scholarly journals Inverse gas chromatrography of chromia. Part II. Finite surface coverage

2002 ◽  
Vol 67 (3) ◽  
pp. 165-178 ◽  
Author(s):  
Antonije Onjia ◽  
Slobodan Milonjic ◽  
Ljubinka Rajakovic
Keyword(s):  
Inverse Gas Chromatography ◽  
Surface Coverage ◽  
Isosteric Heat ◽  
Strong Acid ◽  
Colloidal Dispersion ◽  
Adsorption Ability ◽  
Base Interaction ◽  
Spreading Pressure ◽  
Adsorption Energy Distribution ◽  
Acid Base Interaction

The interactions of n-hexane, benzene, chloroform, and tetrahydrofuran with dried (amorphous) chromia (I) and chromia heated at 1073 K (crystalline) (II), both obtained from a colloidal dispersion, and a commercially available chromia (III) were studied by inverse gas chromatography (IGC) under finite surface coverage conditions. The isotherms, in the temperature range 383 ? 423 K, were used to estimate the surface area, the adsorption energy distribution, the isosteric heat of adsorption, and the spreading pressure on the surfaces of the solids. The uniformly reduced adsorption ability of the heated chromia was attributed to the dehydroxylation of the surface at the higher temperatures. Both solids showed an increased affinity toward chloroform molecules, as a result of strong acid-base interaction.

scholarly journals Surface characterization of polymers by inverse gas chromatography

2007 ◽  
Vol 72 (4) ◽  
pp. 403-406 ◽  
Author(s):  
Aleksandra Nastasovic ◽  
Antonije Onjia
Keyword(s):  
Glycidyl Methacrylate ◽  
Surface Characterization ◽  
Infinite Dilution ◽  
Inverse Gas Chromatography ◽  
Surface Coverage ◽  
Isosteric Heat ◽  
Free Energies ◽  
Acid Base ◽  
Adsorption Energy Distribution

An inverse gas chromatographic (IGC) study of the sorption properties of macroporous crosslinked poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate), PGME, and PGME modified with ethylene diamine, PGME-en, was presented. At infinite dilution, the thermodynamic parameters of adsorption, the dispersive components of the surface free energies, the acid/base constants and the interaction parameters for the initial and modified copolymer samples were investigated. The adsorption isotherms determined by IGC under conditions of finite surface coverage were used to estimate the surface area, the isosteric heat of adsorption and the adsorption energy distribution on the surface of the initial and modified copolymer samples. .

Oxygen-assisted water partial dissociation on copper: a model study

2015 ◽  
Vol 17 (12) ◽  
pp. 8231-8238 ◽  
Author(s):  
Ying-Qi Wang ◽  
Li-Fen Yan ◽  
Gui-Chang Wang
Keyword(s):  
High Activity ◽  
Strong Acid ◽  
Water Dissociation ◽  
Acid Base ◽  
Base Interaction ◽  
Model Study ◽  
Partial Dissociation ◽  
Acid Base Interaction

The strong acid–base interaction, corresponding to the high activity in water dissociation.

Effect of Preparation Methods of HPW/SiO2 Mesoporous Composites on its Catalytic Performance in Fuel Oils Desulfurization

2010 ◽  
Vol 148-149 ◽  
pp. 924-928
Author(s):  
Xue Min Yan ◽  
Yuan Zhu Mi
Keyword(s):  
Catalytic Activity ◽  
Self Assembly ◽  
Electrostatic Force ◽  
Oxidative Desulfurization ◽  
Strong Acid ◽  
Catalytic Performance ◽  
Synthesis Mechanism ◽  
Base Interaction ◽  
Preparation Methods ◽  
Oh Groups

Two kinds of mesoporous HPW/SiO2 composites, which have been synthesized respectively by the amino-functionalized (AF) method and evaporation-induced self-assembly (EISA) method, have been used as catalysts in the oxidative desulfurization process of dibenzothiophene(DBT). The catalytic performance results show that the catalyst synthesized by EISA method holds higher catalytic activity than that synthesized by the AF method. The difference of catalytic activity can be attributed to the different synthesis mechanism of two kinds of composites. In the AF method, the bonding force between HPW and SiO2 is strong acid-base interaction, which damages the Keggin structure. Whereas in the EISA process, electrostatic force and hydrogen bonds between W=O groups and Si-OH groups are main bonding forces. The hydrogen bond holds the electron-withdrawing effect, which increases the activity of nonbonding W=O groups in HPW and then results in the enhancement of the catalytic activity.

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