Studies of aqueous U(iv) equilibrium and nanoparticle formation kinetics using spectrophotometric reaction modeling analysis.

ABSTRACT: Hydrolysis of tetravalent uranium (U(iv)) and U(iv)-nanoparticle formation kinetics were examined over a wide range of temperatures using spectrophotometric reaction modeling analysis. The characteristic absorption bands representing U⁴⁺, U(OH)³⁺, and a proposed oxohydroxo species were newly identified in the UV region (190-300 nm). Dynamic absorption band changes in the UV and visible regions (360-800 nm) were explored to reevaluate the binary ion interaction coefficients for U(iv) ions and the thermodynamic constants of the primary hydrolysis reaction, including complexation constants, enthalpy, and entropy. No further hydrolysis equilibrium beyond the formation of U(OH)³⁺ was identified. Instead, an irreversible transformation of U(iv) ions to U(iv)-nano

SUBMITTER: Cha W 

PROVIDER: S-EPMC9057037 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature