Multistep Crystal Nucleation:  A Kinetic Study Based on Colloidal Crystallization

Complex crystallization pathways are common in protein crystallization, tetrahedrally coordinated systems, and biomineralization, where single or multiple precursors temporarily appear before the formation of the crystal. The emergence of precursors is often explained by a unique property of the system, such as short-range attraction, directional bonding, or ion association. But, structural characteristics of the prenucleation phases found in multistep crystallization remain unclear, and models are needed for testing and expanding the understanding of fluid-to-solid ordering pathways. Here, we report 3 instances of 2-step crystallization of hard-particle fluids. Crystallization in these systems proceeds via a high-density precursor fluid phase with prenucleation motifs in the form of clusters, fibers and layers, and networks, respectively. The density and diffusivity change across the fluid–fluid phase transition increases with motif dimension. We observe crystal nucleation to be catalyzed by the interface between the 2 fluid phases. The crystals that form are complex, including, notably, a crystal with 432 particles in the cubic unit cell. Our results establish the existence of complex crystallization pathways in entropic systems and reveal prenucleation motifs of various dimensions.

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Kinetic study of the reaction of benzoyl peroxide with phenolic compounds. A technique for the evaluation of phenolic O-H bond dissociation energies

Journal de Chimie Physique ◽

10.1051/jcp/1989862057 ◽

1989 ◽

Vol 86 ◽

pp. 2057-2066 ◽

Cited By ~ 2

Author(s):

Claire Rousseau-Richard ◽

Claude Richard ◽

René Martin

Keyword(s):

Phenolic Compounds ◽

Kinetic Study ◽

Benzoyl Peroxide ◽

Bond Dissociation Energies ◽

Bond Dissociation ◽

Dissociation Energies

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A kinetic study of osmium tetroxide catalysed oxidation of methyl digol and ethyl digol by hexacyanoferrate (III) in aqueous alkaline medium

Journal de Chimie Physique ◽

10.1051/jcp/1976730283 ◽

1976 ◽

Vol 73 ◽

pp. 283-286 ◽

Cited By ~ 2

Author(s):

H. S. Singh ◽

A. K. Sisodia ◽

S. M. Singh ◽

R. K. Singh ◽

R. N. Singh

Keyword(s):

Kinetic Study ◽

Alkaline Medium ◽

Osmium Tetroxide ◽

Aqueous Alkaline Medium ◽

Catalysed Oxidation

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A kinetic study of controlling nitrogen in process for boron steel by using30N2isotope gas

Revue de Métallurgie ◽

10.1051/metal:2009004 ◽

2008 ◽

Vol 105 (12) ◽

pp. 601-608

Author(s):

Seung Min Han ◽

Dong Joon Min ◽

Joo Hyun Park ◽

Jung Ho Park ◽

Jong Min Park

Keyword(s):

Kinetic Study ◽

Boron Steel

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Kinetic Study of the Effect of Heparin on the Amidase Activity of Trypsin, Plasmin and Urokinase

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657362 ◽

1983 ◽

Vol 49 (03) ◽

pp. 199-203 ◽

Cited By ~ 10

Author(s):

V M Yomtova ◽

N A Stambolieva ◽

B M Blagoev

Keyword(s):

Kinetic Study ◽

Active Center ◽

Simultaneous Presence ◽

Amidase Activity ◽

Competitive Inhibitors ◽

Uncompetitive Inhibitor

SummaryIt was found that the effect of heparin on the amidase activity of urokinase (E C 3.4.21.31), plasmin (E C 3.4.21.7) and trypsin (E C 3.4.21.4) depended on the substrate used. No effect of heparin on the amidase activity of urokinase and trypsin was observed when Pyro Glu-Gly-Arg-p-nitroanilide (S-2444) and α-N-acetyl-L-lysine-p-nitroanilide (ALNA) were used as substrates. Heparin acted as a uncompetitive inhibitor of trypsin (Ki = 1.2×10-6 M), plasmin (Ki = 4.9×10-6 M) and urokinase (Ki = l.0×10-7 M) when Bz-Phe-Val-Arg-p-nitroanilide (S-2160), H-D-Val-Leu-Lys-p-nitroanilide (S-2251) and plasminogen, respectively, were used as substrates. These results, as well as the data obtained by studying the effect of the simultaneous presence of heparin and competitive inhibitors suggest that although heparin is not bound at the active center of these enzymes, it may influence the effectivity of catalysis.

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