Transmission Electron Microscopy Images Research Articles

Oral Curcumin through Mesoporous Silica Nanomaterials with Distinct Morphologies: Synthesis, Characterization, Biosafety Evaluation, and Antioxidant Activity In Vivo.

Antioxidant play a crucial role in the prevention and treatment of diseases associated with oxidative stress. Curcumin (CUR), as a natural antioxidant, exhibits numerous therapeutic properties, including antioxidant, anti-inflammatory, antibacterial, and antitumor activities. However, its limited bioavailability and poor water solubility hinder its application as an effective antioxidant. In this study, a series of mesoporous silica nanomaterials with distinct morphologies, i.e., mesoporous silica nanoparticles (MSN) and mesoporous silica nanorods (MSR) were synthesized by a template-sediment-etching method. CUR was selected as a model drug and encapsulated into these nanomaterials to improve its bioavailability in vivo. The morphology and size distribution of MSN and MSR were determined through transmission electron microscopy (TEM) imaging and Zetasizer analysis. Fourier transform infrared spectroscopy (FTIR) spectra confirmed the successful encapsulation of CUR within these nanomaterials. Furthermore, these CUR-loaded silica nanomaterials, denoted as CUR@MSN and CUR@MSR, exhibited excellent DPPH and ABTS free radical scavenging activity in vitro. Furthermore, CUR@MSN and CUR@MSR also exhibited obvious in vivo antioxidant activity. This study opens up new avenues for the development of enhanced antioxidants through the utilization of mesoporous silica nanomaterials.

Microstructural insights into the coarse-grained heat-affected zone of a high-strength all-weld metal: Development of a continuous cooling transformation diagram

AbstractThe present study deals with the development of a continuous cooling transformation diagram corresponding to the coarse-grained heat-affected zone of a high-strength all-weld metal with a minimum yield strength of 1100 MPa fabricated via gas metal arc welding. Dilatometry tests were conducted to determine the transition temperatures. High-resolution imaging methods, such as transmission electron microscopy and atom probe tomography, as well as nanoindentation, were employed to resolve the microstructural constituents. At fast cooling rates (t8/5 from 1.4 to 25 s), the microstructure comprises a mixture of martensite and coalesced bainite, with a slight increase in the content of coalesced bainite with faster cooling. This demonstrates that coalesced bainite cannot be avoided in the coarse-grained heat-affected zone of the current alloy by increasing the cooling rate. With slower cooling (t8/5 ≥ 50 s), the microstructure becomes increasingly bainitic, accompanied by a marginal drop in Vickers hardness. At t8/5 times of 500 s and 1000 s, the all-weld metal consists of granular bainite with significant amounts of retained austenite and different shaped martensite-austenite constituents. The coarser massive-type constituents contain body-centered cubic grains, sized in the hundreds of nanometers, with a hardness approximately twice as high as that of the surrounding bainitic matrix.

Eco-friendly Nanostructured Liquid Crystals Loaded with Clove Oil as a Sustainable Approach for Managing Infected Burn Wounds

Infections are a leading complication in patients with burns. Effective antimicrobial treatment with regenerative tissue healing is required. Utilizing components derived from plant origin such as natural oils as a sustainable and eco-friendly approach for managing disease is highly required nowadays. The aim of the current study is to assess the antibacterial and wound-healing activity of clove oil and its novel eco-friendly nanostructured liquid crystals (Eco-friendly-NLCs) formulation in treating infected burn wounds. A 23 full factorial design was used to optimize the Eco-friendly-NLCs. Clove oil and its novel nano-formulation were characterized and subjected to in vitro and in vivo assessments for their efficacy. Twenty rats were used experimentally. The optimum Eco-friendly-NLCs had 189.2 ± 1.9 nm, -22.8 ± 0.7 mV and 0.308 as values for particle size, zeta potential and polydispersity index. Transmission electron microscope images showed discrete spherical shape NLCs with no aggregations. The microbiological and pharmacological results revealed a superior efficacy regarding clove loaded Eco-friendly-NLCs in inhibiting bacterial growth (inhibition zone of 38 mm), significantly reducing inflammatory biomarker levels (p < 0.001), promoting angiogenesis and prompt wound healing. The Eco-friendly-NLCs loaded with clove oil could be considered as a promising formulation providing anti-inflammatory, anti-bacterial and wound healing effects.Graphical

