Liquid Crystalline Mesophases Research Articles

Enhanced supercapacitor performance through synergistic electrode design: Reduced graphene oxide-polythiophene (rGO-PTs) nanocomposite

In this investigation, we introduce an innovative method for the fabrication of a 2D/2D nanocomposite, involving the in-situ functionalization of graphene oxide (GO) with thiophene monomer. This approach employs a modified surfactant-based bi-solvent swollen liquid crystalline lamellar mesophase (SLCLM) nanoreactor system, utilizing dimethyl sulfoxide and water as primary solvents. The nanocomposite is formed via simultaneous reactions at both the edge and basal plane of GO with thiophene monomers, resulting in polymerization and reduction to generate graphene oxide-polythiophene (rGO-PTs) nanocomposite.We assess the pseudocapacitive properties of rGO-PTs in a 2 M HCl electrolyte. The cyclic voltammetry (CV) investigations reveal distinctive redox curves, indicative of the materials capacitive behaviour. In the galvanostatic charge–discharge (GCD) study, the rGO-PTs exhibits a discharge duration of 169.50 s within a potential window of −0.2 to 1 V at a current density of 7.5 A/g. This performance corresponds to a significantly higher specific capacitance of 1412 F/g, sustained over 10000 cycles as asymmetric capacitor. Notably, the rGO-PTs nanocomposite retains 106 % of its initial capacitance even after a number cycles, tested at a scan rate of 50 mV/s. The exceptional durability and electrochemical performance of the rGO-PTs nanocomposite position it as a promising alternative to conventional materials such as metals, metal oxides, pure carbonaceous substances, and polymers. The simplicity of the synthesis process, coupled with the nanocomposites outstanding electrochemical characteristics, underscores rGO-PTs potential for advancing in the field of energy storage and supercapacitor technology.

Theoretical Characterization of Liquid Crystalline Mesophases: Analysis with its link to Phase Transition Temperature

Theoretical Characterization of Liquid Crystalline Mesophases: Analysis with its link to Phase Transition Temperature

Superior electron mobility, red electroluminescence with high quantum efficiency from printable room temperature columnar liquid crystalline perylene bisimide

Synthesis of highly fluorescent compounds is currently a critical requirement to facilitate the economical and metal-independent manufacture of organic light-emitting diodes (OLEDs) on a large scale. This study presents a highly soluble, swallow tail based electron deficient perylene bisimide (PBIST) exhibiting room temperature columnar oblique (Colob) liquid crystalline behavior along with a high photoluminescence quantum yield, positioning itself as a promising candidate for efficient OLEDs. Incorporation of swallow tails helped in enhancing the solubility and reduction of the clearing points. This unique tailor-made molecular design with the liquid crystalline phase allowed a demonstration of n-type field effect mobility of 0.008 cm2 V−1s−1 when annealed in the liquid crystalline mesophase range (at 70 °C) which can be exploited in the fabrication of printable electronic devices. Capitalizing on the high charge transport and luminescence attributes of PBIST, a series of devices were fabricated by utilizing PBIST as a single emitter and dispersed at different concentrations of 0.3, 0.5 and 1 wt% in host material CBP. Impressively, doped devices featuring the CBP as a host at a 0.5 wt% PBIST concentration exhibited an external quantum efficiency (EQE) as high as 7 %, accompanied by a luminance of 1787 cd/m2. The high EQE is attributed mainly to the triplet–triplet annihilation (TTA) process. This notable EQE enhancement signifies a substantial stride towards expanding the utility of multifunctional columnar self-assembled materials for the advancement of OLEDs.

PH-Dependent Lyotropic Liquid Crystalline Mesophase and Ionization Behavior of Phytantriol-Based Ionizable Lipid Nanoparticles.

