FESEM Analysis Research Articles

Impregnation of ZnO over a new hydrogel bead based conducting polymer and alginate for textile dye treatment: Interface charge transfer assessment, real wastewater treatment, and dye selectivity

In this study, we have taken a novel approach to dye removal and real wastewater treatment by employing dual smart strategies: surface charge transfer engineering and developing an easily recoverable photocatalyst. The removal of acid blue 92 (AB92) dye by using a novel 3D polypyrrole-zinc oxide-sodium alginate (PPy-ZnO-SA) nanocomposite under UV-C, visible light, and natural sunlight was investigated. The nanocomposite hydrogel was characterized using various techniques, including XRD, Raman, FESEM, TEM, XPS, PL, DRS, and CV analyses, and the type of effective interactions in different stages of removal was investigated by FTIR analysis. The optimum conditions (reaction time = 284 min, dye concentration = 19.37 mg/L, and dose of beads 36 g/L) were optimized by the central composite design (CCD) approach, and the removal efficiency of AB92 was achieved at 93.80 % and 97.16 % for UV and visible light, respectively. The nanocomposite's performance on various dyes was studied, and the catalyst successfully removed an average of 71.64 % of the cationic dyes and 95.13 % of the anionic dyes under light. After examining both photocatalytic and coagulation treatments, our analysis of actual textile wastewater revealed a COD reduction of 94.04 % and 84.62 % under UV and visible light, respectively.

Fabrication of chitosan coated bentonite clay multifunctional nanosorbents from waste biomass for the effective elimination of hazardous pollutants from waterbodies: A fixed bed biosorption, mechanism, and mathematical model study

The anthropogenic activity and hasty fluctuating technologies have been responsible for the generation of massive effluent which is so hazardous due to the loading of several toxicants. While most industries usually discharge it directly into the environment resulting in harsh damage to the ecology/public security. Therefore, it is critical to treat with a sustainable/cost-effective technique. Here, a new route of fabrication of chitosan-coated activated natural bentonite clay (CCANBC) bionanocomposites/bionanosorbents from waste biomass has been developed. Their potential application for the simultaneous removal of Ni2+ and Eosin Y from wastewater were investigated. The effective parameters like concentration (10–30 ppm), flow rate (2–4 mL/min), and bed height (0.5–1.5 cm) were inspected. The bionanosorbents were characterized by FTIR-ATR, XRD, FESEM, TGA, and BET analysis. Additionally, the effluents were explored by AAS and UV–vis-NIR spectroscopy. According to the findings it has been stated that the CCANBC bionanosorbents possessed significant dynamic edges, greater crystallinity (94.27 %), and higher thermal stability. They have exhibited a remarkable 2D honeycomb-like mesoporous microstructure with substantial specific surface area (19.29 m2/g). These outstanding features could be responsible for the dramatic adsorption enactment around 186.42 and 238.37 mg/g for Ni2+ and Eosin Y. The obtained data were evaluated by several mathematical models for better understanding the experimental BTC curve, reaction mechanism, and adsorption isotherm.

Emerging poly(Ani-co-Py)/Bi2O3/AgI composites for antibacterial and antioxidant applications

Poly(Ani-co-Py) was synthesized using aniline (Ani) and pyrrole (Py) and its composites poly(Ani-co-Py)/Bi2O3/AgI composites were fabricated with the extent of Bi2O3 and AgI maintaining 5 to 15 wt% ratio. FESEM analysis displayed that the freshly prepared copolymers and composites exhibited aggregated and spherical-shaped morphology with diameter 200–300 nm and 50–300 nm, respectively. The EDS data revealed the incorporation of both Bi2O3 and AgI in the composite samples. These poly(Ani-co-Py) and poly(Ani-co-Py)/Bi2O3/AgI composites were used to investigate their antibacterial properties using the resazurine-assisted microtiter plate-based antibacterial test. In the investigation, both the copolymers and composites exhibited antibacterial properties against Escherichia coli and Bacillus subtilis bacteria. Further, poly(Ani-co-Py) and Poly(Ani-co-Py)/Bi2O3/AgI composites with in vitro antioxidant activity was assessed by using free radical (α,α-diphenyl-β-picrylhydrazyl (DPPH) scavenging assay. The synthesized copolymers and composites exhibited IC50 value around 38.74 and 41.70–42.60 µg/mL, respectively indicating their better antioxidant properties. This poly(Ani-co-Py)/Bi2O3/AgI composites could be an emerging materials in the area of antimicrobial and antioxidant activity.

