AFM Analysis Research Articles

Study of the Adsorption of a Textile Dye by Alginate-Bentonite Beads: CCD-RSM Design Conception

In our research described in this paper, a composite was prepared in the form of beads by immobilizing sodium bentonite clay on sodium alginate. The prepared material, Alg-Bt beads, was characterized by FTIR, XRD, AFM, and SEM analysis. The performance of the beads toward the adsorption of the textile dye, Telon Blue (TB), was studied. Different factors influencing the adsorption capacity were evaluated, such as pH, time, the temperature of the medium, and the dose of the adsorbent. The result of the adsorption of TB by the Alg-Bt beads revealed that this adsorbent had an adsorption capacity of 60.39 mg/g, revealed by Langmuir modeling. Consequently, an experimental design was developed using the central composite design (CCD) under response surface methodology (RSM) for the optimization of the best experimental conditions for the adsorption of TB by the Alg-Bt beads. The optimized adsorption capacity was 83.10 mg/g with the following operating conditions: pH = 2.4, contact time = 120 min, pollutant concentration = 100 mg/L, and adsorbent dose = 0.57 g/L. Therefore, it can be confirmed that the design of the experiment method is an effective approach to optimizing the adsorption conditions.

Egyptian seaweed resources from the South Sinai coast to develop alginate-based biohybrid composites for enhanced lead(II) removal from industrial wastewater

Herein, crosslinked-alginate (CAL) was extracted from Egyptian marine biowaste (brown seaweed discarded near seashore of Ras Sedr, Sinai). Novel biohybrid composites were fabricated by hybridizing CAL chains with either carbohydrate polymer (starch, St) or proteinaceous content (albumin, Alb). Physicochemical properties of such biocomposites were characterized using XRD, FTIR, Raman, DLS, SEM and AFM analyses. Compared to CAL, starch as hybridizing agent enthuses existence of stacking-oriented alginate chains of higher amorphicity and lower zeta-potential (-17 mV). Hybridization of alginate matrix with albumin chains yielded high negatively charged (-37.8mV) crystalline biocomposite with smooth surfaces. Performance of St-CAL and Alb-CAL biocomposites toward Pb2+ removal from wastewater was scrutinized. The impact of pH, adsorbate concentration, contact time, and thermodynamic studies on Pb2+ removal using these biocomposites were estimated. Removal efficiency of St-CAL was superior to that of Alb-CAL yielding ~ 70% for 5 succussive runs. Pb2+ adsorption process over St-CAL was spontaneous with exothermic nature at room temperature and followed Freundlich model with pronounced adsorption energy and capacity. Fitness of kinetic models for St-CAL was ranked as pseudo-first-order with escalated intra-particle diffusion rates. Construction of oxygen-rich hybrid carbohydrate systems is willingly applied in future as green cleaner to wastewater from heavy metal ions.

Antibacterial activity of polyethylene film by hyperthermal hydrogen induced cross-linking with chitosan quaternary ammonium salt

In this study, hyperthermal hydrogen-induced cross-linking (HHIC) technology was applied to construct a dense cross-linking layer of antibacterial chitosan quaternary ammonium salt (HTCC) to PE surface through the selective cleavage of CH bonds and subsequent cross-linking of the resulting carbon radicals. Before HHIC treatment, UV-Ozone was used to activate PE surface to facilitate HTCC adsorption. FT-IR and XPS analyses proved the successful cross-linking between PE and HTCC. From AFM analysis, the prepared PE cross-linked HTCC film (PE-c-HTCC) showed the rougher surface with average roughness (Ra) of 9.16 nm. The water vapor permeability (WVP) and oxygen permeability (OP) values of the film were decreased by about 83 % and 97 %, respectively. Additionally, the film exhibited strong antibacterial properties against E. coli and S. aureus. In terms of these properties, the shelf life of fresh beef could be extended for 2 days after packing with the PE-c-HTCC film.

