Herein, a new series of thiophene heterocycles (3a-3g) was synthesized by reacting with thiophene-2-carbohydrazide (2) and various aldehydes (a-g) in the presence of a catalytic amount of acetic acid. The synthesized thiophene heterocycles were characterized by H-1 NMR (proton nuclear magnetic resonance), C-13 NMR (carbon nuclear magnetic resonance), LCMS (liquid chromatography mass spectroscopy), UV-visible, Fourier transform infrared spectroscopy (FT-IR), and polarizing optical microscopy (POM) analytical methods. Density functional theory (DFT) computational studies revealed extensive highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbitals (LUMO) interactions, the electrophilic nature of the thiophene heterocycles, and their energy levels. POM textures showed the absence of birefringent textures for 3a, 3c, 3e-3g, whereas 3b and 3d showed the birefringent textures upon cooling from their higher isotropic temperatures. UV-visible absorbance unveiled maximum absorptivity dwell between 318-360 nm, and the optical band gap (E-g) varies between 3.09eV-3.56 eV. Steady state photoluminescence (SSPL) spectra unveiled violet, blue, green, yellow, lights (broad) at various lambda(excitations) with a large Stokes' shift indicating the formation of virtual energy levels. The average lifetime of the photoexcited species when exciting radiation was removed was measured by phosphorescence decay (PD) studies, showing the average lifetime of thiophene heterocycles 3a-3g dwells between similar to 115.4-123.4 mu s at fixed lambda(excitation) = 380 nm. Further, 3a-3g thiophene imines unveiled quantum yield (QY) at lambda(excitation) = 380 nm revealed which dwells between 6.2 % -51.0 %. The synthesized thiophene heterocycles can be utilized for devices comprising advanced photochromic, fluorescence, and photoluminescence etc.

In the present work, a new series of oxazole derivatives (3a-3j) were synthesized by condensing 1, 3-oxazole-4-carbohydrazide (2) with different aldehydes (a-j) in the presence of a catalytic amount of acetic acid. The synthesized oxazole derivatives were characterized by proton nuclear magnetic resonance (1HNMR ), carbon nuclear magnetic resonance ((NMR)-N-13C ), liquid chromatography mass spectroscopy (LC-MS), UV-visible, Fourier transform infrared spectroscopy (FT-IR), and polarizing optical microscopy (POM) analytical methods. Density functional theory (DFT) computational studies carried out for oxazole derivatives revealed extensive interactions between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbitals (LUMO), their electrostatic potentials, and energy levels. The POM studies revealed the birefringent mesophases in different oxazole derivatives, specifically in derivatives 3c, 3d, 3e, 3f, and 3h, which showed distinct smectic phases, while derivatives 3a, 3g, 3i, and 3j had less ordering. UV-visible studies unveiled maximum absorptivity dwell between 302 nm-326 nm (near UV region), and the optical band gap (Eg) varies between 3.46 eV-3.88 eV. Steady state photoluminescence (SSPL) spectra of oxazole derivatives showed violet, blue, green, yellow, and red colors (broad) and a few weak emission peaks at various excitation wavelengths with large Stokes shift, and the full width half maximum (FWHM) indicates the presence of additional/virtual energy levels during photoexcitation. The SSPL emission spectra redshifted with an increase in the wavelength of excitation and extended to the near infrared region, indicating that photochromic species are long-lived. The phosphorescence decay (PD) studies showed the average lifetime of oxazole derivatives (3a-3j) dwelt between similar to 112.5 mu s to similar to 122.9 mu s at various excitation wavelengths. Further, the quantum yield (QY) of oxazole derivatives (3a-3j) at lambda excitation = 380 nm were between 9.87 % to 91.0 %. The synthesized oxazole derivatives can be utilized for devices comprising advanced photochromic, fluorescence, and photoluminescence etc.

Liquid crystals (LCs) have developed from pure electro-optic (E-O) display materials towards the functional media for reconfigurable microwave and millimetre wave (MMW) antenna systems. This is mainly possible with systems which have electrically controllable dielectric anisotropy ( Δε ) that facilitates tuning of effective permittivity continuously. This tunability permits dynamic adjustment of resonant frequency, phase response, polarization state and radiation pattern without mechanical actuation or high power semiconductor switches. The present paper comprehensively reviews the application of LCs in antenna technologies, including frequency-agile arrays, frequency-reconfigurable microstrip patches, polarization-agile arrays, reflectarrays (RAs), folded RAs, phased arrays, leaky-wave antennas, metasurfaces, flexible liquid crystal polymer (LCP) based wearable antennas, low voltage systems and optically tunable platforms. In the reviewed results, tuning of frequency ranges between 7–18 tanδ ≈ 0.01–0.03), limited response time, temperature sensitivity and alignment precision remain critical constraints. Therefore, future research is directed towards developing high anisotropy, low loss LC mixtures, faster switching mechanisms, improved metasurface integration and scalable transparent or flexible architectures to enable adaptive, energy efficient platforms for next generation 5G/6G, satellite and Internet-of-Things (IoT) communication systems.

