The purpose of this study was to prepare Cu- and Fe-doped TiO₂ thin films using the sol-gel dipping method, thus determining how the addition of different dopants influenced its optical and antibacterial effectiveness. The structural and optical properties of the resulting photocatalysts were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and UV–Vis spectroscopy. The photocatalytic performance was evaluated through the degradation of methylene blue (MB) and the inactivation of Escherichia coli (E.Coli) under visible light irradiation. XRD analysis confirmed that the dominant crystalline phase for both pure and doped TiO₂ calcined at 500 °C was anatase, with crystallite sizes ranging from 11 to 40 nm. The optical properties were studied by UV-vis spectroscopy to measure the band gaps in the wavelength range of 300 to 800 nm. The absorbance spectrum of doped TiO₂ films shows that the absorption edge shifted towards longer wavelengths (redshifted) from 380 nm to 440 nm by increasing the amount of dopants. Tauc plot analysis revealed a band gap narrowing from 3.20 eV for pure TiO₂ to 2.65 eV and 2.40 eV for Fe–TiO₂ and Cu–TiO₂, respectively. In terms of photocatalytic activity, both dopants demonstrated greater MB degradation efficiency than pure TiO₂. Furthermore, antibacterial assays under visible light showed that 0.8Cu–TiO₂ possessed superior antimicrobial activity against E.Coli compared to both pure and Fe-doped TiO₂. The optimal doping levels for enhanced photocatalytic and antibacterial performance were identified as 0.8% Cu and 3.0% Fe, respectively.

An investigation of structural, morphological, and optical properties of post-annealed Cu implanted MgTiO₃ (MTO) thin films has been carried out in the present report. MTO thin films were synthesized in pure Ar atmosphere using RF sputtering. As-deposited samples were annealed at 750°C to induce crystallinity. Subsequently, the crystalline MTO films were implanted with 100 keV Cu ions at a fixed fluence of 3×10¹⁵ ions/cm². Afterward, the implanted samples were annealed at temperatures of 600, 700 and 800°C using Rapid-thermal-annealing (RTA) to alleviate the defects introduced during ion implantation. Crystallinity deteriorates drastically upon implantation, while post-annealing leads to the recrystallization. However, a reduction in crystallinity is further observed at a temperature of 800°C. The impact of RTA treatment on the surface morphology was assessed using Atomic-force-microscopy. Implanted sample exhibits slightly higher transmittance than the pristine film, which gets reduced upon RTA. Bandgap of the pristine film is 4.17 eV which gets reduced to 3.90 eV upon implantation, while post-annealing treatment slightly raises the bandgap, which is an evidence of defects annihilation in the films upon post-annealing treatment. Moreover, the refractive index of implanted MTO film is lesser as compared to pristine and RTA treated samples. MTO thin film exhibits a broad PL emission band extending from near UV to visible region. Quenching in the luminescence is observed upon implantation. Upon annealing the implanted samples at 600 and 700°C, the PL intensity was further reduced. Post annealing at higher temperature of 800°C leads to a substantial increase in emission intensity. Similarly, time-resolved PL indicates a reduction in average decay lifetime of implanted films as compared to the pristine sample, while it is observed to vary with post-annealing treatment. A comprehensive study of recrystallization behavior of RTA treatment of implanted MTO thin films, from structural and optical aspects, was carried out.

