Title of article :
Chemical modification of silica-gel with diethylenetriamine via an end-group protection approach for adsorption to Hg(II)
Author/Authors :
Ying Zhang، نويسنده , , Rongjun Qu، نويسنده , , Changmei Sun، نويسنده , , Chunhua Wang، نويسنده , , Chunnuan Ji، نويسنده , , Hou Chen، نويسنده , , Ping Yin، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2009
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.
Keywords :
Chemical modification of silica-gel , Diethylenetriamine , End-group protection , Hg(II) , Adsorption
Journal title :
Applied Surface Science
Journal title :
Applied Surface Science