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Search results for: scanning electron microscopy (sem)
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Mono- and bimetallic (Pt/Cu) titanium(IV) oxide core–shell photocatalysts with UV/Vis light activity and magnetic separability
PublicationTitanium(IV) oxide is one of the most widely investigated photocatalysts. However, separation of nano-sized particulate titania might result in profitless technologies for commercial applications. Additionally, bare titania is almost inactive under the Vis range of solar spectrum due to its wide bandgap. Therefore, the present study aims to prepare novel coreinterlayer- shell TiO2 magnetic photocatalysts modified with metal nanoparticles...
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Effects of Ca2+, Mg2+, Na+, and K+ substitutions on the microstructure and electrical properties of GdCoO3 ceramics
PublicationGdCoO3-δ, Gd0.975Na0.025CoO3-δ, Gd0.98K0.02CoO3-δ, Gd0.98Ca0.02CoO3-δ, and GdCo0.99Mg0.01O3-δ ceramics were prepared via a solid-state reaction route. Among the dopants studied, substitution with Ca2+ slightly enhanced the densfication of GdCoO3 ceramics. All the lattice parameters of the doped ceramics were larger than those of pure GdCoO3-δ ceramic (a = 5.223 Å, b = 5.389 Å and c = 7.451 Å), and their cell volumes increased by...
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The geometry of free-standing titania nanotubes as a critical factor controlling their optical and photoelectrochemical performance
PublicationTitanium dioxide nanotubes are regarded as one of the most important functional materials and due to their unique electronic properties, chemical stability and photocorrosion resistance, they find applications in, for example, highly efficient photocatalysis or perovskite solar cells. Nevertheless, modification of TiO2 nanotubes is required to overcome their main drawback, i.e. large energy bandgap (>3.2 eV) limiting their ability...
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Micro‑ and nano‑ bentonite to improve the strength of clayey sand as a nano soil‑improvement technique
PublicationNano-additives results in the formation of nano-cementation (NC). This process is recently used to improve the durability of various building materials. NC used to improve the strength of untreated soil materials, also known as nano soil-improvement (NSI). In few years, the role of nano-additives in various types of soils were developed. In this research, the role of micro- and nano- size of bentonite as soil stabilizer was evaluated...
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Ultrasonic spectroscopy of silicon single crystal
PublicationSpecimens of Si single crystals with different crystal orientation [100] and [110] were studied by the electro-ultrasonic spectroscopy (EUS) and Resonant Ultrasonic Spectroscopy (RUS). A silicon single crystal is an anisotropic crystal, so its properties are different in different directions in the material relative to the crystal orientation. EUS is based on interaction of two signals: electric AC signal and ultrasonic signal,...
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Hydroxyapatite deposition on the laser modified Ti13Nb13Zr alloy
PublicationThe Ti13Nb13Zr alloy was subjected to laser modification with the Nd:YAG laser provided that such treatment would increase the surface roughness followed improved adhesion of hydroxyapatite (HAp) coatings The hydroxyapatite was deposited by electrophoretic method in suspension of 0.5 g HA powder and 100 ml ethyl alcohol. The deposition was carried out for 10 min at 10 V voltage followed by drying at room temperature for 24 h and...
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Oil refinery dusts: morphological and size analysis by TEM
PublicationThe objectives of this work were to develop a means of sampling atmospheric dusts on the premises of an oil refinery for electron microscopic study to carry out preliminary morphological analyses and to compare these dusts with those collected at sites beyond the refinery limits. Carbon and collodion membranes were used as asupport for collection of dust particles straight on transmission electron microscopy (TEM) grids. Micrographs...
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Hydrogen Production Mechanism in Low-Temperature Methanol Decomposition Catalyzed by Ni3Sn4 Intermetallic Compound: A Combined Operando and Density Functional Theory Investigation
PublicationHydrogen production from methanol decomposition to syngas (H2 + CO) is a promising alternative route for clean energy transition. One major challenge is related to the quest for stable, cost-effective, and selective catalysts operating below 400 °C. We illustrate an investigation of the surface reactivity of a Ni3Sn4 catalyst working at 250 °C, by combining density functional theory, operando X-ray absorption spectroscopy, and high-resolution...
