Dispersing nanoparticles in liquid crystals (LCs) is used to tune liquid crystal properties, to add functionality, or to exploit the self-organization of the liquid crystals to transfer order onto dispersed particles. Dispersing ferrofluid droplets into liquid crystals (LCs) not only adds magnetic functionality to the LCs, but also produces unique systems. Magnetic functionality can be used to measure the anisotropic viscosities of the LCs on a microscopic scale when moving the ferrofluid inclusions through various thermotropic, lyotropic, and colloidal LCs using an external magnetic field. The magnetite nanoparticles of the ferrofluid form a boundary layer at the interface between the LC and the ferrofluid droplets. The viscosities are calculated using Stokes’ Law, together with the introduction of the boundary layer at the LC–ferrofluid interface. The viscosities for a variety of different liquid crystalline systems were measured as a function of changing environment, such as temperature, concentration, or pitch.

In nematic LCs, ferrofluid droplet chains are formed due to the topological defects in the LC induced by the dispersed ferrofluid droplets. The movement of these chains can be controlled by the external magnetic field. The velocities of water-based ferrofluid droplet chains in nematic 5CB, while varying factors such as the average size of the droplets, the number of droplets in the chain, and the external magnetic field strength, are reported. Adding a surfactant to the LC–ferrofluid emulsions enables the production of ferrofluid droplet chains encoated with a membrane in the LC. A comparitive study between the behaviour of the LC–ferrofluid emulsion with the addition of the surfactant polysorbate 60 (Tween-60) and uncoated ferrofluid droplet chains is reported. Different surfactants and lipids are used to produce membranes around the ferrofluid droplets to create a synthetic structure which mimics a magnetotactic bacterium.

The efficacy of liquid crystal display (LCD) devices heavily hinges on the alignment of mesogens. In traditional LCDs, mesogens are oriented within substrates using the rubbed polyamide technique, which introduces undesirable contaminants and static charges, compromising device performance. This study presents a novel approach wherein plant-derived cellulose nanocrystals (CNCs) serve as an alternative alignment layer, obviating the need for the conventional rubbed polyamide technique. CNCs, extracted from banana pseudo-stem fibers via acid hydrolysis, are leveraged for alignment layer formation on ITO substrates using a rubbing-free vertical deposition technique. LC devices with various pre-alignment layers, including conventional rubbed polyamide and CNC layers, were fabricated and systematically compared. Through AFM, SEM, and profilometric analyses, we confirmed the presence of micro-sized channels and spindle-like structures of the CNCs, resulting from their self-assembly during vertical deposition. The device with the CNC layer exhibited robust mesogenic alignment and was sensitive to CNC layer thickness. The CNCs' spindle-like structure and self-assembling properties, coupled with vertical deposition, facilitated microchannel formation on the substrate, ensuring homogeneous alignment. The increased surface energy of CNC layers significantly improved mesogenic alignment, as evidenced by polarized optical microscopy and contact angle measurements. Moreover, the influence of these alignment layers extended to dielectric relaxation and transition temperature. Electro-optical properties, including spontaneous polarization, switching time, photoluminescence emission, and P-E hysteresis, were found to be comparable to conventionally rubbed polyimide, all while maintaining transparency. Additionally, CNC layers exhibited ion-capturing capabilities, leading to a reduction in device conductivity. This study underscores the potential of CNCs as an alignment layer for LCD applications, offering advantages such as enhanced wettability, density distributions, and overall orientation.

In the field of wastewater treatment, ceramic membranes have emerged as a promising technology due to their high filtration efficiency and durability. Unlike traditional polymer membranes, ceramic membranes are made from inorganic materials such as alumina, silica or other ceramic materials. They can withstand extreme operating conditions, such as high temperatures.and can be produced through compaction processes, sol-gel methods, extrusion, and hydrothermal synthesis techniques. Among these, compaction is the most frequently used method for fabricating.

Clay minerals are major raw materials for ceramic production that undergo a number of characteristic reactions, Clay is more durable and requires lower firing temperatures, as highlighted by several studies on the development of low-cost porous ceramics based primarily on clay as the main raw material.

To produce a membrane with high porosity and acceptable mechanical strength with the minimum of experimentation, we opted for optimized the preparation conditions by adjusting the sintering temperature, time and as well as the rate of marble waste addition.In this study, the Response Surface Methodology (RSM), based on the Doehl-type experimental design,In order to determine the optimal conditions of the preparation, the Doehlert design and Desirability function were applied.

