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Stimuli-responsive circularly polarized luminescence (CPL) materials based on cholesteric liquid crystal (CLC) platforms show great promise for applications in information encryption and anticounterfeiting. In this study, we constructed a mercury ion-responsive CPL system in CLCs by controlling the conjugation degree of axially chiral binaphthyl derivatives. Two chiral binaphthyl derivatives (R/S-1 and R/S-2) were initially used as chiral dopants to demonstrate that CPL inversion (glum values from 0.5/-0.44 to -0.53/0.48) in CLCs could be achieved by modulating the conjugation degree of the chiral binaphthyls. Based on this concept, the thioacetal binaphthyl R-2S was developed and used as a mercury-responsive chiral dopant in CLCs. Under Hg ion treatment, the CPL sign inverted (glum value changed from 0.22 to -0.29) due to the transformation of the thioacetal into an aldehyde group. Additionally, the mercury ion-responsive CPL material was applied in information encryption.

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In this paper, we give an overview of novel main-chain azobenzene-based fluorinated poly(arylene ether)s with different content of azo groups, aiming at providing a better understanding of the link between a number of N═N bonds and the macroscopic response of the material. We discuss chemical synthesis and molecular structure and report on a comprehensive analysis of the polymer properties, thermal behavior, and mechanical strength. We show that a higher content of azobenzene moieties reduces the mechanical strength of the polymer materials. On the other hand, polymers with a higher content of azobenzene demonstrate higher values of induced birefringence due to a larger number of azobenzene in the trans form. The photoisomerization constants of all polymers fall within a very close range. The minor variations are attributed to the number of azobenzene groups in the polymer composition and the conformational arrangements of the polymer chain packing. The developed light-sensitive polymers were employed for dynamic control and manipulation of the liquid crystal orientation by polarization of the incident light. After the double irradiation of the substrates using appropriate photomasks, we made patterned cells that consist of domains with different high-resolution liquid crystal director orientations.

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This review explores the integration of graphene and liquid crystals to advance sensor technologies across multiple domains, with a focus on recent developments in thermal and infrared sensing, flexible actuators, chemical and biological detection, and environmental monitoring systems. The synergy between graphene's exceptional electrical, optical, and thermal properties and the dynamic behavior of liquid crystals leads to sensors with significantly enhanced sensitivity, selectivity, and versatility. Notable contributions of this review include highlighting key advancements such as graphene-doped liquid crystal IR detectors, shape-memory polymers for flexible actuators, and composite hydrogels for environmental pollutant detection. Additionally, this review addresses ongoing challenges in scalability and integration, providing insights into current research efforts aimed at overcoming these obstacles. The potential for multi-modal sensing, self-powered devices, and AI integration is discussed, suggesting a transformative impact of these composite sensors on various sectors, including health, environmental monitoring, and technology. This review demonstrates how the fusion of graphene and liquid crystals is pushing the boundaries of sensor technology, offering more sensitive, adaptable, and innovative solutions to global challenges.

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The reverse-mode smart windows, which usually fabricated by polymer stabilized liquid crystal (PSLC), are more practical for scenarios where high transparency is a priority for most of the time. However, the polymer stabilized cholesteric liquid crystal (PSCLC) film exhibits poor spacing stability due to the mobility of CLC molecules during the bending deformation. In this work, a reverse-mode PSCLC flexible film with excellent bending resistance was fabricated by the construction of polymer spacer columns. The effect of the concentration of the polymerizable monomer C6M and chiral dopant R811 on the electro-optical properties and polymer microstructure of the film were studied. The sample B2 containing 3 wt% of C6M and 3 wt% R811 presented the best electro-optical performance. The electrical switch between transparent and opaque state of the flexible PSCLC film after bending not only indicated the excellent electro-optical switching performance, but also demonstrated the outstanding bending resistance of the sample with polymer spacer columns, which makes the PSCLC film containing polymer spacer columns have a great potential to be applied in the field of flexible devices.