The present work focuses on the synthesis of copper-doped carbon quantum dots (Cu-CQDs) by the hydrothermal method. The high-resolution transmission electron microscopy (HRTEM) and UV—Vis spectrometer results show uniform spherical-shaped Cu-CQDs of 1 to 3 nm size and 4.7 eV band gap, respectively. The synthesized Cu-CQDs were then added to liquid crystal (LC) host with an optimum concentration of 0.3 wt.

Cholesteric liquid crystals (CLCs) are a unique material for optical devices, such as photonic devices, and smart windows with tunable optical properties under controlled voltage, temperature, or mechanical pressure. This work demonstrates dynamic modulation of voltage-driven optical states and dielectric responses of thermally tunable CLCs prepared with varying concentrations of chiral dopant (2.6, 3.0, 4.0, and 5.0 wt%) labelled CLC-1 to CLC-4. Textural and voltage-driven optical switching analyses reveal that, for CLC-1, fingerprint and homeotropic optical state transitions require lower voltages and further decrease from 6.0 - 4.6 V rms , and 23.69-20.39 V rms as temperature increases from 25 - 45 degrees C. The maximum contrast ratios are achieved at 40, 35, 35, and 30 degrees C for CLC-1 to CLC-4, respectively. Among all compositions, CLC-1 exhibits most stable planar-state upon removal of applied field at elevated temperatures. Furthermore, the reduction of dielectric permittivity and shift in relaxation frequency toward higher values are observed with temperature increase. Maximum relaxation frequency of 1.57 x 10 6 Hz is attained for CLC-1 and increased further to 5.48 x 10 6 Hz with temperature. DC conductivity rises by 9.98 %, 11.65 %, 10.76 %, and 8.0 % for CLC-1 to CLC-4, respectively, at elevated temperatures. These results highlight the influence of thermally tuned optical states, switching dynamics, and dielectric responses of CLCs for thermally responsive energy-efficient smart windows.

Dye doped liquid crystals (DDLCs) have become a platform for flexible, tunable, compact and efficient laser emission combining the optical gain of fluorescent dyes with self-organized or disordered structures of liquid crystal (LC) hosts. The present review is a comprehensive analysis of laser emission processes in DDLCs systems with special focus on the way that molecular alignment, optical anisotropy and photonic structures within LCs are used to enable mirrorless lasing. Further, liquid crystalline mesophases are discussed separately. In nematic systems, optical feedback arises from multiple light scattering, leading to random lasing. In contrast, cholesteric systems exhibit distributed feedback (DFB) due to their periodic helical structure. The optical gain is achieved by the addition of fluorescent dyes such as DCM, PM597 and Rhodamine derivatives. The emission properties of the cell are tuned by controlling parameters like pump geometry, polarization, cell thickness, temperature and external fields. The studies also illustrate that doping with plasmonic nanoparticles (NPs) like titanium nitride (TiN), silver (Ag) and barium titanate (BaTiO3) can increase local field intensity and scattering as well as lower the lasing thresholds. The reported threshold values range from few μJ/pulse to few mJ/cm2, with line widths as narrow as 0.3 nm and efficiency up to 1

Nematic liquid crystals (NLCs) exhibit remarkable electro-optical (E-O) properties owing to their fluidity combined with long-range orientational order, which makes them useful in advanced display, photonic and optoelectronic devices. Herein, effect of multi-walled carbon nanotubes (MW-CNTs) on morphological, E-O, dielectric and thermodynamic properties of 5CB LC in planar aligned cells is investigated. Poly(vinyl alcohol) (PVA) coated indium tin oxide (ITO) substrates have been used for homogeneous alignment. MW-CNTs doping (0.005 wt E_g for 0.01 wt

