scholarly journals Determination of the surface properties of kaolinite by inverse gas chromatography

2018 ◽  
Vol 2017 (2) ◽  
pp. 319-328 ◽  
Author(s):  
Ceyda Bilgiç
Keyword(s):  
Gas Chromatography ◽  
Free Energy ◽  
Inverse Gas Chromatography ◽  
Specific Enthalpy ◽  
Free Energy Of Adsorption ◽  
Dispersive Component ◽  
Enthalpy Of Adsorption ◽  
Kaolinite Surface ◽  
Acceptor Numbers

Abstract Inverse gas chromatography (IGC) was applied to characterize the surface of kaolinite. The adsorption thermodynamic parameters (the standard enthalpy (∆H0), entropy (∆S0) and free energy of adsorption (∆G0), the dispersive component of the surface energy (γsd), and the acid/base character of kaolinite surface were estimated by using the retention time of different non-polar and polar probes at infinite dilution region. The specific free energy of adsorption (∆Gsp), the specific enthalpy of adsorption (∆Hsp), and the specific entropy of adsorption (∆Ssp) of polar probes on kaolinite were determined. (∆Gsp) values were correlated with the donor and modified acceptor numbers of the probes to quantify the acidic (KA) and the basic (KD) parameters of the kaolinite surface. The values obtained for the parameters KA and KD indicated a basic character for kaolinite surface.

scholarly journals Correction of some thermodynamic surface properties of Sodium Alginate determined by Inverse Gas Chromatography

2021 ◽  
Author(s):  
Tayssir Hamieh
Keyword(s):  
Gas Chromatography ◽  
Sodium Alginate ◽  
Surface Area ◽  
Surface Properties ◽  
Inverse Gas Chromatography ◽  
Chemical Engineering ◽  
Specific Enthalpy ◽  
Free Energy Of Adsorption ◽  
Dispersive Component

Abstract In their paper published in the Journal of Chemical Engineering Data, Ugraskan et al. [1] made several inaccuracies in the determination of the surface properties of sodium alginate by using the inverse gas chromatography (IGC) technique. The proposed method to determine the dispersive component of the surface energy, I, cannot be correctly evaluated, because it depends on the surface area of n-alkanes or of methylene group. This surface area supposed by Ugraskan et al. [1] constant strongly depends on the temperature. Therefore, the specific free energy of adsorption, (-ΔGsp), and consequently the specific enthalpy of adsorption, (-ΔHsp), cannot be known with accuracy. The wrong values of (-ΔHsp), certainly lead to inaccurate determination of the acid KA and base KD constants of the solid.

Investigation of the surface properties of POSS-modified polyacrylate by inverse gas chromatography

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Qi-chao Zou ◽  
Huan Yu ◽  
Hao Chen
Keyword(s):  
Gas Chromatography ◽  
Free Energy ◽  
Surface Properties ◽  
Surface Free Energy ◽  
Inverse Gas Chromatography ◽  
Specific Interaction ◽  
Polymer Surface ◽  
Butyl Methacrylate ◽  
Free Energy Of Adsorption ◽  
Dispersive Component

AbstractThe surface properties of poly(methyl methacryl-ate-co-n-butyl methacrylate-co-cyclopentyl methacryloxy propyl-polyhedral oligomeric silsesquioxane) (poly(MMA-co -BMA-co-POSSMA)) were studied by means of inverse gas chromatography (IGC) using 10 non-polar and polar solvents as the probes. Thermodynamic parameters of adsorption, such as the dispersive component of the surface energy, the specific interaction contribution to the free energy of adsorption and the acid/base constants of polymer surface were determined. It was found that incorporation of POSSMA into polymer resulted in increasing interactions between polymers and solvents, dispersive component of surface free energy of polymer and acidity of the surfaces of the polymers. The more the POSSMA were embedded, the larger the dispersive component of the surface free energy was, and the acidic character of the polymer surface was more obvious.

scholarly journals Dispersive Surface Energy and Acid-Base Parameters of Tosylate Functionalized Poly(ethylene glycol) via Inverse Gas Chromatography

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Feyza Sesigur ◽  
Dolunay Sakar ◽  
Ozlem Yazici ◽  
Fatih Cakar ◽  
Ozlem Cankurtaran ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Free Energy ◽  
Ethylene Glycol ◽  
Inverse Gas Chromatography ◽  
Basic Medium ◽  
Poly Ethylene Glycol ◽  
Dispersive Component ◽  
Dispersive Surface Energy ◽  
Base Parameters ◽  
Poly Ethylene