GeTe/Sb2Te3 Super‐Lattices: Impact of Atomic Structure on the RESET Current of Phase‐Change Memory Devices

AbstractPhase change memories (PCMs) are at the heart of modern memory technology, offering multi‐level storage, fast read/write operations, and non‐volatility, bridging the gap between volatile DRAM and non‐volatile Flash. The reversible transition between amorphous and crystalline states of phase‐change materials such as GeTe or Ge2Sb2Te5 is at the basis of PCM devices. Despite their importance, PCM devices face challenges including high power consumption during the RESET operation. Current research efforts focus on improving device architecture and exploring alternative phase‐change materials such as GeTe/Sb2Te3 super‐lattices (SLs), for which a reduced programming power consumption is observed compared with standard PCMs. Herein, by combining X‐ray diffraction and scanning transmission electron microscopy imaging of SL thin films with the study of the same SL in PCM devices, it is shown that it is possible to significantly decrease RESET energy of the device, without modifying the SL composition, by reducing the amount of structural defects through annealing treatment. The best device properties are obtained after transforming the SL into a defect‐free, highly out‐of‐plane oriented rhombohedral phase. These results offer a promising avenue for further improving the performance of SL‐based PCM devices through structural optimization.

Synthesis and Characterization of MgO-Fe₂O₃/γ-Al₂O₃ Nanocomposites: Enhanced Photocatalytic Efficiency and Selective Anticancer Properties

In the present work, we achieved the fabrication of MgO-Fe2O3/γ-Al2O3 NCs using a deposition–coprecipitation process. XRD, TEM, and SEM with EDX, XPS, FTIR, and PL spectroscopy were applied to examine the physicochemical properties of the samples. XRD analysis confirmed the successful incorporation of γ-Al2O3, MgO, and Fe2O3 phases. TEM and SEM images indicate that the nanocomposites exhibited an agglomerated morphology with spherical shapes and particle sizes in the range of 6–12 nm. EDX and XPS spectra revealed a composition of MgO-Fe2O3/γ-Al2O3 NCs. FTIR spectra identified characteristic vibrational bands corresponding to the chemical bonds present in the samples, confirming their successful synthesis. PL analysis showed the reduced recombination rate of electron–hole pairs and enhanced charge separation efficiency, which are important factors for improved photocatalytic activity. Photocatalysis results show that the MgO-Fe2O3/γ-Al2O3 NCs exhibited significantly higher photocatalysis efficiencies of 87.5% for Rh B and 90.4% for MB after 140 min, compared to γ-Al2O3 NPs and Fe2O3/γ-Al2O3 NPs. In addition, prepared MgO-Fe2O3/γ-Al2O3 NCs demonstrated superior stability after six runs. Biochemical data showed that the MgO-Fe2O3/γ-Al2O3 NCs exhibited significant toxicity toward A549 cancer cells while displaying low toxicity toward IMR90 normal cells. The IC50 values (µg/mL ± SD) for γ-Al2O3 NPs, Fe2O3/γ-Al2O3 NPs, and MgO-Fe2O3/γ-Al2O3 NCs were 16.54 ± 0.8 µg/mL, 14.75 ± 0.4 µg/mL, and 11.40 ± 0.6 µg/mL, respectively. These results suggest that the addition of Fe2O3 and MgO to γ-Al2O3 not only enhances photocatalytic activity but also improves biocompatibility and anticancer properties. This study highlights that the MgO-Fe2O3/γ-Al2O3 NCs warrant further exploration of their potential applications in environmental remediation and biomedicine.

Localized Boron Sites in Large Pore Borosilicate Zeolite EMM-59 Determined by Electron Crystallography.

