Core-softened water-alcohol mixtures: the solute-size effects
arXiv:2102.09485 · doi:10.1039/D1CP00751C
Abstract
In a recent work [\textit{J. Mol. Liq}, 2020, \textbf{320}, 114420], using molecular dynamics simulations and a core-softened potential approach, we have shown that adding a simple solute as methanol can "kill" the density anomalous behavior as the LLCP is suppressed by the spontaneous crystallization in a hexagonal closed packing (HCP) crystal near the LLPT. Now, we extend this work in order to realize how longer-chain alcohols will affect the complex behavior of water-alcohol mixtures in the supercooled regime. Besides core-softened (CS) methanol, ethanol and 1-propanol were added to a system of identical particles that interact through the continuous shouldered well (CSW) potential. We observed that the density anomaly gradually decreases its extension in phase diagrams until disappearing with the growth of the non-polar chain and the alcohol concentration, differently from the liquid-liquid phase transition (and the LLCP), which remained present in all analyzed mixtures, in according to \textit{Nature}, 2001, \textbf{409}, 692. For our model, the longer non-polar chains and higher concentrations gradually impact the competition between the scales in the CS potential, leading to a gradual disappearing of the anomalies until the TMD total disappearance is observed when the first coordination shell structure is also affected: the short-range ordering is favored, leading to less competition between short- and long-range ordering and, consequently, to the extinction of anomalies. Also, the non-polar chain size and concentration have an effect on the solid phases, favoring the hexagonal closed packed (HCP) solid and the amorphous solid phase over the body-centered cubic (BCC) crystal.
References in corpus (28)
- Robust Structural Identification via Polyhedral Template Matching
- Generic mechanism for generating a liquid-liquid phase transition
- The Putative Liquid-Liquid Transition is a Liquid-Solid Transition in Atomistic Models of Water
- freud: A Software Suite for High Throughput Analysis of Particle Simulation Data
- Core-softened potentials and the anomalous properties of water
- Thermodynamics of supercooled water
- Phase behavior of a system of particles with core collapse
- Evidence of two distinct local structures of water from ambient to supercooled conditions
- Excess entropy, Diffusivity and Structural Order in liquids with water-like anomalies
- The Putative Liquid-Liquid Transition is a Liquid-Solid Transition in Atomistic Models of Water, Part II
- Structural Order for One-Scale and Two-Scale Potentials
- Water-like hierarchy of anomalies in a continuous spherical shouldered potential
- Free energy surface of ST2 water near the liquid-liquid phase transition
- Structural anomalies for a three dimensional isotropic core-softened potential
- Metastable liquid-liquid coexistence and density anomalies in a core-softened fluid
- Isotropic soft-core potentials with two characteristic length scales and anomalous behaviour
- Physics of the liquid-liquid critical point
- Softness dependence of the Anomalies for the Continuous Shouldered Well potential
- Optimized Constant Pressure Stochastic Dynamics
- Structural anomalies of fluids: Origins in second and higher coordination shells
- Structural behavior and dynamics of an anomalous fluid between solvophilic and solvophobic walls: templating, molding and superdiffusion
- Effect of hydrophobic solutes on the liquid-liquid critical point
- Effects of nanopore and fluid structure on anomalies and phase transitions of confined core-softened fluids
- Hydrogen bond correlated percolation in a supercooled water monolayer as a hallmark of the critical region
- Waterlike anomalies in hard core-soft shell nanoparticles using a effective potential approach: pinned vs adsorbed polymers
- Theory of nonionic hydrophobic solutes in mixture solvent: Solvent-mediated interaction and solute-induced phase separation
- Competing interactions near the liquid-liquid phase transition of core-softened water/methanol mixtures
- Relation between occupation in the first coordination shells and Widom line in Core-Softened Potentials