Influence of copper ion cross-linked CMC-PVA film on cell viability and cell proliferation study

In this study, films composed of carboxymethyl cellulose and polyvinyl alcohol were fabricated using the solution casting method. Citric acid (4 %) was employed as a cross-linking agent, while glycerol (3 %) as a plasticizer. Cupric chloride (CuCl2·2H2O) was used for cross-linking at concentrations 0.5 %, 1 %, and 3 % over different times. The cross-linking with copper ions led to a noticeable reduction in elasticity, with the breaking strain ranging from 17.9 %–52.9 %. The ion hydration phenomenon increased the contact angle and swelling ratio. Fourier-transform infrared (FTIR) spectroscopy confirmed esterification reactions and copper ion cross-linking with sodium carboxymethyl cellulose (Na-CMC). The films showed antibacterial activity against Staphylococcus aureus and Escherichia coli. The ion-released mechanism followed was the non-Fickian super case-II type. The concentration and duration of cross-linking significantly influenced cell viability and proliferation. FE-SEM analysis revealed that effective concentrations of CuCl2.2H2O were 0.5 % and 1 %, and cross-linking times were 5–15 min, facilitating cell attachment and proliferation. Films are non-adhesive with water vapor permeation 800–900 g/m2/day. These results indicate the potential use of the films in treating second-degree burn wounds with low to medium exudate levels. This study provides valuable insights into the development of copper-infused materials for advanced wound healing applications.

Insect chitosan derived from Hermetia illucens larvae suppresses adipogenic signaling and promotes the restoration of gut microbiome balance

Chitosan, the deacetylated form of chitin, is considered a valuable source of compounds in the feed and food industries. However, the impact of Hermetia illucens larvae chitosan (HCS) with specific physicochemical characteristics on obesity mediated by lipid accumulation and microbiome dysbiosis has not been fully elucidated. We purified HCS with a low molecular weight (84 kDa), low crystallinity, and a high deacetylation rate, characterizing it through several analytical techniques, including gel permeation chromatography, FT-IR, 1H NMR, FE-SEM, and XRD analysis. HCS effectively inhibited the differentiation of 3T3-L1 preadipocytes by suppressing the production of reactive oxygen species. The adipogenic signaling of preadipocytes, mediated by the phosphorylation of mTOR and PPARγ, which are essential for the expression of fatty acid synthase, was attenuated by HCS. In mouse models fed high-fat diets, the oral administration of HCS prevented changes in white adipose tissue and liver weight and reduced plasma levels of total cholesterol. Additionally, the analysis of the microbiota using 16S rRNA revealed that HCS improved dysbiosis by modulating the composition and abundance of specific bacterial genera, including F. rodentium, L. gasseri, L. reuteri, and L. murinus. These findings highlight the potential of HCS as a candidate for the treatment of obesity-related metabolic diseases.

Effect of carbon ion implantation on the superconducting properties of MgB2 bulks prepared by powder-in-sealed-tube method

We studied the effect of carbon (C) ion implantation on the microstructure and superconducting properties of bulk MgB2 prepared by the powder-in-sealed-tube (PIST) method. FESEM and TEM analysis indicate microstructural changes due to carbon ion implantation. DC magnetization measurements reveal a slight improvement of TC and small ΔTC values due to ion implantation. The JC(B) characteristics of implanted samples show a significant enhancement of JC compared with pristine MgB2 at 10 and 20 K. MgB2 samples implanted with 80 keV carbon ions with a dose of 2 × 1016 ions cm−2 show maximum enhancement in JC i.e., 2.07 × 105 A/cm2 at 5 T and 10 K. The flux pinning force density curves are theoretically analyzed using the Dew-Hughes model. The results reveal that significant enhancements in the flux pinning properties are contributed by the normal point defects caused by carbon ion implantation, which acts as a strong pinning center.