The structure of novel large pore borosilicate zeolite EMM-59 (|C19H42N2|8[B5.2Si218.8O448]) with localized framework boron sites was determined by using three-dimensional electron diffraction (3D ED) and scanning transmission electron microscopy (STEM) imaging. EMM-59 was synthesized using 2,2-(cyclopentane-1,1-diyl)bis(N,N-diethyl-N-methylethan-1-aminium) as an organic structure-directing agent (OSDA). The framework has a three-dimensional intersecting channel system delimited by 12 × 10 × 10-ring openings and contains 28 T and 60 oxygen atoms in the asymmetric unit, making it the most complex monoclinic zeolite. The 3D ED data collected from as-made EMM-59 under cryogenic conditions revealed three symmetry-independent locations of the OSDAs, and STEM imaging showed that the OSDAs are flexible and adopt different molecular conformations in channels with identical structural environments. The framework boron atoms were exclusively found in T-sites of 4-rings, especially those shared by multiple 4-rings. The tetrahedral BO4 with the highest boron content (38.6%) was transformed into a trigonal BO3 after the OSDAs were removed upon calcination. Its location and boron content could also be identified by STEM imaging.

Combining Machine Learning Algorithms with Traditional Methods for Resolving the Atomic-Scale Dynamic Structure Reconstruction of Monolayer MoS2 in High-Resolution Transmission Electron Microscopy

Abstract High-resolution transmission electron microscopy promises rapid atomic-scale dynamic structure imaging. Yet, the precision limitations of aberration parameters and the challenge of eliminating aberrations in Cs-corrected transmission electron microscopy constrain resolution. A machine learning algorithm is developed to determine the aberration parameters with higher precision from small, lattice-periodic crystal images. The proposed algorithm is then validated with simulated HRTEM images of graphene and applied to the experimental images of a molybdenum disulfide (MoS2) monolayer with 25 variables (14 aberrations) resolved in wide ranges. Using these measured parameters, the phases of the exit-wave functions are reconstructed for each image in a focal series of MoS2 monolayers. The images were acquired due to the unexpected movement of the specimen holder. Four-dimensional data extraction reveals time-varying atomic structures and ripple. In particular, the atomic evolution of the sulfur-vacancy point and line defects, as well as the edge structure near the amorphous, are visualized as the resolution has been improved from about 1.75 Å to 0.90 Å. This method can help salvage important transmission electron microscope images and is beneficial for the images obtained from electron microscopes with average stability.

Study of Photoluminescence and Thermoluminescence Properties of Tb3+ Doped Green Emitting YPO4 Nanophosphors.

YPO4 nanophosphors doped with different concentrations of Tb3+ were synthesized using conventional co-precipitation method. The crystalline as well structural features were studied by using powder X-ray diffraction (PXRD) as well as Transmission electron microscope (TEM) images, which revealed highly crystalline nature of the prepared samples having particle sizes of around 40nm. EDAX spectrum also shows the elemental composition of the synthesized nanoparticles which contain Y, P, O, Tb3+as expected. Prepared samples showed emission peaks at 491, 545, 588 and 624nm under UV excitation having excitation wavelengths of 223 and 320nm. The Commission International de I'Eclairage (CIE)study shows the chromaticity co-ordinates for the 600oC annealed samples to be x = 0.239, y = 0.4 which corresponds to cool greenish light suggesting the potential applications of the prepared nanophosphor in white light emitting diodes converted from green phosphors, optical display setups and PDP applications. Thermoluminescence (TL) study was carried out after exposing the samples 5at.wt% Tb3+ doped YPO4 to gamma radiations. Kinetic parameters were calculated using Deconvolution method.

Ultrasmall Bismuth Nanoparticles Supported Over Nitrogen-Rich Porous Triazine-Piperazine Polymer for Efficient Catalytic Reduction.

