Elemental Distribution Maps Research Articles

Effects of titanium (Ti) contents on the wear resistance of low-alloy steel alloys

In this study, the impact of titanium (Ti) on low-alloy steel alloys is examined, focusing on the mechanical properties of the alloy with varying Ti content levels. Heat treatment was conducted to enhance the mechanical properties and performance indicators of the casting samples. The elemental volume distribution mapping and microstructure analysis of the research samples were performed using SEM - Carl Zeiss Ultra Plus Field Emission. Subsequently, the hardness and wear resistance characteristics of samples containing Ti contents of 0, 0.1, 0.3, 0.5, 0.8, and 1.1 were evaluated post heat treatment. Notably, steel samples containing 0.3% and 0.5% Ti, exhibiting structures of ferrite, martensite, and limited bainite, demonstrated superior hardness and wear resistance properties. Abrasive wear resistance tests were conducted using a specialized device with a horizontal diamond disc. The primary objective of this research is to introduce the developed technology for the rolling mill rolls at a prominent metal manufacturing enterprise in the republic, resulting in enhanced economic efficiency through increased production volume. Consequently, achieving a hardness of HB 323 and improving wear resistance by 1.2 times were notable outcomes of the study.

Lunar elemental abundances as derived from Chandrayaan-2

The distribution of Mg, Al, Si, Ca and Fe on the lunar surface are important to understand the petrological characteristics of the Moon and its geological evolution. We derived new elemental distribution maps using the Chandrayaan-2 Large Area Soft X-ray Spectrometer (CLASS) experiment onboard the Chandrayaan-2 Orbiter. These are the first set of maps derived from three years of CLASS data (2019–2022) at a spatial resolution of 150 km × 12.5 km. These maps are free of the topographic shadow effects and space weathering effects because the elemental abundances are derived only using X-ray spectra in the 0.5 to 20 keV energy range. CLASS derived abundances are compared to the elemental maps obtained using the Lunar Prospector Gamma Ray Spectrometer, with abundances of the lunar soil samples, and with XRF measurements of Chandrayaan-1 mission to establish its credibility. These maps derived using X-ray fluorescence spectroscopy are a new resource for lunar geochemical studies based on the most direct detection technique.

Evaluation of tool wear during turning of Ti6Al4V alloy applying MQL technique with Cu nanoparticles diversified in terms of size

In case of hard-to-cut materials, as titanium alloy Ti6Al4V, eco-friendly cooling methods or their modifications are still being developed. Therefore, various types of nanofluids are applied in the cutting process to reduce friction in the cutting zone and thus heat accumulation in the tool corner. This paper presents an analysis of the selected tool wear indicators, as well as the wear mechanisms, after turning with various cooling/lubricating techniques, including: MQL with the addition of copper nanoparticles (CuNPs), dry machining and the MQL technique without nanoparticles. Four sizes of CuNPs were applied: 22 nm, 35 nm, 65 nm and 80 nm. Analysis of SEM images and maps of elemental distributions on the cutting edge working surfaces allowed to determine that the smallest sizes of copper nanoparticles introduced in the cutting fluid result in reduced tool flank wear, as well as the reduced width and depth of the crater wear on the rake face. With the smallest size of copper nanoparticles, a “ball bearing” and tribofilm formation effects were obtained, which prevented intense adhesive and abrasive wear. Turning, applying MQL + CuNPS 22 nm method resulted in a decrease of selected tool wear rates from 25.7% to 55% compared to effects reached during dry machining, and from 11.7% to 39.2% compared to effects of MQL turning without addition of nanoparticles to the cutting fluid.

Effect of cobalt addition on wear behaviour of TiB2 coating produced by TIG cladding process