Single-walled carbon nanotubes (SWCNTs) are filled with metal halides to modify their electronic properties. Metal halides are filled in SWCNTs with a melt method. They have various melting temperatures, and different protocols have beenoptimized for the filling of SWCNTs with metal halides. Nickel chloride (NiCl₂) is a unique metal halide. Filling SWCNTs with nickel chloride is of large interest to researchers because its encapsulation in SWCNTs leads to p-doping. Nickel chloride has a high melting temperature (1001ºC). It is important to develop a method for filling SWCNTs with nickel chloride. In this work, we submit a filling protocol forSWCNTs with nickel chloride, filling the melted compound in the SWCNTs. The protocol was conducted at 1101ºC for 10 hours. The subsequent cooling down period was carried out at rates of 0.02-1ºC/min to crystallize nickel chloride in the SWCNTs. The electronic properties of the nickel chloride-filled SWCNTs were investigated with Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The Raman spectra of the nickel chloride-filled SWCNTs showed large shifts in the peaks and alterations in their intensities. The C 1s XPS spectra showed a shift of the peak in lower binding energies. The observed modifications are the result of the variations in the Fermi level of the nickel chloride-filled SWCNTs. It is shifted down in the filled SWCNTs due to the work function differences between nickel chloride and the SWCNTs.

Background: There are three common gypsum product materials used to create dental molds and dies, which are dental plaster, dental stone, and improved stone. Improved stone is the best choice for making final molds and dies. Dental plaster is the cheapest option, but it demonstrates the lowest compressive strength. Because of these issues, dental plaster is mostly used for temporary molds and dies, not for the final ones. Objectives: The purpose of the study is to assess the compressive strength, wettability, setting time, and setting expansion of conventional type II dental gypsum that has been manually blended with 10 wt.% calcium bentonite clay/activated carbon fiber fillers. Methods: The conventional type II dental gypsum powder and water were mixed to create the control group; the modified group was made by mixing the conventional dental plaster powder with 10 wt.% bentonite-activated carbon and then mixing with water; the third group was created by mixing the improved stone powder and water. Data were analyzed using one-way ANOVA and Tukey tests (p < 0.05). Results: The findings showed that the modified dental plaster demonstrated a higher mean compressive strength and higher wettability than the other tested groups. While the conventional dental plaster showed the highest significant setting expansion, followed by conventional improved stone and modified dental plaster, with no significant difference between them. Moreover, there was no significant difference between the setting time of the three tested groups, either for the initial or the final setting time.

Conclusion: The modified dental plaster, by incorporating 10 wt.% bentonite-activated carbon fillers, could be used as an alternative to conventional improved stone.

Single-walled carbon nanotubes (SWCNTs) are prepared via three methods, arc-discharge, laser ablation, and chemical vapour deposition. The arc-discharge and laser ablation methods result in the powders of the bundled SWCNTs, which are further organized into films. The chemical vapour deposition method leads to ordered SWCNTs, which are further processed to form films. In this work, we formed the films from the arc-discharge SWCNTs, and they had high purity and quality. We performed the filling of the SWCNT films with lead chloride using the melt method. It resulted in high filling ratios of the SWCNTs. Lead chloride and SWCNTs were sealed under high vacuum in quartz ampoules, and they were heated in the tube furnace up to the preparation temperature, 601°C. They were left at this temperature for 6 hours, and then cooled down to room temperature. The obtained samples were characterized with transmission electron microscopy (TEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). TEM confirmed the filling of the SWCNTs. Raman spectroscopy and XPS showed the changes in the electronic properties of the filled SWCNTs. A p-doping with a Fermi level shift of -0.15 eV was revealed. The obtained information is needed for applications of filled SWCNTs in nanoelectronics, catalysis, biomedicine, sensors, magnetic recording, spintronics, and light emission.

The increasing demand for sustainable materials in wastewater treatment has led to exploring plant-based biosorbents. Abies marocana needles, an abundant Moroccan biomass, offer promising potential due to their rich surface chemistry and renewability. This study focuses on synthesizing and characterizing a biosorbent from these needles for dye removal applications.

Raw A. marocana needles were chemically activated using sulfuric acid to improve adsorptive properties. The biosorbent was characterized using Fourier Transform Infrared Spectroscopy (FTIR) for functional groups, Scanning Electron Microscopy (SEM) for surface morphology, analysis for surface area and porosity, X-ray Diffraction (XRD) for crystallinity, and Point of Zero Charge (pHpzc) for surface charge determination. Preliminary adsorption tests with methylene blue dye were conducted to assess performance.

