Identification and sorting of particle chirality using liquid crystallinity

The research article “Identification and sorting of particle chirality using liquid crystallinity”, co-authored by METU member Res. Asst. Özge Batır and Asst. Prof. Emre Büküşoğlu, has been published in Journal of Colloid and Interface Science.

Particles dispersed in liquid crystals (LCs) have been shown to assemble due to the elastic interactions arising from the molecular anisotropy. Studies have shown that the alignment of the particles within LCs were strongly dependent on the surface director of LCs on particles. Different from the past studies involving particles with degenerate planar anchoring of LCs, this study shows that the azimuthal surface director can be used to control and finely tune the positioning of the particles in LCs. Specifically, polymeric particles with two flat surfaces that mediate parallel or non-parallel (chiral) anchoring were synthesized and dispersed in nematic 5CB with spatial variations in the director profile. Besides demonstration of their positioning, it was observed that the particles with same chiral handedness with the LC twist were distributed within the LC film, whereas particles with opposite handedness were repelled from the LC medium due to the elastic energy contributions. In addition, a pronounced effect of the surface anchoring of the particles were present on their orientation during non-equilibrium events such as sedimentation. Overall, the studies presented here will find potential use in sensors, separations, optics or soft robotic applications that will take advantages of chirality or chiral interactions.

Akdeniz, B., Batir, O., & Bukusoglu, E. (2020). Identification and sorting of particle chirality using liquid crystallinity. Journal of Colloid and Interface Science, 574, 11-19. doi:10.1016/j.jcis.2020.04.002

Article access: https://www.sciencedirect.com/science/article/pii/S0021979720304409?via%3Dihub

Keywords:

Alignment; Chirality; Liquid crystals; Particles; Surface anchoring

Other authors:
Akdeniz B. (METU)

Acknowledgments:
This work was supported by the Scientific and Technological Council of Turkey (TÜBİTAK) under the award number 217M268 .