In this paper, the mechanical and tribological characteristics of TiB2 ceramic coating with and without cobalt (Co) addition developed using tungsten inert gas (TIG) cladding process on AISI 304 stainless steel (SS) were investigated. The effect of TIG process conditions as well as cobalt (Co) content on the microstructure, microhardness and resistance to wear were investigated systematically. The phase identification, microstructure, and elemental distribution map of the clad layer formed on the surface of an AISI 304SS substrate were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS), respectively. Vickers microhardness testing apparatus and a pin-on-disc tribometer were used to evaluate the microhardness, resistance to wear, and coefficient of friction (COF), respectively. The result demonstrates that a dense and defect-free composite coating with a strong metallurgical bond to the substrate is possible. The average microhardness of the TiB2 ceramic coating without Co addition was 1704 HV, and the average wear rate was 15.1576 × 10−9 g N−1-m−1. In contrast, the TiB2 ceramic coating with Co addition exhibited an improved average microhardness of 1860 HV and a reduced average wear rate of 22.7364 × 10−9 g N−1-m−1, while the AISI 304SS substrate had an average microhardness of 216 HV and an average wear rate of 200.45×10−9 g N−1-m−1. The conclusion is that the TiB2 ceramic coating with Co addition exhibited superior mechanical and tribological characteristics, demonstrating its suitability for use in wear-resistant components. The higher microhardness of the TiB2 ceramic with Co-added coating indicates enhanced hardness and potential resistance to deformation, while the lower wear rate suggests improved durability and the ability to withstand frictional forces. Therefore, the TiB2 ceramic coating with Co addition shows promise for applications where wear resistance is crucial.

Seeing in the dark: Challenges in the interpretation of x‐ray fluorescence element distribution maps associated with black paints

AbstractDuring the conservation of easel paintings, black draperies or dark backgrounds often prove problematic to treat and understand in terms of condition. Despite most black pigments in Old Master paintings not intrinsically containing high atomic number elements, the investigation of black paints is one of the National Gallery's major uses and most helpful applications of x‐ray fluorescence (XRF) scanning. As a visual tool, XRF element distribution maps of black paints are useful for assessing the extent of overpainting or condition of any surviving original paint beneath, and for revealing the original modelling. However, interpreting the XRF element maps can be challenging. It is important to consider not only the primary compositions of black or dark pigments, but to have an understanding of other possible associated materials and more broadly of historical painting techniques, artists' practices and the paint stratigraphy. Through a series of case studies, this paper demonstrates how a detailed knowledge of historic painting materials and techniques, based on study of documentary sources and archives of materials‐based evidence from the analysis of paint cross‐sections—both from the paintings being studied and related works—aids and enriches interpretation of XRF element maps of black paints. While samples are invaluable in understanding exactly how—and with what materials—such regions were painted, they are not always representative and scanning XRF may be of complementary benefit in providing a more holistic view of pigment distribution. The examples presented range from the fifteenth to the seventeenth century from both Northern Europe and Italy.

Laboratory experiments and modelling of the geochemical interaction of a gabbro-anorthosite with seawater and supercritical CO2: A mineral carbonation study

The potential for mineral carbonation of carbon dioxide (CO2) in a plutonic mafic rock is addressed in this work through a set of laboratory experiments on a gabbro-anorthosite sample from the Torrão - Odivelas Massif (Portugal). The experiment was conducted in two stages under pressure (8 MPa) and temperature (313.15 K) conditions similar to those expected around a CO2 injection well. Stage-I simulated dissolution conditions, with a crushed rock sample (1–3 mm) exposed for 30 days to CO2 supersaturated seawater (0.576 M). Stage-II favoured carbonation conditions; cubic rock specimens (8 cm3) were brought in contact with the Stage-I seawater subsaturated in CO2 (0.095 M).A multi-analytical methodology was applied to follow the mineralogical and geochemical evolution of rock and seawater during both stages. At the end of Stage-I, the aqueous phase showed a marked increase in iron (Fe), magnesium (Mg) and calcium (Ca) ions and milder increase in silicon (Si) and aluminium (Al) ions. At the end of Stage-II, a decrease in Si and Al concentrations was observed while the Fe, Mg, Ca concentrations still increased, albeit at a lower rate. No significant geochemical variations were detected in the bulk solid phase. The bulk X-ray diffraction (XRD) analyses detected halite as a new mineral phase, while the grazing-XRD design revealed the presence of dolomite. Moreover, the elemental distribution mapping demonstrated the spatial association of carbon with magnesium indicating magnesite crystallisation. The geochemical model developed in CrunchFlow code was able to reproduce the experimental observations and simulate the chemical behaviour for longer time periods.Overall, the experiments and model point towards a mineral carbonation potential in the Torrão - Odivelas Massif, with further studies being required to upscale the laboratory results to field scale.