Synergistic Multi-Pronged Interactions Mediate the Effective Inhibition of Alpha-Synuclein Aggregation by the Chaperone HtrA1.

PD and other synucleinopathies are marked by misfolding and aggregation of α-Syn, forming higher-order species that propagate aggregation in a prion-like manner. Understanding how chaperone proteins inhibit α-Syn aggregation and spread is essential for therapeutic development against neurodegeneration. Through an integrative approach of solution-based NMR, AFM, aggregation kinetics, and computational analysis, we reveal how a catalytically inactive variant of the chaperone HtrA1 effectively disrupts aggregation pathways. We find that the inactive Protease and PDZ domains of HtrA1 synergistically bind to key intrinsically disordered sites on both α-Syn monomers and fibrils, thereby effectively inhibiting both aggregation and templated seeding. Our work provides a natural and unique blueprint for designing inhibitors to prevent the formation and seeding of aggregates in neurodegenerative diseases.

Development of textile based supercapacitors using activated carbon from renewable banana peels and conductive polymer composites

Activated carbon was synthesized from banana peel using a two-step chemical activation process and blended with poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT-PSS) to improve the electrochemical performance of screen-printed electrodes fabricated on cotton fabrics. The use of carbonized banana peel (CBP) with PEDOT-PSS to develop reliable and sustainable supercapacitors was investigated. The work includes the design of a CBP: PEDOT-PSS axisymmetric electrode energy storage device with 0.1 M K2SO4 electrolyte. The results showed that the screen-printed cotton fabric delivered an electrical conductivity of 4.1 ± 1.3 S/cm and a specific capacitance, and energy density of 52.1 F g−1 and 7.233 WhKg−1 at 5 mV/s scanning rate, respectively with a three-electrode system. The material showed a remarkable rate performance in an axisymmetric three-electrode cell configuration with an operating potential window of 0–0.5 V. In addition, the fabricated material demonstrated uniform deposition of PEDOT-PSS and CBP on the cotton fabric which was confirmed by both AFM and SEM image analysis. FTIR confirmed the structural properties of the composite. There is more consistency between the ideal supercapacitor modelled with COMSOL Multiphysics and the actual experimental results. The model curves aid in better design and performance and durability monitoring by offering a more thorough and precise characterization of the kinetics and thermodynamics of the supercapacitors. Consequently, the CBP: PEDOT-PSS composite presents a promising option for supercapacitor uses.

Alterations in structural components of extracellular polymeric substance of epilithic bacteria Brevundimonas faecalis BC1 growing on monumental rock under thermal stress

In this study, a comparison of biofilm formation, extracellular polymeric substances (EPS) production, protein and polysaccharides estimation, and protein profiling through SDS-PAGE, FTIR, GC-MS, ESI-MS, SEM, and AFM analysis were done for EPS from epilithic bacteria Brevundimonas faecalis BC1 obtained from monumental rock under normal room temperature and heat stressed condition. Heat stress (60 ± 2 °C) that simulates hot monumental rock surfaces during the summer season caused bacteria BC1 to produce more EPS (8.56 g/L), biofilm, protein and polysaccharides, extra SDS-PAGE protein bands of different molecular weight than their control counterpart. FTIR and GC-MS analysis showed extra polysaccharide formation in the EPS under heat stress and ESI-MS analysis clearly showed differences in structural components of EPS from two different sources. Consistently, SEM and AFM showed more branching structural components with dentate spikes in the EPS obtained from a heat-stressed source than from its counterpart, suggesting their protective role toward heat stress and adhesive potential for biofilm.