Self-assembled lipid nanoparticles (LNPs), serving as essential nanocarriers in recent COVID-19 mRNA vaccines, provide a stable and versatile platform for delivering a wide range of biological materials. Notably, LNPs with unique inverse mesostructures, such as cubosomes and hexosomes, are recognized as fusogenic nanocarriers in the drug delivery field. This study delves into the physicochemical properties, including size, lyotropic liquid crystalline mesophase, and apparent pKa of LNPs with various lipid components, consisting of two ionizable lipids (ALC-0315 and SM-102) used in commercial COVID-19 mRNA vaccines and a well-known inverse mesophase structure-forming helper lipid, phytantriol (PT). Two partial mesophase diagrams are generated for both ALC-0315/PT LNPs and SM-102/PT LNPs as a function of two factors, ionizable lipid ratio (α, 0-100 mol%) and pH condition (pH 3-11). Furthermore, the impact of different LNP stabilizers (Pluronic F127, Pluronic F108, and Tween 80) on their pH-dependent phase behavior is evaluated. The findings offer insights into the self-assembled mesostructure and ionization state of the studied LNPs with potentially enhanced endosomal escape ability. This research is relevant to developing innovative next-generation LNP systems for delivering various therapeutics.

Understanding the role of water in the lyotropic liquid crystalline mesophase of high-performance flexible supercapacitor electrolytes using a rheological approach

The effect of water on the structure, properties, and flexibility of lyotropic liquid crystalline (LLC) C12E23-LiCl-H2O gel electrolytes was explored. Structural techniques, such as X-ray Diffraction (XRD), Polarized Optical Microscopy (POM), and five dynamic measurements, were employed to examine the rheological properties of the LLC mesophase across various water contents. These analyses provided quantitative insights into the influence of water content and LiCl concentration on gel strength, gelation point, and structural recovery. The three-dimensional network of the gel encapsulates Li+ and Cl− ions within hydrophilic domains, showing significant performance in supercapacitor applications. The observed increase in storage modules with decreasing water content is attributed to variations in the quantity and average size of junction points owing to system entanglement. These research findings highlight that excess water molecules, which break down micellar connections, are responsible for the weakening of the gel. Conversely, at low water concentrations, the micellar domains entangle, displaying viscoelastic behavior akin to that of a transitory polymer network.

Discotic liquid crystals of transition metal complexes 60†: synthesis and π-acceptor abilities of novel discotic liquid crystals based on dithiolene nickel complex

We have synthesized thirteen novel metallomesogens based on dithiolene nickel complex showing π-acceptor properties: (o-C12OPhO)4DTNi (1), (m-C12OPhO)4DTNi (2), (p-C12OPhO)4DTNi (3), [o,m-(C12O)2PhO]4DTNi (4), [m,m′-(C12O)2PhO]4DTNi (5), [p,m-(CnO)2PhO]4DTNi (6: n = 10(a), 12(b), 14(c), 16(d)) and Cl-[p,m-(CnO)2PhO]4DTNi (7a–d). By using plarizing microscopic observations, differential scanning chalorimetry, and temperature-variable X-ray diffraction studies, the columnar liquid crystalline mesophases were established for the 6a–d and 7a–d derivatives. It was also revealed from the electrochemical measurements that each of the complexes of 1–7 showed good π-acceptor abilities. In particular, the derivatives, Cl-[p,m-(CnO)2PhO]4DTNi (7a–d), exhibit the most positive reduction potential from +0.08 to +0.07 V versus. SCE.

Inverse Cubic and Hexagonal Mesophase Evolution within Ionizable Lipid Nanoparticles Correlates with mRNA Transfection in Macrophages.

mRNA lipid nanoparticle (LNP) technology presents enormous opportunities to prevent and treat various diseases. Here, we developed a novel series of LNPs containing ionizable amino-lipids showing a remarkable array of tunable and pH-sensitive lyotropic liquid crystalline mesophases including the inverse bicontinuous cubic and hexagonal phases characterized by high-throughput synchrotron radiation X-ray scattering. Furthermore, with an interest in developing mRNA therapeutics for lung macrophage targeting, we discovered that there is a strong correlation between the mesophase transition of the LNPs during acidification and the macrophage association/transfection efficiency of mRNAs. The slight molecular structural differences between the SM-102 and ALC-0315 ionizable lipids are linked to the LNP's ability to transform their internal structures from an amorphous state to the inverse micellar, hexagonal, and finally cubic structures during endosomal maturation. SM-102 LNPs showed exceptionally improved transfection efficiency due to their ability to form a cubic structure at a lower pH than the ALC-0315 analogues, which remained within the hexagonal structure, previously attributed to promoting endosomal escape of the ionizable LNPs. Overall, the new knowledge draws our attention to the important role of mesophase transition in endosomal escape, and the novel LNP libraries reported herein have broad prospects for advancing mRNA therapeutics.

