XXII INTERNATIONAL MATERIALS RESEARCH CONGRESS 2013
11 – 15 August, Cancún, Mexico

These annual international meetings provide an interactive forum to discuss the advances in synthesis, characterization, properties, processing, applications, basic research trends, corrosion prevention, and more, all related to the area of materials science and engineering.

The efforts of several societies, colleagues, sponsors and exhibitors offer an exciting multidisciplinary stage to learn first-hand about new directions in materials research and technology, as well as a valuable opportunity to share and exchange ideas with some of the foremost experts in the field.

SYMPOSIA Nanoscience and Nanotechnology. Nanostructured Carbon Materials-Fundamentals to Applications

The expression "carbon age" has been coined to express the rapid development of new carbon nanomaterials whose unique electronic, optical, mechanical and thermal properties derive from carbon’s different allotropes: diamond, fullerenes, nanotubes, graphene and graphene oxides. This symposium will review recent progress in carbon-based material growth mechanisms, functionalization, and structural control of various nanostructures enroute to 3D architectures and their applications.

The significance of these nanocarbon bulk materials comes from their hierarchical 3D architectures and high-mass specific-surface area. The challenge and opportunity is to design nanostructured bulk materials with controlled architectures at the atomic and nanometer scales and surface functionalization that span multiple length scales to the macro size. Future progress will thus depend on improvements in growth techniques, structural control, surface functionalization, and large-scale synthesis and characterization, as well as advancing in the theoretical understanding and control of interfacial phenomena. Special focus will be given to structure vs property correlations, interfacial phenomena and novel applications. The symposium will bring together scientists from often-separated fields, therefore providing a platform to identify new opportunities in science and applications.

Symposium topics to be addressed include:

• Novel growth techniques of CNTs, graphene, nanocrystalline diamond, graphene oxides, buckyballs and other carbon-related nanostructures
• Atomic-scale nucleation and graphitization in metal and nonmetal catalytic growth processes
• Synthesis and characterization of graphitic nanocarbon bulk materials with 3D architectures
• Doping, surface chemistry and functionalization of graphitic carbon nanomaterials
• Interfacial properties–from fundamentals to applications
• Thermal and mechanical properties of carbon nanostructures
• Catalytic properties of graphene oxides, graphene edges and nanodiamond structures
• Novel phenomena of layer-, edge- and size-controlled graphene and atomic-structure-controlled CNTs
• In-situ monitoring of growth processes and ex-situ characterization of atomic structures
• Applications in energy conversion and storage, electronics, optics, optoelectronics, photonics, catalysis, purification, sensorics and actuation, as well as bioinspired applications
• Modeling and theoretical predictions for novel properties

Dr.Yury Gogotsi "MXenes: TWO-DIMENSIONAL EARLY TRANSITION METAL CARBIDES AND CARBONITRIDES"

Abstract
Two-dimensional (2D) materials are attracting much attention due to their unique properties. The most famous example is graphene, which is an atomically thin layer of carbon atoms bonded together in-plane with sp2 bonds. Recently, we discovered an entirely new family of 2D materials - early transition metal carbides and carbonitrides [1,2].

Selective etching of the A-group element from a MAX phase results in formation of 2D Mn+1Xn layers, labeled “MXene”. Eight different carbides and carbonitrides have been produced to date [2]; the properties of a larger number of 2D compounds have been predicted by DFT. Not only are individual layers formed after exfoliation, but also multi-layer particles and conical scrolls with radii < 20 nm. DFT simulations showed that the band gap of MXenes can be tuned from metallic to semiconductor by changing their surface termination, and their elastic constants along the basal plane are higher than that of the binary carbides. Recently, we reported on the intercalation of Ti3C2, Ti3CN and TiNbC [3].

Intercalation of hydrazine, and its co-intercalation with DMF, resulted in an increase of the c lattice parameter of MXenes. Urea also intercalated Ti3C2. Molecular dynamics simulations suggest that a hydrazine monolayer intercalates between the Ti3C2 layers. Hydrazine also intercalated Ti3CN and TiNbC. When dimethyl sulfoxide was intercalated into Ti3C2, followed by sonication in water, it delaminated forming a stable colloidal solution that was in turn filtered to produce MXene “paper”. One of the many potential applications for 2-D Ti3C2 is in electrical energy storage systems, such as lithium ion batteries and electrochemical capacitors. Additive-free Ti3C2 anodes, produced by filtering an aqueous dispersion of delaminated Ti3C2, showed a higher capacity than graphite anodes and also could be charged/discharged at significantly higher rates.

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