Article
Mathematics, Applied
Lidia Mrad, Longhua Zhao, Malena I. Espanol, Ling Xu, M. Carme Calderer
Summary: We investigated the aggregation phenomenon in lyotropic chromonic liquid crystals and found that the minimizers of the total energy are topologically equivalent to tori, based on the critical points of the Oseen-Frank energy and geometric constraints. The system was modeled as bi-phasic, considering liquid crystal molecules and water, and the total energy was determined by the Flory-Huggins energy of mixing and bending and surface tension contributions. The study focused on the optimal shape of torus after phase separation and the conditions leading to molecular aggregation.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2023)
Article
Physics, Condensed Matter
Silvia Paparini, Epifanio G. Virga
Summary: The study analyzed the shapes of two-dimensional bipolar droplets and proposed a potentially shape bistability phenomenon. Results were in good agreement with experimental data, providing a new direction for further research in the field.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Crystallography
Anshul Sharma, Irvine Lian Hao Ong, Anupam Sengupta
Summary: The nematic and columnar phases of lyotropic chromonic liquid crystals (LCLCs) have been extensively studied for their importance in material science and medical diagnostics. This study focuses on the emergence of time dependent textures in confined LCLCs, using soft lithography, surface characterization, and polarized optical imaging to analyze the confinement-induced LCLC textures. Varying confinement geometry, anchoring conditions, and initial DSCG concentration allows for tuning the temporal dynamics of the N- to M-phase transition and textural behavior of the confined LCLC.
Article
Chemistry, Physical
Federico Caimi, Giovanni Nava, Raouf Barboza, Noel A. Clark, Eva Korblova, David M. Walba, Tommaso Bellini, Liana Lucchetti
Summary: The article investigates the surface alignment of the ferroelectric nematic phase and finds specific behaviors and factors that affect the alignment, such as orientation, defects, and electric field response.
Article
Chemistry, Physical
Lorenza Spina, Maria Penelope De Santo, Caterina Maria Tone, Michela Pisani, Francesco Vita, Riccardo Barberi, Federica Ciuchi
Summary: This study reports advances in understanding the supramolecular arrangement and induced chirality for the chromonic molecule Sunset Yellow and its interaction with salts and L-peptides. The research demonstrates the rise of enhanced chirality in Sunset Yellow microspheres and proposes two possible mechanisms for this phenomenon: intercalation of the chiral dopant or binding. These findings are significant for the potential use of these microspheres in optical and sensing applications.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Mathematics, Applied
Silvia Paparini, Epifanio G. Virga
Summary: Recent experiments have shown that the ground state of chromonic liquid crystals is twisted rather than uniform, leading to a violation of Ericksen's inequality within the classical elastic theory of Frank. Despite this violation potentially making Frank's elastic free-energy functional unbounded below, researchers have determined that the twisted ground state can be locally stable, with specific boundary conditions and a derived formula for the second variation in Frank's elastic free energy playing key roles in this conclusion.
JOURNAL OF NONLINEAR SCIENCE
(2022)
Article
Engineering, Multidisciplinary
Silvia Paparini, Epifanio G. Virga
Summary: Chromonic liquid crystals are attracting interest for their adaptability to living systems. The classical theory for describing their elastic properties requires small twist constants and large saddle-splay constants, violating some inequalities and leading to paradoxical consequences. To overcome these issues, a novel elastic theory is proposed, extending the classical Oseen-Frank stored energy by adding a quartic twist term. The total energy of droplets is bounded below in the quartic twist theory, resolving the known paradoxes.
JOURNAL OF ELASTICITY
(2023)
Article
Chemistry, Physical
Gu-Yuan Li, Jia-Jia Yu, Dong-Ming Mo, Maitiniyazi Bake, Ling-Feng Chen, You-Rong Li
Summary: The electro-optical properties of liquid crystals are crucial for liquid crystal displays, and the use of lyotropic liquid chromonic crystals has attracted research interest in various fields. The experimental study revealed that the threshold voltage and relaxation time of nematic lyotropic chromonic liquid crystals decrease with increasing temperature or decreasing concentration. The concentration of neutral ionic dopants like sodium chloride and magnesium sulfate shows a positive correlation while alkaline ionic dopants like sodium hydroxide exhibit a negative correlation with the threshold voltage and relaxation time. The changes in electro-optical properties are analyzed based on the molecular self-assembly behaviors of lyotropic chromonic liquid crystals, and it is discovered that the viscoelastic theory applicable to nematic thermotropic liquid crystals can also be applied to nematic lyotropic chromonic liquid crystals for the first time.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Multidisciplinary Sciences
Lindsey Hiltner, M. Carme Calderer, Javier Arsuaga, Mariel Vazquez
Summary: This article studies equilibrium configurations of hexagonal columnar liquid crystals and their application in protein capsids, revealing the energy composition of liquid crystals and various constraints. The study finds that the concentric, azimuthal, spool-like configuration is the absolute minimizer, and compares toroidal structures formed by DNA in free solution with those occurring in experiments with other types of lyotropic liquid crystals.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2021)
Article
Chemistry, Multidisciplinary
Silvia Paparini, Epifanio G. Virga
Summary: An elastic quartic twist theory has been proposed to address the inconsistencies encountered by the classical Oseen-Frank theory in chromonic liquid crystals. However, both theories can equally explain experimental data for chromonics confined in cylindrical cavities with degenerate planar anchoring. This paper identifies a way to differentiate these theories by examining the core defects generated by twisted hedgehogs in a fixed spherical cavity with homeotropic anchoring.
