566 research outputs found
Directing two-dimensional molecular crystallization using guest templates
Full text linkThis is the Accepted Manuscript of the following article: Blunt, M., Lin, X., Gimenez López, M.C., Schröder, M., Champness, N.R., Beton, P.H. Chemical Communications, 2008, DOI:10.1039/B801267AThe use of a coronene guest template directs the formation
of a 2D Kagome´network in preference to alternative close
packed and parallel hydrogen-bonded structures of
tetracarboxylic acid tectons self-assembled from solution
on a graphite surface.S
Emerging applications of metal-organic frameworks
No full textMetal–organic frameworks are a unique class of materials well known for their crystallinity and ultra-high porosity. Since their first report over fifteen years ago, research in this area has sought to actively exploit these properties, especially in gas adsorption. In this article we canvass some emerging topics in the field of MOF research that show promise for new applications in areas such as biotechnology, catalysis, and microelectronics.Raffaele Ricco, Constance Pfeiffer, Kenji Sumida, Christopher J. Sumby, Paolo Falcaro, Shuhei Furukawa, Neil R. Champness and Christian J. Doona
Performance of a micro-engineered ultrasonic particle manipulator
No full textAn ultrasonic microfluidic particle manipulator has been modeled and its experimentally measured separation performance has been compared with the modeled results for 1 µm latex particles, and yeast particles in water
Dynamics of inertial disk particles in turbulent channel flow
No full textA suspension of oblate spheroidal (disk-like) particles in turbulent channel flow has been investigated with focus on the translational and rotational particle statistics. The effects of particle aspect ratio and inertia have been explored. The disk-like particles exhibited a significant preferential orientation in the plane of the mean shear. The influence of the particle shape on the orientation and rotation diminished as translational inertia increased from Stokes number 1 to 30. Isotropization of both orientation and rotation could be observed in the core region of the channel. Keywords: oblate spheroids, preferential orientation, shape effects, inertia effects
Inertial effects on non-spherical particle rotation on turbulent channel flow
No full textWe investigated the rotation of non-spherical particles (rod-like and disk-like) in turbulent channel flow with focus on inertial effects. A direct numerical simulation (DNS) with an Eulerian-Lagrangian approach was performed. A wide range of particle aspect ratios, λ, ranging from 0.01 to 50 were considered for Stokes numbers St equal to 1 and 30. In the particle reference frame, statistical results reveal the importance of shape effect on the particle rotation. The rods (λ > 1) are spinning (rotation about their symmetry axis) more than tumbling (rotation about other axes) whereas disks (λ < 1) behave oppositely. With increasing particle inertia, i.e. higher St, the preferential tumbling of the disks and the spinning of the rods are reduced. We ascribe these observations to the varying degree of alignment of the particle symmetry axis with the fluid vorticity vector
Random tiling and topological defects in a two-dimensional molecular network
Full text linkThis is the Accepted Manuscript of the following article: Blunt, M.O., Russell, J.C., Gimenez Lopez, M.C., Garrahan, J.P., Lin, X., Schróder, M., Champness, N.R., Beton, P.H., Science, 2008, DOI:10.1126/science.116333A 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 twodimensional
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 glassesS
In situ ligand synthesis and construction of an unprecedented three-dimensional array with silver(I): A new approach to inorganic crystal engineering
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