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Tau is a protein found in the central nervous system (CNS) and is involved in stabilizing microtubules in axons. Given the link between Tau levels in the body and Alzheimer's disease (AD), there is a demand for straightforward and precise strategies to detect Tau in body fluids. In this study, we report liquid crystal (LC)-based sensors for the real-time detection of Tau protein, a well-known AD biomarker. The sensor uses a detection method based on the orientation change of the LC because of the competitive biomolecular interaction between Tau and Tau aptamers with the cationic polymer poly-L-lysine (PLL). Tau and its aptamers form stable complexes through electrostatic interactions. Owing to the consumption of the aptamer, the positively charged PLL fails to interact with the aptamer but binds to the negatively charged 1.2-dioleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) sodium salt (DOPG). The PLL and DOPG complex alters the orientation of the LC to ensure a planar anchoring of the 4-cyano-4'-pentylbiphenyl (5CB)/aqueous interface; this anchoring intensifies with increasing Tau concentration, thus enabling the observation of a bright optical image. Our LC-based sensor demonstrated a low detection limit of 2.77 pg/mL in phosphate buffered saline (PBS) and 10.86 pg/mL and 19.31 pg/mL in human serum and plasma, respectively. Moreover, it is anticipated to be suitable for point-of-care diagnosis of AD because it does not require specialized analytical equipment and only requires microliters of sample.

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Liquid-liquid phase separation, whereby two liquids spontaneously demix, is ubiquitous in industrial, environmental, and biological processes. While isotropic fluids are known to condense into spherical droplets in the binodal region, these dynamics are poorly understood for structured fluids. Here, we report the unique observation of condensate networks, which spontaneously assemble during the demixing of a mesogen from a solvent. Condensing mesogens form rapidly elongating filaments, rather than spheres, to relieve distortion of an internal smectic mesophase. As filaments densify, they collapse into bulged discs, lowering the elastic free energy. Additional distortion is relieved by retraction of filaments into the discs, which are straightened under tension to form a ramified network. Understanding and controlling these dynamics may provide different avenues to direct pattern formation or template materials.

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Antibiotics are essential for treating infections and reducing risks during medical interventions. However, many commonly used antibiotics lack the physiochemical properties for an efficient oral administration when treating systemic infection. Instead, we are reliant on intravenous delivery, which presents complications outside of clinical settings. Developing novel formulations for oral administration is a potential solution to this problem. We engineered hexosome and cubosome liquid crystal nanoparticles (LCNPs) characterized by small-angle X-ray scattering and cryogenic transmission electron microscopy, and could encapsulate the antibiotics vancomycin (VAN) and clarithromycin (CLA) with high loading efficiencies. By rationally choosing stable lipid building blocks, the loaded LCNPs demonstrated excellent resilience against enzymatic degradation in an in vitro gut model LCNP stability is crucial as premature antibiotic leakage can negatively impact the gut microbiota. In screens against the representative gut bacteria Enterococcus faecalis and Escherichia coli, our LCNPs provided a protective effect. Furthermore, we explored co-administration and dual loading strategies of VAN and CLA, and demonstrated effective loading, stability and protection for E. faecalis and E. coli. This work represents a proof of concept for the early-stage development of antibiotic-loaded LCNPs to treat systemic infection via oral administration, opening opportunities for combination antibiotic therapies.

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Traditionally used phenylethylamine iodide (PEAI) and its derivatives, such as ortho-fluorine o-F-PEAI, in interfacial modification, are beneficial for perovskite solar cell (PSC) efficiency but vulnerable to heat stability above 85 °C due to ion migration. To address this issue, we propose a composite interface modification layer incorporating the discotic liquid crystal 2,3,6,7,10,11-hexa(pentoxy)triphenylene (HAT5) into o-F-PEAI. The triphenyl core in HAT5 promotes π-π stacking self-assembly and enhances its interaction with o-F-PEAI, forming an oriented columnar phase that improves hole extraction along the one-dimensional direction. HAT5 repairs structural defects in the interfacial layer and retains the layered structure to inhibit ion migration after annealing. Ultimately, our approach increases the efficiency of solar cells from 23.36% to 25.02%. The thermal stability of the devices retains 80.1% of their initial efficiency after aging at 85 °C for 1008 hours without encapsulation. Moreover, the optimized PSCs maintained their initial efficiency of 82.4% after aging under one sunlight exposure for 1008 hours. This study provides a novel strategy using composite materials for interface modification to enhance the thermal and light stability of semiconductor devices.

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Gyroid, double diamond and the body-centred "Plumber's nightmare" are the three most common bicontinuous cubic phases in lyotropic liquid crystals and block copolymers. While the first two are also present in solvent-free thermotropics, the latter had never been found. Containing six-fold junctions, it was unlikely to form in the more common phases with rod-like cores normal to the network columns, where a maximum of four branches can join at a junction. The solution has therefore been sought in side-branched mesogens that lie in axial bundles joined at their ends by flexible "hinges". But for the tightly packed double framework, geometric models predicted that the side-chains should be very short. The true Plumber's nightmare reported here, using fluorescent dithienofluorenone rod-like mesogen, has been achieved with, indeed, no side chains at all, but with 6 flexible end-chains. Such molecules normally form columnar phases, but the key to converting a complex helical column-forming mesogen into a framework-forming one was the addition of just one methyl group to each pendant chain. A geometry-based explanation is given.

