, preserving both topology and zero mean curvature throughout. The tetragonal distortions behave analogously, offering an alternative route from the gyroid to the D surface. The cell axis ratios, surface areas and Gaussian curvature moments of all families are given, supplying the necessary geometrical input to a curvature energy description of cubic and intermediate phase stability

Generalizations of the gyroid surface

The deformation of Schoen's gyroid — one of the three examples of triply-periodic minimal surfaces possessing cubic symmetry and genus 3 — is discussed. Lower-symmetry variants (similarly of genus 3) are shown to exist, and the one-variable family of rhombohedrally-distorted gyroids is constructed and parametrised exactly via the Weierstrass representation

A note on the two symmetry-preserving covering maps of the gyroid minimal surface

Our study of the gyroid minimal surface has revealed that there are two distinct covering maps from the hyperbolic plane onto the surface that respect its intrinsic symmetries. We show that if a decoration of $\mathbb{H}^2$ is chiral, the projection of this pattern via the two covering maps gives rise to distinct structures in $\mathbb{E}^3$ . Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2005

Functionalization of single-walled carbon nanotubes via the Bingel reaction

Single-walled carbon nanotubes have been cyclopropanated under Bingel reaction conditions, and the functionalized nanotubes have been characterized by atomic force microscopy using "chemical tagging" techniques