Mechanical Deformation Effects on Flexible Thin Film Transistors: A Comparison Between 6,13‐Bis(Triisopropylsilylethynyl)Pentacene and N,N′‐Bis‐(2‐Ethylhexyl)‐1,7‐Dicyanoperylene‐3,4:9,10‐bis(Dicarboximide) Derivatives

AbstractIn this work, the investigation of the surface strain‐induced electrical changes in two commonly employed solution‐processable organic semiconductors, i.e., 6,13‐bis(triisopropylsilylethynyl)pentacene (TIPS‐Pentacene) and N,N′‐bis‐(2‐ethylhexyl)−1,7‐dicyanoperylene‐3,4:9,10‐bis(dicarboximide) (N1400), is reported. A detailed electromechanical characterization of two sets of flexible organic field‐effect transistors is performed, clearly demonstrating that both systems are affected by mechanical deformation in terms of electrical performance. However, the N1400 system shows a much more stable and reproducible response, even after continuous mechanical stress. XRD and AFM analysis demonstrate that such difference is mainly related to the changes induced on the two thin film morphology by the applied deformations.

Poly(lactic-co-glycolic) acid nanoparticles with thermoresponsive shell for sustained release of dexamethasone

Polymeric nanocarriers based on poly(lactide-co-glycolide) (PLGA) enable drug encapsulation while achieving increased solubility of hydrophobic drugs, enhanced plasmatic half-life, and protecting the drug from early degradation/metabolization. Nevertheless, it is still difficult to effectively regulate the drug release from nanocarriers. Covering the surface of PLGA nanoparticles (NPs) with a thermoresponsive shell may be the key factor for building drug delivery systems with temporal and spatial control. In this respect, PLGA NPs with a mean size of 212 nm, containing dexamethasone (Dex) (Dex/PLGA NPs) have been produced by the dialysis technique without the use of a surfactant. Then, the nanoparticles were covered with poly(N-isopropylacrylamide-co-4-vinyl pyridine) (PVP) by ionic interactions between the amine groups of the PVP and carboxylic groups of PLGA. FT-IR and XPS spectroscopy were used to identify the new functional groups introduced on the PLGA nanoparticles' surface. The assembly of PVP on the PLGA NPs was analyzed by monitoring the particle size with temperature, zeta potential, AFM, and TEM analysis. The in vitro drug delivery investigation showed that temperature has significant control over the release rate of Dex from PVP-coated PLGA NPs. The thermosensitive polymer is hydrated at temperatures lower than LCST (20 °C) and forms a gel around the nanoparticles slowing down the release rate of Dex. Above the LCST, PVP becomes hydrophobic, collapses, inducing a substantially slower and sustained release of Dex, with 84 % released at 200 h.

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.

Development of photoactive biomaterial using modified fullerene nanoparticles.

Medical device-associated biofilm infections continue to pose a significant challenge for public health. These infections arise from biofilm accumulation on the device, hampering the antimicrobial treatment. In response, significant efforts have been made to design functional polymeric devices that possess antimicrobial properties, limiting or preventing biofilm formation. However, until now none of the strategies showed a promissory effect. Thus, antimicrobial photodynamic therapy (aPDT) has been shown as a promising candidate to overcome this problem. Photosensitizers (PS) are the main key component for aPDT and fullerenes have been chosen as PS due to their good quantum yields and lifetimes spans. In this study, polylactic acid (PLA) surface was modified with fullerene (C60) and reaction was proven by XPS analysis. The biopolymer surface was characterized by AFM, SEM, and water contact angle measurements. The obtained results imply that the highest fullerene precipitation was attained when PLA was modified with ethylenediamine (EDA) before the reaction with C60, as the highest carbon increase was identified using XPS following reaction with C60. While samples' hydrophobicity decreased after PLA modification with EDA, it increased after fullerene precipitation. Which implies that bacteria have a lower propensity to attach. Although the surface of the samples became smoother following PLA modification with EDA and reaction with 0.1% C60 precipitation, with 1% C60 precipitation the surface roughness was comparable to unmodified PLA, according to AFM and SEM analyses. Fullerene-based biopolymers could potentially be used in aPDT to make antimicrobial surfaces or medical devices.

