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Daniel A. Beller: Modeling the assembly of colloids with sharp features in nematic liquid crystals

Datum objave: 20. 5. 2013
Fizikalno predavanje
Thursday, 23. 5. 2013, at 10:15, Kuščerjev seminar (4/414), FMF, Jadranska 19, Ljubljana

Modeling the assembly of colloids with sharp features in nematic liquid crystals

Daniel A. Beller (University of Pennsylvania)  

The self-assembly of colloids in nematic liquid crystals via topological defects has been extensively studied for spherical particles, and some investigations have considered the role of particle anisotropy. Recent advances in microfabrication techniques have led to homeotropic- aligning colloids with more complex shapes, such as cylinders and "microbullets", which contain sharp corners. We use Landau-de Gennes numerical modeling to investigate the nematic director field and defect structure around such colloids in a thin-cell geometry, and we determine the colloids' equilibrium alignment directions and effective pair interaction potentials as a function of a few relevant shape parameters. We find that small-scale features of complex colloids have significant effects on defect structure and colloidal assembly in ways not captured by far-field approximations. This raises the possibility of selecting self-assembled colloidal structures by tuning particle shape.