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Margareta Gref - One of the best experts on this subject based on the ideXlab platform.

Ping Yin - One of the best experts on this subject based on the ideXlab platform.

  • adsorption of hg ii from an aqueous solution by silica gel supported Diethylenetriamine prepared via different routes kinetics thermodynamics and isotherms
    Journal of Chemical & Engineering Data, 2010
    Co-Authors: Ying Zhang, Changmei Sun, Chunhua Wang, Hou Chen, Ping Yin
    Abstract:

    The kinetics, thermodynamics, and isotherms of Hg(II) ion adsorption onto silica-gel supported Diethylenetriamine adsorbents, SG-HE-dD, SG-HO-dD, SG-HE-pD, and SG-HO-pD (where SG means silica-gel; HE, heterogeneous; HO, homogeneous; d, direct; p, protection; and D, Diethylenetriamine), prepared by so-called heterogeneous-direct amination, homogeneous-direct amination, heterogeneous end-group protection, and homogeneous end-group protection methods, respectively, were investigated. The results showed that the adsorption processes of Hg(II) ions followed well a pseudofirst-order model onto SG-HE-dD, SG-HO-dD, and SG-HE-pD, while a pseudosecond-order model was followed onto SG-HO-pD. Film diffusion might be dominated in the adsorption process of Hg(II) ions onto the four adsorbents. Thermodynamic analysis revealed that the adsorption behaviors of Hg(II) ions onto the four adsorbents were endothermic processes, resulting in higher adsorption capacities at higher temperature. The Langmuir, Freundlich, and Redl...

  • chemical modification of silica gel with Diethylenetriamine via an end group protection approach for adsorption to hg ii
    Applied Surface Science, 2009
    Co-Authors: Ying Zhang, Changmei Sun, Chunhua Wang, Hou Chen, Ping Yin
    Abstract:

    Abstract Four kinds of silica-gel supported Diethylenetriamine adsorbents with different structures, were prepared by so-called “heterogeneous-direct-amination” (hetero-DA), “homogeneous-direct-amination” (homo-DA), “heterogeneous end-group protection” (hetero-EGP), and “homogeneous end-group protection” (homo-EGP) methods, respectively. The obtained products were named SG-HE-dD, SG-HO-dD, SG-HE-pD and SG-HO-pD, respectively (where SG means silica-gel; HE means heterogeneous, HO means homogeneous, d means direct, p means protected and D means Diethylenetriamine). Their structures were characterized by FT-IR, elemental analysis, porous structure analysis and thermogravimetric analysis. The adsorption capabilities of such adsorbents towards Hg(II) were studied and evaluated by static method. SG-HE-pD and SG-HO-pD showed higher performance towards Hg(II) adsorption than corresponding counterparts SG-HE-dD and SG-HO-dD, even though the former two possessed lower contents of Diethylenetriamine (DETA). The kinetics data indicated that the adsorption process was governed by the film diffusion and followed pseudo-first-order rate model for SG-HE-dD, SG-HO-dD and SG-HE-pD and pseudo-second-order model for SG-HO-pD. The Langmuir model was applied to fit the experimental equilibrium data for all adsorbents. The end-group protection method exhibited its advantage in preparation of effective adsorbent for metal ions uptake compared to the direct-amination method.

Peter R Zalupski - One of the best experts on this subject based on the ideXlab platform.

  • coordination chemistry and f element complexation by Diethylenetriamine n n bis acetylglycine n n n triacetic acid
    Inorganic Chemistry, 2016
    Co-Authors: Colt R Heathman, Travis S. Grimes, Peter R Zalupski
    Abstract:

    Potentiometric and spectroscopic techniques were used to evaluate the coordination behavior and thermodynamic features of trivalent f-element complexation by Diethylenetriamine-N,N″-bis(acetylglycine)-N,N′,N″-triacetic acid (DTTA-DAG) and its di(acetylglycine ethyl ester) analogue [Diethylenetriamine-N,N″-bis(acetylglycine ethyl ester)-N,N′,N″-triacetic acid (DTTA-DAGEE)]. Protonation constants and stability constants of trivalent lanthanide complexes (except Pm3+) were determined by potentiometry. Six protonation sites and three metal–ligand complexes [ML2–, MHL–, and MH2L(aq)] were quantified for DTTA-DAG. Four protonation sites and one metal–ligand complex [ML(aq)] were observed for DTTA-DAGEE, consistent with the presence of two ester groups. Absorption spectroscopy was utilized to measure the stability constants for complexation of trivalent neodymium and americium by DTTA-DAG and trivalent neodymium by DTTA-DAGEE. The coordination environment of trivalent europium in the presence of DTTA-DAG was inv...

  • Coordination Chemistry and f-Element Complexation by Diethylenetriamine-N,N″-bis(acetylglycine)-N,N′,N″-triacetic Acid
    Inorganic Chemistry, 2016
    Co-Authors: Colt R Heathman, Travis S. Grimes, Peter R Zalupski
    Abstract:

    Potentiometric and spectroscopic techniques were used to evaluate the coordination behavior and thermodynamic features of trivalent f-element complexation by Diethylenetriamine-N,N″-bis(acetylglycine)-N,N′,N″-triacetic acid (DTTA-DAG) and its di(acetylglycine ethyl ester) analogue [Diethylenetriamine-N,N″-bis(acetylglycine ethyl ester)-N,N′,N″-triacetic acid (DTTA-DAGEE)]. Protonation constants and stability constants of trivalent lanthanide complexes (except Pm3+) were determined by potentiometry. Six protonation sites and three metal–ligand complexes [ML2–, MHL–, and MH2L(aq)] were quantified for DTTA-DAG. Four protonation sites and one metal–ligand complex [ML(aq)] were observed for DTTA-DAGEE, consistent with the presence of two ester groups. Absorption spectroscopy was utilized to measure the stability constants for complexation of trivalent neodymium and americium by DTTA-DAG and trivalent neodymium by DTTA-DAGEE. The coordination environment of trivalent europium in the presence of DTTA-DAG was inv...