Reduced graphene oxide – CeO2 nanocomposites for photocatalytic dye degradation

Over the past few decades, the widespread use of dyes has led to considerable environmental pollution, posing serious threats to human health and ecosystems. In this context, here focus on a tailored nanocomposite comprising reduced graphene oxide (rGO) and cerium oxide (CeO2) to eradicate methylene blue (MB) dye. The fabrication process involves a facile synthesis wherein CeO2 nanoparticles are anchored onto rGO sheets through co-precipitation treatment by mixing a precursor salt of cerium with graphene oxide (GO) in presence of reducing agent. The resulting nanocomposites were characterized using X-ray diffraction (XRD) analysis which confirms the crystallite size of CeO2 and rGO-CeO2 determined to be 21.61 nm and 10.74 nm respectively. Further FE-SEM analysis vividly illustrates the relatively spherical form of CeO2, which is dispersed on the rGO surface and energy dispersive X-ray spectroscopy (EDX) results provide clear evidence of the presence of carbon, cerium and oxygen in the composite. Additionally, Fourier-transform infrared spectroscopy (FTIR) confirms the composition of the rGO-CeO2 nanocomposites demonstrating the existence of various oxygen-containing groups, including O–H, C=O and Ce–O bonds. Thermogravimetric analysis (TGA) highlights that the rGO-CeO2 nanocomposites exhibits higher thermal stability with only 21.88 % weight loss up to 400 °C. Moreover, the photocatalytic activity of rGO-CeO2 nanocomposite exhibits a remarkable 94.92 % degradation of MB dye within 80 min under optimal conditions of UV light irradiation (λ = 254 nm), with a catalyst dosage of 7 mg in a 20 ppm of MB dye solution at pH 9. In contrast, pristine rGO and CeO2 achieved only 32.27 % and 38.48 % in 100 and 90 min respectively. The kinetics of photocatalysis process were meticulously studied and revealed that they followed pseudo-second order kinetic model suggesting chemisorption of MB dye onto nanocomposites prior to degradation. The stability of the nanocomposite was assessed under optimal conditions, demonstrating robust MB degradation (78 %) even up to the 4th cycle. Overall, the successful outcomes of this study show significant potential for degrading MB dye in wastewater by using the rGO-CeO2 nanocomposite.

Green synthesis of zinc oxide nanoparticles using Enterobacter cloacae microorganism and their application in enhanced oil recovery

Employing safe and inexpensive methods for the synthesis of biocompatible nanoparticles (NPs) can be very challenging. Green synthesis refers to the process of synthesizing nanoparticles without using toxic and dangerous chemicals. One of the applications of nanoparticles is increasing production from oil reservoirs, known as enhanced oil recovery (EOR). The main aim of the current study is the biosynthesis of zinc oxide (ZnO) nanoparticles (NPs) using Enterobacter cloacae (Persian Type Culture Collection (PTCC): 1798) microorganism, extracted from the formation water of one of the southwestern Iranian reservoirs, as a novel approach in EOR applications. Several analytical methods, including Fourier transform infrared (FTIR), field emission scanning electron microscope (FSEM), X-ray diffraction (XRD), dynamic light scattering (DLS), energy dispersive X-ray spectroscopy (EDS), and zeta potential were used to analyze the produced NPs. The FESEM analysis confirmed the amorphous form of the nanoparticles and estimated their size in the range of 32 to 58 nm. In investigating the effect of synthesized nanoparticles on interfacial tension (IFT) and stability tests, three levels of base fluids (distilled water, seawater, and diluted sea water) and five levels of nanoparticle concentrations (0, 100, 500, 1000, and 2000 ppm) were considered. The IFT analysis showed that an increase in nanoparticle concentration causes a decrease in the IFT. Also, ZnO nanoparticles were chosen at concentrations of 500 and 1000 ppm for wettability alteration and the EOR test through injection into porous media. The results for the EOR test demonstrated a maximum oil recovery factor of 56% for nanofluid injection with a concentration of 1000 ppm with diluted seawater as the base fluid. Furthermore, oil recovery factors of 43% and 49% were achieved by injection of distilled water and seawater with a concentration of 1000 ppm, respectively.