Wood hemicelluloses as protective materials for preserving the viability of probiotic Lacticaseibacillus rhamnosus GG during spray drying

Wood hemicelluloses from forest industry side-streams are promising economic and sustainable alternatives for encapsulating bioactive compounds. This study explores their suitability for probiotic encapsulation, specifically for maintaining cell viability and structure. The ability of galactoglucomannans (GGM) and glucuronoxylans (GX) to support the survival of Lacticaseibacillus rhamnosus GG (LGG) during spray drying at solid feed concentrations of 15 and 20 % and inlet air temperatures of 105 and 140 °C (outlet air temperature of 50 °C) was investigated and compared to the results obtained using maltodextrin (MD). Across all investigated conditions, LGG survival rates exceeded 85 % (>107 cfu/g) in GX and GGM microcapsule powders, which similar to that in MD microcapsules despite the differences in pH, particle size, and viscosity of their feed dispersions. The GX microcapsules demonstrated the highest process yield (50–58 %), followed by MD (39–51 %). All the microcapsule powders exhibited an amorphous structure consisting of spherical particles with an average diameter of 10 μm, sufficient for LGG accommodation. Atomic force microscopy analysis confirmed the encapsulation of LGG cells within microcapsules with intact rod-shaped chains post-spray drying. Overall, the spray-dried microencapsulation of probiotics using wood hemicelluloses maintains high probiotic viability and offers an eco-friendly, cost-effective alternative to traditional materials.

Preparation and characterization of Tobacco polysaccharides and its modulation on hyperlipidemia in high-fat-diet-induced mice.

This study aimed to investigate the structural properties of tobacco polysaccharide (TP) and its mechanism of modulating hyperlipidemia in high-fat diet-induced mice. The structural properties of TP were characterized by FT-IR, 1HNMR, SEM, AFM and thermogravimetric analysis. And the regulatory mechanism of TP on lipid metabolism was investigated in hyperlipidemia mice. These results showed that TP had a high composition of reducing monosaccharide and the glycosidic bond type was α-glycosidic bond. The intervention by TP resulted in a significant reduction of body weight and improvement in lipid accumulation. And the modulation mechanism by which TP ameliorated the abnormalities of lipid metabolism was associated with the expression levels of lipid metabolism-related genes and serum exosomes miRNA-128-3p, as well as the modulation of structure and abundance of the gut microbiota in mice. In addition, TP treatment significantly increased the content of short-chain fatty acids (SCFAs) in mice feces. The results of molecular docking and dual-luciferase assay exhibited a good interaction between propionic acid and PPAR-α, and it was hypothesized that the interaction might further ameliorate the hyperlipidemia. Therefore, TP can regulate the expression levels of lipid metabolism-related genes through miRNAs from serum exosomes and SCFAs from gut microbiota.

Novel optical optode for selective detection and removal of ultra-trace level of mercury ions in different environmental real samples

Owing to the high cost and unavailability of different analytical techniques, there is an urgent need to develop new techniques not only for detecting but also removing mercury ions in real samples. Thus, an optical chemical sensor based on the anchoring of phenanthraquinone monophenylthiosemicarbazone in a plasticized cellulose triacetate membrane was fabricated and applied to the recognition and removal of mercury ions from aqueous solutions. The synthesized optode was characterized by FT-IR, SEM, AFM, and thermal analysis. Several parameters, including the pH, temperature, contact time, washing solvent, and washing time, were optimized. Under optimal conditions, a promising optode film platform was utilized for sensing mercury ions, and the concentrations were calculated based on colorimetric analysis (Histogram, RGB) of digital images, visualization, and spectrophotometry. Also, an optical optode was used for complete adsorption of mercury ions from aqueous solutions. In addition, the regeneration of the synthesized optode was evaluated using 0.1 mol L− 1 nitric acid, which effectively removed all adsorbed mercury ions. The obtained data indicated good linearity in the sensing and adsorption of Hg2+ over a concentration range of 0.005–5000 µgL− 1 with a low limit of detection (LOD = 0.066 µgL− 1) and limit of quantification (LOQ, 0.22 µgL− 1). Furthermore, it showed good distinctions in the presence of coexisting ions, high stability (five months), good applicability, and reproducibility (RSD = 1.31%), making it a promising sensor for Hg2+ detection. On the other hand, the kinetic studies revealed that the pseudo-second-order was the best model for describing the adsorption behavior of mercury ions on the optode surface. Also, the thermodynamic parameters indicate spontaneous (ΔG0 < 0) and endothermic (ΔH0 < 0) reactions. Also, the maximum adsorption capacity was found to be 73.2 mg g− 1. Thus, the optodes were successfully applied for the detection and/or removal of Hg2+ in different real samples, including cucumber, fish, soil, and water samples, with excellent recoveries of 98.1–99.5%.

