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The surface wettability of catalysts is typically controlled via surface treatments that promote catalytic performance. Here we report on potential-regulated hydrophobicity/hydrophilicity at cobalt-based oxide interfaces with an alkaline solution. The switchable wetting of single particles, directly related to their activity and stability towards the oxygen evolution reaction, was revealed by electrochemical liquid-phase transmission electron microscopy. Analysis of the movement of the liquid in real time revealed distinctive wettability behaviour associated with specific potential ranges. At low potentials, an overall reduction of the hydrophobicity of the oxides was probed. Upon reversible reconstruction towards the surface oxyhydroxide phase, electrowetting was found to cause a change in the interfacial capacitance. At high potentials, the evolution of molecular oxygen, confirmed by operando electron energy-loss spectroscopy, was accompanied by a globally thinner liquid layer. This work directly links the physical wetting with the chemical oxygen evolution reaction of single particles, providing fundamental insights into solid–liquid interfacial interactions of oxygen-evolving oxides., Surface treatments can tune catalysts’ wettability, which can be used to promote their catalytic performance. Now, a potential-dependent dynamic wetting behaviour of cobalt-based oxide catalysts is identified before and during the oxygen evolution reaction.

The importance of PEG architecture on nanoparticle (NP) functionality is known but still difficult to investigate, especially at a single particle level. Here, we apply DNA Point Accumulation for Imaging in Nanoscale Topography (DNA-PAINT), a super-resolution microscopy (SRM) technique, to study the surface functionality in poly(lactide-co-glycolide)–poly(ethylene glycol) (PLGA–PEG) NPs with different PEG structures. We demonstrated how the length of the PEG spacer can influence the accessibility of surface chemical functionality, highlighting the importance of SRM techniques to support the rational design of functionalized NPs., The importance of PEG architecture on nanoparticle (NP) functionality is known but still difficult to investigate. Here, DNA-PAINT and qPAINT are used to quantify this phenomenon at a single particle and molecular level.

Encapsulation of probiotic bacteria can enhance their functionality when used in combination with antibiotics for treating intestinal tract infections. The interaction strength of encapsulating shells, however, varies among the encapsulation methods and impacts encapsulation. Here, we compared the protection offered by encapsulating shells with different interaction strengths toward probiotic Bifidobacterium breve against simulated gastric fluid and tetracycline, including protamine-assisted SiO2 nanoparticle yolk-shell packing (weak interaction across a void), alginate gelation (intermediate interaction due to hydrogen binding), and ZIF-8 mineralization (strong interaction due to coordinate covalent binding). The presence of encapsulating shells was demonstrated using X-ray-photoelectron spectroscopy, particulate microelectrophoresis, and dynamic light scattering. Strong interaction upon ZIF-8 encapsulation caused demonstrable cell wall damage to B. breve and slightly reduced bacterial viability, delaying the growth of encapsulated bacteria. Cell wall damage and reduced viability did not occur upon encapsulation with weakly interacting yolk-shells. Only alginate-hydrogel-based shells yielded protection against simulated gastric acid and tetracycline. Accordingly, only alginate-hydrogel-encapsulated B. breve operated synergistically with tetracycline in killing tetracycline-resistant Escherichia coli adhering to intestinal epithelial layers and maintained surface coverage of transwell membranes by epithelial cell layers and their barrier integrity. This synergy between alginate-hydrogel-encapsulated B. breve and an antibiotic warrants further studies for treating antibiotic-resistant E. coli infections in the gastrointestinal tract.

A non-thermal plasma treatment generated in air at atmospheric pressure was used for surface modification of medium density fiberboard (MDF) substrate. Untreated and plasma-treated substrates were coated with a waterborne acrylic coating and exposed to accelerated artificial weathering (AAW) in interior mode. Plasma treatment increased the surface free energy of MDF by about 50%, which positively influenced on the wettability of the MDF with the coating. Weathering of the coated MDF caused a decrease in surface gloss and color changes, which were less pronounced for plasma-treated samples. Attenuated total reflection Fourier transform infrared spectra and microscopic analysis revealed degradation of the acrylic resin on the coated MDF due to light irradiation during weathering. After 250 h of weathering, the surface roughness of the coated MDF increased by about 3 μm. The coated MDF surfaces started to lose their hydrophobic character after 50 h of weathering. Finally, the determination of mechanical properties showed that coated MDF became more resistant to scratching during AAW, while the adhesion of the coating film to the MDF substrate was not affected in a significant trend with time of AAW. In both cases, no influence of plasma treatment was detected.