Synthesis of novel colored substrate-free pearlescent pigments of vanadium phosphates with large-size layered platelet morphology

Novel colored substrate-free pearlescent pigments based on vanadium phosphates, VOPO4·2H2O (VOP) and H0.6(VO)3(PO4)3(H2O)3·4H2O (HVP), with layered structures, were synthesized using solution process and hydrothermal synthesis. XRD and SAED analyses confirmed the single crystallinity of VOP and HVP. Hydrogen peroxide (H2O2) was crucial for producing larger plate-like crystal grains of VOP and contributing to the phase formation of HVP. FE-SEM analysis revealed that VOP and HVP consist of layered plate-like particles (platelets) with smooth surfaces, achieving small thicknesses and high aspect ratios (diameter to thickness). Notably, this study is the first to report particle diameters of 221 µm for VOP and 220 µm for HVP and to propose VOP and HVP as potential substrate-free pearlescent pigments. The optical properties are characterized by optical reflectance spectra and CIE L∗a∗b∗ coordinates, while the pearlescent effect was also evaluated. Under an optical microscope, all samples exhibited striking iridescent colors, visible even in different regions within the same particle. Furthermore, 1 wt% of the green HVP pearlescent pigments were successfully dispersed in the poly(methyl methacrylate) (PMMA) matrix, indicating a good suitability for PMMA colorization.

Plant assisted synthesis of silver nanoparticles using Persicaria perfoliata (L.) for antioxidant, antibacterial, and anticancer properties

Persicaria perfoliata (L.) is an herbaceous medicinal plant belonging to the Polygonaceae family. The plant is distributed in Nepal, India, Japan, China, Russia, and Korea. The present study involved the analysis of plant secondary metabolites, synthesis of silver nanoparticles (Ag NPs) using the plant, characterization, and exploration of antioxidant, antidiabetic, antibacterial, and cytotoxic activities. Among six different solvent extracts, the methanol extract displayed the highest total phenolic content (TPC) and total flavonoid content (TFC) of 68.61 ± 0.57 mg GAE/g and 40.69 ± 5.0 mg QE/g respectively. Ag NPs and hexane extract displayed the potential antioxidant activity of IC50 69.40 ± 0.13 and 144.50 ± 1.36 μg/mL in the DPPH assay. The α-amylase inhibition shown by an aqueous extract and the synthesized Ag NPs IC50 of 1188.83 ± 33.52 and 1369.30 ± 46.86 μg/mL respectively. In antibacterial activity, the highest ZOI of 16 mm was displayed by Ag NPs against Klebsiella pneumoniae followed by a ZOI of 11 mm for methanol extract against Shigella sonnei. Similarly, the lowest MIC and MBC of 0.78125 and 1.5625 mg/mL were recorded for both Ag NPs and methanol extract against Staphylococcus aureus. Aqueous extract and Ag NPs did not display significant toxicity against brine shrimp nauplii. Ag NPs displayed an IC50 of 251.86 ± 58.90 μg/mL against HeLa cell lines. Biosynthesized Ag NPs showed a distinct peak at 409 nm in UV–visible spectra. FTIR analysis revealed the involvement of different functional groups of the organic compounds present in plant extract as reducing, capping, and stabilizing agents in the synthesis of Ag NPs. XRD analysis confirmed the crystal structure of Ag NPs, whereas the average grain size of 44.28 nm was determined by FE-SEM analysis. EDX spectra established the elemental composition of Ag NPs. The present study shows the synthesized Ag NPs using plant extract impart the potential biological activities as compared to that of the crude extract.

