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The Structure and Function of the Second Phase of Liquid Water

A special issue of International Journal of Molecular Sciences (ISSN 1422-0067). This special issue belongs to the section "Physical Chemistry and Chemical Physics".

Deadline for manuscript submissions: closed (31 December 2019) | Viewed by 14334

Special Issue Editor

Faculty of Chemistry and Chemical Technology University of Ljubljana, Večna pot 113 1000 Ljubljana, Slovenia

Special Issue Information

Dear Colleagues,

The xistence of two phases of liquid water has been proved many times using various physico-chemical experimental techniques and different computational approaches, respectively.

There are several theoretical models that attempt to account for complex water–water interactions in the liquid phase. In spite of a variety of theoretical approches, it is the common opinion of most authors that liquid water exsists in two phases, with different scales of clustering, leading to low-density and high-density water, which are interrelated in dynamic equilibrium.

A substantial experimetal study has been carried out on interfacial water close to hydrophilic surfaces. The formation of an Exclusion Zone (EZ) composed of layers of water molecules has been proved by a number of techniques. These results opened a number of questiones and challenges to be answered in understanding the basic chemistry of water. In addition, EZ is of outstanding importance in living systems where water is close to hydrophilic surfaces or macromolecules. It has been shown that the quantum electrodynamic approach to negatively charged EZ provides a new opportunity for explaining missing information in biochemistry. Consecuently, these findings are closely related to medical phenomena and will enable a deeper understanding of yet unexplained or even denied facts.

This Special Issue is devoted to all aspects of liquid water structure; to possible mechanisms of the EZ formation and an explanation of its phenomena; to biological and medical implications of EZ, such as its role in biological hydrophilic contacts and highly diluted remedies; and, finally, to possible implications of EZ in technical solutions.

Prof. Dr. Peter Bukovec
Guest Editor

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Keywords

  • Water structuring
  • Exclusion zone
  • Interfacial water
  • Hydrophilic surface
  • Biological effects
  • High dilution effects

Published Papers (4 papers)

