An NMR contribution to the interpretation of the dynamical behavior of water molecules as a function of the magnesium chloride concentration at 25.degree.C

When an ice crystal is born from liquid water, two key changes occur: (i) The molecules order and (ii) the mobility of the molecules drops as they adopt their lattice positions. Most research on ice nucleation (and crystallization in general) has focused on understanding the former with less attention paid to the latter. However, supercooled water exhibits fascinating and complex dynamical behavior, most notably dynamical heterogeneity (DH), a phenomenon where spatially separated domains of relatively mobile and immobile particles coexist. Strikingly, the microscopic connection between the DH of water and the nucleation of ice has yet to be unraveled directly at the molecular level. Here we tackle this issue via computer simulations which reveal that (i) ice nucleation occurs in low-mobility regions of the liquid, (ii) there is a dynamical incubation period in which the mobility of the molecules drops before any ice-like ordering, and (iii) ice-like clusters cause arrested dynamics in surrounding water molecules. With this we establish a clear connection between dynamics and nucleation. We anticipate that our findings will pave the way for the examination of the role of dynamical heterogeneities in heterogeneous and solution-based nucleation.

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The effect of incubation temperature and magnesium chloride concentration on growth of salmonella in home-made and in commercially available dehydrated Rappaport-Vassiliadis broths

Journal of Applied Bacteriology ◽

10.1111/j.1365-2672.1989.tb02535.x ◽

1989 ◽

Vol 67 (6) ◽

pp. 523-528 ◽

Cited By ~ 22

Author(s):

M. PETERZ ◽

C. WIBERG ◽

P. NORBERG

Keyword(s):

Magnesium Chloride ◽

Incubation Temperature ◽

Chloride Concentration

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Preparation and Hygroscopic Property of the Polyacrylamide/MgCl2 Hybrid Hydrogel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.550-553.904 ◽

2012 ◽

Vol 550-553 ◽

pp. 904-907 ◽

Cited By ~ 1

Author(s):

Ying Wang ◽

Li Ren Fan

Keyword(s):

Magnesium Chloride ◽

Chloride Concentration ◽

X Ray Diffraction ◽

Hybrid Hydrogel ◽

Hygroscopic Property ◽

Hygroscopic Swelling ◽

Swelling Rate ◽

Aqueous Solution Polymerization ◽

Pseudo Second Order ◽

Swelling Kinetic

Polyacrylamide/MgCl2 hybrid hydrogel desiccant was prepared from magnesium chloride and polyacrylamide by aqueous solution polymerization. The hybrid hydrogel was synthesized and characterized by X-ray diffraction. The effect of the experimental factors such as content of magnesium chloride, concentration of cross-linking agent, initiator content on hygroscopic performance of the hybrid hydrogel were investigated, furthermore, the hygroscopic swelling kinetic process of the hybrid hydrogel was studied. The results indicate that hybrid hydrogel possessed preferable hygroscopic property under the optimum conditions, the hygroscopic swelling degree achieving 172%. The hygroscopic swelling process of the hybrid hydrogel follows the kinetic pseudo-second-order model, in addition, the swelling rate decreases with the increase of relative humidity.

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