Results_for_oiling_out_crystallization_on_patterns-4.pdf (2.55 MB)
Download fileEffects of chemical and geometric microstructures on the crystallization of surface droplets during solvent exchange
journal contribution
posted on 2021-10-14, 10:08 authored by Howon Choi, Zixiang Wei, Jae Bem You, Huaiyu YangHuaiyu Yang, Xuehua ZhangIn this work, we investigate the crystallization of droplets formed on micropatterned surfaces. By solvent exchange in a microchamber, a ternary solution consisting of a model compound β-alanine, water, and isopropanol was displaced by a flow of isopropanol. In the process, oiling-out droplets formed and crystallized. Our results showed that the shape and size of the crystals on surfaces with chemical micropatterns could be simply mediated by the flow conditions of solvent exchange. More uniform crystals formed on hydrophilic microdomains compared to hydrophobic microdomains or homogeneous surfaces. Varying flow rates or channel heights led to the formation of thin films with microholes, connected networks of crystals, or small diamond-shaped crystals. Physical microstructures (represented by microlenses) on the surface allowed the easy detachment of crystals from the surface. Beyond oiling-out crystallization, we demonstrated that the crystal formation of another solute dissolved in the droplets could be triggered by solvent exchange. The length of crystal fibers after the solvent-exchange process was shorter at a faster flow rate. This study may provide further understanding to effectively obtain the crystallization of surface droplets through the solvent-exchange approach.
Funding
Natural Science and Engineering Research Council of Canada (NSERC)
Future Energy Systems (Canada First Research Excellence Fund)
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Chemical Engineering
Published in
LangmuirVolume
37Issue
17Pages
5290 - 5298Publisher
American Chemical SocietyVersion
- AM (Accepted Manuscript)
Rights holder
© American Chemical SocietyPublisher statement
This document is the Accepted Manuscript version of a Published Work that appeared in final form in Langmuir, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.langmuir.1c00354Publication date
2021-04-23Copyright date
2021ISSN
0743-7463eISSN
1520-5827Publisher version
Language
- en