The activated carbon (AC) supported sulphur-based Ni/Co photocatalysts were prepared using the simple chemical precipitation method. The prepared samples were characterized with advanced scanning electron microscope, x-ray diffraction, Raman, UV-DRS, PL analyses. SEM images presented that AC-supported NiS and CoS nanocomposites were spherical and had rod-like morphologies. To determine photocatalytic performance and the kinetic model, the decomposition of Methyl Violet (MV) was carried out on all the photocatalyst samples. The synergetic effect was performed by comparing NiS/AC, CoS/AC and Ni/CoS/AC composites. The photocatalytic yield of the Ni7Co3/AC nanocomposite sample towards (MV) was found to be 98% in 90 min also under the same experimental conditions other AC-supported samples which CoS/AC, NiS/AC, and Ni3Co7/AC showed 56%, 74% and 78% photodegradation efficiency, respectively. The obtained results showed that the optimal content of component affects the degradation ability and also composites with increased NiS content displaying better photocatalytic performance. Ni7Co3/AC inactivation performance against S. aureus and E. faecalis was outstanding; nearly 100% inactivation was attained in less than 2 h. S. aureus and E. faecalis are both Gram positive (Gr+) bacteria. The Ni7Co3/AC composite deactivated Gr+ bacteria but had no effect against Gr- bacteria during the incubation period., Mugla Sitki Kocman University [15/139], This work was supported by Mugla Sitki Kocman University: [Grant Number 15/139].

Metal additive manufacturing (MAM) of mould components is associated with cost-intensive post-process finishing operations, which are currently one of the main drawbacks preventing wider industrial adoption of MAM. This work analyses the current possibilities and limitations of MAM for plastic injection moulding tool applications, demonstrating the opportunity to limit post-processes to heat treatment and the machining of the MAM insert outer geometry, which was only intended to ensure the assembly of the insert in the injection moulding frame. The results focused on evaluating the as-built insert cavity geometrical characteristics and the dimensional replication performance of the injection moulding process. The as-built cavity surface texture was comparable to a surface roughness that would be alternatively manufactured by electrical discharge machining (EDM). The cavity texture and features was replicated to the plastic injection moulded samples with an average replication fidelity higher than 95 %, enabling the direct production of inserts with integrated enhanced surface properties and aesthetics. Additional geometrical characteristics, such as global cavity dimensions, corner radii, and the staircase effect of selected features, typical of MAM products, were examined to gather further knowledge of the MAM process resolution and the corresponding replication capabilities of the IM process. Additional considerations with regards to the insert mechanical loading conditions and its durability in terms of the expected fatigue lifetime were addressed, verifying the usability of the MAM insert for production batches of at least 2⋅106 injection moulding cycles. Finally, the improvements in terms of lead-time reduction and production costs associated with MAM compared with conventional tooling technologies were evaluated and discussed, confirming the potential of the presented process chain of MAM for injection moulding tools production.

In the present study, undoped whitlockite and ZnO doped-Whitlockite, which is the second most abundant inorganic material in bone structure, were synthesized from sea urchin skeleton. The obtained bioceramic materials were characterized by XRD, FT-IR, and SEM and their antibacterial activities were determined using the inhibition zone diameters of Escherichia coli and Pseudomonas aeruginosa as gram negative bacteria and Staphylococcus aureus as gram positive bacterium after 24 h incubation. The characterization studies showed that nano size homogenous biocereamic whitlockite (Ca2.86Mg0.14(PO4)2) was synthesized from the sea urchin skeleton. After dopping process, the main structure of the whitlockite keeps stable, showing a dopping concentration-independent character. On the other hand, the peaks belonging to ZnO were started to seen in the XRD pattern with increasing the level of ZnO-concentration (after 7 %). All experimental results point out that the obtained whitlockites are viable nominate candidates for bioceramic materials and the results of antibacterial sensitivity prove the inhibitory effect towards Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus for ZnO-doped-whitlockite.