Article
Chemistry, Multidisciplinary
Jin Young Oh, Eun-Mi Kim, Gi-Seok Heo, Dong Hyun Kim, DongWook Lee, Hae-Chang Jeong, Dae-Shik Seo
Summary: The present study demonstrates that ultraviolet-nanoimprint lithography (UV-NIL) can be used to transfer a one-dimensional nano-pattern onto a high-k aluminum oxide thin film mixed with a UV photocuring agent. The imprinted nano-patterns induce geometric deformations in liquid crystal, creating collective and elastic properties that guide homogeneous alignment. The nanoimprint method allows for easier, faster, and more accurate processing of a large area compared to conventional rubbing methods. Additionally, the optical properties of the nano-imprinted aluminum oxide thin film are superior to conventional commercialized cells, significantly affecting the luminance and color gamut of displays.
Review
Materials Science, Multidisciplinary
P. Priscilla, Praveen Malik, Supreet, Ajay Kumar, Riccardo Castagna, Gautam Singh
Summary: This review focuses on the alignment of liquid crystals (LCs) controlled by nanoparticles. It is found that doping nanoparticles in LCs or patterning nanostructures on substrates can achieve the desired alignment of LCs. Using nanoparticles for LC alignment has similar quality to conventional alignment techniques, but it is less time consuming and cost-effective. Furthermore, nanoparticles can greatly improve the electro-optical properties of LC devices.
CRITICAL REVIEWS IN SOLID STATE AND MATERIALS SCIENCES
(2023)
Article
Chemistry, Physical
Gary Yu, Mark R. Wilson
Summary: This study investigates the self-assembly behavior of a perylene dye and develops atomistic and coarse-grained molecular models to simulate the process. The findings show that careful parameter optimization allows for an accurate reproduction of atomistic self-assembly behavior.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Materials Science, Multidisciplinary
Hee Seong Yun, Geonhyeong Park, Dong Ki Yoon
Summary: This study investigates the orientation of LCLCs in a capillary bridge surrounded by air walls made of glass and line-patterned silicon hybrid cells. The optical textures of different structures of LCLCs, such as uniaxial, escaped, and non-symmetric chiral structures, are directly observed and analyzed using polarized optical microscopy. This research has significant implications for dichroic optical films, optoelectronic devices, and sensors.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Multidisciplinary Sciences
Qing Zhang, Rui Zhang, Baoliang Ge, Zahid Yaqoob, Peter T. C. So, Irmgard Bischofberger
Summary: The study uses polarized shearing interference microscopy to investigate the structure and dynamics of lyotropic chromonic liquid crystals, revealing the formation and behavior of pure-twist disclination loops in the fluid. The size and behavior of these loops are determined by the balance between nucleation and annihilation forces, and are influenced by the twisting characteristics of the fluid.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Biochemistry & Molecular Biology
Simona Salerno, Maria Penelope De Santo, Enrico Drioli, Loredana De Bartolo
Summary: This study aimed to investigate the effects of nano- and micro-structured chitosan membranes on human keratinocyte stratification and differentiation. The results showed that membrane surface properties strongly influenced the behavior of human keratinocytes, with keratinocytes developing different epidermal structures on nanoporous and microporous CHT membranes. This approach could be a useful tool for testing the effects and toxicity of substances on human epidermal layers in tissue engineering.
