Surface interaction with water

The physics of how moving water interacts with surfaces both explains why it is advantageous for organisms to attach to surfaces and provides insights into fouling, control limits, and antifouling... 

FIG. 4 Normalized oxygen density profile perpendicular to the surface from simulations of pure water with adsorption energies of 12, 24, 36, and 48 kJ/mol (from bottom to top). The lower curves are shifted downwards by 0.5, 1.0, and 1.5 units. The inset shows the height of the first (diamonds) and second peak (crosses) as a function of adsorption energy. Water interacts with the surface through a Morse potential. (From Ref. 98.)... 

Simultaneously with the STM studies, Kulkarni et al,14 in Cardiff studied by XPS and HREELS the interaction of ammonia with Ni(l 10)-O and Ni(100)-0 surfaces. There was evidence in the N(ls) spectra for more than one nitrogen state present including N(a), but differentiating between NH(a) and NH2(a) was not possible. The intensity in the N(ls) spectrum region was broad over the range 397-400 eV. As the oxygen coverage increased to >0.3, the oxide O2 component became more prominent and the activity for ammonia oxidation decreased, as was observed by STM. Similar conclusions were reached for water interaction with the Ni(110)-O system.15... 

Reconnaissance studies have shown that surface waters originating from waste rock and tailings dumps are typically characterized by low pH, high sulfate levels and variable metal contents. Consequently, the aim of this study is to investigate the nature of ground water interactions with... 

A plot of the Lennard-Jones 9-3 form of Equations 7 and 8 for ST2 water interacting with smectite and mica surfaces is shown in Figure 1. Values for the parameters used in Figure 1 are given in Tables II and III, and in reference (23). The water molecule is oriented so that its protons face the surface and its lone pair electrons face away from the surface, and the protons are equidistant from the surface. Note that the depth of the potential well in Figure 1 for interactions with the smectite surface and mica surface are... 

Halloysite-10A represents a structure with few if any interlayer cations, allowing one to investigate the relatively simple case of water interacting with a clay surface. Similarly, ice-like models have been proposed for water adsorbed on smectite and vermie-ulite surfaces (2, 12, 12). These represent cases of charged clay layers with adsorbed exchangeable cations. 

The sorption of n-butyl alcohol and (err-butyl alcohol on phenyl modified MCM-41 type sorbent having pores of approximately 20 A diameter (i.e. in the microporous range), has been studied. Comparison of butanol sorption with nitrogen, water, and benzene sorption data indicates that steric hindrance significantly affects the sorption of n-butyl alcohol by the microporous silica, far more so than for tert-butyl alcohol. The different shapes of the isotherms obtained on the microporous material (Type I for fert-butyl alcohol, Type IV for 71-butyl alcohol) suggest that the preferred mechanism for adsorption of leiY-butyl alcohol is via organic interactions with surface phenyls, whereas for n-butyl alcohol, a mechanism of polar interaction is more likely. 

The experimental studies of water interactions with clay minerals are very extensive. The structure, dynamics and interactions of interlayer water with the surface of clay minerals were reviewed in several papers [32, 33] and described in a number of books [15, 34, 35]. Therefore, we will review only the most important studies concerning experimental investigations of the structure and interactions of water molecules on clays. 

The heat capacity isotherm is likely to be particularly informative (1) It can be measured over the full range of system composition, from dry protein to the dilute solution, and thus serves to link studies of powders and solutions. (2) The heat capacity is sensitive to changes in the chemistry of water, including interaction with surface hydro-phobic groups, and should sense all time-average events associated with hydration. 

To obtain H NMR spectra for water molecules interacting with surface oxidized groups (carbonyls, carboxyls, hydroxyls), NMR investigations have been made on frozen aqueous suspensions of graphite oxide (GO) [93,94], Graphite oxide is constituted by colloidal particles consisting of completely oxidized... 

The most plausible explanation of these observations could be connected with the preferential interactions of some cosolvents with the proteins. How the water and cosolvent interact with the protein, how the water interacts with the cosolvent, and how much the local composition in the vicinity of the protein surface differs from that in the protein-free solution are natural questions to be asked. 

Forstner, U. Salomons, W, (1983) Trace element speciation in surface waters Interactions with particulate matter. In Trace Element Speciation in Surface Waters and its Ecological Implications, ed. 

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