Two-Dimensional Growth Rate Control of L-Phenylalanine Crystal by Laser Trapping in Unsaturated Aqueous Solution

Ken-ichi Yuyama, Jino George, K George Thomas, Teruki Sugiyama, and Hiroshi Masuhara

The growth rate control of single L-phenylalanine plate-like anhydrous crystal is successfully demonstrated by laser trapping at an air/solution interface of the unsaturated aqueous solution. Focusing a continuous-wave near-infrared laser beam into the solution surface generates one L-phenylalanine crystal at the focal spot. Subsequently, the formed crystal grows two-dimensionally at a constant rate under unsaturated condition while being trapped by the laser. When the laser power is decreased after the crystallization, the growth rate is slowed down accordingly. Thus, the two-dimensional growth rate is controllable by tuning the power of the trapping laser after the crystallization. As the critical phenomenon underlying the growth rate control, we propose the formation of a dense domain of the liquid-like clusters induced prior to the crystallization.

DOI