2020/01/14(Tue) 10:30 -11:30 五樓第一會議室 5F, 1st Meeting Room
Title
Branching out and back: Reconfigurable nematic micro-droplets driven by molecular heterogeneity
Speaker
魏維劭先生 (賓州大學物理與天文學系) Wei-shao Wei, PhD candidate (Department of Physics and Astronomy, University of Pennsylvania)Abstract
Traditionally, polydispersity in matter is often avoided, since it tends to impede self-assembly and state transformation. Here we report reconfigurable nematic liquid crystal oligomer micro-droplets, which reveal, surprisingly, that molecular heterogeneity facilitates equilibrium transitions among dramatically different morphological structures, via spatial segregation. Specifically, fine-tuning the temperature and oligomer chain length distribution alters the balance between interfacial tension and liquid crystal elasticity, driving spontaneous formation of roughened spheres, flowers, and highly branched filamentous networks with uniform and controllable diameters. This feature also provides potential connections to surface patterning in biological world, such as pollen grains. With the capabilities of being produced reversibly and permanently locked into liquid crystal elastomers via UV curing, the demonstrated simple rules thus offer new routes for programmed spatio-temporal networks.
This work is supported by NSF DMR16-07378, PENN MRSEC DMR-1720530, and NASA Grant 80NSSC19K0348.
*The work has been published and highlighted in Nature 2019.
Language
演講語言 (Language): in English
Hosted by