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Cu-HKUST-1 and Hydroxyapatite–The Interface of Two Worlds toward the Design of Functional Materials Dedicated to Bone Tissue Regeneration
PublicationA novel composite based on biocompatible hydroxyapatite (HA) nanoparticles and Cu-HKUST-1 (Cu-HKUST-1@HA) has been prepared following a layer-by-layer strategy. Cu-HKUST-1 was carefully selected from a group of four Cu-based metal−organic frameworks as the material with the most promising antimicrobial activity. The formation of a colloidal Cu- HKUST-1 layer on HA nanoparticles was confirmed by various techniques, e.g., infrared...
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Comparing the permeability of human and porcine small intestinal mucus for particle transport studies
PublicationThe gastrointestinal mucus layer represents the last barrier between ingested food or orally administered pharmaceuticals and the mucosal epithelium. This complex gel structure plays an important role in the process of small intestinal absorption. It provides protection against hazardous particles such as bacteria but allows the passage of nutrients and drug molecules towards the intestinal epithelium. In scientific research, mucus...
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Local structural and chemical ordering of nanosized Pt(3±δ)Co probed by multiple-scattering x-ray absorption spectroscopy
PublicationThis work reports a detailed investigation of the local structure and chemical disorder of a Pt(3±δ)Co thin film and Pt(3±δ)Co nanoparticles. We have used a combination of techniques including x-ray absorption spectroscopy (XAS), x-ray diffraction (XRD), and high-resolution transmission electron microscopy (TEM). The important effect of chemical ordering on pair and three-atom configurations has been studied using computer simulations...
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Phase separation in poly(butylene terephthalate)-based materials prepared by solid-state modification
PublicationThe morphology of a series of poly(butylene terephthalate) (PBT)/fatty acid dimer diol (FADD)-based copolyesters prepared by solid-state modi fi cation (SSM) was studied. It was shown that in copolyesters containing less than 10 wt% FADD two different phases, i.e. a PBT crystalline phase and a PBT-rich amorphous phase, are present. The FADD residues were more or less homogeneously distributed throughout the interlamellar regions....
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Isolation of Citrus lemon extracellular vesicles: Development and process control using capillary electrophoresis
PublicationA new and scalable method for the isolation of extracellular vesicles (EV) from Citrus lemon juice samples was developed. The methodology included preliminary preconcentration of the sample using ultrafiltration (UF) followed by size-exclusion chromatography (SEC) purification and final preconcentration of the eluates. Transmission electron microscopy and proteomic analysis showed that isolates contained exosome-like vesicles, exocyst-positive...
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Encapsulation of Cs3Bi2Br9 perovskite photocatalyst with polythiophene for prolonged activity in oxidizing and humid environment
PublicationDespite their growing popularity in modern technology, halide perovskites suffer from susceptibility to oxidation, limiting their applications. Our aim was to enhance Cs3Bi2Br9 perovskite's performance in humid environments through polythiophene encapsulation. This extended its lifespan while preserving photocatalytic abilities, as demonstrated in toluene decomposition experiments. We confirmed the stability of Cs3Bi2Br9 encapsulated...
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Defective TiO2 Core-Shell Magnetic Photocatalyst Modified with Plasmonic Nanoparticles for Visible Light-Induced Photocatalytic Activity
PublicationIn the presented work, for the first time, the metal-modified defective titanium(IV) oxide nanoparticles with well-defined titanium vacancies, was successfully obtained. Introducing platinum and copper nanoparticles (NPs) as surface modifiers of defective d-TiO2 significantly increased the photocatalytic activity in both UV-Vis and Vis light ranges. Moreover, metal NPs deposition on the magnetic core allowed for the effective separation...
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Nanotubular oxide layers and hydroxyapatite coatings on ‘Ti–13Zr–13Nb’ alloy
PublicationThe presented research was aimed to determine the mechanical properties of the nanotubular oxide layer covered with hydroxyapatite coating. The Ti–13Zr–13Nb alloy was oxidised in 1M phosphoric acid with an addition of 0?5% HF for HF solution at 20 V voltage. The electrochemically assisted deposition of hydroxyapatite was performed at cyclic polarisation in NH4H2PO4 and CaCl2 solution at 80uC. The mechanical properties were determined...
