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The article reports on the scannable lens that is capable of an improved resolution developed by Allard Mosk and his colleagues in Amsterdam as of June 2011. The exploitation of the random scattering behavior of a strongly disordered surface rather than a polished surface of a lens is described to be responsible for the improved resolution. The lens and imaging process used by Mosk and his team is detailed. The author suggests extending the scan range and simplifying the sample placement and modulator tuning for the lens' future success.

The covalent functionalization of single and bilayer graphene on SiO2 (300 nm)/Si was effected through sequential treatment with the alkalide reductant [K(15-crown-5)2]Na and electrophilic aryl or alkyl halides, of which the iodides proved to be the most reactive. The condensation reactions proceeded at room temperature and afforded the corresponding aryl- or alkyl-appended graphenes. For each sample, Raman and X-ray photoelectron spectroscopies were used to evaluate the degrees and uniformities of functionalization. Statistical analyses of the Raman data revealed that the introduction of the organic moieties was accompanied by sp³-rehybridization of the basal plane atoms. When bilayers consisting of 13C and 12C layers were treated, both the top and bottom sheets were decorated with organic groups. The reaction was followed using Raman spectroscopy, and the mechanism was studied by theoretical calculations. Indicative of its structure and reactivity, 4-pyridyl-decorated single-layer graphene was readily benzylated and appears to be an ideal platform to develop functional materials. [ABSTRACT FROM AUTHOR]

Development of cheap, green and up scalable production methods for graphene is one of the most challenging problems in its manufacture on an industrial scale. We report here a large scale substrate-free fluidized bed catalytic chemical vapour deposition (FB-CCVD) process for few layer graphene (FLG) powder production that uses a crystalline oxide catalyst of the general formula A x B 3− x O 4 , wherein the FLG layer thickness and domain sizes can be varied. A and B can be chosen from a list of transition elements including Co, Fe, Ni, Mn, Cu and Zn. The best results in terms of activity and selectivity are obtained for the Co x Fe 3− x O 4 system. We also investigated the reaction mechanism using in situ EXAFS and Raman spectroscopy, and electron tomography. Since FB-CCVD processes are already used for industrial scale production of carbon nanotubes, this process should enable the large scale production of free standing FLG in the near future. [ABSTRACT FROM AUTHOR]

Dense WC-x vol% cobalt (5 ≤ x ≤ 20) composites, with WC grain size of ∼1 µm, were synthesized by field-activated and pressureassisted combustion synthesis (FAPACS) within several minutes from elemental powders. Simultaneous synthesis and densification were accomplished under the combined effects of an electric field and mechanical pressure. The effect of cobalt content on the hardness, fracture toughness, and relative density of dense WC-x vol% cobalt composites was investigated. The relative density of the WC-cobalt composites increased with increased cobalt content. Under the application of a 60 MPa pressure and a 3000 A current, the final products had relatively high densities, 99.4%, for WC-20 vol% cobalt. The hardness of the WC-cobalt composites decreased with increased cobalt content, while the fracture toughness increased. The maximum fracture toughness and hardness values obtained were 9.4 MPa·m[sup ½] for the WC-20lvol % cobalt composition and 2014 kg·mm[sup -2] for the WC-5 vol% cobalt composition. [ABSTRACT FROM AUTHOR]

Raman spectra of large graphene bubbles showed size-dependent oscillations in spectral intensity and frequency, which originate from optical standing waves formed in the vicinity of the graphene surface. At a high laser power, local heating can lead to oscillations in the Raman frequency and also create a temperature gradient in the bubble. Based on Raman data, the temperature distribution within the graphene bubble was calculated, and it is shown that the heating effect of the laser is reduced when moving from the center of a bubble to its edge. By studying graphene bubbles, both the thermal conductivity and chemical reactivity of graphene were assessed. When exposed to hydrogen plasma, areas with bubbles are found to be more reactive than flat graphene. [ABSTRACT FROM AUTHOR]