An inverse gas chromatographic (IGC) study of the sorption properties of poly(ethylene glycol) modified with tosylate (PEG-TOS) was presented. PEG-TOS was synthesized via the tosylation of the corresponding poly(ethylene glycol) (PEG) withp-toluenesulfonyl chloride in the basic medium. The synthesized PEG-Tos was characterized by FTIR-ATR and1HNMR techniques. The retention diagrams of n-hexane, n-heptane, n-octane, n-nonane, n-decane, dichloromethane, chloroform, acetone, tetrahydrofuran, ethyl acetate, and ethanol on the PEG and PEG-Tos were plotted at temperatures in K between 303 and 373 by inverse gas chromatography technique. The dispersive component of the surface-free energy,γSD, of studied adsorbent surface was estimated using retention times of different nonpolar organics in the infinite dilution region. Thermodynamic parameters of adsorption (free energy,ΔGAS, enthalpy,ΔHAS, and entropy,ΔSAS), dispersive components of the surface energies,γSD, and the acid,KA, and base,KD, constants for the PEG and PEG-Tos were calculated and the results were discussed.

scholarly journals Intermolecular interactions between polyarylenephthalides surface and organic compounds of different nature by inverse gas chromatography data

2019 ◽  
Vol 19 (2) ◽  
pp. 229-236
Author(s):  
Vladimir Yu. Gus’kov ◽  
Yulia F. Shaihitdinova ◽  
Rufina A. Zilberg ◽  
Vladimir A. Kraikin ◽  
Valery N. Maistrenko
Keyword(s):  
Gas Chromatography ◽  
Free Energy ◽  
Intermolecular Interactions ◽  
Inverse Gas Chromatography ◽  
Stationary Phases ◽  
Polymeric Materials ◽  
Silica Gels ◽  
Linear Free Energy Relationship ◽  
Free Energy Of Adsorption ◽  
Chromatography Method

     Polyarylenephthalides are a promising class of polymeric materials. They are soluble in organic solvents, but remain resistant to water, as well as to acids and bases. All this makes polyarylenphthalide promising materials for the formation of films on surfaces. However, for this it is necessary to first study the ability of polyarylenephthalides to different intermolecular interactions, as well as the polarity of their surface.Therefore, it is of interest to use the inverse gas chromatography method for studying the adsorption properties of the surface of  polyarylenephthalates, as well as the evaluation of its conditional polarity.      Two polymers of the class of polyarylenephthalides were used as the studied samples: chlorinated (in position 4) poly  phthalidylidenefluorene) (OPS-236) and poly (phthalidylidene diphenyl) (PE-259). They are distinguished by the presence of a methylene group between two benzene rings. Inert solid support Chromaton NAW was used as a solid substrate for the deposition of polyarylenphthalide films. The application was carried out from chloroform by evaporation of the solvent at a temperature of 40 ° C. The amount of the applied polymer was 1% by weight of the inert carrier.      The study was conducted by the method of inverse gas chromatography. Samples were introduced as diluted vapor-air mixtures at the limit of the detector sensitivity. This made it possible to measure the retention parameters in the Henry region and consider the interactions between sorbate molecules to be negligible. The relative conditional polarity of the surface and the contributions of various intermolecular interactionsto adsorption free energy were estimated by the method of linear free energy relationship (LFER). From the obtained LFER-coefficients, the contributions of intermolecular interactions to the adsorption energy were calculated, and the relative conditional polarity of the surface was also estimated. The dispersion and specific component of the Helmholtz free energy of adsorption was calculated by the Dong method.        It has been established that adsorbents based on polyarylenephthalides are able to act as stationary phases for chromatography. It is shown that polyarylenephthalide films are capable of both dispersion and various specific interactions with organic molecules. The surface of polyarylenephthalides can be attributed to stationary phases of medium polarity, more polar than porous polymers based on styrene and divinylbenzene and less polar than silica gels.