Innovative CuO-melanin hybrid nanoparticles and polytetrafluoroethylene for enhanced antifouling coatings

Based on current research, a highly effective, completely biocompatible, and eco-friendly antifouling method was developed. Sepia pharaonis was used to synthesize melanin nanoparticles from its ink. To improve the anti-biofouling characteristics, CuO nanoparticles were synthesized from Padina sp., and a CuO-melanin hybrid nanoparticle complex was created under reflux. The XRD spectrum of the hybrid nanoparticles revealed several prominent peaks, indicating the crystalline structure of the nanoparticles. An EDS analysis identified copper, carbon, and oxygen in the hybrid nanoparticles. According to FE-SEM analysis, CuO-melanin hybrid nanoparticles displayed spherical morphology, with sizes ranging from 15 nm to 55 nm. DLS analysis showed that the hydrodynamic diameter of CuO-melanin hybrid nanoparticles was 187.5 nm. The biological test showed that CuO-melanin nanoparticles had the highst effect on marine bacteria (Phaeobacter sp. (6.25 μg/mL), Alteromonas sp. (12.5 μg/mL)), and algae (Isochrysis galbana Parke) (99 %) after 48 h. The CuO-melanin (3 wt%) exhibited the lowest pseudo-barnacle adhesion strength at 0.021 MPa and the lowest surface free energy, measuring 14.22 mN/m. The field immersion study in a marine environment showed that among the panels tested, the one containing 3 wt% CuO-melanin hybrid nanoparticles with polytetrafluoroethylene yielded the most favorable and efficient outcome, since it led to the lowest measured weight of biofouling at 26.44 g. The findings of this study show that CuO-melanin hybrid nanoparticles combined with polytetrafluoroethylene exhibit highly promising characteristics, make them appealing for antifouling applications.

Enhanced photocatalytic activity of ZnS/TiO2 nanocomposite by nitrogen and tetrafluoromethane plasma treatments

In the present study, the photocatalytic performance of ZnS/TiO2 nanocomposite was investigated through the photodegradation of Acid Blue 113 (AB113) dye under ultraviolet light exposure. TiO2 and ZnS-based nanocomposites suffer from relatively wide bandgap energy and low adsorption capacity which limit their photocatalytic applications. These problems can be suppressed by modifying the surface of nanocomposite particles by the non-thermal plasma. Herein, surface modification of the ZnS/TiO2 nanocomposite was performed using a dielectric-barrier discharge plasma under nitrogen (N2) and tetrafluoromethane (CF4) gases. The characteristics of the plasma-treated nanocomposites were evaluated by XRD, FTIR, Raman, FESEM, EDS, BET, BJH, and DRS analyses. According to the results, by applying plasma treatment, cation and anion vacancies are produced that reduces the band gap energy of the photocatalyst hence improves its performance. The results indicate that the photocatalytic efficiency of the N2-plasma-treated nanocatalyst has been almost two times higher than that of the untreated ZnS/TiO2. It was found that after 25 min of UV irradiation, the AB113 was almost completely degraded in the presence of N2-plasma-treated ZnS/TiO2 nanocomposite (about 95%), whereas, it was degraded by 64% and 46% in the presence of CF4-plasma-treated ZnS/TiO2 and untreated ZnS/TiO2, respectively. This study presents a new approach to designing cost-effective plasma-treated photocatalysts to degrade organic contaminants in wastewater.

