Chemisorption of divalent cations onN-(2-pyridyl)acetamide immobilized on silica gel — a thermodynamic study

摘要: Abstract N-(2-Pyridyl)acetamide covalently immobilized on silica gel (“≡Si-pa”) has a great ability to chemisorb cations from propanonic or ethanolic solutions through the amount of substance divided by mass 1.57.10−4mol·g−1of bidentate groups attached this inorganic support. The chemisorption isotherms obtained with MCl2(M: Ni, Co, Cu, Zn, Cd, Hg) in each solvent are similar and adjustable modified Langmuir equation. sequence maximum capacity is Cu > Co Zn propanone Hg Cd Ni ethanol. enthalpies “≡Si-pa” atT= (298.15 ± 0.02) K showed larger values With exception cobalt {ΔHm= + (6.12 0.01) kJ·mol−1} propanone, all other cation-surface interactions enthalpically favourable both solvents. enthalpic complete series was found standard molar Gibbs free energies agreement spontaneity proposed reactions between cation basic centre, which contribution these chelating processes.