Three-dimensional (3D) templating using liquid crystals (LCs) has emerged as a powerful bottom-up strategy for fabricating hierarchically ordered materials by translating the intrinsic orientational order and topological complexity of liquid crystal (LC) mesophases into solid architectures. The present review systematically analyzes the advances across lyotropic, thermotropic, nematic, cholesteric, blue phase (BP) and LC elastomer systems, highlighting how LC self-assembly enables precise control over structure across nano, micro and macroscopic length scales. Prior key studies demonstrate templated pore sizes ranging from sub-nanometer ion channels ( 1 nm) to mesoporous networks (3–30 nm) and photonic lattices with periodicities of 100–400 nm. Colloidal assemblies with binding energies exceeding 103 kBT and mechanically robust composites exhibiting strengths up to 650 MPa are also reported. Emerging approaches further extend LC templating to architected 3D templates, fibers and responsive devices. Despite these advances, challenges remain in defect control, phase stability, large area uniformity and scalability. The integration of LC templating with advanced 3D printing, hybrid organic–inorganic systems and stimuli responsive materials is expected to enable multifunctional photonic, energy, sensing and soft robotic platforms. The current review provides a unified framework connecting LC physics with materials engineering, design and future directions for next generation 3D templated materials.

The properties of the liquid crystals (LCs) demonstrated significant improvements when amalgamated with various nanomaterials (NMs). In this study, graphene nanoplatelets (GNPs) and multiwalled carbon nanotubes (MWCNTs) were doped on 3a, 3b LCs in small quantities and studied for potentially tailoring energy storage and electrical applications. The 3a, 3b@ MWCNTs, GNPs were characterized by field emission scanning electron microscope (FESEM), polarizing optical microscopy (POM), powdered X-ray diffraction (PXRD), Raman, Brunauer-Emmett-Teller (BET), energy dispersive X-ray (EDX) and Zeta potential analytical methods. Phase analysis of 3a@MWCNTs, GNPs demonstrated orthorhombic crystal structure while 3b@MWCNTs, GNPs showed monoclinic crystal phase. FESEM of 3a, 3b@MWCNTs, GNPs liquid crystal nanocomposites (LCNCs) exhibited small peal shaped/broken leaves/small flakes like microstructure. BET studies of 3a@MWCNTs, GNPs LCNCs unveiled surface area (SBET) of 5.983 m2/g, 8.951 m2/g and pore diameter (DP) of 1.193 nm, 1.11 nm. However, 3b@MWCNTs, GNPs demonstrated SBET of 27.00 m2/g, 33.95 m2/g and DP of 5.29 nm, 5.75 nm. Zeta potential characterized by high anionization levels of 3a@MWCNTs, GNPs LCNCs and maintained consistent stability in colloidal suspensions. POM textures elucidated smectic fan-like mosaic domains of 3a@MWCNTs LCNCs, small stick-like microstructure for 3a@GNPs LCNCs. However, 3b@MWCNTs displayed coin-like textures and 3b@GNPs LCNCs showed large leaf-like continuous mosaic domains. The energy storage performances of 3a@MWCNTs, GNPs LCNCs in 1 M KOH solution, showed specific capacitances (SCs) of 301.61 F/g, 224.69 F/ g at 0.5 A/g. While 3b@MWCNTs, GNPs LCNCs exhibited SCs of 825.45 F/g, 1030.96 F/g at 0.5 A/g. The 3a@MWCNTs, GNPs and 3b@MWCNTs, GNPs LCNCs showed cyclic retention of 70%, 67%, 75%, 86% over 10, 000 cycles. Further, 3a@MWCNTs LCNCs performed with variation in resistance (Rp) Vs capacitance (Cp) at applied voltage of 0-10 V, Cp is negative charge and is in nano farad (nF) indicating the presence of trap states. Cp becomes increasingly negative at various temperatures (T) and applied frequencies (F). 3a@GNPs LCNCs demonstrated negative Cp indicating dipoles were relaxing, trap states are de-shielding and follows the Debye model. On the other hand, 3b@MWCNTs LCNCs showed linear curve for Rp, Cp increases in relation to applied F and charge distribution by the host could not create trap states. 3b@GNPs LCNCs, unveiled positive Cp, Rp exhibits linear relationships. The synthesized LCNCs can be a potential candidate for energy storage and advanced optoelectronic applications.