FTIR confirmed the presence of hydroxyl, carboxyl, and phenolic groups essential for adsorption. SEM revealed a porous, heterogeneous surface after chemical treatment. Surface analysis showed increased surface area and pore volume, indicating enhanced adsorption sites. XRD patterns suggested an amorphous carbonaceous structure favorable for adsorption. The pHpzc value indicated a surface charge conducive to adsorbing cationic dyes. Adsorption tests demonstrated significant methylene blue uptake, confirming effective interaction between dye molecules and biosorbent surface.

The chemically activated A. marocana needle biosorbent exhibits promising structural and chemical properties for organic dye adsorption. This green material offers a cost-effective and environmentally friendly option for wastewater treatment, warranting further optimization for industrial applications.

Introduction: Polymer-stabilized metal nanocomposites (MeNP) showed great nanobiotechnological potential. In addition to the widely studied AgNPs, magnetic MeNPs used for targeted drug delivery are of growing interest. Aims: We aimed to perform in vitro evaluation of the antibacterial and anti-cancer properties of low-nanometer-scale size Ag, Ni, and Co nanoparticles obtained for this study via borohydride reduction in situin a hybrid matrix SiO₂-grafted polyacrilamide (SiO₂-g-PAAm); SiO₂ core r_av 7 nm, M_vPAA ~ 800 kDa, and mean particle diameters (d_av) 6.1 (Ag), 2.7 (Ni), and 1.9 (Co) nm (Zheltonozhskaya et al. 2021; 2023; 2025). Methods: The Bacterial strains Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 25923), and cancer cell lines B95-8 and Wish were used; MDCK cells were used as the control. Antibacterial activity was studied by serial dilutions and well diffusion methods; the MTT test was used for cell viability assay. Results: Antibacterial activity was inherent to AgNP only. For both microbial strains, the MIC of 11.0 µg/ml was at the level of tetracycline. The cytotoxicity was dependent on Me, but not on the cell type. The highest toxicity against B95-8 and Wish cancer cells was found in NiNP (IC₅₀ 1.9 and 2.5 µg/ml, respectively). CoNP exhibited moderate toxicity (IC₅₀ 6.3 and 5.31 µg/ml), while AgNP showed the least toxicity (IC₅₀ 9.2 µg/ml for both cell lines). In MDCK cells, IC₅₀ 20.6 µg/ml was reached by NiNP only. The matrix contributed to cytotoxicity in B95-8 cells but was not toxic to other cell types. Conclusions: Nanocomposites of low-nanometer-scale size MeNPs in a hybrid polymer–inorganic matrix SiO₂-g-PAAm showed high antibacterial and anti-cancer efficiency and were much less toxic in their control of MDCK cells, which makes them promising for anti-bacterial and anti-cancer applications; however, the dependence of their effectiveness on Me and cell typesis in need of further study.

Nematic liquid crystals (NLCs) are soft-materials that combine the fluidity of liquids with the long-range orientational order of crystals. Their optical, dielectric, and elastic anisotropies make them highly responsive to external fields, which has led to their widespread use in display technologies. In the uniaxial nematic phase (N_u), molecules are oriented along a common direction, known as the nematic director. The twist-bend nematic (N_tb) phase is formed by achiral molecules, and exhibits a spontaneously chiral, self-assembled heliconical structure with a nanometer-scale pitch length. As a result of its unique properties, the N_tb phase has attracted significant attention from the research community. Nanoparticles (NPs) exhibits unique properties and behaviors, strongly influencing the properties of NLCs. The impact of NPs on an NLC system is primarily determined by their geometry, size, and chemical composition.

