Development of Cyclic Monoamide Extractants for Selective Separation of U(VI): Effects of Branched Side Chains

To address TBP-related safety and environmental concerns, six cyclic monoamide extractants were studied. All showed efficient and selective U(VI) extraction. Extractants with branched alkyl groups, especially DMoP, exhibited notably enhanced phase stability under high U(VI) concentrations and elevated temperatures. DMoP maintained a stable single phase up to 2 M U(VI) in 6 M HNO₃, indicating strong applicability for high-loading uranium recovery. This enhanced stability is attributed to polarity modulation from the branched structures. These results highlight the potential of branched monoamides as safer, more stable, and effective alternatives to TBP in nuclear fuel reprocessing