scholarly journals Ordered Hydrogen Bonding Structure of Water Molecules Adsorbed on Silver Iodide Particles under Subsaturated Conditions

Author(s):  
Huanyu Yang ◽  
Anthony Boucly ◽  
Jérôme Philippe Gabathuler ◽  
Thorsten Bartels-Rausch ◽  
Luca Artiglia ◽  
...  
2020 ◽  
Author(s):  
Markus Ammann ◽  
Huanyu Yang ◽  
Luca Artiglia ◽  
Anthony Boucly

<p>The hydrogen bonding structure of adsorbed water on a solid substrate may control deposition nucleation, which is a pathway of heterogeneous ice nucleation. Hydrogen bonding of water molecules is also controlling the interface between the solid and liquid water relevant for other heterogeneous freezing modes. The hydrogen bonding structure may be affected by short and long-range interactions between the substrate and the water molecules nearby. Electron yield near edge X-ray absorption fine structure (NEXAFS) spectroscopy at the oxygen K-edge is used to experimentally explore the difference between the hydrogen bonding structure of interfacial H<sub>2</sub>O molecules under different conditions of temperature and water vapor pressure. Experiments reported in this work were performed at the in-situ electron spectroscopy endstation at the ISS beamline at the Swiss Light Source (PSI, SLS). We report electron yield oxygen K-edge NEXAFS spectra and X-ray photoelectron spectra from silver iodide (AgI) particles and milled feldspar samples exposed to water vapor at high relative humidity, but subsaturated with respect to ice. AgI serves as a well-studied reference case; and it contains no oxygen in its lattice, which simplifies the analysis of NEXAFS spectra at the O K-edge. The feldspar samples include a potassium containing microcline and a sodium-rich albite. The analysis of the NEXAFS spectra indicate rather tetrahedrally coordinated adsorbed water molecules on AgI particles. On the feldspars, the mobility of ions, as directly observed by the XPS spectra appears to have a strong impact on the hydrogen bonding structure, as apparent from substantial differences between samples previously immersed in pure water or as prepared. To sum up, we attempt to understand the behavior of the hydrogen bonding structure, which provides rich information about the arrangement of water molecules in the vicinity of a solid surface, that is linked to the ability of the solid to induce ice formation.</p>


Author(s):  
Ning Zhang ◽  
Cong Chen ◽  
Yujing Feng ◽  
Qingnan Pang ◽  
Weizhong Li

The structure of water molecules inside (6, 6) carbon nanotube under two different conditions are studied using molecular dynamics simulation. The structural and thermodynamic properties of the single-file water chain along the nanotube help to determine the hydrogen bonds between water molecules inside the channel. The properties of the systems show that induced pressure and ionic environment have similar effects on the structure of the inner water molecules. However, the Na+ and Cl− ions lead the number of hydrogen bonds inside the nanotube to fluctuate a little more greatly than that under the induced pressure.


Author(s):  
John Finney

‘The water molecule and its interactions’ discusses the structural and electrical properties of the water molecule. A water molecule is made up of two hydrogen atoms connected by covalent bonds to one oxygen atom. Water molecules interact with each other through a type of interaction called hydrogen bonding. A tetrahedral arrangement of four water molecules around a central one is the key to understanding water. It helps to explain the structure of water in its various states, its properties, and how it interacts with other kinds of molecules, allowing exploration of the properties and behaviour of the wide range of chemical, physical, and biological systems in which water is involved.


2015 ◽  
Vol 6 (14) ◽  
pp. 2773-2779 ◽  
Author(s):  
Pramod Kumar Verma ◽  
Hochan Lee ◽  
Joon-Young Park ◽  
Joon-Hyung Lim ◽  
Michał Maj ◽  
...  

2012 ◽  
Vol 26 (14) ◽  
pp. 1250088 ◽  
Author(s):  
RUIJIN LIAO ◽  
MENGZHAO ZHU ◽  
XIN ZHOU ◽  
FUZHOU ZHANG ◽  
JIAMING YAN ◽  
...  