We conducted a comparative study of the effects of spherical, rod-like, and disk-like NPs on the electrooptical properties of a liquid crystal exhibiting both the N_u and N_tb phases. The mesogenic dimer 1'',9''-bis(4-cyanobiphenyl-4’-yl)nonane (CB9CB) was enriched with CdSe/ZnS quantum dots, hydroxyapatite nanorods, and CuFeS₂ nanoplatelets, yielding three corresponding series of LC-NP nanocomposites. The thermodynamic stability, and the ordering of the nematic phases were investigated by means of polarized optical microscopy. The phase diagrams of the nanocomposites as a function of temperature (T) and the NP mass fraction (χ) were constructed. The birefringence of the nematic phases and the conical tilt angle of the heliconical structure were determined and analyzed. The voltage threshold for the reorientation transition of both nematic phases, as well as the switching times of the N_u​ phase, were measured as functions of T and χ.

This study investigates the mechanical performance enhancement of e-glass/basalt fiber reinforced polymer (FRP) sandwich composites through boron carbide (B4C) nanoparticle modification for marine structural applications. The research focuses on developing lightweight, corrosion-resistant composite panels capable of withstanding harsh marine environments while maintaining structural integrity. Three different B4C concentrations (0.6%, 1.0%, and 1.4% by weight) were incorporated into epoxy resin matrices, which were then used to fabricate sandwich panels with varying fiber orientation sequences ([0°/90°], [±45°], and quasi-isotropic layups). The composite structures were evaluated through comprehensive mechanical testing including tensile, flexural, impact, and water absorption tests following ASTM standards.

Finite element analysis (FEA) was performed using ANSYS ACP to simulate stress distribution under hydrostatic pressure conditions representative of underwater applications. Experimental results demonstrated that the 1.0% B4C reinforced quasi-isotropic samples exhibited optimal performance, showing a 27.3% increase in flexural strength (from 412 MPa to 524 MPa) and 18.7% improvement in impact resistance compared to control samples. Water absorption tests revealed a significant reduction (up to 35%) in moisture uptake for B4C-modified specimens. Microstructural analysis using SEM confirmed improved fiber-matrix interfacial bonding in nanoparticle-enhanced samples.

These findings suggest that judicious incorporation of B4C nanoparticles in e-glass/basalt hybrid sandwich structures can substantially enhance mechanical properties while providing excellent moisture resistance, making them suitable for marine applications such as boat hulls, offshore platform components, and underwater vehicle structures. The study provides a framework for optimizing nanoparticle-reinforced hybrid composites for demanding marine environments.

Methylene blue (MB), the most widely used colorant in the textile industry, pollutes water bodies, rendering them unusable, and produces a global environmental challenge due to its high toxicity and harmful effects. In this study, lignin-based metal organic frameworks (lignin MOFs) are prepared from Organosolv lignin to develop a highly efficient, cost-effective, and environmentally friendly adsorbent for the removal of MB from aqueous solutions. The introduction of a room temperature linker salt approach synthesis method using lignin as a bio ligand will facilitate the formation of porous structures with high surface area in MOFs, and combined with the rich functional groups of lignin will result in a good adsorption process. The resulting material was characterized using Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Thermal Gravimetric Analysis (TGA), and nitrogen adsorption–desorption analysis (BET) to confirm its structure, morphology, and porosity. Batch adsorption experiments were conducted to evaluate the adsorption efficiency of the prepared lignin-MOFs in comparison to conventional MIL53(AL). Adsorption kinetics and isotherms were analyzed using the pseudo-second-order model and the Langmuir model, respectively, to understand the adsorption mechanisms. The synthesized lignin-derived MOFs exhibited nanosized particles with a porous, crystalline structure with a high specific surface area and thermal stability, confirming their suitability as a non-toxic adsorbent compared to conventional organic ligand-derived MOFs. Adsorption experiments showed that the prepared lignin material effectively removed MB. This research successfully reveals the potential of utilizing an eco-friendly and low-cost precursor, lignin, to fabricate highly efficient biobased MOFs for water purification.