Various analytical techniques, including X-ray diffraction (XRD), X-ray fluorescence (XRF), thermogravimetric analysis (TDA-TG), scanning electron microscopy (SEM), and Archimedes principal testing, were used to investigate the properties of these ceramic membranes.

We have reported light beam steering demonstration by using a liquid-crystal-loaded metasurface (LC-MS), which was based on voltage-controlled refractive index distribution on the metasurface. We can upgrade a beam steering device to a variable-focal-length lens by introducing parabolic refractive index distribution on LC-MS. Moreover, the focal length is controllable by voltage across the liquid crystal. We show the design method of the variable-focal-length lens and their numeric demonstrations in this paper.

The proposed lens model is one-dimensional and has parabolic refractive index distribution. In designing the device, we employed two procedures of theoretical far-field pattern (FFP) calculation and computer-based electromagnetic near-field pattern (NFP) simulation. The FFP calculation was carried out by means of phase calculation on the basis of classic optics. The results indicated the estimation of the lens effect although the preciseness of the focal length was not assured since the number of pixelated LC-MS was too small to evaluate the phases and steering direction of light beams. Then, our next strategy is electromagnetic field (EMF) simulation using the COMSOL simulator that can calculate EMF near the pixelated LC-MS. The simulation results improve by repeating these two processes. As a result, we found that LC-MS functions as a lens and the focal length is variable. The focal length was controllable within approximately 2.2 times, assuming a maximum refractive index change of 0.1, a pixel number of 11, and a wavelength of 600 nm.

To conclude, we established a design method of a variable-focal-length lens that employs LC-MS. The controllability of the focal length and the lens function were numerically demonstrated. This kind of LC-MS device does not require high voltages in general. Experimental demonstrations would be our next study.

Introduction: In this study the technique of obtaining a composite material based on polyimide track membranes prepared by the deposition of TEOS (tetraethoxysilane) hydrolysis products in medium with acidic catalyst will be considered further. The obtained material sample microstructure and effect of the presence of crystalline forms of silicon dioxide on the overall crystallinity index (CI) of the silica filler will be studied.

Methods: The microstructure of the composite material surface was studied using scanning electron microscopy (SEM TESCAN MIRA 3). The effect of the presence of crystalline forms of silicon dioxide on the overall CI of the silica filler was studied using XRD (ARL X'TRA). For the purpose of this study, the CI was defined as the ratio of the area of the peaks of the crystalline phase in the diffraction pattern to the total area under it. A series of experiments were carried out with a model samples with different wt. % contents of crystalline silica powder and a correlation curve of the crystallinity of the sample and the crystallinity from the diffraction pattern was plotted.

Results: From the surface examination of the samples, it was found that the silica filler deposited in the pores of the polyimide track membrane has a nanofibrous structure. When crystalline powders were added in the amount of 30% wt. of the planned reaction yield, the CI did not exceed ≈32%, which indicates the absence of the formation of a new crystalline phase in the reaction volume.

Conclusion: According to the conducted study advantages of using an acidic catalyst of TEOS, the hydrolysis reaction can be regarded as the most successful, since its use leads to the formation of nanofibrous structures in the pores of the polyimide track membrane. The addition of crystalline forms of silicon oxide studied in this paper did not result in a significant change in the CI of silica filler.

Lecithin liquid crystals are promising carriers for transdermal drug delivery. They are able to include both lipophilic and hydrophilic substances, as well as solid particles. In this work, liquid crystals in a system comprising lecithin, avocado oil, tea tree oil, and water, containing biologically active substances and nanoparticles, were studied.
It was shown that in the range of shear rates from 0.01 to 1.0 s^-1, the introduction of 1.0 and 3.0 mol/L NaCl aqueous solutions increased the viscosity of liquid crystals, on average, by 4 and 9.1 times in comparison with the control sample. The introduction of potassium chloride glucosamine sulfate solutions with mass concentrations of 50, 100, and 150 g/l increased viscosity by 1.3, 2.2, and 3.3 times, while the introduction of 1 wt.% albumin in a citrate buffer solution into the liquid crystalline sample increased its viscosity by 1.5 times.
The addition of 0.3 wt.% of CuO nanoparticles (92±3 nm) increased the viscosity by 2.0 times, and that of CuSO₄ aqueous solution by 2,5 times compared with the control sample. When 0.3 wt.% of CuO microparticles (31,2±3,5 mm) was added, the viscosity decreased by 1.3 times. The kinetics of the release of copper ions from liquid crystals (copper content 2.4 mg/g) by dialysis were studied at T = 37 °C. The release rate of Cu²⁺ for liquid crystals with the CuSO₄ solution was 7,6 · 10^-4 g/(m² · h); for CuO nanoparticles, it was 5,86 · 10^-4 g/(m² · h); and for microparticles, it was 2,36 · 10^-4 g/(m² · h). Therefore, a dimensional effect was observed. This difference can be explained by the fact that copper ions in liquid crystals with CuSO₄ are already in the solution, but for samples with CuO particles, their dissolution is required.
The results obtained will help in the development of medical products based on lecithin liquid crystals.