Article
Chemistry, Multidisciplinary
Biagio Audia, Chiara Fedele, Caterina M. Tone, Gabriella Cipparrone, Arri Priimagi
Summary: Azobenzene-based light-responsive thin films show potential as smart cell-culture substrates due to their reversibly photo-patterned feature. This study investigates the surface stability of these films in water and a biologically relevant aqueous medium, revealing the blistering phenomenon caused by water-material interaction. The blistering can be prevented by changing the substrate, applying an additional coating layer, or controlling film permeability using light. The orientation of blisters can also be controlled with polarized light. A simple model based on osmotic pressure is proposed to explain blister formation.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Lorenza Spina, Federica Ciuchi, Caterina Maria Tone, Riccardo Barberi, Maria Penelope De Santo
Summary: This study investigates chirality in chromonic liquid crystals by doping with a strong helical-twisting-power peptide and confining in a spherical geometry. The results show that the geometrical constraint and the presence of the chiral dopant enhance the chiral effect, leading to a highly ordered helical superstructure. Additionally, the study demonstrates the potential for creating biocompatible and eco-friendly optical devices for sensor and anticounterfeiting applications.
Article
Chemistry, Multidisciplinary
Antonio Ferraro, Mauro Daniel Luigi Bruno, Giuseppe Papuzzo, Rosa Varchera, Agostino Forestiero, Maria Penolope De Santo, Roberto Caputo, Riccardo Cristofaro Barberi
Summary: Multilevel anticounterfeiting Physical Unclonable Function (PUF) tags based on thin films of silver (Ag), Zinc Oxide (ZnO), and PolyVinylPyrrolidone (PVP) are successfully demonstrated. The low adhesion of silver to glass and the resulting degradation during ZnO deposition are used to induce morphological randomness. The system exhibits low common minutiae for different tags and peculiar optical response due to plasmonic labels. It offers a cost-effective solution for practical object protection.
Article
Chemistry, Multidisciplinary
Fabrizio Corrado Adamo, Federica Ciuchi, Maria Penelope De Santo, Paola Astolfi, Isabelle Warner, Eric Scharrer, Michela Pisani, Francesco Vita, Oriano Francescangeli
Summary: The study demonstrates that nanoscale structural characterization of BCM films prepared using the Langmuir-Blodgett technique reveals stable molecular films forming over water, which can be transferred onto silicon substrates to create a bilayer structure with a bottom layer of flat molecules and an upper layer of upright molecules. This suggests that Langmuir-Blodgett films of BCMs offer a useful means to control the alignment of this class of liquid crystals.
Article
Chemistry, Physical
Lorenza Spina, Maria Penelope De Santo, Caterina Maria Tone, Michela Pisani, Francesco Vita, Riccardo Barberi, Federica Ciuchi
Summary: This study reports advances in understanding the supramolecular arrangement and induced chirality for the chromonic molecule Sunset Yellow and its interaction with salts and L-peptides. The research demonstrates the rise of enhanced chirality in Sunset Yellow microspheres and proposes two possible mechanisms for this phenomenon: intercalation of the chiral dopant or binding. These findings are significant for the potential use of these microspheres in optical and sensing applications.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Materials Science, Multidisciplinary
Antonio Ferraro, Giuseppe Emanuele Lio, Mauro Daniel Luigi Bruno, Sara Nocentini, Maria Penolepe De Santo, Diederik Sybolt Wiersma, Francesco Riboli, Roberto Caputo, Riccardo Cristoforo Barberi
Summary: This work utilizes a hidden photonic multilayer structure to protect a printed QR code on paper, enabling recognition under specific illumination conditions and providing resistance to cloning and tampering attacks. It can be easily integrated into an industrial supply chain to protect consumer goods.
ADVANCED MATERIALS TECHNOLOGIES
(2023)
Article
Chemistry, Multidisciplinary
Caterina Maria Tone, Alessandra Zizzari, Lorenza Spina, Monica Bianco, Maria Penelope De Santo, Valentina Arima, Riccardo Cristoforo Barberi, Federica Ciuchi
Summary: Microfluidics allows confinement of liquid crystals in micrometric spheres, providing rich interactions at the LCLC-microfluidic channel interfaces. By using a microfluidic flow-focusing device, pure and chiral doped SSY microdroplets were produced and their topological textures were studied. The precise control of LCLC microdroplets is crucial for applications in biosensing and anticounterfeiting.
Review
Chemistry, Multidisciplinary
Maria Penelope De Santo, Lorenza Spina, Federica Ciuchi
Summary: Chromonic liquid crystals have attracted attention due to their self-assembly in supramolecular structures and the possibility to induce chirality. This review focuses on the research on chiral chromonic liquid crystals confined in spherical geometry and compares the results with thermotropic liquid crystals. The effects of different anchoring conditions and chiral dopants on the topologies of commercially available nematic chromonics are investigated, suggesting a potential application in the sensor field.
APPLIED SCIENCES-BASEL
(2023)