Enhanced performance and anti-fouling properties of polyether sulfone (PES) membranes modified with pistachio shell-derived activated carbon (PSAC)@ZIF-8&ZIF-67 to remove dye contaminants

This study aims to improve the properties of polyether sulfone (PES) membranes by using an innovative composite filler. Pistachio shell-derived activated carbon (PSAC) was initially synthesized via chemical activation, followed by surface modification with ZIF-8 and ZIF-67. Subsequently, modified membranes with varying weight percentages of this composite were fabricated using the phase inversion method. The PSAC@ZIF-8&ZIF-67/PES membranes were characterized through FESEM, AFM, pore size, zeta potential, porosity, and water contact angle analyses. The incorporation of the composite in the membranes was confirmed through ATR-FTIR, XRD, and EDS mapping analyses. The finding indicated that adding 0.6 wt% of nanoparticles improved membrane hydrophilicity, increased surface charge, and enhanced porosity. Additionally, the mixed membranes exhibited reduced sedimentation and higher dye removal than unmodified membranes. The optimum amount of composite is determined as 0.6 wt%. At this condition, pure water flux (PWF) increased dramatically from 22.56 L/m2h to 96.26 L/m2h. The mixed matrix membrane demonstrated superior efficiency in removing malachite green (MG) (97 %) and crystal violet (CV) dyes (93 %) and achieved the highest recovery ratio of 61.9 %, indicating a more remarkable membrane ability to combat fouling. The developed membrane demonstrated enhanced hydrophilicity, dye removal efficiency, and antifouling properties, making it promising for environmental applications.

Ceramic supported polyamide composite nanofiltration membrane with a glutaraldehyde cross-linked chitosan interlayer

Interfacial polymerization has been applied to prepare polyamide (PA) membrane on ceramic substrate. However, the low compatibility of the organic PA layer with the ceramic substrate and the intrusion of the PA layer into the ceramic substrate impedes the performance of the obtained membrane. Herein, building on previous work, a thinner interlayer (a glutaraldehyde (GA) cross-linked chitosan (CCM) interlayer) is constructed on a ceramic ultrafiltration substrate (∼5 nm) for the subsequently interfacial polymerization to improve the performance of the obtained membrane. FTIR, XPS and FESEM analyses confirm the successful construction of a smooth interlayer with a thickness of ∼250 nm and the subsequently formation of a homogeneous, rough polyamide (PA) layer with a thickness of ∼15 nm. The obtained membrane has a hydrophilic surface and a negative charged property. The molecular weight cut-off (MWCO) of the obtained membrane is 404 Da. A thinner interlayer of the composite membrane leads to a water flux of 149.46 L m−2 h−1 (0.4 MPa) with rejections of Na2SO4 84.71 %, MgSO4 81.07 %, MgCl2 63.39 %, CaCl2 58.7 %, and NaCl 51.87 %. The interlayer regulates the macroporous structure of the ceramic substrate to prevent the intrusion of the PA layer. Furthermore, the interlayer enhances the connection between the PA layer and the ceramic substrate, which enhances the stability of the PA/CCM membrane (stable performance during 20 h continuous filtration). Overall, this work provides a simple way (construct a glutaraldehyde (GA) cross-linked chitosan interlayer) to prepare composite nanofiltration membranes on ceramic substrate, which has potential applications in dyes desalination.

The performance of PdNi alloy catalysts supported on glassy carbon electrode toward formic acid electro-oxidation

In this research, PdNi alloy electrocatalysts with different compositions were prepared using the hydrothermal method and characterized using FE-SEM, EDX, and XRD analyses. The electro-oxidation of formic acid was investigated on the prepared samples using electrochemical techniques. It was observed that the electrocatalytic activity as well as the stability of samples were increased by increasing the Ni content. Among the studied samples, the PdNi4.09 sample exhibited superior electrocatalytic activity with a mass activity of 2982.46 mA/mgPd which was considerably higher than commercial Pd/C catalyst. Additionally, the PdNi4.09 sample was the most effective sample against CO intermediate poisoning. The role of Ni was attributed to the formation of Ni–O or Ni–OH entities near the Pd site that accelerated the oxidation of Pd–CO entities and therefore reduced the poisoning of Pd active sites for formic acid oxidation.