Oxazoline derivatives exhibiting chiral liquid crystalline mesophases

ABSTRACT We have designed new chiral mesogens, OXm/n, containing an oxazoline chiral motif derived from natural L-serine amino acid. Our effort was concentrated on the evaluation of the synthetic accessibility of these new compounds and preserving their optical purity, which was determined using chiral high-performance liquid chromatography. We established materials mesomorphic properties and confirmed the phase identification by X-ray scattering studies. Depending on the ratio between the terminal alkyl chain lengths, the studied materials exhibited various smectic mesophases. The derivatives OXm/n with conformationally rigid oxazoline chiral moiety were compared with the structurally similar smectogens, ZLm/n, having a flexible (S)-lactate chiral unit, in order to investigate the effect of rigidisation of the chiral unit on the mesomorphic properties.

Synthesis and characterization of dendronized side chain liquid crystalline Poly(2-oxazoline)s towards biomimetic ion channels

The polymerization of dendronized monomers is an attractive option to synthesize liquid crystalline columnar polymers with side chain dendrons. Following this approach, we report for the first time in the present study the synthesis of a family of side chain liquid crystalline (SCLC) poly(2-oxazoline)s, poly(2-(3,4,5-tris(4-dodecyloxybenzyloxy)phenyl)-2-oxazoline) (PTOx) from its oxazoline monomer precursor, 2-(3,4,5-tris(4-dodecyloxybenzyloxy)phenyl)-4,5-dihydro-1,3-oxazole) (TAPOx), by cationic ring-opening polymerization (CROP). The optimisation of the reaction parameters (temperature, type of initiator, terminating agent, solvent and monomer concentration), combined with the nature of the CROP allowed us to obtain high molecular weight SCLC poly(2-oxazoline)s. NMR investigations were consistent with the targeted molecular weights of the synthesized PTOx and the living nature of TAPOx polymerization. Regarding the mesomorphic characterization, all synthesized acyl-substituted poly(ethyleneimine)s exhibited liquid crystalline mesophases in a broad temperature range. XRD studies demonstrated that these dendronized poly(2-oxazoline)s self-assemble into columnar structures. Mesomorphic and thermal properties suggest that these family of poly(2-oxazoline)s could be excellent candidates to build up membranes for proton transport applications.

Cholesterol-substituted 3,4-ethylenedioxythiophene (EDOT-MA-cholesterol) and Poly(3,4-ethylenedioxythiophene) (PEDOT-MA-cholesterol)

Cholesterol is a rigid, crystalline, non-polar natural substance that exists in animal blood and cell membranes. Some of its derivatives are known to form ordered liquid crystalline mesophases under suitable conditions. In this work, we carefully examined the influence of cholesterol substitution on the characteristics of 3,4-ethylenedioxythiophene (EDOT-MA-cholesterol) and its corresponding polymer poly(3,4-ethylenedioxythiophene) (PEDOT-MA-cholesterol) synthesized by both chemical and electrochemical polymerization. We found evidence for an ordered lamellar (smectic-like) structure in the EDOT-MA-cholesterol monomer by differential scanning calorimetry (DSC), polarized optical microscopy (POM), and X-ray diffraction techniques. The ordered phase was observed to form on cooling from the isotropic melt at about 80 °C. Due to the insulating and bulky cholesterol side group on the EDOT monomer, we found that there was a maximum charge density for electrodeposition at ∼ 0.155 C.cm−2. A series of electrodepositions were performed from 0 to 0.155 C.cm−2 for probing the change of the charge transport with more charges used for the electrodeposition. We found that the impedance increased in the high-frequency range (above 104 Hz) and decreased in the low-frequency range (below 102 Hz). Three equivalent circuit models were proposed for fitting impedance data at different charge densities for a better understanding of the film growth process. The suppressed cyclic voltammogram (CV) of PEDOT-MA-cholesterol showed that the charge storage capability was essentially eliminated in the thickest films. The limited doping of the films was corroborated by their diminished electrochromic behavior, polaron-dominating absorption in UV-vis, overoxidized S 2p X-ray Photoelectron Spectroscopy (XPS) signal of electrodeposited films, and proton Nuclear Magnetic Resonance (1H NMR) of chemically polymerized samples. Dense film morphologies were confirmed by scanning electron microscopy (SEM). Grazing incident X-ray diffraction (GIWAXS) indicated the disrupted stacking of conjugated chains, which correlated with the decreased conductivity of the PEDOT-MA-cholesterol films. The measurement of the electrical conductivity gave a value of around 3.30 × 10−6 S.cm−1 which is about six orders of magnitude lower than has been seen in PEDOT (∼3 S.cm-1).