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Implementation of SiN thin film in fiber-optic sensor working in telecommunication range of wavelengths
PublicationMirrors are used in optical sensors and measurement setups. This creates a demand for mirrors made of new materials and having various properties tailored to specific applications. In this work, we propose silicon covered with a thin silicon nitride layer as a mirror for near-infrared measurements. SiN layer was deposited on a standard silicon wafer with a Low-Pressure Chemical Vapor Deposition furnace. Then, the created layer...
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Ceramic composites for single-layer fuel cells
PublicationComposite materials consisting of acceptor doped lanthanum orthoniobate electrolyte phase (La0.98Ca0.02NbO4) and Li2O:NiO:ZnO semiconducting phase were synthesized. The precursor powder of La0.98Ca0.02NbO4 was prepared in nanocrystalline (mechanosynthesis) and microcrystalline (solid-state synthesis) form. The composite can be applied in a single-layer fuel cell, because of the presence of two phases acting as an anode and a cathode...
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AlP compound and P-doping for promotion of electrocatalytic activity of N-doped carbon derived from metal-organic framework
PublicationWater splitting plays a key role in future fuels, where two processes occur - the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). Nitrogen-doped carbon derived from...
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Luminescence recognition material as an INHIBIT logic gate in presence of Pb2+ and Cu2+ ions in aqueous solutions
PublicationA recognition material consisting of silica xerogel with amino-modified surface selectively recognizes Pb2+ and Cu2+ (but only in presence of Pb2+ ions) in aqueous solutions of other metal ions. The analytical action of the material is based on a significant change in luminescence emission spectra of the material after chemisorption of Pb2+ ions. In the presence of Pb2+ in octahedral coordination environment, a new broad and strong...
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Proton-Electron Hole Interactions in Sr(Ti,Fe)O3−δ Mixed-Conducting Perovskites
PublicationOxides in which total electrical conductivity is determined by the partial conductivities of three types of charge carriers i.e. holes/ electrons, oxygen ions, and protons are key components of well-functioning proton ceramic fuel cells. Apart from electrochemical properties also easily modified microstructure is an important feature of the electrodes. In the paper, a group of SrTi1−xFexO3−δ (STF, x = 0.2–0.8) perovskites prepared...
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Ellipsometric investigation of nitrogen doped diamond thin films grown in microwave CH4/H2/N2 plasma enhanced chemical vapor deposition
PublicationThe influence of N2 concentration (1%–8%) in CH4/H2/N2 plasma on structure and optical properties of nitrogen doped diamond (NDD) films was investigated. Thickness, roughness, and optical properties of the NDD films in the VIS–NIR range were investigated on the silicon substrates using spectroscopic ellipsometry. The samples exhibited relatively high refractive index (2.6 6 0.25 at 550 nm) and extinction coefficient (0.05 6 0.02...
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Tuning the photocatalytic performance through magnetization in Co-Zn ferrite nanoparticles
PublicationIn this work, the link between the photocatalytic performance of Co-Zn ferrite nanoparticles and the net magnetic moment is analyzed. CoxZn1-xFe2O4 nanoparticles (0 ≤ x ≤ 1) were synthesized by co-precipitation method and different physicochemical techniques were employed to characterize the samples (X-ray diffraction, Transmission Electron Microscopy (TEM), BET surface area, Diffuse Reflectance Spectroscopy (DRS), Photoluminescence spectroscopy,...
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3D Hierarchical Boron-Doped Diamond-Multilayered Graphene Nanowalls as an Efficient Supercapacitor Electrode
PublicationSynthesis of stable hybrid carbon nanostructure for high-performance supercapacitor electrode with long life-cycle for electronic and energy storage devices is a real challenge. Here, we present a one-step synthesis method to produce conductive boron-doped hybrid carbon nanowalls (HCNWs), where sp2-bonded graphene has been integrated with and over a three-dimensional curved wall-like network of sp3-bonded diamond. The spectroscopic...