Tin sulfide dendritic hybrids enhanced by metallic carbon nanotubes for superior supercapacitor performance

This study presents a facile, one-step solvothermal approach to enhance the performance of SnS2-based supercapacitor electrodes through the incorporation of metallic single-walled carbon nanotubes (m-SWNTs) via a one-step solvothermal method. The resulting dendritic heterostructures exhibit significantly improved electrochemical properties compared to pristine SnS2. Comprehensive characterization using XRD, XPS, FE-SEM, and BET analysis reveals that m-SWNT incorporation leads to a significant 111.3 % increase in specific surface area and a 255.1 % increase in pore volume for the optimized SNSC5 sample. This structural modification translates to enhanced electrochemical performance, with SNSC5 demonstrating a high specific capacitance of 161 F.g−1 at 1 A.g−1, excellent cyclic stability (94.2 % retention after 5000 cycles), and a high power density of 84.7 Wkg−1. The synergistic effect of the dendritic morphology and m-SWNT network facilitates improved electron transport and ion accessibility. Furthermore, a symmetric solid-state supercapacitor device based on SNSC5 successfully powered LEDs when charged by a solar panel, showcasing its potential for practical energy storage applications. This work provides valuable insights into the design of high-performance electrode materials for next-generation supercapacitors.

Synthesis and spectroscopic analysis of NaCaYF6:Nd3+, Yb3+NIR emitting phosphor

Near Infra–red (NIR) emitting NaCaYF6:Nd3+and co–doped with Yb3+phosphor has been prepared by hydrothermal synthesis. The formation of Gagarinite structure of the host matrix with space group P63/m was confirmed by XRD and Rietveld analysis. FESEM analysis confirms the spherical morphology along with the homogeneity, and mapping of elemental composition by EDS analysis. NIR emission at 1065 nm due to 4F3/2→4I11/2 electronic transition of Nd3+ ion upon the exposure to 577 nm light. The prominent PL emission at 994 nm from NaCaYF6:Nd3+,Yb3+ phosphor was obtained due to 2F5/2→2F7/2 electronic transition of Yb3+ion. Yb3+ emission was sensitized by Nd3+ activator. The intensity of Yb3+emission increases at the cost of the Nd3+ luminescence. The results are ascribed to the energy transfer from Nd3+to Yb3+. The theoretical Judd-Ofelt (J-O) analysis was also reported to confirm the obtained luminescence behaviour and energy transfer (ET) mechanism of the phosphor. The obtained results specify that the phosphor has a potential application such as in–vivo, in−vitro imaging and NIR laser applications.

Eco-friendly synthesis of betanin-conjugated zinc oxide nanoparticles: antimicrobial efficacy and apoptotic pathway activation in oral cancer cells.

Phytochemical-based synthesis of nanoparticles (NPs) is an eco-friendly approach with various biomedical applications. Betanin, a natural pigment in beetroot, has antioxidant, anti-inflammatory, and antimicrobial properties. When conjugated with zinc oxide nanoparticles (ZnO NPs), these properties are enhanced. This study aimed to synthesize betanin-ZnO nanoparticles (BE-ZnO-NPs) and evaluate their biological potential. BE-ZnO-NPs were synthesized and characterized using UV-Visible spectroscopy, FTIR, FE-SEM, HR-TEM, EDX, XRD, DLS, and zeta potential analysis. In silico studies assessed interactions with oral pathogen proteins, and antibacterial activity was tested against Enterococcus faecalis, Candida albicans, Staphylococcus aureus and Streptococcus mutans. Antioxidant potential and cytotoxicity on KB cells were evaluated through scavenging assays, MTT assay, and qRT-PCR. Betanin synthesized ZnO NPs UV-Vis results showed surface plasmon resonance at 388 nm, and FTIR confirmed betanin role as a capping agent. FE-SEM and TEM revealed particles of 37 nm. EDX confirmed zinc content, and XRD showed a hexagonal structure. Zeta potential was -3.3 mV, and DLS indicated a size of 38.73 nm. In silico analysis showed strong binding to E. faecalis (-8.0 Kcal/mol). BE-ZnO-NPs demonstrated antibacterial activity at 100 µg/mL, with inhibition zones of 18 ± 0.14 mm for E. faecalis and 14 ± 0.18 mm for S. mutans. In contrast, BE demonstrated antibacterial activity at 100 µg/mL, with zone of inhibition of 10.6 ± 0.14 mm for E. faecalisand 11.4 ± 0.18 mm for S. mutans.Antioxidant assays revealed dose-dependent scavenging activity. Cytotoxicity showed an IC50 of 24.29 µg/mL, with qRT-PCR indicating apoptosis through the BCL2/BAX/P53 pathway. BE-ZnO-NPs exhibited significant antibacterial and antioxidant activities and demonstrated the ability to induce apoptosis in oral cancer cells via the BCL-2/BAX/P53 signalling pathway. These findings highlight the potential of BE-ZnO-NPs as promising antimicrobial agents for tooth infections and as therapeutic agents for oral tumour treatment.