The development of inexpensive and reusable nanocatalysts to convert the hazardous pollutant 4-nitrophenol (4-NP) into a valuable platform chemical 4-aminophenol (4-AP) is quite demanding due to environmental and public health concerns. Herein, we report a facile strategy for the preparation of supported Bi nanoparticles (NPs) over the surfaces of nitrogen-rich porous covalent triazine-piperazine-3D nanoflowers (BiNPs@3D-NCTP). SEM and TEM image analysis suggested 3D-flower-like morphology of the materials. The powder X-ray diffraction (PXRD) analysis also confirmed the loading of Bi NPs. N2 sorption analysis suggested BET surface areas of 663 and 364 m2g-1 for the 3D-NCTP and BiNPs@3D-NCTP materials, respectively. The large surface area, bimodal pores and 3D nanoflower architecture enable uniform loading of Bi nanoparticles, while its nitrogen-rich functionality stabilizes and acts as a capping agent restricting further nanoparticle expansion. BiNPs@3D-NCTP showed a 99.85% conversion for the 4-NP to 4-AP within four minutes. The normalized rate constant of 38.3 min-1 mg-1 of BiNPs@3D-NCTP catalyst for reducing of 4-NP suggested its superior catalytic efficiency. Nitrogen-rich functionality activates the catalytic site to accelerate the reaction, while bimodal pores can promote diffusion of reactant molecules. After five catalytic cycles, the nanocatalyst showed high chemical stability and negligible activity loss.

A Study on Gas‑sensing Behavior of Reduced Graphene Oxide (rGO) Green Method, Enhansing the Performance of Green-synthesized Reduced Graphene Oxide

This paper presents a comparative study on gas-sensing behavior of reduced graphene oxide (rGO) synthesized by chemical and green synthesis route. GO is synthesized by Hummers method and then reduced employing two reducing agents hydrazine hydrate [represented by (rGO)1] and L-citrulline [represented by (rGO)2]. Synthesized products were then obtained in the form of thin films, and tested for 10 ppm NO2 and CO at operating temperatures of 50, 100, and 150 °C. The green-synthesized reduced graphene oxide (rGO)2 exhibits higher relative response of 254.7% as compared to conventionally synthesized (rGO)1 (93.9%) and GO (22.7%) for 10 ppm NO2 at operating temperature of 150 °C. Furthermore, a switching of conductivity from usual p-type behavior to n-type on exposure of NO2 is observed at all operating temperatures (50, 100, and 150 °C) for GO, (rGO)1, and (rGO)2. The XRD, FTIR, and Raman confirm the oxidation and reduction process. (rGO)2 shows high thermal stability as observed through TGA. FESEM and TEM images show wrinkled sheet structure for GO as well (rGO)1 and (rGO)2. The data observed from the characterization of resultant products have made it possible to explain better reduction of GO through green-reducing agent and enhanced gas-sensing performance of green-synthesized reduced graphene oxide.

Effect of ball milling on bulk MoS2 and the development of Al–MoS2 nanocomposites by powder metallurgy route

Abstract The present study provides an in-depth investigation of the exfoliation of molybdenum disulfide (MoS2) using high-energy ball milling and the subsequent development of aluminum‒molybdenum disulfide (Al–MoS2) nanocomposites via a powder metallurgy (PM) route. X-ray diffraction confirmed that the commercially available bulk MoS2 did not develop new phases after intense ball milling for up to 30 h. The effects of ball milling on the thermal stability and morphological changes in MoS2 powder have also been reported. The milling action caused a shift in the band gap of MoS2, from 1.2 to 1.44 eV due to quantum confinement phenomena confirmed by UV–visible absorption spectroscopy. The impacts of ball milling on the specific surface area and mean pore diameter of MoS2 were determined by the Brunauer–Emmett–Teller surface area analysis technique. Additionally, the investigation through Fourier transform infrared spectroscopy verifies the presence of functional groups, such as hydroxyl (O–H), alkane (C–H), and ether (C–O), on the MoS2 surface. The milling resulted in a significant reduction in particle size from an initial mean size of 1.2 µm–480 nm. Field emission scanning electron microscopy micrographs of the exfoliated MoS2 revealed a thin, cracked, and flake-like morphology. High-resolution transmission electron microscopy images revealed that the high-energy ball milling resulted in few-layered MoS2 nanoplatelets after 30 h of ball milling. Subsequently, the investigation extended its focus to the development of Al–MoS2 nanocomposites using the PM route, incorporating MoS2 into the Al matrix at different weight percentages (1, 2, 3, and 5 wt.%). Al-5 wt.% MoS2 nanocomposite showed the highest relative density of 93.09 %, the maximum hardness of 743.6 MPa, and the best wear performance among all the Al–MoS2 nanocomposites. The hardness of Al-5 wt.% MoS2 nanocomposite was 109.11 % higher than that of the pure Al sample developed similarly. A maximum compressive strength (σ max) of 494.67 MPa was observed in Al-5 wt.% MoS2 nanocomposite, which was 1.84 times the value of σ max obtained from sintered pure Al sample.