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A novel room-temperature liquid crystal of tetraphenylethylene derivative (TPE-DHAB) was synthesized using an ionic self-assembly strategy. The TPE-DHAB complex exhibits typical aggregation-induced emission properties and a unique helical supramolecular structure. Moreover, the generation and handedness inversion of circularly polarized luminescence (CPL) can be achieved through further chiral solvation, providing a facile approach to fabricate room-temperature liquid crystalline materials with controllable supramolecular structures and tunable CPL properties through a synergistic strategy of ionic self-assembly and chiral solvation process.

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This review article mainly delves into the comprehensive development, thermal stabilization, characteristics, and applications of Blue Phase III (BPIII) derived from non-calamitic, mainly T-shaped and bent-core liquid crystals (BCLC). The discussion begins with discovering and characterizing various liquid crystal (LC) phases of BCLCs, emphasizing the significance of the nematic (N) phase in three and four-ring BCLCs. Following this, the focus shifts to the stabilization, properties, and potential applications of BPIII, particularly those derived from non-conventional liquid crystals. The review highlights the exceptional electro-optical (E-O) properties of BPIII, including high Kerr constants and distinct phase transitions. Studies reveal the impact of chirality on thermal behavior, microscopic observations, and the influence of molecular structures on mesophase formation. Investigations into asymmetrical chiral liquid crystal diads and hydrogen-bonded complexes underscore the importance of molecular design in expanding BPIII ranges. Furthermore, achiral unsymmetrical BCLC designs reveal significant insights into the interplay between molecular structure, phase transitions, and E-O behavior. Additionally, the structural transformation and E-O properties of highly polar BCLCs are examined to stabilize BPIII at room temperature, achieving notable Kerr constants and low voltage requirements. These collective studies provide a thorough understanding of BPIII and its promising applications in materials science and technology.

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This paper reports the design and development of thin-film resonant absorbers for narrowband and multiband operation in the frequency regions centered at 10 GHz. The structure of the resonant metasurface absorber (RMA) is based on a liquid crystal polymer (LCP) thin-film spacer with a copper patch array on the front surface and un-patterned copper film on the back surface of the LCP film. The design and simulation works were carried out using full-wave analysis of the RMA characteristics. The copper-based periodic patch array acts as a metasurface. The perfect RMA for a given LCP film thickness can be obtained through impedance optimization by adjustment of the dimensions of the lattice periods. The electric and magnetic field distributions were studied. The resonant film absorber based on a 100 µm thick LCP film has an electrical thickness of λ / 300 at 10 GHz. The experimental work was conducted using a narrowband RMA prototype consisting of 11 × 11 cells. The measured result of the resonant absorption is at 10.1 GHz, which is in close agreement with the design frequency of 10 GHz. For multiband functionality, double- and quad-band film resonant absorbers have been designed based on a coplanar supercell utilizing the superposition of the resonance effect. The LCP film-based absorbers have the potential to be used in EM shielding and sensing applications in centimeter-wave applications.

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BACKGROUND: Liquid crystal monomers (LCMs) have been classified as emerging organic pollutants. Efficient isolation and extraction is a critical step in the determination, and then knowing the occurrence and distribution of LCMs in environmental waters. However, the reported sample preparation techniques still suffer some dilemmas such as using large amount of organic solvent, low extraction capacity, tedious operation procedure and employment of expensive extraction column. To circumvent the disadvantages, new extraction format and adsorbent with quickness, less consumption of organic solvent, superior extraction performance and low cost should be developed for the analysis of LCMs. RESULTS: Using 1H,1H,2H,2H-heptadecafluorodecyl acrylate and 9-vinylanthracene as mixed functional monomers, a task specific magnetic adsorbent (TSMA) was prepared by one-pot hydrothermal technique for the highly efficient capture of LCMs under magnetic solid phase extraction (MSPE) format. Due to the abundant functional groups, the developed TSMA/MSPE presented satisfactory capture performance towards LCMs. Satisfactory enrichment factors (132-212) and high adsorption capacity (18 mg/g) were obtained. Additionally, the relevant adsorption mechanism was studied by the combination of density functional theory calculation and experiments about adsorption kinetics and adsorption isotherm. Under the beneficial conditions, a sensitive and reliable method for the monitoring of studied LCMs in environmental waters was established by the combination of TSMA/MSPE with HPLC equipped with diode array detector (DAD). The achieved limits of detection and spiked recoveries were 0.0025-0.0061 µg/L and 81.0-112 %, respectively. Finally, the developed method was employed to monitor LCMs levels in the North Creek watershed of Jiulong River. SIGNIFICANCE AND NOVELTY: The current study provided a new adsorbent for quick and efficient capture of LCMs at trace levels. In addition, a sensitive, reliable and anti-intereference method for the monitoring of trace LCMs in actual waters was established. Moreover, for the first, the contents, occurrence and distribution of LCMs in North Creek watershed was investigated based on the developed method.

