Real Time Recrystallization Study of 1, 2 Dodecanediol on Highly Oriented Pyrolytic Graphite (HOPG) by Tapping Mode Atomic Force Microscopy

Real-time atomic force microscopy (AFM) imaging revealed for the first time, the detailed growth/dissolution mechanism of Lauryl glycol (LG) or 1, 2 dodecanediol molecules on HOPG at the nano-level after recrystallizing them from chloroform solution. At the early stage of recrystallization, parallelogram-like-structures having lengths of several microns and distinct widths (between ~ 100 - 400 nm) were observed. Growth/dissolution behavior of these parallelogram-like-structures as a function of time was investigated. While dissolution occurred along all three dimensions, growth was found to be strictly two dimensional. Both the growth and dissolution process were found to be logarithmic in nature. The average growth rates along their length and width were found to be 11 nm/min and 1.5 nm/min respectively. Average dissolution rate in percentage on HOPG surface was found to be ~ 0.078%/min. Based upon the recrystallization of LG molecules schematics are drawn for a better understanding of the recrystallization process.