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The Effect of Surface Modification of Ti13Zr13Nb Alloy on Adhesion of Antibiotic and Nanosilver-Loaded Bone Cement Coatings Dedicated for Application as Spacers
PublicationSpacers, in terms of instruments used in revision surgery for the local treatment of postoperative infection, are usually made of metal rod covered by antibiotic-loaded bone cement. One of the main limitations of this temporary implant is the debonding effect of metal–bone cement interface, leading to aseptic loosening. Material selection, as well as surface treatment, should be evaluated in order to minimize the risk of fraction...
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Influence of alkali metal cations on the photoactivity of crystalline and exfoliated amorphous WO3 – photointercalation phenomenon
PublicationIn order to investigate the effect of photointercalation on photoelectrochemical properties, two types of WO3-based photoanodes, bulk and exfoliated have been prepared and investigated. An aqueous exfoliation method is introduced for the simple fabrication of amorphous and hydrated WO3 nanomaterial using commercial bulk WO3 precursor. The comparison of obtained material with bulk WO3 was performed using Raman, UV–vis, and XPS as...
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Effect of sisal fiber filler on thermal properties of bio-based polyurethane composites
PublicationThis work is mainly focused on study of thermal and thermomechanical properties of obtained bio-based polyurethane (coded as bio-PU) composites via using different types of bio-components (bio-glycol, modified soybean oil and sisal fiber) in the procedure. The chemical structure, morphology and mechanical properties were also investigated and described in this manuscript in order to know more perfect characterization of produced...
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Structural and electronic properties of diamond-composed heterostructures
PublicationDiamond is a promising material for 21st century electronics due to its high thermal and electronic conductivity, biocompatibility, chemical stability, high wear resistance, and possibility of doping. However, the semiconductor properties of diamond, especially free-standing films, have not been fully explored. Nor have their integration with polymers and fragile materials and their applications as electronic components. In this...
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Wire Arc Additive Manufactured Mild Steel and Austenitic Stainless Steel Components: Microstructure, Mechanical Properties and Residual Stresses
PublicationWire arc additive manufacturing (WAAM) is an additive manufacturing process based on the arc welding process in which wire is melted by an electric arc and deposited layer by layer. Due to the cost and rate benefits over powder-based additive manufacturing technologies and other alternative heat sources such as laser and electron beams, the process is currently receiving much attention in the industrial production sector. The gas...
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Enhanced photoelectrochemical performance of inorganic-organic hybrid consisting of BiVO4 and PEDOT:PSS
PublicationThe PEDOT:PSS (poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)) was electrodeposited on a thin layer of bismuth vanadate (BiVO 4 ) prepared using the pulsed laser deposition technique onto FTO. The inorganic-organic junction was characterized by Raman spectroscopy, UV-Vis spectroscopy and sc anning electron microscopy. Chronoamperometry curves, recorded under simulated solar light illumination,...
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Impact of strontium non-stoichiometry of SrxTi0.3Fe0.7O3-δ on structural, electrical, and electrochemical properties for potential oxygen electrode of intermediate temperature solid oxide cells
PublicationThis work presents the results of a comprehensive study on the impact of the A-site non-stoichiometry of SrxTi0.3Fe0.7O3-δ (x = 0.90, 0.95, 1.00, 1.05) ceramics on their physicochemical properties. The materials were fabricated by the conventional solid-state reaction method and their structure was determined by X-ray diffractometry, X-ray photoelectron spectroscopy and electron microscopy. Their sintering and thermal expansion...
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Free-standing TiO2 nanotubes decorated with spherical nickel nanoparticles as a cost-efficient electrocatalyst for oxygen evolution reaction
PublicationHere, we report significant activity towards the oxygen evolution reaction (OER) of spherical nickel nanoparticles (NPs) electrodeposited onto free-standing TiO2 nanotubes (TNT) via cyclic voltammetry. It has been shown that simple manipulation of processing parameters, including scan rate and number of cycles, allows for formation of the NPs in various diameters and amounts. The polarization data with respect to transmission electron...
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Electrochemical performance of thin free-standing boron-doped diamond nanosheet electrodes
PublicationIn the following work we describe preparation and the electrochemical performance of thin and free-standing heavy boron-doped diamond (BDD) nanosheets. The investigated foils were deposited on Ta substrate using microwave plasma-enhanced chemical vapor deposition technique (MPECVD). Foils of two B-dopant densities were investigated, obtained on the base of 10 k and 20 k ppm [B]/[C] ratio in the gas admixture. The obtained foils...
