Structure and Properties of Water in its Various States

Abstract

Water is a unique substance with properties that are not predictable from those of other materials. It has a complex phase space where all of its physical and structural forms possess unexpected properties. Mostly, these are consequences of the ability of the water molecule to form strongly hydrogen‐bonded intricate structures. The extensive hydrogen bonding provides water with the ability to transfer protons and electrons rapidly between the water molecules and to produce positively charged hydrogen ions and negatively charged hydroxide ions. In the many solid phases, each water molecule forms exactly four hydrogen bonds in a tetrahedral arrangement with two hydrogen atoms near each oxygen atom. This arrangement is also present, if much more loosely, in liquid water, where the overall structuring is far more complex. Such liquid water behaves as though it is a mixture of two liquids that change relative composition with variations in temperature and pressure. The properties of liquid water are particularly affected at low temperature when supercooled and at very low temperatures when water glasses are formed. Even gaseous water is affected by this hydrogen bonding.

Interfacial behavior of methane and organic solvents with low freezing points upon interaction with hydrophilic and hydrophobic nanosilicas

“…12. Theoretical 1 H NMR spectra of a water cluster with 44H 2 O in vacuum (curve 1) calculated using the GIAO method with the ωB97XD/ccpVDZ//ωB97XD/ccpVDZ basis set, and taking into account solvation in water with the SMD/ωB97XD method using ccpVDZ//SMD/ωB97XD/ccpVDZ (curve 2) and aug-ccpVTZ//SMD/ωB97XD/ccpVDZ (curve 3) basis sets Adsorbed water can be differentiated according to the temperature ranges of its freezing [15,20]. If it is frozen at 265 K < T < 273 K that it can be attributed to weakly bound water (WBW).…”

“…The applications of the low-temperature 1 H NMR spectroscopy and NMR cryoporometry, based on the freezing point depression of liquids located in pores dependent on the pore size, to numerous objects were described in detail elsewhere [15,[20][21][22][23]. Note that high-molecular weight compounds and solids do not contribute to the 1 H NMR spectra recorded here due to a large difference in the transverse relaxation times of liquid or fluid (mobile) small compounds (such as water, methane, acetone, ethanol, etc.)…”

“…First, each water molecule in any cluster tends to form several (2)(3)(4) hydrogen bonds with neighboring molecules that is easier than the formation of such bonds with surface sites only [15,19]. Second, the energy of molecular interactions in a surface cluster and of the cluster with the surface could be greater (due to the first reason) than that for water bound to the surface with keeping continuous adsorption monolayer [15,19,20].…”

“…The adsorption leading to reduction of the Gibbs free energy causes freezing/melting point depression [15,[20][21][22][23]. The narrower the pore, the lower the freezing temperature of adsorbate in this pore that is described by the Gibbs-Thomson relation [15,[21][22][23].…”

“…This allows one to study the temperature and interfacial behaviors of adsorbates (e.g. having the hydrogen atoms) at a surface of solids having the surface hydroxyls because the surface hydroxyls are characterized by the values of T 2 smaller by 3-5 orders of magnitude than that of mobile small molecules in the adsorption phase [15][16][17][18]20].…”