Detection and visualization of micron-scale U-Ca phosphates as a key to redox and acid-base conditions in ores: sandstone-hosted uranium deposit

The presence and nature of uranium minerals subject to high leachability is one of the most significant factors in the exploitation of low-grade ores. The detection of these minerals is a challenging task due to their small size and low abundance. This paper presents a novel method of data processing that allows distinguishing and visualization of micron-scale U minerals. For this purpose, core samples of U-bearing sandstones from the Břevniště deposit (Czech Republic) were used. After their study by inductively coupled plasma spectroscopy, optical and scanning electron microscopy (SEM-EDS) and X-ray diffraction analysis, the presence of authigenic grains of U minerals occurring in various associations and their chemical compositions were confirmed by an electron microprobe. However, the use of these conventional instruments for the analysis of heterogeneous ore material with valuable information hidden, showed the necessity for a special data treatment. Matrix transformation of raw SEM-EDS data allowed for even more accurate visualizations such as contour and point maps of elemental distribution. Then, mathematical and visual correlations of transformed data revealed relationships among some measured elements (Ca, P, U, Zr, Nb, Fe, S) and their spectral overlaps. Conditions of ore formation were predicted based on the visualizations, correlations and the paragenesis of ningyoite in uranium ore. Herein suggested approach can help to identify economically significant minerals in complex mineralizations worldwide and increase the mining potential of the deposits.

Cell type-specific mapping of ion distribution in Arabidopsis thaliana roots

Cell type-specific mapping of element distribution is critical to fully understand how roots partition nutrients and toxic elements with aboveground parts. In this study, we developed a method that combines fluorescence-activated cell sorting (FACS) with inductively coupled plasma mass spectrometry (ICP-MS) to assess the ionome of different cell populations within Arabidopsis thaliana roots. The method reveals that most elements exhibit a radial concentration gradient increasing from the rhizodermis to inner cell layers, and detected previously unknown ionomic changes resulting from perturbed xylem loading processes. With this approach, we also identify a strong accumulation of manganese in trichoblasts of iron-deficient roots. We demonstrate that confining manganese sequestration in trichoblasts but not in endodermal cells efficiently retains manganese in roots, therefore preventing toxicity in shoots. These results indicate the existence of cell type-specific constraints for efficient metal sequestration in roots. Thus, our approach opens an avenue to investigate element compartmentation and transport pathways in plants.

Elemental imaging approach to comparative analysis of historical inks. Proof of concept based on non-invasive examinations of the Chopin manuscript as a case study

This work presents an indirect method of investigating the elemental diversity of historical inks. The manuscript of Fryderyk Chopin's Impromptu in A flat major, Op. 29 was examined as an example of the proposed approach for testing documents containing different inks. Preliminary in situ X-ray fluorescence (XRF) measurements carried out it the museum storage room provided qualitative reference data for the object. Then, selected areas on the item were examined with indicator papers soaked in 4,7-diphenyl-1,10-phenanthroline (Bphen). The reaction with the ligand enabled the immediate colorimetric detection of Fe(II) in the form of magenta Fe(Bphen)3 complex. The overall condition of the manuscript with regard to the risk of ink corrosion was assessed in this way. More chemical information were obtained by the proposed elemental imaging-based approach to evaluate chemical heterogeneity of the used indicator paper samples using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The recorded data were visualised in the form of elemental distribution maps. The Fe enriched areas indicated Regions of Interest (ROIs) to approximate composition of the inks from the manuscript. All calculations were done solely for the data mathematically singled out from these areas. The varying proportions of AI, Mn, Co and Cu relative to Fe correlated with the ROIs of the composer's handwriting, editor's notes and stave lines, demonstrating the applicability of the proposed approach for comparative studies.

Multiple geological events controlling rock types development: A case study of Wufeng-Longmaxi formation in southern Sichuan Basin, China