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The influence of polypropylene-block/graft-polycaprolactone copolymers on melt rheology, morphology, and dielectric properties of polypropylene/polycarbonate blends
PublicationThe paper discusses the relationship between rheology and morphology of immiscible polypropylene (matrix))/polycarbonate (dispersed phase) blends compatibilized with novel polypropylene-polycaprolactone block and graft copolymers. Transmission electron microscopy (TEM) experiments revealed uniform droplet morphologies and a reduction of the average size of the dispersed phase upon addition of the compatibilizer. The results suggested...
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Porosity and swelling properties of novel polyurethane–ascorbic acid scaffolds prepared by different procedures for potential use in bone tissue engineering
PublicationIn this work, a novel polyurethane (PU) system based on poly(ethylene-butylene) adipate diol, 1,6-hexamethylene diisocyanate, 1,4-butanediol, and ascorbic acid was used to prepare scaffolds with potential applications in bone tissue engineering. Two fabrication methods to obtain porous materials were chosen: phase separation (PS)/salt particle leaching (PL) and solvent casting (SC)/salt PL. The calculated porosity demonstrated...
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Photocatalytical degradation of toluene and cyclohexane using LED illumination
PublicationA sol-gel process followed by hydrothermal reaction was used to prepare coupled WO3-TiO2 photocatalysts with varying amounts of WO3 in respect to TiO2 (3 mol% and 5 mol% respectively). Additionally, photocatalysts have been subjected to different calcination temperatures of 400ºC and 800ºC, which allowed us to compare how these affect photodegradation efficiency. Photocatalysts were characterized under a scanning electron microscope,...
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Assessment of Corrosive Behaviour and Microstructure Characterization of Hybrid Friction Stir Welded Martensitic Stainless Steel
PublicationThis study examined the effect of induction heating on the microstructure and corrosion characteristics of hybrid friction stir welded AISI 410 stainless steel. Five joints have been produced with different friction stir welding parameters like welding speed, spindle speed, plunge depth, and induction power. Their microstructures were evaluated using a scanning electron microscope, and chemical composition was examined using...
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Characterization of Highly Filled Glass Fiber/Carbon Fiber Polyurethane Composites with the Addition of Bio-Polyol Obtained through Biomass Liquefaction
PublicationThis work aims to investigate the process of obtaining highly filled glass and carbon fiber composites. Composites were manufactured using previously obtained cellulose derived polyol, polymeric methylene diphenyl diisocyanate (pMDI). As a catalyst, dibutyltin dilaurate 95% and Dabco® 33-LV were used. It was found that the addition of carbon and glass fibers into the polymer matrix causes an increase in the mechanical properties...
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Ultrastructural analysis of the submandibular sialoliths: Raman spectroscopy and electron back-scatter studies
PublicationThe aim of work was the epidemiological analysis of the occurrence of sialolithiasis of the submandibular gland in adults and the evaluation of the ultrastructure of salivary stones. The study sample consisted of 44 sialoliths. Analysis of the structure and chemical composition of sialoliths was performed using a Scanning Electron Microscope and Raman Spectroscopy. Comparing our results with the literature we can say that the epidemiology...
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Degradation of implantable materials – in vivo and in vitro research
PublicationThe article concerns the biological and electrochemical degradation of metallic implants in vivo and in vitro studies. The in vivo research dealt with degradation of plates used to join bones, as well as endoprostheses. The most common damages were: metalosis, breaking in the microstructure changes, breaking in area of holes, as well as plastic deformation throughout the length of an implant. The material used for the research...
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EXPERIMENTAL AND NUMERICAL INVESTIGATIONS OF CONCRETE BEHAVIOUR AT MESO-LEVEL DURING QUASI-STATIC SPLITTING TENSION
PublicationThe paper describes experimental and numerical results of quasi-static splitting tensile tests on concrete specimens at meso-scale level. The loading strip was made of plywood or steel. Fracture in concrete was detected at the aggregate level by means of three non-destructive methods: 3D x-ray micro-computed tomography, 2D scanning electron microscope and manual 2D digital microscope. The discrete element method was used to directly...