Novel chiral 1,4-bis(β-cyanostyryl)benzene liquid crystals with high circularly polarized luminescence tuned by length of alkyl chains

Although some AIE-based CPL materials had been presented, the design and synthesis novel AIE-based CPL materials and studies on the relationship of structure–property were still a challenging work. Herein, series of novel 1,4-bis(β-cyanostyryl)benzene derivatives 2a, 2b and 2c bearing chiral alkyl chains were prepared, and the influence of length of alkyl chains on CPL properties were investigated for the first time. Samples 2a, 2b and 2c were synthesized by simple procedure with 83–88 % yields. Samples 2b and 2c with longer chains displayed the typical liquid crystalline properties. All of them showed strong fluorescence in both solution and aggregated states. Their chiroptical properties of CD and CPL signals were influenced strongly by the molecular stacking in various states. The self-assembly in mesophase resulted in the best chiroptical properties. The longer alkyl chains contributed to stronger CD and CPL signals. The highest glum value attained 1.6 × 10-2 for sample 2c based on the effective chirality transfer and amplification of liquid-crystalline mesophase.

Synthesis and study the mesomorphic behaviour of some new 1,3,4-thiadiazoline derivatives

ABSTRACT Investigation of mesomorphic properties of new 1,3,4-thiadiazolines (which are synthesised via many steps in Scheme 1) was carried out in this study. These compounds are designed to have a heterocyclic unit, a carboxylate linkage group and a polar ether chain at the end of the molecule adjacent to the benzene ring, which enhance the dipolar interactions forces (varied from one to eight carbons) to investigate the association properties of their phases. The structure of the target compounds and the intermediates were confirmed by 1H NMR, 13C NMR, mass and FTIR spectral techniques. Polarised microscopic studies revealed that all the compounds in the series exhibited enantiotropic liquid crystalline properties. This was further confirmed using differential scanning calorimetric experiments. The synthesised compounds type [V]n in this study displayed different liquid crystalline mesophases and the homologous [V] having an alkoxy terminal group (n = 1–3) exhibited nematic phase, whilst the last derivatives of the series (4–8), displayed smectic A phase.

Amyloid Fibrils Enhance the Topical Bio-Adhesivity of Liquid Crystalline Mesophase-Based Drug Formulations.

Despite their distinctive secondary structure based on cross β-strands, amyloid fibrils (AF) are stable fibrous protein aggregates with features similar to collagen, one of the main components of the extracellular matrix, and thus constitute a potential scaffold for enhancing cell adhesion for topical applications. Here, the contribution of AF to skin bio-adhesivity aiming toward topical treatments is investigated. Liquid crystalline mesophase (LCM) based on phytantriol is formulated, with the aqueous phase containing either water or a solution of 4wt% amyloid fibrils. Then resveratrol is added as a model anti-inflammatory molecule. The developed LCM presents a double gyroid Ia3d mesophase. The incorporation of AF into the LCM increases its bio-adhesive properties. In vitro release and ex vivo permeation and retention confirm the controlled release property of the system, and that resveratrol is retained in epidermis and dermis, but is also permeated through the skin. All formulations are biocompatible with L929 cells. The in vivo assay confirms that systems with AF lead to a higher anti-inflammatory effect of resveratrol. These results confirm the hypothesis that the incorporation of AF in the LCM increases the bio-adhesiveness and efficiency of the system for topical treatment, and consequently, the therapeutical action of the encapsulated drug.

