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Abdelkader Bengueddach - One of the best experts on this subject based on the ideXlab platform.

  • Kinetics and thermodynamics adsorption of phenolic compounds on organic-inorganic hybrid Mesoporous Material
    International Journal of Innovation and Applied Studies, 2013
    Co-Authors: Mourad Makhlouf, Rachida Hamacha, Frédéric Villiéras, Abdelkader Bengueddach
    Abstract:

    The objective of this work is thus to study the kinetics, thermodynamics and adsorption isotherms of two phenolic compounds phenol (PhOH) and P-hydroxy benzoic acid (4AHB) on a Mesoporous Material Type MCM- 48 functionalized with an organosilane Type trimethylchlorosilane (TMCS) (MCM-48-G). At first, the study of the kinetics, thermodynamics and adsorption isotherms of phenolic compounds in each single solution was performed. In a second step, a similar study was performed on a mixture of these two molecules. Several kinetic models (pseudo-first order, pseudo-second order) were used to determine the kinetic parameters of adsorption. Several adsorption models (Langmuir, Freundlich) were also used to determine the thermodynamic parameters of adsorption isotherms. The effect of three-dimensional pores of MCM-48 and comparison of adsorption of PhOH and 4AHB was examined. It was found that MCM-48-G to a significant adsorption capacity for PhOH and 4AHB, this may be related to the hydrophobicity created by the organic function of TMCS in the MCM-48-G.The results of adsorption and PhOH 4AHB were analyzed using the Freundlich and Langmuir models. It was observed that the adsorption of 4AHB was higher than PhOH. Thermodynamics of adsorption showed that the values obtained for our sample confirm well the interactions with phenol and 4AHB are physical in nature. The adsorption of pollutants on our MCM-48 (G) is a spontaneous and exothermic process.

  • cumene cracking on modified Mesoporous Material Type mcm 41
    Turkish Journal of Chemistry, 2006
    Co-Authors: Ahmed Belhakem, Abdelkader Bengueddach
    Abstract:

    The effect of ionic exchange degree of H(X)-AlMCM-41 Materials, the method of its exchange and its grain form were investigated for Mesoporous catalytic activity in the cumene cracking reaction. Benzene, propylene and xylene derivatives are the main products of this reaction. Olefins like butene and pentene appeared as the products of secondary reactions. No saturated hydrocarbons, which are typical products of secondary reactions obtained with HNaY zeolites, were formed, except for traces of butane. Generally the exchanged H(X)-AlMCM-41 Materials by the substitution of Na+ by NH4+ are more active than those exchanged directly with acid solution (substitution of Na+ by H+) even if both the methods used exhibit a comparable content of acid sites within catalysts at a low exchange degree. However, the first method of exchange exhibited significant acidity for Mesoporous Materials when the ionic exchange degree was increased up to 90%. It was probably due not only to the percentage of exchanged degree but also to the distribution of acid sites within the Materials.

  • cumene cracking on modified Mesoporous Material Type mcm 41
    Bulletin of The Chemical Society of Ethiopia, 2006
    Co-Authors: Ahmed Belhakem, Abdelkader Bengueddach
    Abstract:

    The effect of ionic exchange degree of aluminated Mesoporous Materials H(X)-AlMCM-41 Materials, the method of its exchange mode and its grains form were investigated for the Mesoporous catalytic activity in the cumene (i.e. isopropylbenzene) cracking reaction. Benzene, propylene and xylene derivatives are the main products of this reaction. Olefins like butene and pentene appeared as the products of secondary reactions. No saturated hydrocarbons, except traces of butane, nor ethylbenzene and toluene were formed and seemed to be typical products of secondary reactions obtained with HNaY zeolites. Generally the exchanged H(X)-AlMCM-41 Materials by the substitution of Na + by NH 4 + are more active than those exchanged directly with acid solution (substitution of Na + by H + ) even if both the two methods used exhibit a comparable content of acid sites within catalysts at a low exchange degrees. However, the first method of exchange has exhibited an important acidity for Mesoporous Materials when the ionic exchange degree was increased up to 90%; it was probably due not only to the percentage of exchanged degree but also to the distribution of acid sites within the Materials. KEY WORDS : MCM-41 Mesoporous, Grains forms, Cumene cracking Bull. Chem. Soc. Ethiop. 2006 , 20(1), 89-97.

V. F. Selemenev - One of the best experts on this subject based on the ideXlab platform.

  • Studies on functionalized Mesoporous Materials—Part I: characterization of silylized Mesoporous Material of Type MCM-41
    Journal of Porous Materials, 2014
    Co-Authors: S. I. Karpov, F. Roessner, V. F. Selemenev
    Abstract:

    The synthesis of organic–inorganic composite Materials was performed by the surface modification of Mesoporous Material Type MCM-41 by chlorodimethylphenylsilane and dichloromethylphenylsilane. Applying IR spectroscopy, low temperature nitrogen adsorption/desorption (isotherms BET), thermogravimetric measurements and technique of competitive adsorption of toluene and water it was shown that the degree of silylation, hydrophobicity, surface and volume properties (pore size distribution, pore volume) strongly depends on the nature of silylation agent and the ratio of calculated amount of silanol groups to the modifier. Two Types of condensation reaction take place: (1) the reaction of the modifier with surface silanol groups, and (2) an inter-molecular condensation of the modifier, resulting in additional pore blocking. Only 24–36 % of the surface silanol groups react with modifier agent. The Materials are stable up to temperatures of about 170 °C that is higher than the corresponding polymeric resins. The TG/DTA data allowed concluding that the degree of grafting depends on the ratio silylation agent to SiOH groups. As shown by Fourier transform diffuse reflectance mode spectroscopy only free silanol groups react with modifier.

