Graham Trent R, Han Kee Sung, Dembowski Mateusz, Krzysko Anthony J, Zhang Xin, Hu Jianzhi, Clark Sue B, Clark Aurora E, Schenter Gregory K, Pearce Carolyn I, Rosso Kevin M
Pacific Northwest National Laboratory , Richland , Washington 99354 , United States.
The Voiland School of Chemical and Biological Engineering , Washington State University , Pullman , Washington 99164 , United States.
J Phys Chem B. 2018 Dec 6;122(48):10907-10912. doi: 10.1021/acs.jpcb.8b10145. Epub 2018 Nov 27.
Pulsed field gradient nuclear magnetic resonance (PFG-NMR) measurements were successfully applied to the Al ( I = 5/2) nucleus in concentrated electrolytes to investigate the diffusion of aluminate ions [Al(OH)] in simulant high-level nuclear waste (3 M NaOH) between 25 and 85 °C. The temperature-dependent diffusion coefficients obtained from H, Na, and Al PFG-NMR were well fit by a Vogel-Fulcher-Tammann model and a power law equation. Comparison of Al diffusion coefficients of 0.1 M Al(OH) in ∼3 M MOH (where M = Na, K, (CH)N) at room temperature varied in agreement with the expected changes in solution viscosity via Stokes-Einstein relationship, confirming that the dominant Al species at these conditions are Al(OH) monomers. This Al PFG-NMR study extends an established methodology to a previously unexplored nucleus enabling this experimental technique to be leverage for exploring ion transport, speciation, and solution structure in concentrated electrolytes.
脉冲场梯度核磁共振（PFG-NMR）测量成功应用于浓电解质中的铝核（I = 5/2），以研究铝酸根离子[Al(OH)]在模拟高放核废料（3 M NaOH）中25至85 °C温度范围内的扩散。通过H、Na和Al的PFG-NMR获得的与温度相关的扩散系数，能很好地用Vogel-Fulcher-Tammann模型和幂律方程拟合。室温下，在约3 M MOH（其中M = Na、K、(CH)N）中0.1 M Al(OH)的Al扩散系数比较结果，与通过斯托克斯-爱因斯坦关系预期的溶液粘度变化一致，证实了这些条件下主要的Al物种是Al(OH)单体。这项Al PFG-NMR研究将一种既定方法扩展到了一个此前未探索的核，使这种实验技术能够用于探索浓电解质中的离子传输、物种形成和溶液结构。