Self-assembly of cellulose nanocrystals confined to square capillaries.

Biological systems exploit restricted degrees of freedom to drive self-assembly of nano- and microarchitectures. Simplified systems, such as colloidal nanoparticles that behave as lyotropic liquid crystalline mesophases in confined geometric spaces, may be used to mimic biological structures. Cellulose nanocrystals (CNCs) are colloidally stable nanoparticles that self-assemble into chiral nematic (ChN) liquid crystalline mesophases. To date, the self-assembly of ChN mesophases of CNCs has been studied under confinement conditions within curved surfaces or under drying conditions that impose curvatures that can be exploited to control ChN ordering; however, their self-assembly has not been investigated in geometries with square cross-sections under static conditions. Here, we show that because of surface anchoring on perpendicular surfaces, the ChN CNC phase is unable to bend with the 90° angle of the square capillary under increasing confinement. Instead, the ChN phase forms radial layers in the shape of concentric squircle shells. With increasing layer distance from the capillary wall, the squircles transition into concentric cylinder shells. In larger capillaries, the radial shell layers appear as a continuous spiral pattern that engulfs fragmented ChN pseudolayers, a defect to accommodate the cylindrical confinement of the mesophase. These results are useful for understanding the fundamentals of self-assembling systems and development of new technologies.

Lyotropic Liquid Crystalline Mesophases of Lithium Dihydrogen Phosphate and 10-Lauryl Ether Stabilized with Water or Phosphoric Acid.

The molten phase of transition metal and lithium salts self-assemble with non-ionic surfactants to form lyotropic liquid crystalline (LLC) mesophases, which are important in the development of gel-electrolytes and mesoporous materials. Here, we show that LiH2 PO4 forms a semi-stable LLC mesophase with 10-lauryl ether (C12 H25 (OCH2 CH2 )10 OH, C12 E10 ), decoded as Li-EO-X (X is LiH2 PO4 /C12 E10 mole ratio and between 2 and 200). The stability of the Li-EO-X phase is improved by increasing salt concentration (X>20) in the media. The semi-stable Li-EO-X mesophase is further stabilized by adding either water by controlling the humidity or H3 PO4 (PA) to the media. The phase behaviour of the above samples was investigated using POM, XRD, conductivity, and ATR-FTIR measurements. The addition of PA not only brings stability and higher conductivity (increase from 0.1 to 8.9 mS/cm) to the mesophase but also produce an LLC gel-electrolyte with a high buffer capacity that may be useful and important in various applications.

Edible cellulose-based colorimetric timer.

A biocompatible and edible colorimetric timer is obtained by exploiting the dynamic colour changes of the cholesteric liquid crystalline mesophases of hydroxypropyl cellulose (HPC) in aqueous suspensions. The edible timer is encapsulated between semi permeable membranes made of shellac. The cholesteric organisation of the HPC provides vibrant colouration, while the shellac layers allow tuning of the evaporation rate of water from the mesophase, which results in a colour change. Due to the biocompatibility of the components and the direct read-out of the system, i.e. the colour change can be visually detected, and the developed timer can be implemented as a colorimetric sensor with potential to be used in food packaging, and as a smart labelling system.

Boost Up the Mechanical and Electrical Property of CNT Fibers by Governing Lyotropic Liquid Crystalline Mesophases with Aramid Polymers for Robust Lightweight Wiring Applications

Monofilament type of polyaromatic amide (PA) and carbon nanotube (CNT) composite fibers is presented. A concept of a lyotropic liquid crystal (LLC) constructed via a spontaneous self-assembly is introduced to mitigate the extremely low compatibility between PA and CNT. These approaches provide an effective co-processing route of PA and CNT simultaneously to fabricate the uniform, continuous, and reliable composite fibers through a wet-spinning. Interestingly, the addition of a small amount PA into the dope solution of CNT governs the LLC mesophase not only in a spinneret stage but also in a coagulant region. Thus, the developed PA/CNT composite fibers have the high uniaxial orientational order and the close interfacial packing compared to the pure CNT fibers. The PA/CNT composite fibers achieve the outstanding tensile strength, electrical conductivity, and electrochemical response, while maintaining a lightweight. They also exhibit the chemical, mechanical, and thermal robustness. All of these advantages can make flexible, sewable, and washable PA/CNT composite fibers ideal nanocomposite materials for use in next-generation information and energy transporting system by replacing conventional metal electrical conductors.Graphical The lyotropic liquid crystal self-assembly governed by doping the aramid polymers shows the ability to construct mechanically strong and continuous carbon nanotube-based composite fibers that can be used in the lightweight and robust electrical wiring for extreme environmental applications.