During Late Ordovician to Early Silurian, global geological events such as volcanic activity, glaciation, and mass extinction affected sedimentary environments and organic matter (OM) accumulation, and controlled the development of organic-rich shales. Taking the Wufeng-Longmaxi Formation (WF-L Fm) shales in southern Sichuan Basin as the research object, based on the core, thin section and scanning electron microscopy (SEM) observations, combined with X-ray fluorescence (XRF) two-dimensional element distribution maps, X-ray diffraction (XRD), trace elements, carbon isotope composition and total organic carbon (TOC) data, the relationship between geological events and sedimentary environments, OM accumulation as well as rock types development are analyzed, and the sedimentary environments response to geological events is elaborated. Eight rock types have been identified, and the minerals occurrence model has been characterized. By using Cu content, Mo content, δ13C and TOC to measure paleoproductivity, Sr content and Sr/Cu to judge paleoclimate, Sr/Ba to measure paleosalinity, and U/Th, V/Cr, V/Ni, and Ni/Co to analyze redox conditions, the sedimentary environments of the WF-L Fm shales can be furtherly divided into 7 intervals. In general, the deep water hypoxic-anoxic environments from Interval Ⅰ to Interval Ⅴ is conducive to the formation of organic-rich shales. The organic-rich shales formed in the anoxic environments from Interval Ⅰ to Interval Ⅴ are related to the fact that volcanic activities not only release a large amount of nutrients, promote biological prosperity and improve productivity, but also make the water in a sulfide anoxic environment, which is conducive to the preservation of OM. The rapid rise and fall of sea level caused by the Hirnantian glaciation harmed the living environments of organisms, led to the mass extinctions and provided material sources for OM accumulation, resulting in high TOC in the rock types of Interval IV. Irregular gravity flow can enhance terrigenous input in deep water for a short time and dilute OM, which is one of the reasons for the low TOC in the rock types of Interval Ⅵ to Interval VII. Upwelling current enhances nutrient flux in surface water and improves primary productivity of water, thus affecting the development of WF-L Fm organic-rich shales. Based on the aforementioned interpretations, the sedimentary model of the southern Sichuan Basin was established.

Layout of ancient Greek papyri through lead-drawn ruling lines revealed by Macro X-Ray Fluorescence Imaging

The use of lead-drawn ruling lines by ancient scribes for the layout of Greek papyrus rolls was known to us only from classical authors and was postulated by a few scholars in modern times. In situ application of noninvasive Macro X-Ray Fluorescence Imaging Spectroscopy (MA-XRF) to unrolled papyri from Herculaneum, dating from about 200 BC to the 1st century AD, has provided the first direct evidence of such practice in ancient book production. The key experimental proof of periodic lines drawn in lead was gathered by a highly sensitive MA-XRF mobile instrument, which allowed detection of ultra-low trace residues of metals with detection limits that rival synchrotron light instruments. Elemental distribution maps of Pb have revealed three different systems of textual layout in ancient papyrus rolls and have resolved the dispute around so-called Maas’ Law, by delivering experimental proof that slanted text columns were a deliberate aesthetic choice of scribes.

Green Fabrication of Anticorrosive, Antibacterial, and SERS Active Nanohybrid Coatings by Dual-Spinneret Electrospinning

The development of sustainable and nontoxic corrosion coatings in abiotic and biotic environments has recently attracted significant attention. Herein, we developed nanohybrid coatings containing polysulfone (PSU), cyclodextrin (CD), zeolite (10 μm size), and biogenic silver nanoparticles (AgNPs, 40 nm diameter) via direct one-step dual-spinneret electrospinning. In the fabricated nanohybrid coatings, zeolites were used as a nontoxic anticorrosive inhibitor, and biogenic AgNPs serve as antibacterial agents due to their environmentally friendly and low-cost characteristics. Scanning electron microscopy and transmission electron microscopy analyses indicated that the zeolite and AgNP-embedded nanofibers have homogeneous and bead-free morphologies. Moreover, the elemental distribution mapping of the fabricated platforms demonstrated a well-distributed mixture of PSU/zeolite and CD/AgNPs in the nanofiber mats which were fabricated via such a dual-spinneret technique. The surface-enhanced Raman scattering activities of the fabricated nanofiber mats were also evaluated using methylene blue, rhodamine 6 G, crystal violet, and malachite green as probe molecules. Additionally, the antibacterial response of the fabricated nanohybrid coatings against four pathogenic bacteria (Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 23213, Pseudomonas aeruginosa ATCC 27853, and Klebsiella pneumoniae ATCC 700603) was investigated, which indicated the critical role of zeolite/AgNPs in suppressing the bacterial growth. Tafel measurements also showed that the PSU/zeolite/HPβCD/AgNPs hybrid coating reduced the corrosion current density of the Cu surface in the presence of P. aeruginosa ATCC 27853, which is a biofilm-producing bacteria, compared to the uncoated surface. The antimicrobial and corrosion inhibition ability of the fabricated nanohybrid coatings offers promising opportunities for the microbiologically influenced corrosion inhibition applications.

