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Vita F, Adamo FC, Campana M, Bordokas B, Ciuchi F, De Santo MP, Hermida-Merino D, Lisovsky A, Pisani M, Pontoni D, Scharrer E, Francescangeli O. Macroscopic Biaxial Order in Multilayer Films of Bent-Core Liquid Crystals Deposited by Combined Langmuir-Blodgett/Langmuir-Schaefer Technique. NANOMATERIALS (BASEL, SWITZERLAND) 2024; 14:357. [PMID: 38392730 PMCID: PMC10892925 DOI: 10.3390/nano14040357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 01/29/2024] [Accepted: 02/09/2024] [Indexed: 02/24/2024]
Abstract
Bent-core liquid crystals, a class of mesogenic compounds with non-linear molecular structures, are well known for their unconventional mesophases, characterized by complex molecular (and supramolecular) ordering and often featuring biaxial and polar properties. In the nematic phase, their unique behavior is manifested in the formation of nano-sized biaxial clusters of layered molecules (cybotactic groups). While this prompted their consideration in the quest for nematic biaxiality, experimental evidence indicates that the cybotactic order is only short-ranged and that the nematic phase is macroscopically uniaxial. By combining atomic force microscopy, neutron reflectivity and wide-angle grazing-incidence X-ray scattering, here, we demonstrate that multilayer films of a bent-core nematic, deposited on silicon by a combined Langmuir-Blodgett and Langmuir-Schaefer approach, exhibit macroscopic in-plane ordering, with the long molecular axis tilted with respect to the sample surface and the short molecular axis (i.e., the apex bisector) aligned along the film compression direction. We thus propose the use of Langmuir films as an effective way to study and control the complex anchoring properties of bent-core liquid crystals.
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Affiliation(s)
- Francesco Vita
- Department of Science and Engineering of Matter, Environment and Urban Planning (SIMAU), Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy; (F.C.A.); (M.P.)
| | - Fabrizio Corrado Adamo
- Department of Science and Engineering of Matter, Environment and Urban Planning (SIMAU), Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy; (F.C.A.); (M.P.)
| | - Mario Campana
- ISIS Neutron and Muon Source, Rutherford Appleton Laboratory, Harwell Campus, Didcot OX11 0QX, UK;
| | - Blake Bordokas
- Department of Chemistry, University of Puget Sound, Tacoma, WA 98416, USA; (B.B.); (A.L.); (E.S.)
| | - Federica Ciuchi
- CNR-Nanotec c/o Physics Department, University of Calabria, Ponte Bucci, Cubo 31C, 87036 Arcavacata di Rende, Italy; (F.C.); (M.P.D.S.)
| | - Maria Penelope De Santo
- CNR-Nanotec c/o Physics Department, University of Calabria, Ponte Bucci, Cubo 31C, 87036 Arcavacata di Rende, Italy; (F.C.); (M.P.D.S.)
- Physics Department, University of Calabria, Ponte Bucci, Cubo 31C, 87036 Arcavacata di Rende, Italy
| | - Daniel Hermida-Merino
- DUBBLE@ESRF BP CS40220, 38043 Grenoble, France;
- Departamento de Física Aplicada, Centro de Investigación en Nanomateriais e Biomedicina (CINBIO), Universidade de Vigo, Campus Lagoas-Marcosende, E36310 Vigo, Spain
| | - Angela Lisovsky
- Department of Chemistry, University of Puget Sound, Tacoma, WA 98416, USA; (B.B.); (A.L.); (E.S.)
| | - Michela Pisani
- Department of Science and Engineering of Matter, Environment and Urban Planning (SIMAU), Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy; (F.C.A.); (M.P.)
| | - Diego Pontoni
- ESRF—The European Synchrotron, 71 Avenue des Martyrs, 38043 Grenoble, France;
| | - Eric Scharrer
- Department of Chemistry, University of Puget Sound, Tacoma, WA 98416, USA; (B.B.); (A.L.); (E.S.)
| | - Oriano Francescangeli
- Department of Science and Engineering of Matter, Environment and Urban Planning (SIMAU), Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy; (F.C.A.); (M.P.)
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Rytel K, Kędzierski K, Barszcz B, Biadasz A, Majchrzycki Ł, Wróbel D. The influence of zinc phthalocyanine on the formation and properties of multiwalled carbon nanotubes thin films on the air–solid and air–water interface. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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