A comparative study of the Anti-Diabetic effects of avocado seed extracts and biosynthesized silver nanoparticles in Alloxan-Induced diabetic Albino mice

In this research, a comparative study of the anti-diabetic effects of Avocado (Persea americana) seed extracts and biosynthesized silver nanoparticles (Ag NPs) in alloxan-induced diabetic albino mice was conducted. The animals were assigned into twenty-one groups of five animals each; the diabetes was induced by intraperitoneal injection of 150 mg/kg of the prepared alloxan monohydrate. After 15–25 days of using 7.5 mg/ml aqueous extract of P. americana seeds, it was found that blood sugar levels dropped significantly. In addition, over the 20–25 days treatment period, levels of blood sugar were reduced considerably when doses of 5.0 or 10 mg/ml of the aqueous extract were introduced. However, throughout this treatment period, animals injected with 2.5, 5.0, 7.5, or 10.0 mg/ml of P. americana seed aqueous extract showed a significant rise in weight. In addition, over 20–25 days of treatment, animals treated with 7.5 and 10.0 mg/ml P. americana seed alcoholic extract showed a substantial decrease in blood sugar levels. Over the 25 days of treatment, animals treated with 7.5 mg/ml P. americana seed in alcoholic extract also showed a noticeable rise in weight. On the other hand, the prepared Ag NPs were synthesized and characterized using color changes, UV–visible spectroscopy, SEM, and AFM analysis. A substantial reduction in blood sugar levels was noted with 2.5 mg/ml of biosynthesized Ag NPs, while mice weights significantly increased. The highest substantial reduction in glycaemia occurred by combining 7.5 mg/ml aqueous extract and 2.5 mg/ml biosynthesized Ag NPs, resulting in a high increase in animal weight across all combination concentrations. Regarding the interaction between combination concentrations and treatment periods, animals’ weight increased significantly in all combined concentrations during the 20–25 days compared to the control. Furthermore, an increase in LDL and VLDL concentrations was observed in the negative control group compared to the positive control and other treated groups.

Biologically synthesized Tellurium/Zirconium bimetallic nanoparticles for antibacterial and electrochemical collagen detection

In the current exploration, photochemical stability and chemotherapeutic appraisal of Cinnamomum camphora (C.camphora) mediated bioactivity via Tellurium/Zirconium nanoparticles (TeZr BNPs) were conducted. The bioactive bimetallic nanoparticles (BNPs) exists a characterization by employing various studies such as UV, XRD, SEM-EDX, DLS, FTIR, HR-TEM, AFM, BET, and XPS analysis. Screening analysis of methanol soluble components in C. camphoraextract identified the components in the plant product by HPLC mass spectroscopy. Furthermore, inhibition activities of TeZr BNPs against monoderm (+) and diderm (−) pathogens were tested by the agar contact method. The results of these studies showed the maximum hindrance zone with TeZr BNPs against three different microorganisms:Staphylococcus aureus (ATCC6538), Escherichia coli (ATCC 8739), and Vibrio cholera(ATCC 14033) showing 28 %, 26 %, and 27 % inhibition, respectively, confirming the inhibitory potential of TeZr BNPs. The sequences of the inhibition zones were as follows: Staphylococcus aureus > Escherichia coli > Vibrio cholera. Further, the cytotoxic potential of C. camphora mediated TeZr BNPs was evaluated by anticancer, antioxidant, and anti-inflammatory activities. The photolysis steadiness of bioactive TeZr BNPs towards photodynamic therapy was confirmed by collagen degradation. This is the first description of bimetallic nanoparticles for degrading collagen. Hence, TeZr BNPs can be effectively applied in photodynamic therapy.