Identifying the atomic structure of organic-inorganic interfaces is challenging with our current research tools. Interpreting the structure of complex molecular adsorbates from microscopy images can be difficult, and using atomistic simulations to find the most stable structures is limited to partial exploration of the potential energy surface due to the high-dimensional phase space. In this study, we present the recently developed Bayesian Optimization Structure Search (BOSS) method as an efficient solution for identifying the structure of non-planar adsorbates. We apply BOSS with density-functional theory simulations to detect the stable adsorbate structures of (1S)-camphor on the Cu(111) surface. We identify the optimal structure among 8 unique types of stable adsorbates, in which camphor chemisorbs via oxygen (global minimum) or physisorbs via hydrocarbons to the Cu(111) surface. This study demonstrates that new cross-disciplinary tools, like BOSS, facilitate the description of complex surface structures and their properties, and ultimately allow us to tune the functionality of advanced materials., 16 pages, 10 figures, 5 tables. Peer-reviewed version. Published in the Beilstein Journal of Nanotechnology

Wettability is usually measured in special core analyses of limited plug samples according to typically costly and time-consuming procedures. For comparative purposes, wettability is considered an index. The two most frequently used wettability indices are the Amott–Harvey wettability index and the U.S. Bureau of Mines (USBM) index. The Amott–Harvey wettability index is linked to imbibition characteristics and the USBM index is associated with the area under capillary pressure curves. To provide a fast analytical method, a mathematical model for predicting the wettability of chalk is presented. The model is calibrated using experimental wettability data and subsequently applied to two wells in Danish chalk oil fields in the North Sea and to outcrop chalk samples. The model supplements traditional labor-intensive laboratory measurements and predicts water wettability variations with depth by modeling both depth and porosity dependencies; in addition, it provides estimates of the effects of the aging time and displacement temperature of chalk wettability measurements in the laboratory. © The Author(s) 2020 Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/)

Cells are attractive carriers for the transport and delivery of nanoparticulate cargo. The use of cell-based carriers allows one to enhance control over the biodistribution of drug-loaded polymers and polymer nanoparticles. One key element in the development of cell-based delivery systems is the loading of the cell-based carrier with the nanoparticle cargo, which can be achieved either by internalization of the payload or by immobilization on the cell surface. The surface modification of cells with nanoparticles or the internalization of nanoparticles by cells is usually monitored with fluorescence-based techniques, such as flow cytometry and confocal microscopy. In spite of the widespread use of these techniques, the use of fluorescent labels also poses some risks and has several drawbacks. Fluorescent dyes may bleach, or leach from, the nanoparticles or alter the physicochemical properties of nanoparticles and their interactions with and uptake by cells. Using poly(d,l-lactic acid) nanoparticles that are loaded with Coumarin 6, BODIPY 493/503, or DiO dyes as a model system, this paper demonstrates that the use of physically entrapped fluorescent labels can lead to false negative or erroneous results. The use of nanoparticles that contain covalently tethered fluorescent dyes instead was found to provide a robust approach to monitor cell surface conjugation reactions and to quantitatively analyze nanoparticle-decorated cells. Finally, it is shown that optical diffraction tomography is an attractive, alternative technique for the characterization of nanoparticle-decorated cells, which obviates the need for fluorescent labels.

Before acquiring highest-resolution data of Ceres, questions remained about the emplacement mechanism and source of Occator crater’s bright faculae. Here we report that brine effusion emplaced the faculae in a brine-limited, impact-induced hydrothermal system. Impact-derived fracturing enabled brines to reach the surface. The central faculae, Cerealia and Pasola Facula, postdate the central pit, and were primarily sourced from an impact-induced melt chamber, with some contribution from a deeper, pre-existing brine reservoir. Vinalia Faculae, in the crater floor, were sourced from the laterally extensive deep reservoir only. Vinalia Faculae are comparatively thinner and display greater ballistic emplacement than the central faculae because the deep reservoir brines took a longer path to the surface and contained more gas than the shallower impact-induced melt chamber brines. Impact-derived fractures providing conduits, and mixing of impact-induced melt with deeper endogenic brines, could also allow oceanic material to reach the surfaces of other large icy bodies., The second extended phase of the Dawn mission provided high resolution observations of Occator crater of the dwarf planet Ceres. Here, the authors show that the central faculae were sourced in an impact-induced melt chamber, with a contribution from the deep brine reservoir, while the Vinalia Faculae were sourced by the deep brine reservoir alone.