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

  • synthesis characterization and structure effects on selectivity properties of silica gel covalently bonded Diethylenetriamine mono and bis salicyaldehyde and naphthaldehyde schiff s bases towards some heavy metal ions
    Talanta, 2001
    Co-Authors: Ezzat M Soliman, Mohamed E Mahmoud, Salwa A Ahmed
    Abstract:

    Four silica gel-immobilized new metal chelate Schiff(,)s bases were synthesized (I-IV). Silica gel chemically bonded Diethylenetriamine mono-naphthaldehyde and mono-salicyaldehyde Schiff's bases (phases I and III) were produced via the interaction of silica gel-modified Diethylenetriamine with naphthaldehyde and salicylaldehyde, respectively. However, phases II and IV arose through the interaction of bis-naphthaldehyde and bis-salicylaldehyde Schiff(,)s bases of Diethylenetriamine with 3-chloropropyltrimethoxysilane modified silica gel. The characterization of such new phases, their capabilities towards selective extraction or separation of Fe(III), Ni(II), Cu(II), Zn(II), Cd(II) and Pb(II) ions were studied and evaluated by both batch and column techniques as a function of pH and time of contact. Phases III and I showed high performance towards Cu(II) extraction, where their Cu(II) sorption determined to be 0.957 and 0.940 mmol g(-1), respectively. However, for phases IV and II, the great affinity was devoted to Fe(III) extraction followed by Cu(II) ions. The reactivity of metal ion sorption was discussed in the light of effects of bulkiness as well as orientation of immobilized chelate on sorbent reactivity. Donor sites of phases III and I (Diethylenetriamine and azomethene nitrogens along with phenolic hydroxyl group oxygen) are fully active, whereas phases IV and II are partially active with only participation of oxygen and azomethene nitrogen. The order of increasing thermal stability (IV

Ying Zhang - One of the best experts on this subject based on the ideXlab platform.

  • adsorption of hg ii from an aqueous solution by silica gel supported Diethylenetriamine prepared via different routes kinetics thermodynamics and isotherms
    Journal of Chemical & Engineering Data, 2010
    Co-Authors: Ying Zhang, Changmei Sun, Chunhua Wang, Hou Chen, Ping Yin
    Abstract:

    The kinetics, thermodynamics, and isotherms of Hg(II) ion adsorption onto silica-gel supported Diethylenetriamine adsorbents, SG-HE-dD, SG-HO-dD, SG-HE-pD, and SG-HO-pD (where SG means silica-gel; HE, heterogeneous; HO, homogeneous; d, direct; p, protection; and D, Diethylenetriamine), prepared by so-called heterogeneous-direct amination, homogeneous-direct amination, heterogeneous end-group protection, and homogeneous end-group protection methods, respectively, were investigated. The results showed that the adsorption processes of Hg(II) ions followed well a pseudofirst-order model onto SG-HE-dD, SG-HO-dD, and SG-HE-pD, while a pseudosecond-order model was followed onto SG-HO-pD. Film diffusion might be dominated in the adsorption process of Hg(II) ions onto the four adsorbents. Thermodynamic analysis revealed that the adsorption behaviors of Hg(II) ions onto the four adsorbents were endothermic processes, resulting in higher adsorption capacities at higher temperature. The Langmuir, Freundlich, and Redl...

  • chemical modification of silica gel with Diethylenetriamine via an end group protection approach for adsorption to hg ii
    Applied Surface Science, 2009
    Co-Authors: Ying Zhang, Changmei Sun, Chunhua Wang, Hou Chen, Ping Yin
    Abstract:

    Abstract Four kinds of silica-gel supported Diethylenetriamine adsorbents with different structures, were prepared by so-called “heterogeneous-direct-amination” (hetero-DA), “homogeneous-direct-amination” (homo-DA), “heterogeneous end-group protection” (hetero-EGP), and “homogeneous end-group protection” (homo-EGP) methods, respectively. The obtained products were named SG-HE-dD, SG-HO-dD, SG-HE-pD and SG-HO-pD, respectively (where SG means silica-gel; HE means heterogeneous, HO means homogeneous, d means direct, p means protected and D means Diethylenetriamine). Their structures were characterized by FT-IR, elemental analysis, porous structure analysis and thermogravimetric analysis. The adsorption capabilities of such adsorbents towards Hg(II) were studied and evaluated by static method. SG-HE-pD and SG-HO-pD showed higher performance towards Hg(II) adsorption than corresponding counterparts SG-HE-dD and SG-HO-dD, even though the former two possessed lower contents of Diethylenetriamine (DETA). The kinetics data indicated that the adsorption process was governed by the film diffusion and followed pseudo-first-order rate model for SG-HE-dD, SG-HO-dD and SG-HE-pD and pseudo-second-order model for SG-HO-pD. The Langmuir model was applied to fit the experimental equilibrium data for all adsorbents. The end-group protection method exhibited its advantage in preparation of effective adsorbent for metal ions uptake compared to the direct-amination method.