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Research

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20 pages, 3416 KiB  
Article
Reaction of 1-propanol with Ozone in Aqueous Media
by Erika Reisz, Agnes Tekle-Röttering, Sergej Naumov, Winfried Schmidt and Torsten C. Schmidt
Int. J. Mol. Sci. 2019, 20(17), 4165; https://doi.org/10.3390/ijms20174165 - 26 Aug 2019
Cited by 7 | Viewed by 3615
Abstract
The main aim of this work is to substantiate the mechanism of 1-propanol oxidation by ozone in aqueous solution when the substrate is present in large excess. Further goals are assessment of the products, their formation yields as well as the kinetic parameters [...] Read more.
The main aim of this work is to substantiate the mechanism of 1-propanol oxidation by ozone in aqueous solution when the substrate is present in large excess. Further goals are assessment of the products, their formation yields as well as the kinetic parameters of the considered reaction. The reaction of ozone with 1-propanol in aqueous solution occurs via hydride transfer, H-abstraction and insertion. Of these three mechanisms, the largest share is for hydride transfer. This implies the extraction of an hydride ion from the activated C−H group by O3 according to reaction: (C2H5)(H)(HO)C−H + O3 → [(C2H5)(H)(HO)C+ + HO3]cage → (C2H5)(H)(HO)C+ + HO3. The experimentally determined products and their overall formation yields with respect to ozone are: propionaldehyde—(60 ± 3)%, propionic acid—(27.4 ± 1.0)%, acetaldehyde—(4.9 ± 0.3)%, acetic acid—(0.3 ± 0.1)%, formaldehyde—(1.0 ± 0.1)%, formic acid—(4.6 ± 0.3)%, hydrogen peroxide—(11.1 ± 0.3)% and hydroxyl radical—(9.8 ± 0.3)%. The reaction of ozone with 1-propanol in aqueous media follows a second order kinetics with a reaction rate constant of (0.64 ± 0.02) M−1·s−1 at pH = 7 and 23 °C. The dependence of the second order rate constant on temperature is described by the equation: l n   k I I = ( 27.17 ± 0.38 ) ( 8180 ± 120 ) × T 1 , which gives the activation energy, Ea = (68 ± 1) kJ mol−1 and pre-exponential factor, A = (6.3 ± 2.4) × 1011 M−1 s−1. The nature of products, their yields and the kinetic data can be used in water treatment. The fact that the hydride transfer is the main pathway in the 1-propanol/ozone system can probably be transferred on other systems in which the substrate is characterized by C−H active sites only. Full article
(This article belongs to the Special Issue The Structure and Function of the Second Phase of Liquid Water)
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10 pages, 2230 KiB  
Article
Molecular Simulation Study on the Microscopic Structure and Mechanical Property of Defect-Containing sI Methane Hydrate
by Shouyin Cai, Qizhong Tang, Sen Tian, Yiyu Lu and Xuechao Gao
Int. J. Mol. Sci. 2019, 20(9), 2305; https://doi.org/10.3390/ijms20092305 - 09 May 2019
Cited by 18 | Viewed by 2765
Abstract
The study of changes in the related mechanical property and microscopic structure of methane hydrate during the decomposition process are of vital significance to its exploitation and comprehensive utilization. This paper had employed the molecular dynamics (MD) method to investigate the influence of [...] Read more.
The study of changes in the related mechanical property and microscopic structure of methane hydrate during the decomposition process are of vital significance to its exploitation and comprehensive utilization. This paper had employed the molecular dynamics (MD) method to investigate the influence of defects on the microscopic structure and mechanical property of the sI methane hydrate system, and to discover the mechanical property for the defect-containing hydrate system to maintain its brittle materials. Moreover, the stress-strain curve of each system was analyzed, and it was discovered that the presence of certain defects in the methane hydrate could promote its mechanical property; however, the system mechanical property would be reduced when the defects had reached a certain degree (particle deletion rate of 9.02% in this study). Besides, the microscopic structures of the sI methane hydrate before and after failure were analyzed using the F3 order parameter value method, and it was found that the F3 order parameters near the crack would be subject to great fluctuations at the time of failure of the hydrate structure. The phenomenon and conclusions drawn in this study provide a basis for the study of the microscopic structure and mechanical characteristics of methane hydrate. Full article
(This article belongs to the Special Issue The Structure and Function of the Second Phase of Liquid Water)
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12 pages, 15394 KiB  
Article
Giant Water Clusters: Where Are They From?
by Tatiana Yakhno, Mikhail Drozdov and Vladimir Yakhno
Int. J. Mol. Sci. 2019, 20(7), 1582; https://doi.org/10.3390/ijms20071582 - 29 Mar 2019
Cited by 3 | Viewed by 2083
Abstract
A new mechanism for the formation and destruction of giant water clusters (ten to hundreds of micrometers) is proposed. Our earlier hypothesis was that the clusters are associates of liquid-crystal spheres (LCS), each of which is formed around a seed particle, a microcrystal [...] Read more.
A new mechanism for the formation and destruction of giant water clusters (ten to hundreds of micrometers) is proposed. Our earlier hypothesis was that the clusters are associates of liquid-crystal spheres (LCS), each of which is formed around a seed particle, a microcrystal of sodium chloride. In this study, we show that the ingress of LCSs into water from the surrounding air is highly likely. We followed the evolution of giant clusters during the evaporation of water. When a certain threshold of the ionic strength of a solution is exceeded, the LCSs begin to “melt”, passing into free water, and the salt crystals dissolve, ensuring re-growth of larger crystals as a precipitate on the substrate. A schematic diagram of the dynamics of phase transitions in water containing LCSs during evaporation is proposed. The results illustrate the salt dust cycle in nature. Full article
(This article belongs to the Special Issue The Structure and Function of the Second Phase of Liquid Water)
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13 pages, 1051 KiB  
Review
Exclusion Zone Phenomena in Water—A Critical Review of Experimental Findings and Theories
by Daniel C. Elton, Peter D. Spencer, James D. Riches and Elizabeth D. Williams
Int. J. Mol. Sci. 2020, 21(14), 5041; https://doi.org/10.3390/ijms21145041 - 17 Jul 2020
Cited by 23 | Viewed by 5553
Abstract
The existence of the exclusion zone (EZ), a layer of water in which plastic microspheres are repelled from hydrophilic surfaces, has now been independently demonstrated by several groups. A better understanding of the mechanisms which generate EZs would help with understanding the possible [...] Read more.
The existence of the exclusion zone (EZ), a layer of water in which plastic microspheres are repelled from hydrophilic surfaces, has now been independently demonstrated by several groups. A better understanding of the mechanisms which generate EZs would help with understanding the possible importance of EZs in biology and in engineering applications such as filtration and microfluidics. Here we review the experimental evidence for EZ phenomena in water and the major theories that have been proposed. We review experimental results from birefringence, neutron radiography, nuclear magnetic resonance, and other studies. Pollack theorizes that water in the EZ exists has a different structure than bulk water, and that this accounts for the EZ. We present several alternative explanations for EZs and argue that Schurr’s theory based on diffusiophoresis presents a compelling alternative explanation for the core EZ phenomenon. Among other things, Schurr’s theory makes predictions about the growth of the EZ with time which have been confirmed by Florea et al. and others. We also touch on several possible confounding factors that make experimentation on EZs difficult, such as charged surface groups, dissolved solutes, and adsorbed nanobubbles. Full article
(This article belongs to the Special Issue The Structure and Function of the Second Phase of Liquid Water)
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