The interfaces of water micro- and nanodroplets drive environmental, medical, catalytic, biological, and chemical biphasic processes. The interfacial droplet structure and electrostatics greatly determine the reactivity and efficiency of these processes. Droplet interfacial properties are elusive and generally inferred from bulk measurements and are therefore anything but exact. Here, we quantify the interfacial ordering of water and the electrostatic surface potential of nanoscale water droplets in an apolar liquid using angle-resolved polarimetric second-harmonic scattering. We also present a method to determine the amount of free charges in the hydrophobic phase, reaching a sensitivity that is 3 orders of magnitude better than conductivity measurements. Investigating the structural and surface electrostatic changes induced by AOT surfactant adsorption, we find that both the hydrogen bonding as well as the electrostatics strongly depend on the surfactant concentration. Above the critical micelle concentration, the interface mediates micelle self-assembly.

Combinations of wood and metal are interesting hybrid composite materials, joining together the low density of wood with the stiffness and strength of metals. Different types of adhesives are used to connect wood and metal elements, but the compatibility between adhesives used and load-bearing materials must be sufficient, which often is challenging. In adhesive bonding technology, surface treatments are a crucial step in the process. In this study, an atmospheric plasma discharge was employed to enhance the adhesion strength of joints between common beech (Fagus sylvatica L.) wood, metals (steel and aluminum alloy), and four different types of adhesives. The optical properties of plasma discharges and its influence on treated substrates’ surface morphology depended on the inherent properties of the treated materials. X-ray photoelectron spectroscopy revealed the surface oxidation of all the materials after plasma treatment. Consequently, the surface free energy of all materials increased as well. The positive effect of the plasma treatment on the tensile shear strength of single-lap joints shows a high potential of atmospheric plasma treatment technology for enhancement of adhesives strength of joints combining wooden elements, wood and steel, or wood and aluminum alloys. In addition to that, expensive epoxy and polyurethane adhesives could be replaced by more affordable polyvinyl acetate and melamine-urea-formaldehyde adhesives, and still perform at equal levels if the plasma was applied prior to bonding.

We developed MUSIC-mode atomic force microscopy (AFM) to emulate intermittent contact mode AFM without a feedback loop and in the absence of lateral forces. This single-pass approach is based On maps of amplitude-phase-distance curves and allows the height and to phase images to be simultaneously obtained for almost any amplitude set point. This is advantageous for determining the shape and nanomechanical properties of very soft and fragile samples. As an example, we studied supramolecular aggregates of oligothiophenes, which form approximate to 15-nm wide fibrils with a rigid core and a soft shell.

The mycelium composites composed of fungal mycelium and plant substrate are a practical alternative to petroleum plastic-based foam materials. However, the effects of the physiological traits of fungus on the composites’ microscopic structure and mechanical properties remain poorly understood. Here, we compared two basidiomycetes with distinct mycelium morphology and white-decay modes. Cross-sectional observation revealed that the mycelium composites possess a core/shell structure with the shell formed of dense aerial mycelium and the core of plant particles and spongy aerial mycelium. Dense and continuous mycelium networks provided by Trametes hirsuta strengthen the mechanical properties of the composite compared to the coarse mycelium networks of Pleurotus ostreatus. In particular, the firm mycelial shell skeleton confers high flexibility and shape-retention to the composite in the wet state. This unique characteristic of the mycelium composite indicates its potentials in new industrial applications.

International audience; Pathogenic bacterial biofilms invading surfaces in food and medical fields are a challenge to overcome. Despite all the strategies applied to fight their formation, the microbiological risk associated to bacterial biofilms remains an important threat for at risk population and for food and healthcare sectors. The prevention of biofilm formation might be an effective approach to confront this problem. In this study, stainless steel surfaces were functionalized by nisin, a natural antimicrobial peptide. The mechanism of action of immobilized nisin against sensitive bacteria is not fully understood. Therefore, nisin was grafted onto the surface by either its carboxylic group or its amino group. The generated coating's chemical, topographical and antibacterial properties were studied to understand the nisin mode of action, when immobilized, and identify the section of the bacteriocin responsible for the antimicrobial activity. The antimicrobial activity of the elaborated coatings was tested against Listeria monocytogenes. Indeed, the surfaces coated with nisin linked by its amino group showed an efficient antibacterial activity while the surface with nisin linked by its carboxylic group showed less antimicrobial effect. The antimicrobial results showed almost 2 log reduction of colony forming units for efficient antibacterial coatings while the other showed no bacterial reduction. The surface properties analysis permitted to understand the chemical and topographical characteristics of treated surfaces including nisin conformation and quantification. A tight relation was concluded between the surface topography, the nisin conformation, and the antibacterial activity of the bacteriocin-coated surfaces.