In many modern devices used to convert or store electricity, such as dye-sensitized solar cells (DSSCs), fuel cells, lithium-ion batteries or supercapacitors, one of the critical elements is the organic electrolyte, the stability and physicochemical properties of which significantly affect the efficiency of the processes of converting or storing electrical energy. The essence of the concept of using liquid crystals in such devices is that properly ordered structures at the nanometer scale lead to an increase in ionic conductivity in a specific direction and fulfill the role of stabilizing the system mechanically and thermally. Moreover, temperature induction of phase transitions enables switching off functions in a given electrolytic structure.

DSSCs with porous semiconductor titanium dioxide (TiO₂) electrodes were sensitized using ruthenium-based dyes purchased from Solaronix. In this experiment, the following ruthenium dyes were used: cis-diisothiocyanato-bis (2.2'-bipyridil-4.4'-dicarboxylic acid) ruthenium (II), known as N3; cis-diisothiocyanato-bis (2.2'-bipyrida-4, 4'-dicarboxylato) ruthenium (II) bis(tetrabutylammonium), marked as N719; and the amphiphilic ruthenium dye cis-diisothiocyanato-(2.2'-bipyridil-4.4'-dicarboxylic acid)-(2.2'-bipyridil-bipipyridil-4.4'-dinonyl) ruthenium (II), known in the literature as Z907. The electrolyte (AN-50) with a low viscosity contained iodide/tri-iodide as a redox couple, and a redox concentration of 50 mM was used.

The current–voltage (I-U) characteristics were determined for the ruthenium-based dyes mentioned above in order to check the influence of their structure on the efficiency of the DSSC cells. Next, it was checked what effect the addition of a nematic liquid crystal of 4- cyano-4'-pentylbiphenyl (5CB) to the iodide electrolyte had on the I-U characteristics. Modification of the I-U characteristics was found, in particular a change in the values of I_SC current and U_OC voltage.

Green synthesis of nanoparticles is more promising versus chemical and physical methods as it is environmentally friendly, cost-effective, and non-toxic. Considering environmental sustainability, this study was designed to explore Itsit (Trianthema portulacastrum) efficacy for green synthesis of nanoparticles. The main objective of this study was to investigate the potential of zinc oxide (ZnO) nanoparticles developed from Itsit extract, through green methods for the treatment of textile dyes. This investigation reports that using the plant extract of Itsit, synthesis of nanoparticles of zinc oxide occurs in which zinc oxide is used as a precursor. In the green method, the plant extract that includes the biomolecules is used to reduce the zinc ions into zinc atoms like ZnO nanoparticles. Flavonoids, phenolic compounds, terpenoids, alkaloids, and flavone are all plant metabolites, the potential reducing agents used for ZnO nanoparticle preparation. The zinc oxide nanoparticles were prepared and characterized through UV--visible, FT-IR, and Zetasizer. The application of nanoparticles developed for their photocatalytic potential was investigated for the decolorization of a synthetic dye, phenol red. The ZnO nanoparticles prepared from Itsit showed 38% decolorization of phenol red, showing its promising catalytic potential under sunlight. Based on these findings, it can be concluded that Itsit demonstrated promising photocatalytic potential for the remediation of textile dye and could be employed for the treatment of textile wastewater.

Commercial alloys of Al-1 (wt.%) (91.9 -94.6Al, 4.8-5.8Mg, 0.5 Si =Fe, 0.1Cu, 0.05-0.08Mn, 0.005Be), Al-2 (90.8-94.7Al, 1.2-1.8Mg, 0.5Si = Fe, 3.8-4.9Cu, 0.3-0.9Mn, 0.1Ni), and Ti (94.2-96.9Ti, 1.0-2.5Al, 0.15Si, 0.3Fe, 0.3Zr, 0.7-2.0Mn, 0.15O, 0.3X) contain impurities, but bear no indication of their composition and structure, on which the performance characteristics of the materials depend. The purpose of this work was to develop an method and program for determining the alloys’ composition. The use of a complex of X-ray phase and elemental (EDX) analyses, crystal chemical calculations (the theory of closest packing—CP, metal radii—r(M)Å, and Vegard’s—V or Retger’s—R rules) allowed us to determine the compositions of these alloys.