Fabrication of ZnIn2S4/CeO2 S-scheme heterojuntion for the enhanced removal of tetracycline under visible light irradiation

A series of S-scheme ZnIn2S4/x-CeO2 heterojunction were designed and fabricated through in-situ precipitation and hydrothermal method. XRD, SEM, TEM, EDX, XPS, UV-vis DRS and adsorption-photocatalytic techniques were employed to investigate its crystal phase structure, morphology, size, elemental composition, photo-response property and elimination ability for tetracycline. XRD analysis revealed CeO2 and ZnIn2S4 in ZnIn2S4/x-CeO2 sample presented cubic and hexagonal phase structure, respectively. SEM and TEM images indicated that CeO2 particles with irregular-shaped of around 20nm were attached on the smooth surface of ZnIn2S4 microparticles with ca. 4 μm. All the as-synthesized ZnIn2S4/x-CeO2 samples could harvest more visible-light and the absorption edges were red-shifted in comparison with pure CeO2. ZnIn2S4/0.3-CeO2 sample exhibited remarkably enhanced photocatalytic performance and its removal efficiency for tetracycline reached 87.29% within 100min. The detailed experimental and DFT calculation indicated that the enhanced photocatalytic property was mainly ascribed to the synergistic effect of wide light-response range, suitable band position and successful fabrication of S-scheme heterostructure, which was in favor of rapid transfer and available separation of photo-generated e-/h+ pairs. The scavenger experiments and the ESR data revealed that the •O2– and h+ active species played the dominant role in tetracycline removal over ZnIn2S4/0.3-CeO2 system. In addition, the as-synthesized ZnIn2S4/0.3-CeO2 samples had excellent stability and the removal efficiency still reached 70.73% after being repeatedly used for 4 times. Furthermore, the possible enhanced photocatalytic mechanism over ZnIn2S4/x-CeO2 was proposed to get a better understanding of photocatalytic process. This work provided the guidance to fabricate CeO2-based heterojunction with promising prospect for the efficient elimination of antibiotic residues from wastewater.

Unveiling the role of sintering temperatures in the physical properties of Cu-Mg ferrite nanoparticles for photocatalytic application

This research presents an explicit analysis of the effects of sintering temperature (Ts) on the structural, morphological, magnetic, and optical properties of Cu0.5Mg0.5Fe2O4 nanoferrites synthesized via the sol-gel method. To accomplish it, Cu-Mg ferrite NPs were sintered at temperatures ranging from 300 to 800 °C in increments of 100 with a constant holding duration of 5 h. Thermogravimetric analysis was used to observe the degradation of organic components and the thermally stable zone of the material. XRD analysis and SAED patterns revealed the formation of a single face-centred cubic (fcc) spinel structure with an Fd–3m space group. The particle's crystallite sizes have grown from 4.54 to 102.54 nm as Ts have increased, consistent with TEM results. Further evidence for the creation of spinel structure was provided by two prominent absorption bands in FTIR spectroscopy below 1000 cm−1. The particles were found to have a densely packed, nearly spherical morphology, as confirmed by TEM images. The EDS was utilized to identify the chemical species that were present in the sample. A significant correlation was observed between particle size and magnetic properties. The field-dependent magnetization investigations revealed that particles with crystallite sizes of 4.54 and 5.10 nm were superparamagnetic, while those measuring 11.68, 23.81, 42.95, and 102.54 nm exhibited ferrimagnetic characteristics. Furthermore, it was revealed that an increase in sintering temperature results in a concurrent amplification of crystallites, which subsequently heightens the saturation magnetization of the prepared NPs from 9.49 to 33.04 emu/g. The coercivity value clarifies the sintering effect of transforming the particle from a single-domain to a multi-domain magnetic state. The finite-size scaling formula precisely characterizes the changes in Curie temperature. In addition, the semiconducting characteristics of Cu-Mg ferrite NPs were confirmed through DRS, which unfolded an optical band gap within the range of 1.84–2.26 eV. The Mulliken electronegativity approach unveiled the prospective efficacy of these NPs in photocatalytically generating O2 from water. Cu-Mg nanoferrites exhibit a favourable bandgap and potential as a photocatalyst, rendering them a potentially fruitful addition to the family of ferrite materials utilized in photocatalytic and associated solar energy applications.

