PNNL

Abstract

The exact atomic structures of layered minerals have been difficult to characterize because the layers often possess out-of-plane hydrogen atoms that cannot be detected by many analytical techniques. However, the ordering of these bonds are thought to play a fundamental role in the structural stability and solubility of layered minerals. We report a new strategy of using the intense radiation field of a focused electron beam to probe the effect of differences in hydrogen bonding networks on mineral solubility while simultaneously imaging the dissolution behavior in real time via liquid cell electron microscopy. We show the loss in hydrogens from interlayers of boehmite (?-AlOOH) resulted in 2D nanosheets exfoliating from the bulk that subsequently and rapidly dissolved. However gibbsite (?-Al(OH)3), with its higher concentration of OH terminating groups, was more accommodating to the deprotonation and stable under the beam.