  • studies on functionalized Mesoporous Materials part i characterization of silylized Mesoporous Material of Type mcm 41
    Journal of Porous Materials, 2014
    Co-Authors: S. I. Karpov, F. Roessner, V. F. Selemenev
    Abstract:

    The synthesis of organic–inorganic composite Materials was performed by the surface modification of Mesoporous Material Type MCM-41 by chlorodimethylphenylsilane and dichloromethylphenylsilane. Applying IR spectroscopy, low temperature nitrogen adsorption/desorption (isotherms BET), thermogravimetric measurements and technique of competitive adsorption of toluene and water it was shown that the degree of silylation, hydrophobicity, surface and volume properties (pore size distribution, pore volume) strongly depends on the nature of silylation agent and the ratio of calculated amount of silanol groups to the modifier. Two Types of condensation reaction take place: (1) the reaction of the modifier with surface silanol groups, and (2) an inter-molecular condensation of the modifier, resulting in additional pore blocking. Only 24–36 % of the surface silanol groups react with modifier agent. The Materials are stable up to temperatures of about 170 °C that is higher than the corresponding polymeric resins. The TG/DTA data allowed concluding that the degree of grafting depends on the ratio silylation agent to SiOH groups. As shown by Fourier transform diffuse reflectance mode spectroscopy only free silanol groups react with modifier.

S. I. Karpov - One of the best experts on this subject based on the ideXlab platform.

  • Studies on functionalized Mesoporous Materials—Part I: characterization of silylized Mesoporous Material of Type MCM-41
    Journal of Porous Materials, 2014
    Co-Authors: S. I. Karpov, F. Roessner, V. F. Selemenev
    Abstract:

    The synthesis of organic–inorganic composite Materials was performed by the surface modification of Mesoporous Material Type MCM-41 by chlorodimethylphenylsilane and dichloromethylphenylsilane. Applying IR spectroscopy, low temperature nitrogen adsorption/desorption (isotherms BET), thermogravimetric measurements and technique of competitive adsorption of toluene and water it was shown that the degree of silylation, hydrophobicity, surface and volume properties (pore size distribution, pore volume) strongly depends on the nature of silylation agent and the ratio of calculated amount of silanol groups to the modifier. Two Types of condensation reaction take place: (1) the reaction of the modifier with surface silanol groups, and (2) an inter-molecular condensation of the modifier, resulting in additional pore blocking. Only 24–36 % of the surface silanol groups react with modifier agent. The Materials are stable up to temperatures of about 170 °C that is higher than the corresponding polymeric resins. The TG/DTA data allowed concluding that the degree of grafting depends on the ratio silylation agent to SiOH groups. As shown by Fourier transform diffuse reflectance mode spectroscopy only free silanol groups react with modifier.

  • studies on functionalized Mesoporous Materials part i characterization of silylized Mesoporous Material of Type mcm 41
    Journal of Porous Materials, 2014
    Co-Authors: S. I. Karpov, F. Roessner, V. F. Selemenev
    Abstract:

    The synthesis of organic–inorganic composite Materials was performed by the surface modification of Mesoporous Material Type MCM-41 by chlorodimethylphenylsilane and dichloromethylphenylsilane. Applying IR spectroscopy, low temperature nitrogen adsorption/desorption (isotherms BET), thermogravimetric measurements and technique of competitive adsorption of toluene and water it was shown that the degree of silylation, hydrophobicity, surface and volume properties (pore size distribution, pore volume) strongly depends on the nature of silylation agent and the ratio of calculated amount of silanol groups to the modifier. Two Types of condensation reaction take place: (1) the reaction of the modifier with surface silanol groups, and (2) an inter-molecular condensation of the modifier, resulting in additional pore blocking. Only 24–36 % of the surface silanol groups react with modifier agent. The Materials are stable up to temperatures of about 170 °C that is higher than the corresponding polymeric resins. The TG/DTA data allowed concluding that the degree of grafting depends on the ratio silylation agent to SiOH groups. As shown by Fourier transform diffuse reflectance mode spectroscopy only free silanol groups react with modifier.

Ahmed Belhakem - One of the best experts on this subject based on the ideXlab platform.

