Na4EDTA and EDTA were adopted as new additives to intensify the seeded precipitation process of sodium aluminate solution. The effects of the two additives at certain concentrations on the seeded precipitation rate of...Na4EDTA and EDTA were adopted as new additives to intensify the seeded precipitation process of sodium aluminate solution. The effects of the two additives at certain concentrations on the seeded precipitation rate of sodium aluminate solution, particle size distribution (PSD) and morphology of precipitated gibbsite were investigated using titration method, particle size analyzer and scanning electron microscope (SEM), respectively. The results show that the two additives can accelerate the seeded precipitation rate of sodium aluminate solution. At relatively high concentration, the facilitative effect of EDTA on sodium aluminate solution is more obvious than that of Na4EDTA. EDTA makes gibbsite particles thinner than Na4EDTA. The Na+ and H+ result in the different effects on the seeded precipitation rate of sodium aluminate solution in spite of the same EDTA anion in the two additives.展开更多
The reaction of the ligands,ethylenediaminetetraacetic acid terasodium salt(Na 4EDTA)and N—N heterocyclic diamines like2,2’-bipyridine(bipy)with iron(Ⅱ)sulfate with 1∶2∶2 stoichiometric ratios form the mononuclea...The reaction of the ligands,ethylenediaminetetraacetic acid terasodium salt(Na 4EDTA)and N—N heterocyclic diamines like2,2’-bipyridine(bipy)with iron(Ⅱ)sulfate with 1∶2∶2 stoichiometric ratios form the mononuclear ternary complex of formulae,[Fe_(2)(EDTA)(bipy)2]at pH~7.The FTIR and Raman laser spectra of the iron(Ⅱ)complex show that 2,2’-bipyridine is present asa bidentate ligand and the ethylenediaminetetraacetic acid terasodium salt as monodentate carboxylate anion.The electronic spectra and magnetic moments data suggest the six coordination number.It has two iron(Ⅱ)centers in octahedral environments,which are interlinked by carboxylato-O atoms of ethylenediaminetetraacetate and by nitrogen atoms of the two 2,2-bipyridine ligands in a chelating mode.Thermal analysis study show thatiron(Ⅱ)complex containing EDTA and 2,2’-bipyridine on its thermalde composition form the corresponding Fe_(2)O_(3) oxide in nano size at the temperature range~475℃.The iron(Ⅱ)complex was performed as a convenient low cost precursor for the preparation of Fe_(2)O_(3) nanoparticles by the the thermal decomposition method.The iron(Ⅲ)oxide composition has been discussedusing FTIR,X-ray diffraction(XRD),transmission electron microscopy(TEM)and energy-dispersive X-ray spectroscopy(EDX).展开更多
基金Project(20476107) supported by the National Natural Science Foundation of ChinaProject(2005CB623702) supported by the National Basic Research Program of China
文摘Na4EDTA and EDTA were adopted as new additives to intensify the seeded precipitation process of sodium aluminate solution. The effects of the two additives at certain concentrations on the seeded precipitation rate of sodium aluminate solution, particle size distribution (PSD) and morphology of precipitated gibbsite were investigated using titration method, particle size analyzer and scanning electron microscope (SEM), respectively. The results show that the two additives can accelerate the seeded precipitation rate of sodium aluminate solution. At relatively high concentration, the facilitative effect of EDTA on sodium aluminate solution is more obvious than that of Na4EDTA. EDTA makes gibbsite particles thinner than Na4EDTA. The Na+ and H+ result in the different effects on the seeded precipitation rate of sodium aluminate solution in spite of the same EDTA anion in the two additives.
基金Taif University Researches Supporting Project number(TURSP-2020/241),Taif University,Taif,Saudi Arabia。
文摘The reaction of the ligands,ethylenediaminetetraacetic acid terasodium salt(Na 4EDTA)and N—N heterocyclic diamines like2,2’-bipyridine(bipy)with iron(Ⅱ)sulfate with 1∶2∶2 stoichiometric ratios form the mononuclear ternary complex of formulae,[Fe_(2)(EDTA)(bipy)2]at pH~7.The FTIR and Raman laser spectra of the iron(Ⅱ)complex show that 2,2’-bipyridine is present asa bidentate ligand and the ethylenediaminetetraacetic acid terasodium salt as monodentate carboxylate anion.The electronic spectra and magnetic moments data suggest the six coordination number.It has two iron(Ⅱ)centers in octahedral environments,which are interlinked by carboxylato-O atoms of ethylenediaminetetraacetate and by nitrogen atoms of the two 2,2-bipyridine ligands in a chelating mode.Thermal analysis study show thatiron(Ⅱ)complex containing EDTA and 2,2’-bipyridine on its thermalde composition form the corresponding Fe_(2)O_(3) oxide in nano size at the temperature range~475℃.The iron(Ⅱ)complex was performed as a convenient low cost precursor for the preparation of Fe_(2)O_(3) nanoparticles by the the thermal decomposition method.The iron(Ⅲ)oxide composition has been discussedusing FTIR,X-ray diffraction(XRD),transmission electron microscopy(TEM)and energy-dispersive X-ray spectroscopy(EDX).
