Impregnation of different ionic liquids onto cationic starch and their comparisonin the extraction of Th(IV)

Abstract

Cationic starch (CS) was prepared by using epichlorohydrin (EPI) and 3-chloro-2-hydroxypropyltrimethy-lammonium chloride (CHPTMA) and ionic liquids (ILs) having different anionic groups [1-butyl-3-methyl imida-zolium tetra uoroborate (BMI+BF4), 1-butyl-3-methyl imidazolium bromide (BMI+Br), 1-butyl-3-methyl imida-zolium hexa uorophosphate (BMI+PF6), and 1-butyl-3-methyl imidazolium bis-[(tri uoromethyl)sulfonyl]imide (BMI+[(TF)2N])] were impregnated onto CS. Thorium(IV) ions were preconcentrated by using IL impregnated CS. The ef-fects of ILs were investigated for extraction of Th(IV) by CS and the results were compared. Th(IV) was preconcentratedwith approximately 73% sorption capacity by CS and increased up to 98%{100% for IL impregnated sorbents at pH 7.0.The sorption capacities of Th(IV) were 0.453 mmol g1, 0.399 mmol g1, 0.281 mmol g1, and 0.183 mmol g1forCS{BMI+Br, CS{BMI+[(TF)2N], CS{BMI+PF6and CS{BMI+BF4, respectively. The elution occurred with HCland NaOH solutions at pH 7.0.