Sat, 26 Jul 2008 06:18:45 BST CiteULike: dchen's crystalization http://www.citeulike.org/user/dchen/tag/crystalization CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dchen/article/2883410 <i>Physical Review E (Statistical, Nonlinear, and Soft Matter Physics), Vol. 75, No. 6. (2007)</i><br /><br />Using grand canonical Monte Carlo simulations, we study the crystallization of colloidal hard spheres under gravity. More specifically, we investigate the nature of the freezing transition as a function of gravity and chemical potential of the hard spheres. We find a discontinuous freezing transition where several fluid layers close to the bottom of the sample freeze simultaneously, i.e., at the same chemical potential. We also find that the number of layers that freezes at the same chemical potential decreases for higher gravitational field strength. Upon increasing the chemical potential further, the crystalline film thickness increases continuously. Crystallization of colloidal hard spheres under gravity Matthieu Marechal Marjolein Dijkstra doi:10.1103/PhysRevE.75.061404 Physical Review E (Statistical, Nonlinear, and Soft Matter Physics), Vol. 75, No. 6. (2007) 2008-06-11T16:52:31-00:00 2007 Physical Review E (Statistical, Nonlinear, and Soft Matter Physics) 75 6 APS 2007 colloids crystalization gravity pre simulation http://www.citeulike.org/user/dchen/article/2749598 <i>Physical Review Letters, Vol. 98, No. 26. (2007)</i><br /><br />We analyze the structure of Haliotis rufescens nacre, or mother-of-pearl, using synchrotron spectromicroscopy and x-ray absorption near-edge structure spectroscopy. We observe imaging contrast between adjacent individual nacre tablets, arising because different tablets have different crystal orientations with respect to the radiation's polarization vector. Comparing previous data and our new data with models for columnar nacre growth, we find the data are most consistent with a model in which nacre tablets are nucleated by randomly distributed sites in the organic matrix layers. Architecture of Columnar Nacre, and Implications for Its Formation Mechanism Rebecca Metzler Mike Abrecht Ronke Olabisi Daniel Ariosa Christopher Johnson Bradley Frazer Susan Coppersmith PUPA Gilbert doi:10.1103/PhysRevLett.98.268102 Physical Review Letters, Vol. 98, No. 26. (2007) 2008-05-03T18:21:34-00:00 2007 Physical Review Letters 98 26 APS 2007 biology crystalization focus material http://www.citeulike.org/user/dchen/article/1702049 <i>Physica A: Statistical and Theoretical Physics, Vol. 233, No. 1-2. (15 November 1996), pp. 102-116.</i><br /><br />Phase behaviour, crystallisation kinetics and particle dynamics are compared for two colloidal suspensions of hard spherical particles with different particle size distributions; one is narrow and roughly symmetrical and the other is broader and skewed towards smaller particles. Both suspensions exhibit the equilibrium phase behaviour expected for a system of identical hard spheres and they show a glass transition, indicated by the cessation of homogeneous nucleation and the partial arrest of concentration fluctuations, at approximately the same volume fraction, [Phi]g [approximate] 0.58. Interestingly, compared to the suspension with the narrower size distribution, crystallisation rates are significantly slower in the more polydisperse suspension. In its colloidal glass state no crystal growth occurs on secondary nuclei, such as the shear-aligned crystals that can be induced in both suspensions by regular rocking. Effect of particle size distribution on crystallisation and the glass transition of hard sphere colloids SI Henderson TC Mortensen SM Underwood W van Megen doi:10.1016/S0378-4371(96)00153-7 Physica A: Statistical and Theoretical Physics, Vol. 233, No. 1-2. (15 November 1996), pp. 102-116. 2007-09-27T16:45:30-00:00 1996 Physica A: Statistical and Theoretical Physics 233 1-2 102 116 colloids crystalization glass polydisperse simulation