Gas chromatographic, quentum-chemical, and molecular statistical studies of cluster adsorption of water and methanol molecules on hydrophilic surface sites of hydrophobic adsorbents

2008 ◽  
Vol 70 (4) ◽  
pp. 478-485 ◽  
Author(s):  
Yu. I. Tarasevich ◽  
E. V. Aksenenko ◽  
A. I. Zhukova ◽  
S. V. Bondarenko
Keyword(s):  
Hydrophilic Surface ◽  
Surface Sites ◽  
Adsorption Of Water ◽  
Statistical Studies ◽  
Hydrophobic Adsorbents

scholarly journals Interaction of Water and other Polar Substances with Hydrophilic Centres on the Surface of Hydrophobic Adsorbents

1997 ◽  
Vol 15 (7) ◽  
pp. 497-505 ◽  
Author(s):  
Yu.I. Tarasevich ◽  
A.I. Zhukova ◽  
E.V. Aksenenko ◽  
S.V. Bondarenko
Keyword(s):  
Carbon Black ◽  
Graphitized Carbon Black ◽  
Adsorption Heat ◽  
Macroporous Silica ◽  
Graphitized Carbon ◽  
Quantum Chemical Methods ◽  
Adsorption Of Water ◽  
Black Surface ◽  
Hydrophobic Adsorbents ◽  
Molecule Interaction

The adsorption of water and other polar substances on to the surface of graphitized carbon black and macroporous silica modified by polymethylhydride silicone has been studied using gas chromatography. The adsorption heat values of the substances studied were determined and the concentration of surface hydrophilic centres estimated. Conclusions have been drawn concerning the number of water molecules adsorbed on to hydrophilic centres at low surface occupation values. In the case of water adsorption on the graphitized carbon black surface, the chromatographic data for the adsorption heat have been compared with the energy of water molecule interaction with the surface clusters modelling the micropores existing on the basal surface of carbon black particles as calculated using quantum chemical methods.

Measurements of hydrophobic and hydrophilic surface sites by flow microcalorimetry

Langmuir ◽  
1993 ◽  
Vol 9 (10) ◽  
pp. 2721-2725 ◽  
Author(s):  
A. J. Groszek ◽  
S. Partyka
Keyword(s):  
Hydrophilic Surface ◽  
Flow Microcalorimetry ◽  
Surface Sites

Statistical Studies on Galaxy Evolution from IR Observations

2002 ◽  
Vol 4 ◽  
pp. 375-375
Author(s):  
T. T. Takeuchi ◽  
T. T. Ishii ◽  
T. Totani
Keyword(s):  
Galaxy Evolution ◽  
Statistical Studies

The Adaptation of Medical Records to Epidemiological Use

1965 ◽  
Vol 04 (03) ◽  
pp. 136-140
Author(s):  
Cl Jeanty
Keyword(s):  
Medical Records ◽  
Clinical Pathology ◽  
Time Variable ◽  
Special Care ◽  
General Description ◽  
Causal Relations ◽  
Laboratory Techniques ◽  
Original Record ◽  
Statistical Studies

A method is described in an attempt to make medical records suitable for epidemiologigri: purposes. Every case of a disease is recorded on an appropriate punched card with the object of working towards a general description of a disease through the collation of several cases of the same diagnosis. This punched card represents a very great condensation of the original record. Special care has been applied to state as precisely as possible the time variable, particularly as far as its origin and unit of measure are concerned, in order to demonstrate the existence of causal relations between diseases. Such cards are also intended to make easier statistical studies in clinical pathology, in evaluation of new laboratory techniques, and in therapeutical trials.

