Supercooling Behavior and Dipole-Glass-like Relaxation in a Three-Dimensional Water Framework

Abstract

The dynamic behaviors of a new type of three-dimensional (3D) water framework symbiotic with 1D stacking organic guests, including an order–disorder transition of hydrogen atoms, a supercooling phenomenon during phase transition, and a dipole-glass-like relaxation behavior due to locally trapped water molecules, are presented. This extremely scarce 3D water framework, together with the rich dynamic behaviors it exhibits, provides new clues to design new ice-like models for promoting the fundamental understanding of the dynamic behavior of water in diverse solid-states.

Unique Dynamics of Water Confined on the Surface of Metal Oxide Clusters

“…As observed, the slope, i. e., the energy barrier of relaxation, abnormally increase gradually with decreasing temperature, which can be interpreted as a distribution of potential energy barriers resisting the molecular mobility (jumps over low barriers) and ionic defect migration (proton hopping). A similar temperature dependence of this α relaxation is observed in the protein hydration water and a three dimensional water framework [18–19] . The fitting of the dipolar glassy model suggested that the protons trapped by the confinement effect behave as locally correlated dipole nanodomains with random dipole directions and broadly distributed sizes, eventually giving a broadly distributed relaxation time.…”

“…The typical spectrum of the dielectric losses associated with relaxation of water molecules in the hydrated solid acid versus frequency and temperature is displayed in Figure 2. The dynamic properties of the absorbed water exhibit dipolar glassy relaxations, [18] originated from water reorientation and charged defects‐such as H 3 O + ‐moving with a diffusive or hopping mechanism along the HB network, which are different from those of the bulk water. The observation is originated from the geometrical confinement of the liquid in the crystalline framework and the strong interaction of the water molecules with active surface sites of SiW 12 .…”

Fast identification of optimal pure platinum nanoparticle shapes and sizes for efficient oxygen electroreduction

“…26 The pure Pt nanocatalysts proposed in this study may likely be synthesized using templates, for which metalorganic frameworks are suitable. 36 High-resolution transmission electron microscopy could be used to resolve their structures at the subnanoscale. 37 Beside high mass activity and controllable structure sensitivity, electrocatalyst stability is a critical aspect in fuel cell environments.…”

Designing and Constructing a High‐Temperature Molecular Ferroelectric by Anion and Cation Replacement in a Simple Crown Ether Clathrate

“…[1][2][3][4][5][6] Especially molecular ferroelectric materials have become an ew research focus due to their light weight, flexible, environment-friendly and easily synthesis comparet ot raditional inorganic ferroelectrics. [1,[7][8][9][10][11][12][13] Although ag reat progress have been made in the field of molecular ferroelectrics, the current research of molecular ferroelectrics still facealot of challenges. Most new molecular ferroelectrics usually come from the known ferroelectric system such as the derivativeo fR ochelle salt, some typical ABX 3 organic-inorganic hybridsa nd the organic amine crathrate etc.…”

“…Ferroelectric have been found wide application in modern functional materials including random‐access memory (RAM), capacitance, sensor, electro‐optical (photoelectricity and piezoelectricity) and infrared detector etc . Especially molecular ferroelectric materials have become a new research focus due to their light weight, flexible, environment‐friendly and easily synthesis compare to traditional inorganic ferroelectrics …”