Al-1. Substitutional solid solution (SSS) (Al_1-xMg_x) (sp.gr. Fm3m; а_exp=4.088(7)Å) with type (ST) of Cu (98%) + impurities (2%): a_CP(Al)=4.045Å, “a_CP(Mg)”=4.526Å - (Al_0.90Mg_0.10)_CP+V (~350°C) [1]; EDX (wt.%): 91Al, 8Mg, 0.2Fe, 0.3Si, 0.5Mn.

Al-2. SSS (Al_1-xCu_x) (STCu; а_exp=4.036(4)Å): a_exp(Al)=4.049Å, a_exp(Cu)=3.615Å; a_CP(Al)=4.045Å, a_CP(Cu)=3.620Å - (Al_0.97Cu_0.03)_V =(Al_0.98Cu_0.02)_CP+V (~500°C) [2]; EDX (wt.%): 98.3Al, 0.7Mg, 0.3Fe, 0.4Si, 0.1Mn, 0.1Cu, 0.1Ni.

Ti. SSS (Ti_1-xAl_x) (sp.gr. P6₃ /mmc; a_exp=2.942, c_exp=4.678Å, c/a=1.590, V=35.064ų) with ST derived from Mg (c/a=1.633): a_exp(Ti)=2.950Å, c_exp(Ti)=4.684Å, V=35.300ų; a_CP(Ti)=2.940Å, c_CP(Ti)=4.675Å, V_CP=34.994ų; “a_CP(Al)”=2.860Å, “c_CP(Al)”=4.547Å, V_CP=32.208ų - (Ti_0.92Al_0.08)_CP+R; “a_CP(Mn)”=2.540Å, “c_CP(Mn)”=4.039Å, V_CP=22.566ų - (Ti_0.98Mn_0.02)_CP+R; (Ti_1.00-0.80Al_0-0.12Mn_0-0.08) (700°Ð¡) [3]; EDX (wt.%): 84.6Ti, 2.5Al, 1.0Mn, 0.2Si, 0.1Fe, 11.6О.

Thus, the composition of Al-1, Al-2, and Ti alloys are different from those indicated by the certificates.

Funding: Ministry of Science and Higher Education of the Russian Federation grant â„– FSFZ-2024-0003.

[1] R. Mola et al. Archivae of Foundryengineering. 2008. V.8. P.127

[2] W. Bedjaoui et al. Int. J. Automot. Mech. Eng. 2022. V.19. P.9734

[3] X.M. Huang et al. J. of Alloys and Compounds 2021. V.861. P. 158578

In this work, a theoretical model of the surface plasma oscillations' propagation in a conductive layer is constructed. We assume that the layer is located between two insulating layers with the same dielectric constants. We suppose that the surface wave frequency is much lower than the plasma resonance frequency. The case of specular reflection of charge carriers from the semiconductor layer boundaries is considered. Analytical expressions for the propagation coefficients, longitudinal, and transverse attenuation parameters are derived. An analysis of the dependencies of the surface wave parameters on the semiconductor layer thickness, surface wave frequency, and the dielectric constant of insulating layers was carried out. We established that at low frequencies (about ten THz), we observe a linear frequency dependence of the surface wave propagation coefficient. The longitudinal attenuation is practically absent, which may be due to the absence of excess charge at the layer boundaries. At a certain frequency, the longitudinal attenuation coefficient becomes non-zero, and it grows sharply with increasing frequency. The appearance of non-zero longitudinal attenuation is accompanied by a deviation of the frequency propagation coefficient dependence from the linear law. With a further increasing frequency, the propagation and attenuation parameters grow, reach a maximum, and then reduce. It follows from the above that when a non-monochromatic wave arrives at the conductive layer, a redistribution of harmonics across amplitudes occurs during surface wave propagation. This effect can be used to create plasmonic waveguides that filter frequencies corresponding to the minimum longitudinal attenuation coefficient (plasmonic filters). We established that with rising semiconductor layer thickness and dielectric constant of insulating layers, the propagation and attenuation parameter maxima shift towards lower frequencies. Thus, by varying the thickness and selecting the material of the insulating layers with the desired optical characteristics, it is possible to change plasmonic filter pass frequency.