Metal-organic framework nanopesticide carrier for accurate pesticide delivery and decrement of groundwater pollution

The motivation of the present study was a synthesis of the nanocomposites of UiO-66@ZnO/Biochar to embed carbendazim (CBZ) pesticide inside its porous structures for smart spraying and cleaner production. CBZ@UiO-66@ZnO/Biochar had the purpose of not only smart spraying to avoid releasing a large amount of CBZ into the groundwater but also of accurately delivering the CBZ pesticide to the desired grass/plant. High-resolution electron microscopy was introduced to characterise the morphologies of prepared composites with spatial elemental distribution mapping. X-ray diffraction (XRD) patterns and micro-Raman spectroscopy were employed for the crystal structures of UiO-66@ZnO. Spectral UV–Vis and Fourier transform-infrared (FT-IR) tools were utilized to estimate the UiO-66@ZnO/Biochar-based adsorption and release of CBZ into the dimethyl sulfoxide (DMSO)-water mixture. Our results indicated that the adsorption capacities of CBZ into the DMSO-water mixture onto UiO-66@ZnO and UiO-66@ZnO/Biochar nanocomposites were obtained at 68.8% and 72.6%. The half-life of photodegradation rate constants for CBZ@UiO-66@ZnO/Biochar was found to be 12.3 times longer than that of free CBZ. Notably, CBZ@UiO-66@ZnO/Biochar inhibitory concentration 50% (IC50) determination was estimated at 73.8 μg/L and 209 μg/L for Fusarium oxysporum and Aspergillus niger. This work provides a comprehensive experimental scheme for the chemisorption process of CBZ onto the UiO-66@ZnO/Biochar composite materials and the nanopesticide applications in sustainable agriculture towards cleaner productions.

Thiol-ene-mediated degradable POSS-PEG/PEG hybrid hydrogels as potential cell scaffolds in tissue engineering

Tissue engineering provides therapeutic strategies for the loss or failure of human organs and tissues. As a three-dimensional biomaterial that simulates extracellular matrix (ECM) in tissue engineering, hydrogels have attracted much attention and been used as cell scaffolds. Herein, three POSS-PEG/PEG hydrogels with different solid contents were designed and developed through thiol-ene click reaction between a star-shaped cross-linker allyl-terminated poly(ethylene glycol)-functionalized polyhedral oligosiloxane (POSS-PEG-Allyl) and poly(ethylene glycol)-dithiol (SH-PEG-SH). The chemical structures, microscopic morphologies, element distribution mapping, rheological properties, swelling properties, in vitro degradation and cytocompatibility of the hydrogels were further investigated. The results showed that the hybrid hydrogels contain a large amount of water, which can create a suitable water environment for cell growth. The mechanical strength of the hybrid hydrogels is improved by introducing POSS nanoparticles to the hydrogel system, and the ester groups in the cross-linker allow the hydrogel network can be biodegrade by hydrolytic cleavage. The mechanical strength and the degradation rate can be adjusted by the solid content of the hybrid hydrogels. Besides, the hybrid hydrogel has excellent cell compatibility and porous internal structure, which provide conditions for cell growth and proliferation. Therefore, it can be considered that the hybrid hydrogel has great application potential as a cell scaffold material.

Revealing the Materials, Painting Techniques, and State of Preservation of a Heavily Altered Early 19th Century Greek Icon through MA-XRF

Macroscopic X-ray fluorescence analysis (MA-XRF) is a non-destructive analytical technique that allows for the rapid and thorough investigation of paintings; therefore, it is nowadays increasingly involved in relevant studies. In the present work, a state-of-the-art MA-XRF set-up is utilized to identify the painting materials and techniques and document the state of preservation of an early 19th-century AD Greek religious panel painting (“icon”). The artifact in consideration has received extensive restoration interventions in the past and is considerably decayed; for these reasons, the interpretation of the relevant MA-XRF elemental intensity distribution maps is challenging. In this framework, it is demonstrated how the elemental distribution maps can be explored and interpreted to lead to a thorough investigation of the painting in consideration. In particular, the MA-XRF data interpretation allowed for the identification of the original palette that includes the rather rarely employed–in icon painting-yellow lead-antimonate pigment, led to the spotting of an invisible inscription, to the documentation of the preparation/gesso layer and the preliminary drawing. Additionally, it was possible to discriminate between the original painting and the later interventions, while the collected data revealed that the painting originally had two cross-bars attached to its back. Ultimately, the presented case study can be utilized as a guide for the proper interpretation of MA-XRF data from decayed and altered icons.