Appraising the corrosion inhibitory efficacy and adsorption mechanism of leaf extract of Datura discolor on low-carbon steel in low pH media via gravimetric experiments and AFM analysis

BackgroundThe study investigated the inhibitory action of Datura discolor leaf extract against the corrosion of low-carbon steel in 0.5 M solutions of three acids. The purpose was to ascertain the effect of extract concentration, immersion time and temperature variation on corrosion inhibitory efficiency, and to relate to existing reports which show that organic molecules in most plant extracts inhibit corrosion. Extraction of the leaves was done by maceration using methanol, and solvent was removed by evaporation to dryness. Classical gravimetric (mass loss) experiments were used, and experimental data were fitted to adsorption isotherm models to ascertain the best approximation. Surface examination of the low-carbon steel substrates was carried out using the atomic force microscope.ResultsInhibitory protective efficiency of extract was found to appreciate with increasing Datura discolor leaf extract concentration at a fixed temperature, with values ranging 77.6–88.8%, 91.35–98.08% and 19.64–44.64% in H2SO4, HCl and HNO3 solutions respectively at 27 °C. Elevation of temperature was found to depreciate the inhibitor efficiency at constant inhibitor concentration. Best isotherm model fitting was obtained with Langmuir model both at 27 °C and 60 °C and in all the hostile media, while Temkin model gave good approximation only at 60 °C and in H2SO4 and HCl solutions only. The negative values of free energy of adsorption (ΔGads0)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$(\\Delta G_{{{\ ext{ads}}}}^{0} )$$\\end{document} suggested that the adsorptive interaction of the inhibitor with the substrate surface was very spontaneous. Values of ΔGads0\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Delta G_{{{\ ext{ads}}}}^{0}$$\\end{document} were all consistent, fluctuating between − 16.35 and − 17.63 kJ mol−1 in both H2SO4 and HCl solutions, and between − 9.76 and − 10.25 kJ mol−1 in HNO3 solution, and this suggests that adsorption of the inhibitor molecules occurred via physisorption. Values of the activation energy of the corrosion reaction (Eact)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$(E_{{{\ ext{act}}}} )$$\\end{document} are all < 40 kJ mol−1, suggesting that the inhibition occurred by a physical adsorption mechanism.ConclusionsThe study concludes that Datura discolor crude leaf extract suppressed the corrosion reactions, and the inhibition was found to arise from the physisorptive interaction of the organic molecules with the substrate/solution interface, forming a stabilize inhibitor film on the substrate surface as revealed by the atomic force micrographs.

Optimization of carrier mobility in Pr-doped SrTiO3 thin films through controlled Sr-segregation for optoelectronic applications

Functional oxides employed in electronic components hold significant promise for future electronic devices. Strontium titanate based thin films have several emergent features due to unsaturated bonds, dimension restriction, production of oxygen vacancies and point defects that make them attractive for optoelectronic applications. Here we prepared Pr-doped strontium titanate thin films via RF magnetron sputtering in a pure Argon environment at various gas pressures followed by heat treatment. The structural parameters, analyzed via XRD and Raman spectroscopy, were correlated with the electrical transport properties. Intriguing morphological features such as Stranski–Krastanov (SK) growth and cation segregation observed by FESEM and AFM analysis were further examined to elucidate the conduction mechanism in the films. The optical studies unveiled significant transparency in the visible spectrum. Photoluminescence emission studies at specific wavelengths shed light on the involvement of oxygen vacancies. By carefully controlling annealing conditions and optimizing sputtering parameters, thin films devoid of Sr segregation with highest reported carrier mobility of 33.9 cm2/V s were prepared. The high mobility leading to enhanced conductivity render the films suitable for a wide range of optoelectronic applications.

