title: Comparison of synthesis of chelating resin silica-gel-supported diethylenetriamine and its removal properties for transition metal ions.
abstract: Four kinds of silica-gel (SG)-supported diethylenetriamine (DETA) chelating resins SG-DETA-1, SG-DETA-2, SG-DETA-3, and SG-DETA-4 were prepared by functionalization of silica-gel via 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) routes, respectively. These functionalized reactions on silica-gel were confirmed through elemental analysis, infrared spectroscopy, X-ray diffractometry, porous analysis, and thermogravimetry. Element analysis revealed that the direct-amination routes and homogeneous condition were more beneficial than the corresponding end-group protection routes and heterogeneous condition to the syntheses of chelating resins with high N content. Several metal ions, such as Ag(+), Cu(2+), Ni(2+), Hg(2+), Zn(2+) and Pb(2+), were chosen as representatives to investigate the relationship between adsorption capacities and N content of ligands onto the surface of silica-gel. The experiments results showed that all resins, SG-DETA-1, SG-DETA-2, SG-DETA-3 and SG-DETA-4, had a better adsorption for Hg(2+) and Cu(2+) than others. One conclusion should be drawn from the above compared experiments, that is, higher N content of silica-gel resins does not ensure a higher utilization ratio of N.
authors: School of Chemistry and Materials Science, Ludong University, Yantai 264025, China.
authors: Ying
authors: Y
authors: Zhang
authors: Rongjun
authors: R
authors: Qu
authors: Changmei
authors: C
authors: Sun
authors: Hou
authors: H
authors: Chen
authors: Chunhua
authors: C
authors: Wang
authors: Chunnuan
authors: C
authors: Ji
authors: Ping
authors: P
authors: Yin
authors: Yufang
authors: Y
authors: Sun
authors: Huabin
authors: H
authors: Zhang
authors: Yuzhong
authors: Y
authors: Niu
mesh_terms: D002614:Chelating Agents / Q000138:chemical synthesis* / Q000737:chemistry; D007477:Ions; D019216:Metals, Heavy / Q000737:chemistry* / Q000302:isolation & purification*; D015394:Molecular Structure; D011073:Polyamines / Q000138:chemical synthesis* / Q000737:chemistry; D016062:Porosity; D058428:Silica Gel; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D002614:Chelating Agents; D007477:Ions; D019216:Metals, Heavy; D011073:Polyamines; C005391:diethylenetriamine; D058428:Silica Gel; D012822:Silicon Dioxide