Chitosan/Lactic Acid Systems: Liquid Crystalline Behavior, Rheological Properties, and Riboflavin Release In Vitro.

Chitosan or its derivatives exhibit lyotropic liquid crystalline mesophases under certain conditions due to its semi-rigid structures. This work describes the development of chitosan-based biocompatible systems that include new components: lactic acid and non-ionic surfactants. Polarized optical microscopy studies revealed that these systems are capable of forming gels or lyotropic liquid crystals (LLCs) in a certain range of chitosan and lactic acid concentrations. According to the viscosity studies, the rheological flow of the LLCs can be accurately described by the Casson flow model. The intermolecular interactions of the LLC components were studied by FTIR spectroscopy. According to the FTIR data, hydrogen bonding is supposed to be responsible for the formation of the LLCs. In the studied systems, this LLC complex exists as the [ChitH+·CH3-CH(OH)-COO-] ion pair. The studied gel and LLCs were shown to possess the most prolonged release capabilities for riboflavin among similar binary LLC systems. The supramolecular organization and rheological characteristics of the studied chitosan-based systems were found to affect the release of riboflavin.

Tailoring the self-assembly of lipid-based lyotropic liquid crystalline mesophases with biocompatible ionic liquid aqueous solutions

Interest in lipid-based lyotropic liquid crystalline nanoparticles (LCNPs) as drug delivery vehicles continues to grow, owing to their unique structural features. The structure of these particles can be controlled to suit specific applications, through tailoring the lipid composition and solvent conditions. Ionic liquids (ILs) are liquid salts comprising tailorable cations and anions, of which some are known to support the self-assembly of amphiphiles, and hence can be used as designer solvents for LCNPs. We employed dynamic light scattering, small angle X-ray scattering, and cryogenic transmission electron microscopy to examine the particle size and lyotropic liquid crystalline mesophase behavior of monoolein (MO)-based LCNPs in aqueous solutions containing 13 choline ILs with a selection of amino acid and carboxylate anions at 6 concentrations 20, 10, 5, 1, 0.33, and 0.16 wt%. Our results show the formation of LCNPs with various liquid crystalline nanostructures, including the inverse bicontinuous primitive cubic (Q2) phase with the Im3m crystallographic space group, the inverse hexagonal (H2), and the inverse discontinuous micellar cubic (I2) phases. The internal nanostructures of the MO nanoparticles depended on three main factors, the anion of the ILs, the IL concentration, and the pH of the solution. This study elucidates the potential application of IL solvents as a powerful tool to tailor the internal nanostructure of MO-based LCNPs, and advances the exploration of IL-enabled responsive LCNPs systems as prospective nanocarriers.

Structure and dynamics of tail-free discotic liquid crystals: Simulations of fluorinated triphenylene.

Recently, a large family of at least 14 discotic liquid crystals was discovered that are exceptions to the conventional paradigm that discotic mesogens tend to feature long, flexible tails on their periphery. To understand why these materials are liquid crystals, as well as the structural determinants of discotic phase behavior, we studied a group of closely related small tail-free disk-like molecules, including both mesogenic and non-mesogenic compounds differing only in the position of a single fluorine substituent. The rigidity and structural simplicity of these molecules make them well suited to for study by large, fully all-atom simulations. Using a combination of static and dynamic metrics, we were able to identify several key features of the columnar mesophase and, thereby, conclusively identify a columnar liquid crystalline mesophase present in a subset of our systems. Our simulations feature molecules hopping between columns in the columnar mesophase and distinctive molecular rotations in 60° steps about the columnar axis. The ability to create and characterize columnar mesophases in silico provides a potent tool for untangling the structural determinants of liquid crystalline behavior in these and other tail-free discotic liquid crystals.