Influence of Hafnium Addition on the Microstructure, Microhardness and Corrosion Resistance of Ti20Ta20Nb20(ZrMo)20-xHfx (where x = 0, 5, 10, 15 and 20 at.%) High Entropy Alloys.

The presented work aimed to investigate the influence of the hafnium/(zirconium and molybdenum) ratio on the microstructure, microhardness and corrosion resistance of Ti20Ta20Nb20(ZrMo)20-xHfx (where x = 0, 5, 10, 15 and 20 at.%) high entropy alloys in an as-cast state produced from elemental powder and obtained via the vacuum arc melting technique. All studied alloys contained only biocompatible elements and were chosen based on the thermodynamical calculations of phase formation predictions after solidification. Thermodynamical calculations predicted the presence of multi-phase, body-centered cubic phases, which were confirmed using X-ray diffraction and scanning electron microscopy. Segregation of alloying elements was recorded using elemental distribution maps. A decrease in microhardness with an increase in hafnium content in the studied alloys was revealed (512-482 HV1). The electrochemical measurements showed that the studied alloys exhibited a high corrosion resistance in a simulated body fluid environment (breakdown potential 4.60-5.50 V vs. SCE).

2H-MoS 2 Modified Nitrogen-Doped Hollow Mesoporous Carbon Spheres as the Efficient Catalytic Cathode Catalyst for Aprotic Lithium-Oxygen Batteries

2H-MoS ₂ Modified Nitrogen-Doped Hollow Mesoporous Carbon Spheres as the Efficient Catalytic Cathode Catalyst for Aprotic Lithium-Oxygen Batteries

A Fast Automatic Method for Deconvoluting Macro X-Ray Fluorescence Data Collected From Easel Paintings

Macro X-ray Fluorescence (MA-XRF) scanning is increasingly widely used by researchers in heritage science to analyse easel paintings as one of a suite of non-invasive imaging techniques. The task of processing the resulting MA-XRF datacube generated in order to produce individual chemical element maps is called MA-XRF deconvolution. While there are several existing methods that have been proposed for MA-XRF deconvolution, they require a degree of manual intervention from the user that can affect the final results. The state-of-the-art AFRID approach can automatically deconvolute the datacube without user input, but it has a long processing time and does not exploit spatial dependency. In this paper, we propose two versions of a fast automatic deconvolution (FAD) method for MA-XRF datacubes collected from easel paintings with ADMM (alternating direction method of multipliers) and FISTA (fast iterative shrinkage-thresholding algorithm). The proposed FAD method not only automatically analyses the datacube and produces element distribution maps of high-quality with spatial dependency considered, but also significantly reduces the running time. The results generated on the MA-XRF datacubes collected from two easel paintings from the National Gallery, London, verify the performance of the proposed FAD method.

Suzuki hardening and segregation in Co0.95Cr0.8Fe0.25Ni1.8Mo0.475 high-entropy alloys

A Co0.95Cr0.8Fe0.25Ni1.8Mo0.475 high-entropy alloy was heavily cold-rolled and subsequently aged at 773 K. Aging-induced Suzuki hardening was observed. High-angle annular dark-field scanning transmission electron microscopy imaging and the corresponding energy dispersive X-ray spectroscopy elemental distribution mapping suggested the enrichment of Co atoms at stacking faults (SFs), which pinned down partial dislocations and enhanced the resistance of the alloy to plastic deformation. Furthermore, the enrichment of Co and Mo atoms at SFs was observed in a low dislocated, strain-aged specimen. The significant difference in the SF density of the specimens led to difference in segregation. The local stacking fault energy (SFE) with the segregation of Co and Mo atoms was calculated as −30.6 mJ/m2 at the aging temperature. The negative SFE did not restrict the SF expansion, indirectly resulting in the formation of wide SFs.

Supramolecular Aggregation Processes on Carbon Surfaces Occurring in Bovine Serum Albumin Solutions

The processes of supramolecular aggregation occurring on carbon surfaces in aqueous solutions of bovine serum albumin (BSA) during drying were studied using modern scanning electron microscopy (SEM). The carbon materials studied were highly oriented pyrolytic graphite (HOPG) and glassy carbon (GC). Based on the analysis of SEM images and EDX-scanning element distribution maps, a possible mechanism for the formation of the observed intricate structures on the surface was proposed. The formation of fuzzy lacy structures resembling shadow replicas was explained by relatively strong hydrophobic–hydrophobic interactions of albumin molecules with carbon surfaces.