The effect of ultrasonic waves on the structure, morphology, and thermal conductivity of graphene oxide as nanofluids for direct absorption solar collector application

This research aims to explore how ultrasonic waves affect the structure and morphology of graphene oxide (GO) as a nanofluid, influencing its thermal conductivity (TC), stability, and photo-thermal conversion properties. GO was rapidly synthesized under ultrasonic bath irradiation using modified and improved Hummers' methods. Ultrasonic irradiation creates different structural and morphological defects in the GO that depend on the sonication time. The relationship between the exposure time to ultrasound and the creation of structural and morphological defects in graphene oxide nanosheets was investigated using UV–Vis, FTIR, Raman spectroscopies, AFM, and TEM analysis. The study examined how the structure and morphology of graphene oxide nanosheets affect the thermophysical and photo-thermal conversion properties of nanofluids by comparing heat transfer and stability. The simultaneous characterizing of the structure and morphology indicates that TC and stability are related to the sonication time. Indirect sonication with low intensity can carefully control the oxidation reaction of GO. Sonication for 30 min creates GO nanosheets that yield stable nanofluids with a 32.31 % enhancement in TC, with no extra treatment needed. This particular nanofluid has excellent photo-thermal conversion properties thanks to its high optical absorption, good stability, and thermal conductivity. This can increase the solar-thermal conversion efficiency (η) up to 72.5 %, making it a promising candidate for use as the working fluid in direct absorption solar collectors (DASCs)

SiO2 sputtering by low-energy Ar+, Kr+, and Xe+ ions in plasma conditions

Modern plasma technologies applied for nm-size devices require localizing ions’ impact within up to atomic layer to avoid uncontrollable damage of underlying structures. The decrease in energy of ions incident on a surface is one of the ways to achieve this. In this work, SiO2 sputtering by Ar+, Kr+, and Xe+ ions at energies of 20–200 eV was studies in the low-pressure ICP-discharge at a plasma density typical for plasma processing. The rf-bias waveform tailoring due to high discharge asymmetry allowed generating and controlling ion narrow energy spectrum with FWHM 5 ± 2 eV. Real time in-situ control over ion composition and flux as well as sputtering rate provided accurate determination of the SiO2 sputtering yield, Y(Ei). It is shown that at ion energy above ∼70 eV, the “classical” kinetic sputtering mechanism prevails. In this case, Y(Ei) rapidly grows with ion energy, while decreasing with the decrease in ion mass. Below ∼70 eV, the change of Y(Ei) is strongly slow down while the sputtering yield still stays high enough (>10−3), demonstrating the plasma impact on the sputtering mechanism. The obtained trends of Y(Ei) under the plasma exposure are discussed in light of possible SiO2 surface modification studied by AFM and angular XPS analysis.

Impact of Cold Atmospheric Plasma Treatment on Native and Glycated Collagen

ABSTRACTCollagen is a major structural protein in the body, providing critical stability to the skin. Recent advancements have highlighted cold atmospheric plasma (CAP) as a versatile tool for various applications, including biomolecule modification, sterilization, food preservation, and wound healing. This study investigates the effects of CAP on both native and glycated collagen, analyzing the resulting changes. SEM and AFM analyses reveal that CAP induces protein self‐assembly in both glycated and non‐glycated collagen. Thioflavin assays further demonstrate that CAP‐treated glycated collagen exhibits greater fluorescence intensity compared to untreated glycated samples, indicating an increase in β‐sheet content and suggesting enhanced self‐assembly. These findings provide insights into the potential applications of CAP in modulating protein structures and understanding various biological processes and diseases.