Halochromic aerogels with Ca2⁺-induced tailored porosity based on alginate/gellan integrated with Echium amoenum anthocyanins: Characterization and application for freshness monitoring of rainbow trout fillet

This study aimed to fabricate a food freshness halochromic aerogel based on alginate, gellan, and Echium amoenum anthocyanins (EA). The porosity and morphological properties of the aerogels (AG2, AG6, and AG10) were regulated by varying the concentration of CaCl2 (2, 6, 10 %). FE-SEM analysis revealed that increasing the CaCl2 content led to the formation of aerogels with enhanced overall porosity and larger pore sizes. The AG6 aerogel, characterized by a density of 23.44 ± 0.04 mg/cm³, a porosity of 91.66 ± 0.06%, and an average pore size of 306.93 ± 122.89 μm, was identified as the optimal support for the incorporation of the EA pigment. FT-IR analysis verified the formation of hydrogen bonds between the AG6 aerogel and EA molecules. Incorporating anthocyanin increased the crystallinity and thermal stability of the aerogel, as evidenced by XRD and DSC analyses. The AG6EA aerogel displayed a color shift from red to yellow over a pH range of 2–12. The AG6EA aerogel demonstrated high sensitivity to ammonia vapor and proper color stability and reversibility. The AG6EA aerogel color transitioned from purple to blue and then green through rainbow trout storage, correlating with changes in pH, total volatile basic nitrogen (TVB-N), and total viable microbial count (TVC and TPC) of the fish samples. This research extends a new insight to develop cutting-edge, susceptible, and accurate pH indicators capable of quality assessment of protein-based food products.

Harnessing nanostructures and fiber architecture: A synergistic leap in shape memory polymer composites

This research investigates the synergistic effects of carbon fiber orientation and nanostructure reinforcement across 21 configurations of shape memory polymer composites. It examines uni-directional (UD), bi-directional Twill (BDT), and bi-directional Plain (BDP) fiber architectures, along with varying concentrations of MWCNT and GnP at 0.4%, 0.6%, and 0.8%. The fabrication process involves initially preparing nanostructure-modified epoxy nanocomposites through ultrasonication followed by hand layup techniques to fabricate three-phase shape memory polymer composites. Optimal tensile performance is observed in GnP-modified UD composites at a 0.6 wt% concentration, achieving a tensile strength of 728.32 MPa and a modulus of 71.29 GPa. Furthermore, enhancements in thermomechanical and shape memory properties are noted in GnP-modified BDT composites and are further improved in GnP-modified BDP composite configurations. GnP-modified composites outperform MWCNT ones due to GnP’s sheet structure aligning parallel to the load and its larger surface area, which facilitate enhanced interaction with the matrix. These improvements, supported by FESEM analysis, highlight enhanced interfacial bonding and result in high shape recovery ratios, with all configurations exceeding 90%, despite polymer modification.