Hydrophobic effects of o-phenanthroline and 2,2[prime]-bipyridine on adsorption of metal (II) ions onto silica gel surface

Journal Article · Fri Oct 15 00:00:00 EDT 1993 · Journal of Colloid and Interface Science; (United States)

DOI:https://doi.org/10.1006/jcis.1993.1403· OSTI ID:5700539

Park, Yeong Jae; Jung, Kyung Hoon ^[1]; Park, Kyoung Kyun; Eom, Tae Yoon ^[2]

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1. Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of). Center for Molecular Science and Dept. of Chemistry
2. Korea Atomic Energy Research Inst., Taejon (Korea, Republic of)

The effects of o-phenanthroline and 2,2[prime]-bipyridine on the adsorption of metal (11) (Fe, Co, Ni and Cu) ions onto silica gel surface have been studied. The adsorption is expressed in terms of the measured concentrations of both metal and ligand at equilibrium. Each adsorption of the four metal ions is increased with the presence of the ligands. In addition, adsorption increases slowly with pH at low pH values and then increases rapidly up to near the pK[sub a] value of silica gel ([double bond]6.5). The adsorption of each metal ion at low pH is increased with increased ligand concentration. However, at high pH the adsorptions of Fe(II) and Cu(II) are decreased with increased ligand concentration whereas the adsorptions of Co(II) and Ni(II) are always increased. At low pH values the ligand to metal ratio adsorbed on the silica gel surface is ca. 3:1 while at high pH values it is 1:1, 2:1, and 3:1, corresponding to the initial ligand to metal ion concentration ratio. The addition of ethanol to the phenanthroline-SiO[sub 2] solution results in a decrease in the adsorption of phenanthroline. The effect of ethanol is also observed in the Fe(II)-phenanthroline-SiO[sub 2] system. The behavior of the adsorption is interpreted qualitatively by hydrophobic expulsion, the formation of surface complexes, and electrostatic interaction. It is concluded that hydrophobic expulsion plays an important role in the adsorption of metal ions in the presence of hydrophobic ligands on silica gel surface.

• OSTI ID: 5700539
• Journal Information: Journal of Colloid and Interface Science; (United States), Vol. 160:2; ISSN 0021-9797
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
BIPYRIDINES
CATALYTIC EFFECTS
COBALT
ADSORPTION
COPPER
IRON
NICKEL
PHENANTHROLINE-ORTHO
SILICA GEL
SORPTIVE PROPERTIES
ENVIRONMENTAL TRANSPORT
ETHANOL
PH VALUE
SURFACE PROPERTIES
ADSORBENTS
ALCOHOLS
AROMATICS
AZAARENES
AZINES
ELEMENTS
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
MASS TRANSFER
METALS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHENANTHROLINES
PYRIDINES
REAGENTS
SORPTION
TRANSITION ELEMENTS
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