The sol-gel technique to prepare calix[6]crown-containing organosilicon resins and their adsorption properties towards metal ions

Two organosilicon resins (PCA[6]C4 and PCA[6]C4-TAE) were prepared from p-tert-butylcalix[6]-1,4-crown-4 (CA[6]C4) via condensation with 3-glycidoxypropyltrimethoxysilane (KH560) or reacting its derivative p-tert.-butylcalix[6]-14-crown-4 tetraethylacetates (CA[6]C4-TAE) with gamma-aminopropyl-triethoxysilane (KH550), followed by copolymerization with tetraethoxysilane via the sol-gel process, respectively. The adsorption capacity of PCA[6]C4 and PCA[6]C4-TAE toward alkali metal ions (Li+, Na+, and K+), transition metal and heavy metal ions (Ni2+, Co2+, Cu2+, Pb2+, Ag+, and Hg2+) were determined and the thermodynamic and dynamic parameters of the resins toward H was deduced. (C) 2002 Elsevier Science B.V. All rights reserved.