Hydrolysis is an important component of the aging of cellulose, and it severely affects the insulating performance of cellulosic materials. The diffusion behavior of water molecules in amorphous cellulose and their destructive effect on the hydrogen bonding structure of cellulose were investigated by molecular dynamics. The change in the hydrogen bonding structure indicates that water molecules have a considerable effect on the hydrogen bonding structure within cellulose: both intermolecular and intramolecular hydrogen bonds decreased with an increase in ingressive water molecules. Moreover, the stabilities of the cellulose molecules were disrupted when the number of intermolecular hydrogen bonds declined to a certain degree. Both the free volumes of amorphous cells and water molecule-cellulose interaction affect the diffusion of water molecules. The latter, especially the hydrogen bonding interaction between water molecules and cellulose, plays a predominant role in the diffusion behavior of water molecules in the models of which the free volume rarely varies. The diffusion coefficient of water molecules has an excellent correlation with water molecule-cellulose interaction and the average hydrogen bonds between each water molecule and cellulose; however, this relationship was not apparent between the diffusion coefficient and free volume.


2013 ◽  
Vol 68 (1-2) ◽  
pp. 91-100 ◽  
Author(s):  
Narasimhan Loganathan ◽  
Andrey G. Kalinichev

Molecular dynamics (MD) computer simulations were performed for an aqueous film of 3 nm thickness adsorbed at the (001) surface of ammonium-substituted muscovite mica. The results provide a detailed picture of the near-surface structure and topological characteristics of the interfacial hydrogen bonding network. The effects of deuterium=hydrogen isotopic substitution in N(H=D)4+ on the dynamics and consequently on the convergence of the structural properties have also been explored. Unlike many earlier simulations, a much larger surface area representing 72 crystallographic unit cells was used, which allowed for a more realistic representation of the substrate surface with a more disordered distribution of aluminium=silicon isomorphic substitutions in muscovite. The results clearly demonstrate that under ambient conditions both interfacial ammonium ions and the very first layer of water molecules are H-bonded only to the basal surface of muscovite, but do not form H-bonds with each other. As the distance from the surface increases, the H-bonds donated to the surface by both N(H=D)4+ and H2O are gradually replaced by the H-bonds to the neighbouring water molecules, with the ammonia ions experiencing one reorientational transition region, while the H2O molecules experiencing three such distinct consecutive transitions. The hydrated N(H=D)4+ ions adsorb almost exclusively as inner-sphere surface complexes with the preferential coordination to the basal bridging oxygen atoms surrounding the aluminium=silicon substitutions.


2017 ◽  
Vol 5 (4) ◽  
pp. 26-32 ◽  
Author(s):  
Azaria Robiana ◽  
M. Yashin Nahar ◽  
Hamidah Harahap

Glycerin residue is waste oleochemical industry that still contain glycerin. To produce quality and maximum quantity of glycerin, then research the effect of pH acidification using phosphoric acid. Glycerin analysis includes the analysis of pH, Fatty Acid and Ester (FAE), and analysis of the levels of glycerin. The maximum yield obtained at pH acidification 2 is grading 91,60% glycerin and Fatty Acid and Ester (FAE) 3,63 meq/100 g. Glycerin obtained is used as a plasticizer in the manufacture of bioplastics. Manufacture of bioplastics using the method of pouring a solution with varying concentrations of starch banana weevil (5% w/v and 7% w/v), variations of the addition of glycerin (1 ml, 3 ml, 5 ml and 7 ml), and a variety of gelatinization temperature (60°C, 70°C, and 80°C). Analysis of bioplastics include FTIR testing, tensile strength that is supported by SEM analysis. The results obtained in the analysis of FTIR does not form a new cluster on bioplastics starch banana weevil, but only a shift in the recharge area only, it is due to the addition of O-H groups originating from water molecules that enter the polysaccharide through a mechanism gelatinitation that generates interaction hydrogen bonding strengthened. The maximum tensile strength of bioplastics produced at a concentration of starch 7% w/v, 1 ml glycerine and gelatinization temperature of 80°C is 3,430 MPa. While the tensile strength bioplastic decreased with increasing glycerin which can be shown from the results of SEM where there is a crack, indentations and lumps of starch insoluble.


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