Surface Properties of Magnesium-Aluminium Hydrotalcite-Like Compound Characterized by Inverse Gas Chromatography

2019 ◽  
Vol 1152 ◽  
pp. 1-8
Author(s):  
Liang Qin Zhou ◽  
Dong Yuan ◽  
Xing Wen Zheng ◽  
Jin Long Fan ◽  
Cheng Qian
Keyword(s):  
Gas Chromatography ◽  
Surface Properties ◽  
Inverse Gas Chromatography ◽  
Retention Volume ◽  
X Ray Diffraction ◽  
Straight Chain ◽  
Free Energy Of Adsorption ◽  
Dispersive Component ◽  
X Ray ◽  
Acid And Base

In this paper, the Mg-Al hydrotalcite-like compound (Mg-Al-HTLC) was synthesized by hydrothermal method at 373K. Structure and morphology of Mg-Al-HTLC was obtained with X-ray diffraction (XRD), scanning electron microscope (SEM) and Fourier transform infra-red spectroscopy(FTIR). A series of polar and non-polar molecules were used for probes, surface properties of Mg-Al-HTLC was studied by inverse gas chromatography (IGC) at 353K, 363K, 373K, 383K respectively. The retention volume was utilized for evaluating the free energy of adsorption (-ΔGSP), the dispersive component of the surface energy(γsD), as well as the enthalpy and entropic component(ΔHSP, -ΔSSP). XRD results reveal that the Mg-Al-HTLC has high crystallinity and perfect layered structure. The results of IGC show that Mg-Al-HTLC would adsorb straight-chain alkanes spontaneously, and the values of γsDwere similar at all temperature. It reveals Mg-Al-HTLC is a material with particular characteristics of both acid and base. This study illustrates that, as a method to evaluate the surface properties of material , IGC method is dependable and significant.

scholarly journals New approach to determine the surface and interface thermodynamic properties of H-β-zeolite/rhodium catalysts by inverse gas chromatography at infinite dilution

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tayssir Hamieh ◽  
Ali Ali Ahmad ◽  
Thibault Roques-Carmes ◽  
Joumana Toufaily
Keyword(s):  
Gas Chromatography ◽  
Linear Regression ◽  
Surface Energy ◽  
Infinite Dilution ◽  
Inverse Gas Chromatography ◽  
Acid Base ◽  
Dispersive Component ◽  
Β Zeolite ◽  
Gamma S

AbstractThe thermodynamic surface properties and Lewis acid–base constants of H-β-zeolite supported rhodium catalysts were determined by using the inverse gas chromatography technique at infinite dilution. The effect of the temperature and the rhodium percentage supported by zeolite on the acid base properties in Lewis terms of the various catalysts were studied. The dispersive component of the surface energy of Rh/H-β-zeolite was calculated by using both the Dorris and Gray method and the straight-line method. We highlighted the role of the surface areas of n-alkanes on the determination of the surface energy of catalysts. To this aim various molecular models of n-alkanes were tested, namely Kiselev, cylindrical, Van der Waals, Redlich–Kwong, geometric and spherical models. An important deviation in the values of the dispersive component of the surface energy $${\gamma }_{s}^{d}$$ γ s d determined by the classical and new methods was emphasized. A non-linear dependency of $${\gamma }_{s}^{d}$$ γ s d with the specific surface area of catalysts was highlighted showing a local maximum at 1%Rh. The study of RTlnVn and the specific free energy ∆Gsp(T) of n-alkanes and polar solvents adsorbed on the various catalysts revealed the important change in the acid properties of catalysts with both the temperature and the rhodium percentage. The results proved strong amphoteric behavior of all catalysts of the rhodium supported by H-β-zeolite that actively react with the amphoteric solvents (methanol, acetone, tri-CE and tetra-CE), acid (chloroform) and base (ether) molecules. It was shown that the Guttmann method generally used to determine the acid base constants KA and KD revealed some irregularities with a linear regression coefficient not very satisfactory. The accurate determination of the acid–base constants KA, KD and K of the various catalysts was obtained by applying Hamieh’s model (linear regression coefficients approaching r2 ≈ 1.000). It was proved that all acid base constants determined by this model strongly depends on the rhodium percentage and the specific surface area of the catalysts.

Determination of the Polar and Total Surface Energy Distributions of Particulates by Inverse Gas Chromatography

Langmuir ◽  
2011 ◽  
Vol 27 (2) ◽  
pp. 521-523 ◽  
Author(s):  
Shyamal C. Das ◽  
Ian Larson ◽  
David A. V. Morton ◽  
Peter J. Stewart
Keyword(s):  
Gas Chromatography ◽  
Surface Energy ◽  
Inverse Gas Chromatography ◽  
Total Surface Energy ◽  
Energy Distributions
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