journal article·2019-12Open access

Directed self-assembly of a helical nanofilament liquid crystal phase for use as structural color reflectors

Wongi Park, Taewoo Ha, Teun-Teun Kim, Anna Zep, Hyungju Ahn, Tae Joo Shin, Kyung Ik Sim, Taek Sun Jung, Jae Hoon Kim, Damian Pociecha, Ewa Gorecka, Dong Ki Yoon

NPG Asia Materials· Volume 11· Issue 1

Abstract

Abstract The fabrication of molecular structures with a desired morphology, e.g., nanotubes, nanoribbons, nanosprings, and sponges, is essential for the advancement of nanotechnology. Unfortunately, realization of this objective is expensive and complicated. Here, we report that irradiating a film comprising azobenzene derivatives with UV light produces oriented arrays of helical nanofilaments via the photoisomerization-induced Weigert effect. As a result, structural colors are observed due to the extrinsic chiral reflection in the visible wavelength range, and the reflected color can be tuned by adjusting the molecular length of the azobenzene derivative. This simple fabrication method can be used for fabricating large, reversible, and patternable color reflectors, providing a new platform for interference-based structural coloration as it exists in nature, such as morpho butterflies, green-winged teal, and various beetles.
Source: crossref · Quality: baseline

Research context

OpenAlex topics: Liquid Crystal Research Advancements · Metamaterials and Metasurfaces Applications · Advanced Materials and Mechanics

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

References (26)

Show source-provided references
1. Hough, L. E. et al. Helical nanofilament phases. Science 325, 456–460 (2009).10.1126/science.1170027 ↗
2. Zhang, C., Diorio, N., Lavrentovich, O. D. & Jákli, A. Helical nanofilaments of bent-core liquid crystals with a second twist. Nat. Commun. 5, 3302 (2014).10.1038/ncomms4302 ↗
3. Yoon, D. K. et al. Orientation of a helical nanofilament (B4) liquid-crystal phase: topographic control of confinement, shear flow, and temperature gradients. Adv. Mater. 23, 1962–1967 (2011).10.1002/adma.201004482 ↗
4. Le, K. V., Takezoe, H. & Araoka, F. Chiral superstructure mesophases of achiral bent-shaped molecules—hierarchical chirality amplification and physical properties. Adv. Mater. 29, 1602737 (2017).10.1002/adma.201602737 ↗
5. Li, L., Salamonczyk, M., Jákli, A. & Hegmann, T. A dual modulated homochiral helical nanofilament phase with local columnar ordering formed by bent core liquid crystals: effects of molecular chirality. Small 12, 3944–3955 (2016).10.1002/smll.201600882 ↗
6. Kim, H. et al. Multistep hierarchical self-assembly of chiral nanopore arrays. Proc. Natl Acad. Sci. USA. 111, 14342–14347 (2014).10.1073/pnas.1414840111 ↗
7. Lee, S. et al. Physico-chemical confinement of helical nanofilaments. Soft Matter 11, 3653–3659 (2015).10.1039/C5SM00417A ↗
8. Toshchevikov, V., Petrova, T. & Saphiannikova, M. Kinetics of light-induced ordering and deformation in LC azobenzene-containing materials. Soft Matter 13, 2823–2835 (2017).10.1039/C7SM00115K ↗
9. Zheng, Z.-G et al. Three-dimensional control of the helical axis of a chiral nematic liquid crystal by light. Nature 531, 352–356 (2016).10.1038/nature17141 ↗
10. Zheng, Z.-G. et al. Light-patterned crystallographic direction of a self-organizied 3D soft photonic crystal. Adv. Mater. 29, 1703165 (2017).10.1002/adma.201703165 ↗
11. Kim, H. et al. Linakage-length dependent structuring behaviour of bent-core molecules in helical nanostructures. Soft Matter 12, 3326–3330 (2016).10.1039/C5SM03100A ↗
12. Krietenstein, B. The perfect boundary approximation technique facing the challenge of high precision field computation. In Proceedings of the XIX International Linear Accelerator Conference (LINAC98). 860–862 (1998).
13. Zep, A., Sitkowska, K., Pociecha, D. & Gorecka, E. Photoresponsive helical nanofilament of B4 phase. J. Mater. Chem. C 2, 2323–2327 (2014).10.1039/C3TC32325K ↗
14. You, R. et al. Nanoconfined heliconical structure of twist-bend nematic liquid crystal phase. Liq. Cryst. 46, 316–325 (2019).10.1080/02678292.2018.1508770 ↗
15. Weiland, T. A discretization method for the solution of Maxwell’s equations for six-componen fields. Electron. Commun. 31, 116–120 (1977).
16. Xiang, J. et al. Electrically tunable selective reflection of light from ultraviolet to visible and infrared by heliconical choleterics. Adv. Mater. 27, 3014–3018 (2015).10.1002/adma.201500340 ↗
17. Jahani, S. & Jacob, Z. All-dielectric metamaterials. Nat. Nanotechnol. 11, 23–26 (2016).10.1038/nnano.2015.304 ↗
18. Shin, J., Shen, J.-T. & Fan, S. Three-dimensional metamaterials with an ultrahigh effective refractive index over a broad bandwidth. Phys. Rev. Lett. 102, 093903 (2009).10.1103/PhysRevLett.102.093903 ↗
19. Chung, K. et al. Flexible, angle-independent, structural color reflectors inspired by morpho butterfly wings. Adv. Mater. 24, 2375–2379 (2012).10.1002/adma.201200521 ↗
20. Lee, H. S., Shim, T. S., Hwang, H., Yang, S.-M. & Kim, S.-H. Colloidal photonic crystals toward structural color palettes for security materials. Chem. Mater. 25, 2684–2690 (2013).10.1021/cm4012603 ↗
21. Cho, S., Shim, T. S., Kim, J. H., Kim, D.-H. & Kim, S.-H. Selective coloration of melanin nanospheres through resonant mie scattering. Adv. Mater. 29, 1700256 (2017).10.1002/adma.201700256 ↗
22. Noh, J. et al. Experimental observation of optical Weyl points and Fermi arc-like surface states. Nat. Phys. 13, 611–617 (2017).10.1038/nphys4072 ↗
23. Yang, B. et al. Ideal Weyl points and helicoid surface states in artificial photonic crystal structure. Science 359, 1013–1016 (2018).10.1126/science.aaq1221 ↗
24. Slobozhanyuk, A. et al. Three-dimensional all-dielectric photonic topological insulator. Nat. Photonics 11, 130–136 (2017).10.1038/nphoton.2016.253 ↗
25. Jin, D. et al. Infrared topological plasmons in graphene. Phys. Rev. Lett. 118, 245301 (2017).10.1103/PhysRevLett.118.245301 ↗
26. Peng, Y.-G. et al. Experimental demonstration of anomalous Floquet topological insulator for sound. Nat. Commun. 7, 13368 (2016).10.1038/ncomms13368 ↗