We report here an eco-friendly route to tune the physical properties of a highly birefringent nematic liquid crystal (NLC, LC-PD40300, Δε = +16.8) with wide nematic temperature range by doping of green zinc oxide nanoparticles (ZnO NPs). ZnO NPs (diameter: 5.9 ± 1.2 nm) were hydrothermally synthesized using Justicia adhatoda (Vasaka) leaf extract which acted as both reducing and capping agent. FTIR and XRD confirm ligand-assisted formation of phase-pure wurtzite ZnO, while UV-Vis shows a quantum-confined excitonic edge at 355 nm (Eg = 2.75 eV). Afterwards, these NPs were dispersed (concentration: 0.05, 0.1 and 0.5 wt

Polymer-dispersed liquid crystals (PDLCs) have extensive applications for electrically driven smart displays. Herein, the effect of different concentrations (0.2 wt%, 0.4 wt%, and 0.8 wt%) of silica (SiO2) nanoparticles (NPs) in PDLCs has been studied. Morphological behaviour shows that LC droplet size increases with the increase of SiO2 NPs' concentration due to widening of pore size from 2.50 mu m to 3.48 mu m. As a result, threshold and operating voltages show reductions of similar to 30.3%, 31.8%, 39.9% and 20.6%, 26.7%, 28.6% for 0.2 wt%, 0.4 wt%, and 0.8 wt% SiO2 NPs doped PDLCs, respectively, compared with the pure PDLC. Contrast ratio (CR) is slightly higher (55.17) for 0.2 wt% SiO2 NPs doped PDLC than pure (52.17) PDLC. Further, the dielectric permittivity (epsilon(y)) is higher in 0.2 wt% SiO2 NPs doped PDLC than pure, 0.4 wt% and 0.8 wt% SiO2 NPs doped PDLCs in 10 Hz to 100 Hz frequency range. However, epsilon(y) reaches a maximum for 0.8 wt% SiO2 NPs doped PDLC above 1 kHz, while it is lower below 1 kHz than observed for 0.4 wt% SiO2 NPs. The dielectric loss is found to be lowered with the doping of NPs at intermediate and higher frequencies. Thus, these results recommend that doping of NPs has a synergistic role for tuning the performance of PDLCs and optimize them for electro-optical responsive display devices.

The present study focuses on the thermal stability of homeotropic alignment (HA) of liquid crystals (LCs) induced with zinc oxide (ZnO) nanoparticles (NPs) and explores the robustness of NP-induced HA under varying thermal conditions. Therefore, the morphological and electro-optical (E-O) properties are analyzed across a temperature range of 20–60°C, emphasizing the preservation of uniform alignment and device functionality. The results demonstrate that NP doping not only facilitates HA but also maintains it consistently at elevated temperatures. The prepared display cells with HA of LCs show reduced threshold (VT) and operating (VO) voltages and minor deterioration in contrast ratio at higher temperature. The findings confirm the thermal reliability of NP-induced HA of LCs for high-temperature optoelectronic applications.

Blue phase liquid crystals (BPLCs) possess remarkable optical properties, including selective visible light reflection, sub-millisecond response times and wide viewing angles without the need for alignment layers. These attributes make them highly promising for advanced display technologies. However, the narrow temperature range and high operating fields required for blue phase liquid crystal (BPLC) devices present significant challenges. Consequently, the integration of liquid crystals (LCs) with nanoparticles (NPs) to form BPLC composites has garnered considerable attention. This review summarizes experimental and synthetic methodologies, compares design strategies, and discusses both current cum potential applications of these composite materials.

Abstract In order to enhance the functionality and sustainability of energy storage devices, a lot of research has been conducted on novel electrodes. As a result, graphene oxide (GO) has received considerable attention owing to its high specific surface area and adjustable nature. However, its limited conductive ability and reactive sites hinder its practical applications, therefore, nitrogen doping is reported as one of the useful strategies to improve the electrochemical performance of GO by tuning the electronic state and creating new reactive sites. The current review presents detailed advances of bio derived nitrogen-doped graphene oxide (N-GO) including synthetic techniques, structural modifications and potential electrochemical applications. Biomass sources such as agriculture residue, plants and marine organisms have been investigated as renewable carbon and nitrogen sources. Synthesis routes like hydrothermal process, thermal annealing, chemical activation, and plasma modification were discussed about their effect on nitrogen incorporation and material properties. Bio-based N-GO materials reported the higher specific surface areas, up to 1946 m 2 g -1 , with nitrogen content levels of ~8-12 at.%. These materials display excellent electrochemical properties, having specific capacitances ranging between 260-481 Fg -1 , energy densities as high as ~ 68 Wh kg -1 and excellent cycling stability, showing capacitance retention above 90-98%, after 10,000-20,000 cycles. The improvements in electrochemical performance can be linked to the better design of nitrogen sites (including pyridinic, pyrrolic, and graphitic nitrogens), hierarchical porosity and enhanced conductivity. Thus, bio-based N-GO can be regarded as a cost-effective and environmentally friendly material base with excellent performance characteristics suitable for the development of future generation supercapacitors and batteries.