  • cumene cracking on modified Mesoporous Material Type mcm 41
    Turkish Journal of Chemistry, 2006
    Co-Authors: Ahmed Belhakem, Abdelkader Bengueddach
    Abstract:

    The effect of ionic exchange degree of H(X)-AlMCM-41 Materials, the method of its exchange and its grain form were investigated for Mesoporous catalytic activity in the cumene cracking reaction. Benzene, propylene and xylene derivatives are the main products of this reaction. Olefins like butene and pentene appeared as the products of secondary reactions. No saturated hydrocarbons, which are typical products of secondary reactions obtained with HNaY zeolites, were formed, except for traces of butane. Generally the exchanged H(X)-AlMCM-41 Materials by the substitution of Na+ by NH4+ are more active than those exchanged directly with acid solution (substitution of Na+ by H+) even if both the methods used exhibit a comparable content of acid sites within catalysts at a low exchange degree. However, the first method of exchange exhibited significant acidity for Mesoporous Materials when the ionic exchange degree was increased up to 90%. It was probably due not only to the percentage of exchanged degree but also to the distribution of acid sites within the Materials.

  • cumene cracking on modified Mesoporous Material Type mcm 41
    Bulletin of The Chemical Society of Ethiopia, 2006
    Co-Authors: Ahmed Belhakem, Abdelkader Bengueddach
    Abstract:

    The effect of ionic exchange degree of aluminated Mesoporous Materials H(X)-AlMCM-41 Materials, the method of its exchange mode and its grains form were investigated for the Mesoporous catalytic activity in the cumene (i.e. isopropylbenzene) cracking reaction. Benzene, propylene and xylene derivatives are the main products of this reaction. Olefins like butene and pentene appeared as the products of secondary reactions. No saturated hydrocarbons, except traces of butane, nor ethylbenzene and toluene were formed and seemed to be typical products of secondary reactions obtained with HNaY zeolites. Generally the exchanged H(X)-AlMCM-41 Materials by the substitution of Na + by NH 4 + are more active than those exchanged directly with acid solution (substitution of Na + by H + ) even if both the two methods used exhibit a comparable content of acid sites within catalysts at a low exchange degrees. However, the first method of exchange has exhibited an important acidity for Mesoporous Materials when the ionic exchange degree was increased up to 90%; it was probably due not only to the percentage of exchanged degree but also to the distribution of acid sites within the Materials. KEY WORDS : MCM-41 Mesoporous, Grains forms, Cumene cracking Bull. Chem. Soc. Ethiop. 2006 , 20(1), 89-97.

F. Roessner - One of the best experts on this subject based on the ideXlab platform.

  • Studies on functionalized Mesoporous Materials—Part I: characterization of silylized Mesoporous Material of Type MCM-41
    Journal of Porous Materials, 2014
    Co-Authors: S. I. Karpov, F. Roessner, V. F. Selemenev
    Abstract:

    The synthesis of organic–inorganic composite Materials was performed by the surface modification of Mesoporous Material Type MCM-41 by chlorodimethylphenylsilane and dichloromethylphenylsilane. Applying IR spectroscopy, low temperature nitrogen adsorption/desorption (isotherms BET), thermogravimetric measurements and technique of competitive adsorption of toluene and water it was shown that the degree of silylation, hydrophobicity, surface and volume properties (pore size distribution, pore volume) strongly depends on the nature of silylation agent and the ratio of calculated amount of silanol groups to the modifier. Two Types of condensation reaction take place: (1) the reaction of the modifier with surface silanol groups, and (2) an inter-molecular condensation of the modifier, resulting in additional pore blocking. Only 24–36 % of the surface silanol groups react with modifier agent. The Materials are stable up to temperatures of about 170 °C that is higher than the corresponding polymeric resins. The TG/DTA data allowed concluding that the degree of grafting depends on the ratio silylation agent to SiOH groups. As shown by Fourier transform diffuse reflectance mode spectroscopy only free silanol groups react with modifier.

  • studies on functionalized Mesoporous Materials part i characterization of silylized Mesoporous Material of Type mcm 41
    Journal of Porous Materials, 2014
    Co-Authors: S. I. Karpov, F. Roessner, V. F. Selemenev
    Abstract:

    The synthesis of organic–inorganic composite Materials was performed by the surface modification of Mesoporous Material Type MCM-41 by chlorodimethylphenylsilane and dichloromethylphenylsilane. Applying IR spectroscopy, low temperature nitrogen adsorption/desorption (isotherms BET), thermogravimetric measurements and technique of competitive adsorption of toluene and water it was shown that the degree of silylation, hydrophobicity, surface and volume properties (pore size distribution, pore volume) strongly depends on the nature of silylation agent and the ratio of calculated amount of silanol groups to the modifier. Two Types of condensation reaction take place: (1) the reaction of the modifier with surface silanol groups, and (2) an inter-molecular condensation of the modifier, resulting in additional pore blocking. Only 24–36 % of the surface silanol groups react with modifier agent. The Materials are stable up to temperatures of about 170 °C that is higher than the corresponding polymeric resins. The TG/DTA data allowed concluding that the degree of grafting depends on the ratio silylation agent to SiOH groups. As shown by Fourier transform diffuse reflectance mode spectroscopy only free silanol groups react with modifier.