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Chiral liquid crystals (CLCs) self-assemble into a helical structure and can efficiently reflect circularly polarized light with corresponding handedness. Utilizing a curved glass substrate and polymerization of photoaligned CLCs, the operation of focusing and diffraction of incident light can be performed efficiently by a single component. When focusing and diffraction in a planar CLC cell are combined between two glass plates, the imaging suffers from astigmatism in the resulting spectrum. In this work, we demonstrate the operation of a spectrometer with low astigmatism using a polymerized CLC layer on a curved substrate. Two samples are fabricated, and the resulting components are operating in the wavelength range of 500-650 nm. Numerical optical modeling is used to minimize transverse aberrations and obtain a highly linear mapping on a camera sensor. In this way, it is demonstrated that a single reflective thin-film optical CLC component with a thickness of only a few micrometers can be used to realize a compact and efficient spectrometer.

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Liquid crystal elastomers (LCEs), consisting of polymer networks and liquid crystal mesogens, show a reversible phase change under thermal stimuli. However, the kinetic performance is limited by the inherently low thermal conductivity of the polymers. Transforming amorphous bulk into a fiber enhances thermal conductivity through the alignment of polymer chains. Challenges are present due to their rigid networks, while cross-links are crucial for deformation. Here, we employ hydrodynamic alignment to orient the LCE domains assisted by controlled in situ cross-linking and to remarkably reduce the diameter to submicrons. We report that the intrinsic thermal conductivity of LCE fibers at room temperature reaches 1.44 ± 0.32 W/m-K with the sub-100 nm diameter close to the upper limit determined in the quasi-1D regime. Combining the outstanding thermal conductivity and thin diameters, we anticipate these fibers to exhibit a rapid response and high force output in thermomechanical systems. The fabrication method is expected to apply to other cross-linked polymers.

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Liquid crystal elastomers (LCEs) exhibit unique mechanical properties of soft elasticity and reversible shape-changing behaviors, and so serve as potentially transformative materials for various protective and actuation applications. This study contributes to filling a critical knowledge gap in the field by investigating the microscale mesogen organization of nematic LCEs with diverse macroscopic deformation. A polarized Fourier transform infrared light spectroscopy (FTIR) tester is utilized to examine the mesogen organizations, including both the nematic director and mesogen order parameter. Three types of material deformation are analyzed: uniaxial tension, simple shear, and bi-axial tension, which are all commonly encountered in practical designs of LCEs. By integrating customized loading fixtures into the FTIR tester, mesogen organizations are examined across varying magnitudes of strain levels for each deformation mode. Their relationships with macroscopic stress responses are revealed and compared with predictions from existing theories. Furthermore, this study reveals unique features of mesogen organizations that have not been previously reported, such as simultaneous evolutions of the mesogen order parameter and nematic director in simple shear and bi-axial loading conditions. Overall, the findings presented in this study offer significant new insights for future rational designs, modeling, and applications of LCE materials.

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Many polypeptides form stable, helical secondary structures enabling the formation of lyotropic liquid crystalline (LLC) phases. Contrary to the well-studied polyglutamate, their counterparts based on polyaspartates exhibit a much lower helix inversion barrier. Therefore, the helix sense is not solely dictated by the chirality of the amino acid used, but additionally by the nature and conformation of the polymer sidechain. In this work, polymers responsive to irradiation with visible light are designed achieving conformational transitions from helix-to-coil and helix-to-helix. The synthesis and the application as LLC mesogens of several (co-)polyaspartates bearing ortho-fluorinated azobenzene (FAB) as a photochromic group are presented. Many of the obtained polymers undergo changes in their secondary structure upon E-Z-isomerization of the FAB-containing sidechain. Of special interest are copolymers that exhibit photo-responsive helix inversion without loss of their helical secondary structure. These copolymers form stable LLC phases in helicogenic solvents, where the effect of photo-switching on the macroscopic behavior is studied by NMR spectroscopy. Especially, the irradiation of the different LLC phases of the helix inversion polymers displays a change in the LLC order experienced by the solvent. These peculiar properties are promising for future applications as photo-responsive alignment media for structure elucidation in NMR.

