TEKUĆI KRISTALI - LIQUID CRYSTALS
The liquid crystalline materials are well known for their application in flat panel displays, and yet they exhibit a plethora of peculiar properties that offer great potential for fundamental science as well as innovative applications beyond the displays sphere.
Current research is focused on a fast-developing area of liquid crystal science in which bulk, helical arrangements are formed from constituents, which are not themselves chiral. One of the most recent examples of spontaneous chirality is the twist-bend nematic phase (NTB). Formation of degenerate helices does not require molecular chirality, instead, it is facilitated by the shape of bent molecules.
Our work streams toward a better understanding of the relationship between the structure and mesomorphic properties in order to enable control of self-organising processes at the supramolecular level and therefore provide the materials with enhanced properties.
The research activity includes:
- Design and synthesis of new bent-shaped mesomorphic materials which exhibit chiral organization
- Characterization of liquid-crystalline properties
- Conformational analysis
- Study of intermolecular interaction
I. Dokli, A. Ožegović, A. Šimanović, M. Hromin, A. Knežević, A. Višnjevac, A. Lesac, "Enantioselective Synthesis of 3-Aryl-3-hydroxypropanoic Esters as Subunits for Chiral Liquid Crystals", J. Org. Chem. 87 (2022) 14045-14057. DOI: 10.1021/acs.joc.2c01662
C. Meyer, P. Davidson, T. Sergan, V. Sergan, D. Stoenescu, A. Knežević, I. Dokli, A. Lesac, I. Dozov, " Nematic-like elastic coefficients of the SmAb phase", Liq. Cryst. (2022) DOI: 10.1080/02678292.2022.2114026
C. Meyer, P. Davidson, D. Constantin, V. Sergan, D. Stoenescu, A. Knežević, I. Dokli, A. Lesac, I. Dozov, "A Fréedericksz-like transition in a biaxial smectic A phase", Phys Rev. X 11 (2021) 031012.
A. Knežević, I. Dokli, J. Novak, D. Kontrec, A. Lesac*, "Fluorinated twist-bend nematogens: the role of intermolecular interaction" Liq. Cryst. 47 (2020) 756-766.
A. Knežević, M. Sapunar, A. Buljan, I. Dokli, Z. Hameršak, D. Kontrec, A. Lesac*, "Fine-tuning effect of p–p interactions on the stability of the NTB phase" Soft Matter 14 (2018) 8466-8474.
A. Lesac*, U. Baumeister, I. Dokli, Z. Hameršak, T. Ivšić, D. Kontrec, M. Viskić, A. Knežević, R. J. Mandle, "Geometric aspects influencing N-NTB transition - implication of intramolecular torsion" Liq. Cryst. 45 (2018) 1101-1110.
T. Ivšić, M. Vinković, U. Baumeister, A. Mikleušević, A. Lesac*, "Towards understanding the NTB phase: a combined experimental, computational and spectroscopic study ", RSC Adv. 6 (2016) 5000-5007.
M. Šepelj, A. Lesac*, U. Baumeister, S. Diele, H. L. Nguyen and, D. W. Bruce* "Intercalated Liquid-crystalline Phases Formed by Symmetric Dimers with an a,w-Diiminoalkylene Spacer", J. Mater. Chem., 17 (2007) 1154 – 1165.
M. Šepelj, A. Lesac*, U. Baumeister, S. Diele, D. W. Bruce*, Z. Hameršak "Dimeric Salicylaldimine-based Mesogens with Flexible Spacers: Parity-dependent Mesomorphism" Chem. Mater., 18 (2006) 2050-2058.