A First-Principles Computational Comparison of the Aqueous Anatase TiO2 (001) Interface and the Disordered, Fluorinated TiO2 Interface

2018 ◽  
Author(s):  
Kyle Reeves ◽  
Damien Dambournet ◽  
Christel Laberty-Robert ◽  
Rodolphe Vuilleumier ◽  
Mathieu Salanne
Keyword(s):  
Density Of States ◽  
Density Functional ◽  
Water Dissociation ◽  
Water Molecules ◽  
Chemical Doping ◽  
Charge Balance ◽  
Functional Theory ◽  
Adsorption Of Water ◽  
Properties Of Materials ◽  
Computational Comparison

Chemical doping and other surface modifications have been used to engineer the bulk properties of materials, but their influence on the surface structure and consequently the surface chemistry are often unknown. Previous work has been successful in fluorinating anatase TiO<sub>2</sub> with charge balance achieved via the introduction of Ti vacancies rather than the reduction of Ti. Our work here investigates the interface between this fluorinated titanate with cationic vacancies and a<br>monolayer of water via density functional theory based molecular dynamics. We compute the projected density of states for only those atoms at the interface and for those states that fall within 1eV of the Fermi energy for various steps throughout the simulation, and we determine that the<br>variation in this representation of the density of states serves as a reasonable tool to anticipate where surfaces are most likely to be reactive. In particular, we conclude that water dissociation at the surface is the main mechanism that influences the anatase (001) surface whereas the change in<br>the density of states at the surface of the fluorinated structure is influenced primarily through the adsorption of water molecules at the surface.

A First-Principles Computational Comparison of the Aqueous Anatase TiO2 (001) Interface and the Disordered, Fluorinated TiO2 Interface

2018 ◽  
Author(s):  
Kyle Reeves ◽  
Damien Dambournet ◽  
Christel Laberty-Robert ◽  
Rodolphe Vuilleumier ◽  
Mathieu Salanne
Keyword(s):  
Density Of States ◽  
Density Functional ◽  
Water Dissociation ◽  
Water Molecules ◽  
Chemical Doping ◽  
Charge Balance ◽  
Functional Theory ◽  
Adsorption Of Water ◽  
Properties Of Materials ◽  
Computational Comparison

Chemical doping and other surface modifications have been used to engineer the bulk properties of materials, but their influence on the surface structure and consequently the surface chemistry are often unknown. Previous work has been successful in fluorinating anatase TiO<sub>2</sub> with charge balance achieved via the introduction of Ti vacancies rather than the reduction of Ti. Our work here investigates the interface between this fluorinated titanate with cationic vacancies and a<br>monolayer of water via density functional theory based molecular dynamics. We compute the projected density of states for only those atoms at the interface and for those states that fall within 1eV of the Fermi energy for various steps throughout the simulation, and we determine that the<br>variation in this representation of the density of states serves as a reasonable tool to anticipate where surfaces are most likely to be reactive. In particular, we conclude that water dissociation at the surface is the main mechanism that influences the anatase (001) surface whereas the change in<br>the density of states at the surface of the fluorinated structure is influenced primarily through the adsorption of water molecules at the surface.

Mercury Removal from Wastewater by Steamed Hoof Powder

1999 ◽  
Vol 40 (7) ◽  
pp. 109-116 ◽  
Author(s):  
M. H. Ansari ◽  
A. M. Deshkar ◽  
P. S. Kelkar ◽  
D. M. Dharmadhikari ◽  
M. Z. Hasan ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Adsorption Capacity ◽  
Adsorption Process ◽  
Adsorption Equilibrium ◽  
Light Metal ◽  
Mercury Removal ◽  
High Adsorption ◽  
Surface Sites ◽  
Ph Values ◽  
High Adsorption Capacity

Steamed Hoof Powder (SHP), size &lt; 53μ, was observed to have high adsorption capacity for Hg(II) with &gt;95% removal from a solution containing 100 mg/L of Hg(II) with only 0.1% (W/V) concentration of SHP. The SHP has good settling properties and gives clear and odour free effluent. Studies indicate that pH values between 2 and 10 have no effect on the adsorption of Hg(II) on SHP. Light metal ions like Na+, K+, Ca2+ and Mg2+ up to concentrations of 500 mg/L and heavy metals like Cu2+, Zn2+, Cd2+, Co2+, Pb2+, Ni2+, Mn2+, Cr3+, Cr6+, Fe2+ and Fe3+ up to concentrations of 100 mg/L do not interfere with the adsorption process. Anions like sulphate, acetate and phosphate up to concentrations of 200 mg/L do not interfere. Chloride interferes in the adsorption process when Hg(II) concentration is above 9.7 mg/L. The adsorption equilibrium was established within two hours. Studies indicate that adsorption occurs on the surface sites of the adsorbent.

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