Effect of complexing ligands on the adsorption of Cu(II) onto the silica gel surface. 1: Adsorption of ligands
- Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of)
- Korea Atomic Energy Research Inst., Taejon (Korea, Republic of)
The adsorption of several ligands on silica gel was investigated in aqueous solutions. The ligands used were 2,2{prime},6{prime},2{double_prime}-terpyridine, pyridine, 3,4-lutidine, 2-aminomethyl pyridine, 2-pyridine methanol, picolinic acid, salicylic acid, and 5-sulfosalicylic acid. The adsorption behaviors of these ligands were interpreted by means of three adsorption modes: ion exchange, hydrogen bonding, and hydrophobic interaction. For 2,2{prime},6{prime},2{double_prime}-terpyridine, pyridine, and 3,4-lutidine, the adsorption maxima appeared near their respective pK{sub a} values and were found to be due mainly to ion exchange, whereas the adsorption of these ligands at low pH was strongly attributed to hydrophobic interaction. The adsorption of 2-aminomethyl pyridine increased with increasing pH over the entire pH range investigated and was due mainly to ion exchange. Picolinic acid was adsorbed mainly by hydrogen bonding either via pyridine N atoms at low pH or via carboxylic O atoms at high pH. 2-Pyridine methanol was adsorbed by hydrophobic interaction at low pH and by hydrogen bonding at high pH. The adsorptions of salicylic and 5-sulfosalicylic acid were very small over the entire pH ranges investigated. For the adsorption mechanism, the Stern model was used to fit adsorption data.
- OSTI ID:
- 63214
- Journal Information:
- Journal of Colloid and Interface Science, Journal Name: Journal of Colloid and Interface Science Journal Issue: 1 Vol. 171; ISSN 0021-9797; ISSN JCISA5
- Country of Publication:
- United States
- Language:
- English
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