On the effect of precession for magnetic differential phase contrast imaging

The separation of diffraction effects from phase contrast is a major challenge for differential phase contrast (DPC) imaging in scanning transmission electron microscopy (STEM). The application of electron beam precession has previously been proven successful in homogenizing the direct beam and improving the imaging of both long-range electric and magnetic fields. However, magnetic STEM-DPC imaging performed in a low magnification (LM) STEM mode suffers from significant aberrations of the probe forming lens and the consequent impediment of small precession angles. By investigating the application of precession path segmentation to LM-STEM precessed scans for the imaging of LSMO and FeAl thin film samples, the initially reported benefits of precession were discovered to be less substantial than originally assumed. The segmentation methodology reveals that precession induced beam phase shifts account for a large part of the DPC induction profile smoothing, and the precession path is non-circular, leading to streaking artifacts in the reconstructed induction maps.

Staged evolutionary features of the aromatic structure in high volatile A bituminous coal (hvAb) during gold tube pyrolysis experiments

Low-temperature pyrolysis of coal is a crucial step in the coal thermal conversion process and involves very complex physical and chemical reactions that can have different effects on the coal's structure. The thermal evolution behavior and transformation mechanism of the coal microstructure are not yet fully understood, which also limits the efficient utilization of coal to a certain extent. The aromatic structural features (including size, molecular ordering, nematic symmetry, stacking, and curvature) of the char produced from low-temperature pyrolysis of high volatile A bituminous coal (hvAb) from the Xutuan coal mine, China, were quantitatively assessed via high-resolution transmission electron microscopy (HRTEM) image processing and analytical techniques. The thermal transformation process and the mechanisms controlling it were explored. The results show that, except for the unexpected slight growth of aromatic sheets at 440 °C, the lower pyrolysis temperature (< 521 °C) contributed weakly to their size growth, whereas at higher temperatures (561–600 °C), it significantly increased their size. The aromatic molecular ordering tended to gradually change in three stages: increasing between 340 and 440 °C, decreasing between 440 and 521 °C and increasing again between 521 and 600 °C. The nematic symmetry strength of aromatic fringes also followed a similar pattern with temperature at different scales. Additionally, in addition to a very minor development trend at 440 °C, the stacking did not significantly change at temperatures below 521 °C but developed appreciably further with increasing temperatures at 561–600 °C; however, the average spacing of the stacks did not appear to be significantly reduced at all temperatures. The curvature of the aromatic sheets also varied in different temperature stages, i.e., initially slightly increasing (340–380 °C), then gradually decreasing (380–480 °C), later increasing again (480–521 °C), and eventually decreasing (521–600 °C). The properties of the chemical composition and structure of the initial coal play important roles in the thermal reaction behavior, and the physical and chemical reactions that dominate at the different temperature stages may be responsible for such wiggly trends in the evolution of the aromatic structure. Notably, the properties of the mesophase (approximately 440 °C) strongly influence the subsequent structural transformation. These findings could provide useful information for the microstructure–property relationships and preparation of coal-based carbon materials.

