title: Large decrease of fluctuations for supercooled water in hydrophobic nanoconfinement.
abstract: Using Monte Carlo simulations, we study a coarse-grained model of a water layer confined in a fixed disordered matrix of hydrophobic nanoparticles at different particle concentrations c. For c=0, we find a first-order liquid-liquid phase transition (LLPT) ending in one critical point at low pressure P. For c>0, our simulations are consistent with a LLPT line ending in two critical points at low and high P. For c=25%, at high P and low temperature, we find a dramatic decrease of compressibility, thermal expansion coefficient, and specific heat. Surprisingly, the effect is present also for c as low as 2.4%. We conclude that even a small presence of hydrophobic nanoparticles can drastically suppress thermodynamic fluctuations, making the detection of the LLPT more difficult.
authors.affiliation: Center for Polymer Studies and Department of Physics, Boston University, Boston, Massachusetts 02215, USA.
authors.forename: Elena G
authors.initials: EG
authors.lastname: Strekalova
authors.forename: Marco G
authors.initials: MG
authors.lastname: Mazza
authors.forename: H Eugene
authors.initials: HE
authors.lastname: Stanley
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Franzese
mesh_terms: D003080:Cold Temperature; D057927:Hydrophobic and Hydrophilic Interactions; D049329:Nanostructures / Q000737:chemistry*; D044367:Phase Transition; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water