Synthesis of a Novel Macroporous Silica-Calix[4]arene-Crown Polymeric Composite and Its Adsorption for Alkali Metals and Alkaline-Earth Metals

Abstract

A macroporous silica-based 1,3-[(2,4-diethylheptylethoxy)oxy]-2,4-crown-6-calix [4]arene (Calix[4]arene-R14) supramolecular recognition polymeric composite, (Calix[4] + MODB)/SiO 2 -P, was synthesized. The synthesis was performed by impregnation and immobilization of Calix[4]arene-R14 and methyloctyl-2-dimethylbutanemide (MODB) molecules in the pores of a macroporous SiO 2 -P polymeric particle support with a mean diameter of 50 µm. MODB was used to modify the Calix[4]arene-R14 through intermolecular interaction force. The static-state adsorption of some typical alkali metals and alkaline-earth metals such as Na(I), K(I), Cs(I), Rb(I), Sr(II), and Ba(II) onto (Calix[4] + MODB)/SiO 2 -P was investigated. The effects of contact time, HNO 3 concentration in the range of 0.3-7.0 M, and temperature on the adsorption were examined.(Calix[4] + MODB)/SiO 2 -P exhibited strong adsorption ability and excellent selectivity for Cs(I) over all tested elements, which showed weak or almost no adsorption except for Rb(I). The adsorption onto (Calix[4] + MODB)/SiO 2 -P of the tested metals in HNO 3 medium was exothermic. The thermodynamic parameters for the adsorptions of Cs(I) and Rb(I) were determined. It was found that, in 3.0 M HNO 3 , application of the (Calix[4] + MODB)/SiO 2 -P polymeric composite in the partitioning of Cs(I), one of the heat generators, from highly active liquid waste in the SPEC (strontium/cesium partitioning from HLW by extraction chromatography) process is promising.

Nanomaterials and nanotechnologies in nuclear energy chemistry

“…By a similar approach, Zhang et al synthesized several other macroporous silica-based supramolecular recognition polymeric composites, which were modified by 1,3-[(2,4-diethyl-heptylethoxy)oxy]-2,4-crown-6-calix [4]arene (calix [4]arene-R14), (calix [4]+Oct)/SiO 2 -P [49]. The noctanol was used to modify calix [4]arene-R14 through hydrogen bonding.…”

“…5. It makes the adsorption ability of Cs(I) ion onto (calix [4]tOct)/SiO2-P high, whereas the other metals show poor adsorption [49]. As the processing of HLLW normally represents harsh chemical conditions such as high nitric acid concentration and extremely high level of radiation, the chemical and radiation stability of the impregnated nanoporous silica is particularly important.…”

Extraction behavior of cesium and some typical fission and non-fission products with a new 1,3-di(1-decyloxy)-2,4-crown-6-calix[4]arene

“…Following evaluation of the adsorption and column chromatographic separation properties of SSRMs, the partitioning technologies, the so-called SPEC (Strontium/Cesium Partitioning from HLW by Extraction Chromatography) process, has been proposed [20]. The heat generators, Cs(I) and Sr(II), were separated utilizing two macroporous SSRMs, Calix [4] arene-mono-crown/SiO 2 -P and 4,4 ,(5 )-di(tert-butylcyclohexano)-18-crown-6 (DtBuCH18C6)/SiO 2 -P [21][22][23][24][25]. The long-lived minor actinides and the other tested metals showed weak or almost no adsorption onto the SSRMs.…”

Preparation of a macroporous silica–pyridine multidentate material and its adsorption behavior for some typical elements

“…In the first column packed with (Calix [4]arene-R14þM)/SiO 2 -P, the elements was effectively separated into the following two groups: (1) Na(I), K(I), Sr(II), Ba(II), Pd(II), Zr(IV), RE(III) (La-Lu and Y), Rh(III), Ru(III), MA(III), and Mo(VI) (Sr-containing group), and (2) Cs(I)-Rb(I) (Cs-group) by eluting with 4.0 M HNO 3 and water, respectively. [14][15][16] Meanwhile, the long-lived MA(III) and Pd(II) flowed into the MA-Pd-group effluent along with all of REs(III), alkali metals, alkaline earths, and the others. The parti-tioning of Cs(I) and Sr(II) from HLW by extraction chromatography was achieved.…”

“…The parti-tioning of Cs(I) and Sr(II) from HLW by extraction chromatography was achieved. [14][15][16] Meanwhile, the long-lived MA(III) and Pd(II) flowed into the MA-Pd-group effluent along with all of REs(III), alkali metals, alkaline earths, and the others.…”