TY - JOUR
T1 - Non-Photochemical Pulsed-Laser-Induced Nucleation in a Continuous-Wave-Laser-Induced Phase-Separated Solution Droplet of Aqueous Glycine Formed by Optical Gradient Forces
AU - Gowayed, Omar
AU - Tasnim, Tasfia
AU - Fuentes-Rivera, José J.
AU - Aber, Janice E.
AU - Garetz, Bruce A.
N1 - Funding Information:
The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.cgd.9b01255 . Cleaning and assembly techniques for the sample holders, α- and γ-glycine crystal structures, tables and graphs of numbers of crystals and average cumulative probabilities of nucleation of crystals inside and outside of the LIPS boundary, PXRD patterns collected from the crystals inside versus outside of the LIPS boundary, derivation of the formula for calculating the minimum radius of a cluster that can be optically trapped( PDF ) Time-lapse videos of each of the four types of experiments ( AVI1 , AVI2 , AVI3 , AVI4 ) This work was supported primarily by the MRSEC Program of the National Science Foundation under Award Number DMR-1420073. The authors are grateful for shared facilities provided through the Materials Research Science and Engineering Center (MRSEC) program of the National Science Foundation under Award Number DMR-1420073. Any opinions, findings, and conclusions or recommendations expressed in this paper are those of the authors and do not necessarily reflect the views of the National Science Foundation. The authors declare no competing financial interest.
PY - 2019/12/4
Y1 - 2019/12/4
N2 - A centimeter-sized, laser-induced phase-separated (LIPS) solution droplet, which was formed by tightly focusing a continuous-wave near-infrared laser beam at the glass/solution interface of a millimeter-thick layer of glycine in D2O with a supersaturation ratio, S, of 1.36 was irradiated with a single unfocused nanosecond near-infrared laser pulse in order to study the effect of non-photochemical laser-induced nucleation (NPLIN) on the droplet, as well as to help characterize the behavior of the LIPS droplet. Additionally, a control NPLIN experiment was conducted on an S = 1.50 supersaturated solution of glycine/D2O in the same cell to better understand the differences between NPLIN in a LIPS droplet and an ordinary supersaturated solution. These experiments revealed that NPLIN could nucleate crystals within a LIPS droplet, although the growth of these crystals was inhibited during the first 5 min of the droplet's relaxation. For the first 40 min of its relaxation, the LIPS droplet was observed to be more labile to spontaneous nucleation than the control S = 1.50 solution, although the growth of spontaneously nucleated crystals was also inhibited during the first 5 min of the droplet's relaxation. This suggests that although the macroscopic phase boundary between the LIPS droplet and the surrounding solution disappeared after approximately 5 min, the full microscopic relaxation of the LIPS droplet took at least 40 min. The resulting crystals were analyzed using powder X-ray diffraction, and 100% of crystals formed within the LIPS droplet induced by NPLIN with linearly polarized light and by spontaneous nucleation were α-glycine, while crystals formed outside of the LIPS droplet were mixtures of α- and γ-glycine. The results suggest that the LIPS droplet and the surrounding solution are not equilibrium phases of aqueous glycine, but phases in which optical gradient forces have induced a partitioning of large and small solute clusters.
AB - A centimeter-sized, laser-induced phase-separated (LIPS) solution droplet, which was formed by tightly focusing a continuous-wave near-infrared laser beam at the glass/solution interface of a millimeter-thick layer of glycine in D2O with a supersaturation ratio, S, of 1.36 was irradiated with a single unfocused nanosecond near-infrared laser pulse in order to study the effect of non-photochemical laser-induced nucleation (NPLIN) on the droplet, as well as to help characterize the behavior of the LIPS droplet. Additionally, a control NPLIN experiment was conducted on an S = 1.50 supersaturated solution of glycine/D2O in the same cell to better understand the differences between NPLIN in a LIPS droplet and an ordinary supersaturated solution. These experiments revealed that NPLIN could nucleate crystals within a LIPS droplet, although the growth of these crystals was inhibited during the first 5 min of the droplet's relaxation. For the first 40 min of its relaxation, the LIPS droplet was observed to be more labile to spontaneous nucleation than the control S = 1.50 solution, although the growth of spontaneously nucleated crystals was also inhibited during the first 5 min of the droplet's relaxation. This suggests that although the macroscopic phase boundary between the LIPS droplet and the surrounding solution disappeared after approximately 5 min, the full microscopic relaxation of the LIPS droplet took at least 40 min. The resulting crystals were analyzed using powder X-ray diffraction, and 100% of crystals formed within the LIPS droplet induced by NPLIN with linearly polarized light and by spontaneous nucleation were α-glycine, while crystals formed outside of the LIPS droplet were mixtures of α- and γ-glycine. The results suggest that the LIPS droplet and the surrounding solution are not equilibrium phases of aqueous glycine, but phases in which optical gradient forces have induced a partitioning of large and small solute clusters.
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U2 - 10.1021/acs.cgd.9b01255
DO - 10.1021/acs.cgd.9b01255
M3 - Article
AN - SCOPUS:85075144546
SN - 1528-7483
VL - 19
SP - 7372
EP - 7379
JO - Crystal Growth and Design
JF - Crystal Growth and Design
IS - 12
ER -