Structural incorporation of Cm(III) in trioctahedral smectite hectorite: A time-resolved laser fluorescence spectroscopy (TRLFS) study

Structural incorporation of the actinide curium in the octahedral layer of the trioctahedral Mg-rich smectite hectorite was studied using time-resolved laser fluorescence spectroscopy. Organo-hectorite nanoparticles were synthesized at 90 °C in the presence of Cm(III). Within 120 h, hectorite particles were formed. Time-resolved laser fluorescence spectroscopy was used to identify Cm(III) species during various synthesis steps and to characterize the structural incorporation mechanism. The formation of a Cm-containing Mg hydroxide precursor and the reaction with aqueous silica in a pH range of 9–10 to form TOT layers were identified to be key steps for trivalent actinide incorporation in hectorite via coprecipitation.