Maria del Carmen Gimenez-Lopez

Bio: Maria del Carmen Gimenez-Lopez is an academic researcher from University of Santiago de Compostela. The author has contributed to research in topics: Carbon nanotube & Nanoparticle. The author has an hindex of 17, co-authored 35 publications receiving 1425 citations. Previous affiliations of Maria del Carmen Gimenez-Lopez include University of Nottingham & University of Wrocław.

Self-assembly of a sulphur-terminated graphene nanoribbon within a single-walled carbon nanotube

Abstract: The ability to tune the properties of graphene nanoribbons (GNRs) through modification of the nanoribbon's width and edge structure widens the potential applications of graphene in electronic devices. Although assembly of GNRs has been recently possible, current methods suffer from limited control of their atomic structure, or require the careful organization of precursors on atomically flat surfaces under ultra-high vacuum conditions. Here we demonstrate that a GNR can self-assemble from a random mixture of molecular precursors within a single-walled carbon nanotube, which ensures propagation of the nanoribbon in one dimension and determines its width. The sulphur-terminated dangling bonds of the GNR make these otherwise unstable nanoribbons thermodynamically viable over other forms of carbon. Electron microscopy reveals elliptical distortion of the nanotube, as well as helical twist and screw-like motion of the nanoribbon. These effects suggest novel ways of controlling the properties of these nanomaterials, such as the electronic band gap and the concentration of charge carriers.

Random Tiling and Topological Defects in a Two-Dimensional Molecular Network

Abstract: A molecular network that exhibits critical correlations in the spatial order that is characteristic of a random, entropically stabilized, rhombus tiling is described. Specifically, we report a random tiling formed in a two-dimensional molecular network of p-terphenyl-3,5,3',5'-tetracarboxylic acid adsorbed on graphite. The network is stabilized by hexagonal junctions of three, four, five, or six molecules and may be mapped onto a rhombus tiling in which an ordered array of vertices is embedded within a nonperiodic framework with spatial fluctuations in a local order characteristic of an entropically stabilized phase. We identified a topological defect that can propagate through the network, giving rise to a local reordering of molecular tiles and thus to transitions between quasi-degenerate local minima of a complex energy landscape. We draw parallels between the molecular tiling and dynamically arrested systems, such as glasses.

Encapsulation of single-molecule magnets in carbon nanotubes

Abstract: Next-generation electronic, photonic or spintronic devices will be based on nanoscale functional units, such as quantum dots, isolated spin centres or single-molecule magnets. The key challenge is the coupling of the nanoscale units to the macroscopic world, which is essential for read and write purposes. Carbon nanotubes with one macroscopic and two nanoscopic dimensions provide an excellent means to achieve this coupling. Although the dimensions of nanotube internal cavities are suitable for hosting a wide range of different molecules, to our knowledge, no examples of molecular magnets inserted in nanotubes have been reported to date. Here we report the successful encapsulation of single-molecule magnets in carbon nanotubes, yielding a new type of hybrid nanostructure that combines all the key single-molecule magnet properties of the guest molecules with the functional properties of the host nanotube. The findings may pave the way to the construction of spintronic or ultrahigh-density magnetic data storage devices.

Guest-induced growth of a surface-based supramolecular bilayer

Abstract: Self-assembly of planar molecules on a surface can result in the formation of a wide variety of close-packed or porous structures. Two-dimensional porous arrays provide host sites for trapping guest species of suitable size. Here we show that a non-planar guest species (C(60)) can play a more complex role by promoting the growth of a second layer of host molecules (p-terphenyl-3,5,3″,5″-tetracarboxylic acid) above and parallel to the surface so that self-assembly is extended into the third dimension. The addition of guest molecules and the formation of the second layer are co-dependent. Adding a planar guest (coronene) can displace the C(60) and cause reversion to a monolayer arrangement. The system provides an example of a reversible transformation between a planar and a non-planar supramolecular network, an important step towards the controlled self-assembly of functional, three-dimensional, surface-based supramolecular architectures.

Broad family of carbon nanoallotropes: classification, chemistry, and applications of fullerenes, carbon dots, nanotubes, graphene, nanodiamonds, and combined superstructures.

Abstract: and Applications of Fullerenes, Carbon Dots, Nanotubes, Graphene, Nanodiamonds, and Combined Superstructures Vasilios Georgakilas,† Jason A. Perman,‡ Jiri Tucek,‡ and Radek Zboril*,‡ †Material Science Department, University of Patras, 26504 Rio Patras, Greece ‡Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University in Olomouc, 17 listopadu 1192/12, 771 46 Olomouc, Czech Republic

Integrated materials design of organic semiconductors for field-effect transistors

Abstract: The past couple of years have witnessed a remarkable burst in the development of organic field-effect transistors (OFETs), with a number of organic semiconductors surpassing the benchmark mobility of 10 cm2/(V s). In this perspective, we highlight some of the major milestones along the way to provide a historical view of OFET development, introduce the integrated molecular design concepts and process engineering approaches that lead to the current success, and identify the challenges ahead to make OFETs applicable in real applications.

New advances in nanographene chemistry

Abstract: Nanographenes, or extended polycyclic aromatic hydrocarbons, have been attracting renewed and more widespread attention since the first experimental demonstration of graphene in 2004. However, the atomically precise fabrication of nanographenes has thus far been achieved only through synthetic organic chemistry. The precise synthesis of quasi-zero-dimensional nanographenes, i.e. graphene molecules, has witnessed rapid developments over the past few years, and these developments can be summarized in four categories: (1) non-conventional methods, (2) structures incorporating seven- or eight-membered rings, (3) selective heteroatom doping, and (4) direct edge functionalization. On the other hand, one-dimensional extension of the graphene molecules leads to the formation of graphene nanoribbons (GNRs) with high aspect ratios. The synthesis of structurally well-defined GNRs has been achieved by extending nanographene synthesis to longitudinally extended polymeric systems. Access to GNRs thus becomes possible through the solution-mediated or surface-assisted cyclodehydrogenation, or “graphitization,” of tailor-made polyphenylene precursors. In this review, we describe recent progress in the “bottom-up” chemical syntheses of structurally well-defined nanographenes, namely graphene molecules and GNRs.