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Assessment of organic coating degradation via local impedance imaging
PublicationThe paper presents a new approach to organic coating condition evaluation at micrometer scale using localized impedance measurements. It is based on atomic force microscopy (AFM) in contact mode. Impedance is measured between conductive AFM tip and metal substrate covered with organic coating. A single-frequency voltage perturbation signal is applied between the electrodes and current response signal is registered. As the tip is...
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Evaluation of organic coatings condition with AFM-based method
PublicationThe paper presents an atomic force microscopy (AFM)-based approach to evaluation of local protective properties of organic coatings. Apart from topography, it provides local ac and dc characteristics of examined coating. The method consists in application of ac voltage perturbation signal between conductive AFM tip and coated metal substrate. The resulting current is used to determine local impedance characteristics. Both impedance...
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Silver-modified titania with enhanced photocatalytic and antimicrobial properties under UV and visible light irradiation
PublicationCommercial titania photocatalysts were modified with 2 wt% of silver by photodeposition. The properties of the samples were characterized by DRS, XPS, XRD, FE-SEM and STEM. The modified samples exhibited activity under visible light and enhanced activity under UV irradiation for 2-propanol and acetic acid oxidation, respectively. The time-resolved microwave conductivity (TRMC) analysis indicated that enhanced activity (2.5–8-fold...
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Development and evaluation of RADA-PDGF2 self-assembling peptide hydrogel for enhanced skin wound healing
PublicationBackground: Wound healing complications affect numerous patients each year, creating significant economic and medical challenges. Currently, available methods are not fully effective in the treatment of chronic or complicated wounds; thus, new methods are constantly sought. Our previous studies showed that a peptide designated as PDGF2 derived from PDGF-BB could be a promising drug candidate for wound treatment and that RADA16-I...
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NOx Photooxidation over Different Noble Metals Modified TiO2
PublicationWe compared the activity enhancement effect of noble metal deposited on TiO2 in photocatalytic nitrogen oxides oxidation. Titanium dioxide was decorated with Ag, Au, Pt or Pd in the sol-gel process. Synthesized catalysts were characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller measurement (BET), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and energy dispersive X-ray analysis (EDX)....
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The new silica-based coated SPME fiber as universal support for the confinement of ionic liquid as an extraction medium
PublicationThe new silica-based SPME fiber coating is reported for the first time as universal support purposed to confinement of ionic liquid as an extraction medium. Fiber coating was prepared by the sol-gel process, using potassium silicate (K2SiO3) as a precursor and dimethylformamide (DMF) as a pore-forming medium. The concept of synthesis assumes obtaining a solid porous material on the surface of the glass rod and, being characterized...
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Corrosion Properties of Dissimilar AA6082/AA6060 Friction Stir Welded Butt Joints in Different NaCl Concentrations
PublicationA solid-state friction stir welding method which is increasingly used in the marine and shipbuilding industry, has been developed to produce welds with high mechanical properties. In seawater, the oxide layer of aluminium is attacked by Cl− ions resulting in its disruption and formation of pitting corrosion. It is particularly important to determine the electrochemical properties of the produced welds and to evaluate the efect...
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Nanotubular Oxide Layer Formed on Helix Surfaces of Dental Screw Implants
PublicationSurface modification is used to extend the life of implants. To increase the corrosion resistance and improve the biocompatibility of metal implant materials, oxidation of the Ti-13Nb- 13Zr titanium alloy was used. The samples used for the research had the shape of a helix with a metric thread, with their geometry imitating a dental implant. The oxide layer was produced by a standard electrochemical method in an environment of...
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Discrete element method simulations of fracture in concrete under uniaxial compression based on its real internal structure
PublicationThe paper describes experimental and numerical results of concrete fracture under quasi-static uniaxial compression. Experimental uniaxial compression tests were performed on concrete cubic specimens. Fracture in concrete was detected at the aggregate level by means of three non-destructive methods: three-dimensional X-ray microcomputed tomography, two-dimensional scanning electron microscope and manual two-dimensional digital...