Fluorinated single-walled carbon nanotubes (F-SWNTs) form important intermediates in SWNT sidewall functionalization, leading to a variety of materials and biological applications. By simulating the infrared (IR) signals for the 1,2-and 1,4-addition structures, in which fluorine atoms are arranged in ortho or para positions, respectively, on the aromatic skeleton of the (10,10) SWNT surface, we identify peaks that are unique to each structure. Our full molecular dynamics simulations show that the [-C(sp 3 )-C(sp 3 )-] collective vibrational peak at 400 cm -1 is optically active only in the 1,2-isomer, while the 1300 cm -1 band arising due to the F-C(sp 3 ) stretching motion coupled with the neighboring C(sp 2 ) atoms is seen in the IR spectrum of only the 1,4-isomer. The reported results suggest simple and clear experimental means for distinguishing between the two fluorinated structures and provide a valuable tool for controlled SWNT sidewall functionalization.

Fluorination of graphene and other carbon nanostructures is used extensively as a tool for tuning graphene’s mechanical, electronic, and optical properties, and as an intermediate step in graphene functionalization. However, by penetrating through graphene surfaces, fluorine atoms create defects that deteriorate the desired properties. Using molecular dynamics simulation, we predict distinct infrared (IR) signatures that can be used to detect fluorination patterns and defects. We show that two strong peaks around 1000 and 1500 cm–1 in the IR signal in the graphene plane identify fluorine chains. Defects involving a single fluorine atom exhibit a clear IR peak at 800 cm–1 originating from the wagging motion of the F–C­(sp3) bond. A pair of neighboring fluorines produces a unique peak at 1150 cm–1 arising as a result of the stretching vibration of the C­(sp3)–C­(sp3) bond hosting the fluorines. The reported results provide straightforward and efficient means for spectroscopic characterization of fluorinated graphene and related materials.

Multilayered fluorinated graphene exhibits novel properties and finds applications in electrodes, membranes, thermal materials, transistors, and so on. These applications rely heavily on interlayer interactions that arise from sheet stacking. Because the properties of multilayered fluorinated graphene are very sensitive to the synthetic conditions, characterization of the graphene structure becomes particularly important. We theoretically analyzed the structure and interactions in multilayer fluorinated graphene by IR spectroscopy. Significant differences between the multiple-and single-layer signals were observed with the F−F vibrational motions around 700 cm −1 , because these motions are strongly affected by fluorines of neighboring layers. The intensity and profile of the F−F vibration peaks near 700 cm −1 change dramatically depending on the number of layers and the fluorine-addition pattern. These findings suggest that IR spectroscopy can be used for comprehensive characterization of the structure of multilayered fluorinated graphene.

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In the course of the investigation of concrements formation in human bodies, which come from body fluid, the author has been making efforts to clear whether any similarity exists between the concrements formation and the crystllization of rock forming minerals, which comes from solution, or not. And the results about the crystallization in igneous rocks, so far obtained, are as follows.