SnO2-TiO2/reduced graphene oxide nanocomposites: Green synthesis and enhanced photocatalytic efficiency for dye removal

Titanium oxide nanoparticles (TiO2 NPs) have been interested in potential applications, including gas-sensing, energy storage, environmental remediation, and medical fields. In the present work, fabricated SnO2-TiO2/RGO nanocomposites (NCs) have been produced through a green precipitation approach. XRD, TEM, SEM, EDX, XPS, FTIR, UV, and PL analyses have been carefully applied to invistage the physicochemical properties of prepared NPs and NCs. The XRD data showed that the crystal structure of the TiO2 NPs was affected by the introduction of SnO2 NPs and RGO sheets. The spherical shape of the prepared samples and their morphologies were confirmed using TEM and SEM images. EDX and XPS analyses confirmed that tin (Sn), titanium (Ti), oxygen (O), and carbon (C) were further present in the SnO2-TiO2/RGO NCs. FT-IR spectra determines the functional groups with bands between the compositions of obtained NPs and NCs. Besides, the band gap energies of prepares samples were estimated from UV–vis spectra. It displayed that the absorption peak of the synthesized TiO2 NPs was improved after the addition of SnO2 NPs and an RGO sheet. PL analysis indicate that the PL intensity of the prepared TiO2 NPs was decreased with the addition of SnO2 NPs and RGO sheets due to a decrease in the recombination rate of electrons (e−)-holes (h+). As shown in photocatalytic results, the photodegradation of methylene blue (MB) dye of SnO2-TiO2/RGO NCs was reached 92.20% after 140 min of UV irradiation. These results suggest that the addition of RGO sheets occupied a role in enhanced the photocatalytic performance of the prepared NCs. This study highlighted that these samples could be applied in various applications such as photocatalytic and therapeutic areas.

Rapid photocatalytic degradation of selective organic dyes using metal oxide-metal sulphide and its inverted nanocomposites

The chemical precipitation approach was employed to synthesize novel heterostructures, namely CeO2-ZnS and SnO2-ZnS, along with inverted nanocomposites ZnS-CeO2 and ZnS-SnO2. The nanocomposites were subjected to characterization using various techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–Vis absorption spectra, and photoluminescence spectra. The TEM images demonstrated particles that were homogeneous, well-dispersed, and comparatively tiny with a sphere-like structure. This indicates successful synthesis and desirable morphological properties of the nanocomposites. The integration of varied nanoparticles within a heterostructure commonly gives rise to synergistic effects, imparting superior properties to the composite compared to the individual components. These nanocomposites tested for their photocatalytic degradation efficiency using Rose Bengal (RB) and Crystal Violet (CV) dyes under natural sunlight and they exhibited approximately 95 % degradation rate. The degradation results demonstrated a significant enhancement in the photocatalytic efficiency of ZnS-CeO2 and CeO2-ZnS nanocomposites. This improvement was attributed to the effective recombination suppression of photogenerated electron-hole pairs, leading to the generation of highly reactive free radicals. The first-order kinetic rate constant for CeO2-ZnS was determined to be 0.52 min−1 for CV and 0.53 min−1 for RB. The present research work has the potential to offer a novel approach to the construction of new heterojunction photocatalysts and to provide a more profound understanding of the treatment of textile organic dyes.

Preparation, characterization, and structural studies of methylcellulose/CuO hybrid materials

Flexible hybrid materials composites of methylcellulose (MC) and CuO are fabricated successfully with solution-casting preparation method as confirmed by the energy-dispersive X-ray spectroscopy (EDX), transmission electron microscope (TEM), and Fourier transform infrared methods. The EDX of MC/CuO recorded the peaks of C, O, and Cu with percentage ratios of 49.61%, 47.35%, and 3.04%, which verify the appropriate formation of the MC/CuO. The TEM image shows that the size of CuO is from 11 to 51 nm. The images from the SEM also show that the CuO nanoparticles are evenly distributed throughout the MC/CuO composite. The impact of CuO on MC transparency is also investigated via UV/vis spectroscopy. The optical parameters of the polymer and composites films were recorded. The bandgap energy of MC is reduced from 4.83 to 4.69, 4.33, and 4.2 eV when mixed with 1.5%, 3%, and 4.5% CuO, respectively, while the band tail is increased from 1.6 to 2.93, 3.66, and 4.15 eV. Carbon cluster numbers also rise from 50 for MC to 54, 63, and 67 for the addition of CuO concentrations of 1.5%, 3%, and 4.5%, respectively. The purpose of this work is fabrication of new nanocomposite materials with innovative flexible properties that may find application in high-performance optoelectronics.

