Rifi E H, Rastegar F, Brunette J P
Laboratoire de Chimie Minerale et Analytique, E.H.I.C.S., C.N.R.S. URA 405, 1 Rue Blaise Pascal, Strasbourg Cedex, France.
Talanta. 1995 Jun;42(6):811-6. doi: 10.1016/0039-9140(95)01493-u.
The uptake of cesium, strontium and europium from dilute nitric acid solutions by a poly(sodium acrylate-acrylic acid) PAA hydrogel has been investigated. pH variations are consistent with cation exchange processes: COO(-), Na (+)H (+), COO(-), Na (+)M (m+) ( M (m+) = Cs (+)and Sr (2+)) and COOH Eu (3+). Saturation of the gel is achieved for metal/carboxylate ratios R = 0.5. The swelling ratios of gels loaded with metal cations are those of uncharged, shrunk gels (Sr, Eu) or of charged, swollen gels (Cs) in agreement with the formation of uncharged (COO)(2)Sr, (COO)(2)EuX (X = NO(3) or OH) type complexes and (COO(-), Cs(+)) ion pairs. The metal cations are extracted in the gels following the order of their affinities with carboxylic groups Eu(3+) > Sr(2+) > Cs(+). An increase of the ionic strength of the metal aqueous solution up to 0.5M NaNO(3) leads to slightly decrease the europium uptake by the PAA hydrogel, but 0.1M NaNO(3) is sufficient to prevent the Sr and Cs extractions.
研究了聚（丙烯酸钠-丙烯酸）PAA水凝胶从稀硝酸溶液中对铯、锶和铕的吸附情况。pH值变化与阳离子交换过程一致：COO(-)、Na(+)H(+)、COO(-)、Na(+)M(m+)（M(m+) = Cs(+)和Sr(2+)）以及COOH Eu(3+)。当金属/羧酸盐比率R = 0.5时，凝胶达到饱和。负载金属阳离子的凝胶的溶胀率与不带电、收缩的凝胶（Sr、Eu）或带电、溶胀的凝胶（Cs）的溶胀率一致，这与形成不带电的(COO)2Sr、(COO)2EuX（X = NO3或OH）型配合物和(COO(-)、Cs(+))离子对相符。金属阳离子按照它们与羧基的亲和力顺序Eu(3+) > Sr(2+) > Cs(+)被萃取到凝胶中。将金属水溶液的离子强度增加到0.5M NaNO3会导致PAA水凝胶对铕的吸附略有下降，但0.1M NaNO3足以阻止Sr和Cs的萃取。
