The effect of urea on the morphology of NaCl crystals: A combined theoretical and simulation study

Amides as anticaking agents for sodium chloride: is a triple branched variant necessary?

The creeping pattern observed when a saturated sodium chloride solution containing 1% (w/w) methylglycine diacetamide is allowed to dry at ambient temperature.

Revealing the parameters to design the habit modifiers for rock-salt crystals: empirical to rational approach

Morphology of rock-salt crystals can be influenced by internal and external factors like temperature, super saturations, solvent, and impurities. Many impurities and additives have been reported to date for the habit modification of common salt; however, the selection of such impurities is largely empirical. The partition coefficient or log P, which is a measure of hydrophobic hydrophilic property of a material, very aptly signifies the ability of additives to modulate the morphology of sodium chloride crystals. Application of the partition coefficient of additives led to the discovery of two new habit modifiers (cytosine and DMSO) for rock-salt crystals. The predicted results have been verified by experimental studies. Furthermore, the known habit modifiers and also the nonhabit modifiers for sodium chloride crystals corroborate the importance of this parameter to define the morphology of salt crystals. This study is of fundamental importance, which otherwise was rather empirical for the last two centuries.

Local fluctuations in solution mixtures

An extension of the traditional Kirkwood-Buff (KB) theory of solutions is outlined which provides additional fluctuating quantities that can be used to characterize and probe the behavior of solution mixtures. Particle-energy and energy-energy fluctuations for local regions of any multicomponent solution are expressed in terms of experimentally obtainable quantities, thereby supplementing the usual particle-particle fluctuations provided by the established KB inversion approach. The expressions are then used to analyze experimental data for pure water over a range of temperatures and pressures, a variety of pure liquids, and three binary solution mixtures - methanol and water, benzene and methanol, and aqueous sodium chloride. In addition to providing information on local properties of solutions it is argued that the particle-energy and energy-energy fluctuations can also be used to test and refine solute and solvent force fields for use in computer simulation studies.

A Kirkwood-Buff Derived Force Field for Aqueous Alkali Halides

A classical nonpolarizable force field is presented for the simulation of aqueous alkali halide solutions (MX), where M = Li(+), Na(+), K(+), Rb(+), Cs(+) and X = F(-), Cl(-), Br(-), I(-), and their interactions with biomolecules. The models are specifically designed to reproduce the experimental Kirkwood-Buff integrals, and thereby the solution salt activities, as a function of salt concentration. Additionally, we demonstrate that these models reasonably reproduce other experimental properties including ion diffusion constants, dielectric decrements, and the excess heats of mixing. The parameters are developed by considering the properties of aqueous NaX and MCl solutions using a previously established model for NaCl. Transferability of the parameters to other salts is then established by the successful simulation of additional aqueous salt solutions, KI and CsBr, not originally included in the parameterization procedure.