Azelaic acid-based lyotropic liquid crystals gel for acne vulgaris: Formulation optimization, antimicrobial activity and dermatopharmacokinetic study

The proposed study aimed to develop a topical gel containing azelaic acid (AZA)-based lyotropic liquid crystals (LLCs) for the treatment of acne vulgaris. AZA-based LLCs were optimized by varying Poloxamer-407 and polyvinyl alcohol concentration using a central composite design, which showed that both independent variables had a significant effect on the formulation. The highest desirable trial of AZA-based LLCs (Batch-7) containing 300 mg poloxamer-407 and 100 mg polyvinyl alcohol depicted the particle size, zeta potential, and entrapment efficiency of 184.2 nm, −16.1 mV, and 79.96 %, respectively. TEM images confirmed the globular vesicles of LLCs, and ATR-FTIR and DSC results confirmed the compatibility of formulation excipients. In vitro, the release of AZA, AZA-based LLCs, AZA-based LLC gel, and marketed gel showed a release of 23.29, 95.24, 91.07 and 59.88 %, respectively, after 24 h in phosphate buffer pH 6.8. Ex vivo release of AZA-based LLC gel displayed an 86.56 % release after 24 h. The antimicrobial activity of AZA-based LLC gel exhibited a comparable efficacy with marketed gel against Cutibacterium acnes, Staphylococcus epidermis and Staphylococcus aureus. The acute dermal irritation study indicated excellent safety and skin compatibility of AZA-based LLC gel without any erythema and edema. The dermatopharmacokinetic study displayed an enhanced drug retention for AZA-based LLC gel (146.121 ± 21.13 µg/cm2) than marketed gel (58.58 ± 15.95 µg/cm2) in the dermal layer, which would improve its therapeutic effect. These outcomes proved that AZA-based LLC gel has the potential to enhance skin penetration and retention for effective management of acne vulgaris.

Formulation and evaluation of anti-rheumatoid arthritis effects of Ag nanoparticles containing Allium sativum L. Leaf extract

Rheumatoid arthritis is a persistent inflammatory disorder that typically impacts individuals aged 20 to 40. It is characterized by inflammation of the synovial membrane, degradation of cartilage, and joint pain among its various symptoms. Researchers have recently developed, analyzed, and altered biomarkers and nanomaterials that are frequently employed to improve the diagnostic and therapeutic approaches for rheumatoid arthritis. Here, we have created and formulated a novel therapeutic agent that incorporates silver nanoparticles@Allium sativum L. leaves to treat arthritis. The characterization of silver nanoparticles (AgNPs) was performed utilizing various techniques. The FE-SEM and TEM images demonstrated that the majority of these nanoparticles exhibited a spherical shape (10 to 50 nm). Additionally, a notable peak at a wavelength of 403 nm in the UV–Vis spectrum confirmed the successful formulation of the Ag NPs. The antioxidant assay revealed that the IC50 values for the silver nanoparticles@Allium sativum L. and BHT in relation to DPPH were 21 and 44 µg/mL, respectively. In vivo assessments were performed utilizing models involving formaldehyde, CFA, and turpentine oil at various dosage levels. Silver nanoparticles@Allium sativum L. exhibited anti-arthritic properties with the most significant potential observed at 1 mg/kg. Data from the CFA model revealed a more substantial protective effect on arthritic lesions and alterations in body weight. The recent results indicates the recovery of rheumatoid arthritis criteria including synovial cavity swelling and edema inhibition percentage in turpentine test, paw diameter in CFA test and paw edema in formaldehyde test. In conclusion, these data support the administration of silver nanoparticles as potent therapeutic agents for rheumatoid arthritis treatment in humans.