Covalent grafting of Diglycolamide functionalities over Merrifield resin for the uptake of trivalent f-block metal ions from acidic aqueous feed

Abstract

In the present work, N, N-Dibutyl diglycolamide functionalities were covalently grafted over Merrifield resin by following novel green chemistry principles during the entire process of synthesis. Minimal use of hazardous chemicals, improved yields and moderate reaction conditions were the bedrocks throughout the process. This grafted resin was used as an adsorbent for the uptake of trivalent f-block elements from aqueous nitric acid feed (3M HNO3). The synthesized resin MRBB (N, N-Dibutyl diglycolamide grafted over n-butyl aminated Merrifield resin) was characterized with grafting percentage of >66%. Am 3+ an actinide was used as a radiotracer for preliminary studies to check the efficacy of synthesized polymeric adsorbent. After optimization of synthesis parameters, Eu 3+ salt, a surrogate lanthanide ion was used in an aqueous feed to optimize the operating parameters of adsorption. The distribution coefficients KD for different conditions were in the range of thousands but for a similar kind of work with malonamides the range was just in hundreds as reported in the available literature. The adsorption kinetics predominantly follows pseudo-second order reaction with k2 = 6.3 x 10 -5 g/(mg-min). The work is an important contribution in sustainable organic, polymer and nuclear chemistry.