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The rapid and accurate identification of live pathogens with high proliferative ability is in great demand to mitigate foodborne infection outbreaks. Herein, we have developed an ultrasensitive image-based aptasensing array to directly detect live Salmonella typhimurium (S.T) cells. This method relies on the long-range orientation of surfactant-decorated liquid crystals (LCs) and the superiority of aptamers (aptST). The self-assembling of hydrophobic surfactant tails leads to a perpendicular/vertical ordered film at the aqueous/LC interface and signal-off response. The addition of aptST perturbed LCs' ordering into a planar/tilted state at the aqueous phase due to electrostatic interactions between the surfactant with the aptST, and a signal-on response. Following the conformational switch of aptST in the presence of live S. typhimurium, a relative reversing signal-off response was observed upon the target concentration. This aptasensor could promptly confirm the presence of S. typhimurium without intricate DNA-extraction or pre-enrichment stats over a linear range of 1-1.1 × 106 CFU/mL and a detection limit of 1.2 CFU/mL within ∼30 min. These results were successfully validated using molecular and culture-based methods in spiked-milk samples, with a 92.61-104.61 % recovery value. Meanwhile, the flexibility of this portable sensing platform allows for its development and adoption for the precise detection of various pathogens in food and the environment.

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Tree bark has been proven as an effective passive air sampler, particularly where access to active sampling methods is limited. In this study, 60 target liquid crystal monomers (LCMs; comprising 10 cyanobiphenyl and analogs (CBAs), 13 biphenyl and analogs (BAs), and 37 fluorinated biphenyl and analogs (FBAs)) were analyzed in 34 tree barks collected from the vicinity of a liquid crystal display (LCD) manufacturer situated in the Pearl River Delta, South China. The concentrations of LCMs in tree barks ranged from 1400 to 16000 ng/g lipid weight, with an average of 5900 ng/g lipid weight. Generally, bark levels of BAs exponentially decreased within 5 km of the LCD manufacturer. The profiles of LCMs in tree barks are similar to previously reported patterns in gaseous phase, suggesting bark's efficacy as a sampler for gaseous LCMs. The inclusion of different congeners in existing studies on the environmental occurrence of LCMs has hindered the horizontal comparisons. Therefore, this study established a list of priority LCMs based on environmental monitoring data and the publicly accessible production data. This list comprised 146 LCMs, including 63 REACH registered LCMs that haven't been analyzed in any study and 56 belonging to 4 types of mainstream LCMs.

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Liquid crystal monomers (LCMs) are emerging organic pollutants due to their potential persistence, toxicity, and bioaccumulation. This study first characterized the levels and compositions of 19 LCMs in organisms in the Pearl River Estuary (PRE), estimated their bioaccumulation and trophic transfer potential, and identified priority contaminants. LCMs were generally accumulated in organisms from sediment, and the LCM concentrations in all organisms ranged from 32.35 to 1367 ng/g lipid weight. The main LCMs in organisms were biphenyls and analogues (BAs) (76.6%), followed by cyanobiphenyls and analogues (CBAs) (15.1%), and the least were fluorinated biphenyls and analogues (FBAs) (11.2%). The most abundant LCM monomers of BAs, FBAs, and CBAs in LCMs in organisms were 1-(4-propylcyclohexyl)-4-vinylcyclohexane (15.1%), 1-ethoxy-2,3-difluoro-4-(4-(4-propylcyclohexyl) cyclohexyl) benzene (EDPBB, 10.1%), and 4'-propoxy-4-biphenylcarbonitrile (5.1%), respectively. The niche studies indicated that the PRE food web was composed of terrestrial-based diet and marine food chains. Most LCMs exhibited biodilution in the terrestrial-based diet and marine food chains, except for EDPBB and 4,4'-bis(4-propylcyclohexyl) biphenyl (BPCHB). The hydrophobicity, position of fluorine substitution of LCMs, and biological habits may be important factors affecting the bioaccumulation and trophic transfer of LCMs. BPCHB, 1-(prop-1-enyl)-4-(4-propylcyclohexyl) cyclohexane, and EDPBB were characterized as priority contaminants. This study first reports the trophic transfer processes and mechanisms of LCMs and the biomonitoring in PRE.

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