385206 Identification of Polar Plots of Crystal Dissolution Rates Using Hot-Stage Microscopy

Thursday, November 20, 2014: 4:21 PM
301 (Hilton Atlanta)
Meenesh R. Singh, Joint Center for Artificial Photosynthesis, Lawrence Berkeley National Laboratory, Berkeley, CA and Doraiswami Ramkrishna, Chemical Engineering, Purdue University, West Lafayette, IN

Polar plots are the representations of the anisotropic surface properties such as surface energies and growth rates of crystalline materials. The steady-state morphologies of growing crystals are usually obtained from Wulff constructions on the polar plots of growth rates,1 whereas the morphologies of dissolving crystals are known to have no steady-states.2Here we show that the dissolving crystal can attain steady-state morphologies under certain conditions. The Wulff construction on the polar plots of dissolution time (or slowness) can be used to identify such steady-state morphologies. It is shown that the dissolving crystal can attain faceted morphology composed of fast dissolving faces. The evolution of dissolving crystal towards faceted morphology involves disappearance of slow-dissolving faces, which also causes vanishing of curvatures from crystal surface. This article presents a method to experimentally determine polar plots from the dynamic images of crystals obtained from hot-stage microscopy. The method relies on the solution of the characteristics for crystal dissolution. The methodology is demonstrated to obtain polar plots of Succinic acid at different sub-saturations.         


 (1)       Singh, M. R.; Verma, P.; Tung, H.-H.; Bordawekar, S.; Ramkrishna, D., Screening Crystal Morphologies from Crystal Structure. Crystal Growth & Design 2012, 13, (4), 1390-1396.

(2)        Snyder, R. C.; Doherty, M. F., Faceted crystal shape evolution during dissolution or growth. AIChE journal 2007, 53, (5), 1337-1348.

Extended Abstract: File Not Uploaded
See more of this Session: Nucleation and Growth
See more of this Group/Topical: Separations Division