In this investigation, liquid crystalline nanocomposite (LCNCs) of azobenzene derivatives3a(methyl 4-[(E)-(4-butoxy-2,5-difluorophenyl)diazenyl]-3-methoxybenzoate), and3b(methyl 4-{(E)-[2,5-difluoro-4-(hexyloxy)phenyl]diazenyl}-3-methoxybenzoate) were doped with 0.5 wt.% europium oxide (Eu2O3), niobium oxide (Nb2O5) nanoparticles (NPs) and named as3a@Eu2O3,3b@Nb2O5LCNCs. The powdered x-ray diffraction confirms the purity and integration of Eu2O3, Nb2O5NPs. Field emission scanning electron microscope studies demonstrate a non-uniform worm/flake-like morphology with agglomeration of LCNCs. A slight shift in optical band gap was observed for3a, 3bLCNCs, and broad absorption bands were observed in ultraviolet-visible studies. The existence of birefringent textures of3a@Eu2O3and3b@Nb2O5LCNCs is confirmed using a polarizing optical microscope. Room temperature photoluminescence (PL) studies demonstrate pronounced luminescence maxima with sharp emission peaks of violet, blue, green emissions under excitation at 380 nm, 460 nm, 360 nm, and 375 nm. Steady state PL (SSPL) of3a@Eu2O3LCNC exhibits luminescence maxima associated with vibrant red, blue, and greenish-yellow colors, while SSPL of3b@Nb2O5LCNC shows emission peaks of brilliant blue, yellow, green, orange, red colors at variousλexcitations. Furthermore, the large Stokes shift and full width at half maximum of3a@Eu2O3and3b@Nb2O5LCNCs are attributed to the presence of additional/virtual energy levels during the photoexcitation process. The fluorescence decay studies of3a@Eu2O3LCNC display average lifetime dwell between 19.8 ns and 0.276 ns, while3b@Nb2O5exhibits 9.69 ns to 10.20 ns, at various excitation wavelengths. The quantum yield varies between -7.77 × 10-2% to 5.23 × 10-2% and 0.86% to 0.14% for3a@Eu2O3and3b@Nb2O5LCNCs, respectively, upon increase inλexcitations. Polarization studies of3a@Eu2O3LCNC atλexcitation/emissionangle (0°) showed intense defect-centered blue, red emission bands (445 nm, 613.8 nm) attributed to the excited state virtual orbitals that undergo non-radiative decay with higher energy content. Thus, the results obtained for synthesized3a, 3bLCs doped with Eu2O3and Nb2O5NPs make these usable for advanced optoelectronics, photonic, fluorescence/photo-luminescence device applications.

Abstract The growing demand for energy-efficient displays, adaptive photonic elements, and low-power optical technologies has build up interest in carbon nanomaterials dispersed liquid crystal (LC) systems. These nanomaterials offer unique electrical, optical and interfacial properties that can significantly make advancement for faster, more responsive and more sustainable electro-optical (EO) devices. This review provides a comprehensive overview of how various carbon nanomaterials such as carbon nanotubes (CNTs), graphene oxide (GO), carbon dots (CDs) and fullerenes interact with LCs to influence alignment behavior, dielectric response, interfacial anchoring and device performance. The manuscript presents trends, compares advantages and limitations of each nanomaterial category as well as explains the underlying mechanisms governing their influence on LC order and switching characteristics. Key challenges related to dispersion stability, interface control and long-term reliability are highlighted, along with future opportunities for developing next-generation LC-based photonic and optoelectronic systems. This perspective is intended to guide material selection and inspire further innovation in LC–nanomaterial hybrid technologies.

This review presents a comprehensive analysis of the use of metal and metal oxide nanoparticles (NPs) (Ag, Au, Ni, CuS, ZnO, ITO, TiO2, and BaTiO3) to enhance homeotropic alignment (HA) and electro-optical (EO) properties of nematic liquid crystals (NLCs). Compared to traditional polyimide (PI) based alignment technologies, NPs assisted technology provides a layer free and scalable pathway to obtain uniform HA with decreased complexity in processing. The novelty of this review lies in its systematic attempt to correlate NPs type, size, concentration and surface chemistry with alignment behavior and EO parameters including threshold voltage (Vth), operating voltage (Vop), contrast ratio (CR), dielectric anisotropy (Δε) and response time. The reported studies illustrate the reductions of up to 68