In the present work, we elucidate the interplay among energetic bombardment effects in magnetron sputtering and defect generation in two-dimensional (2D) materials. Using deposition of gold (Au) layers on single-layer graphene (SLG) as a model system, we study the effect of pressure-distance (pd) product during magnetron sputtering on the pristine SLG properties. Raman spectroscopy, complemented by X-ray photoelectron spectroscopy, shows that for pd = 8.2 Pa center dot cm, Au layer deposition causes defects in the SLG layer, which gradually diminish and eventually disappear with increasing pd to 82.5 Pa center dot cm. Stochastic and deterministic simulations of the sputtering process, the gas-phase transport, and the interaction of sputtered and plasma species with the substrate surface suggest that defects in SLG primarily emanate from ballistic damage caused by backscattered Ar atoms with energies above 100 eV. With increasing pd, and thereby gas-phase scattering, such high energy Ar species become thermalized and hence incapable of causing atomic displacements in the SLG layer. The overall results of our study suggest that control of backscattered Ar energy is a potential path toward enabling magnetron sputtering for fabrication of multifunctional metal contacts in devices founded upon 2D materials. Funding Agencies|Linkodping University ("LiU Career Contract) [Dnr-LiU-2015-01510]; Swedish research councilSwedish Research CouncilEuropean Commission [VR-2015-04630]; Aforsk foundation [AF 19-137]; Olle Engkvist foundation [SOEB 190-312]; Wenner-Gren foundations [UPD2018-0071, UPD2019-0007]

Co9S8 is an interesting sulfide material with metallic conductivity that has shown promise for various energy applications. Herein, we report a new atomic layer deposition process producing crystalline, pure, and highly conductive Co9S8 thin films using CoCl2(TMEDA) (TMEDA = N,N,N ',N '-tetramethylethylenediamine) and H2S as precursors at 180-300 degrees C. The lowest resistivity of 80 mu omega cm, best uniformity, and highest growth rate are achieved at 275 degrees C. Area-selective deposition is enabled by inherent substrate-dependency of film nucleation. We show that a continuous and conductive Co9S8 film can be prepared on oxide-covered silicon without any growth on Si-H. Besides silicon, Co9S8 films can be grown on a variety of substrates. The first example of an epitaxial Co9S8 film is shown using a GaN substrate. The Co9S8 films are stable up to 750 degrees C in N-2, 400 degrees C in forming gas, and 225 degrees C in O-2 atmosphere. The reported ALD process offers a scalable and cost-effective route to high-quality Co9S8 films, which are of interest for applications ranging from electrocatalysis and rechargeable batteries to metal barrier and liner layers in microelectronics and beyond.

Urban overheating has a serious impact on building energy consumption. Daytime radiative cooling materials are an interesting passive solution for refrigeration. However, their costs and complex manufacturing hinder their current application. In this study, a series of scalable and lowcost daytime radiative cooling (DTRC) materials were designed, fabricated, and tested in a moderate climate (Cfb-Köppen-Geiger classification) and compared to aluminum and Vikuiti. The methodology was: i) material selection and design, (ii) optimization, (iii) fabrication, (iv) characterization, and (v) testing. The materials were fabricated using different substrates, aluminum and Vikuiti, and two kinds of formulations for the emissive layers based on silica-derived polymer polymethylsilsesquioxane (PMSQ) with embedded silica nanoparticles. The resulting aluminum DTRC materials had a mean solar reflectivity of 0.7 and 0.34 emissivity in the atmospheric window, the samples with Vikuiti had 0.97 and 0.89, respectively. During the experiment, the samples were exposed to different ambient conditions without a convection barrier and were contained in an extruded polystyrene board to eliminate conduction. The samples reached 7.32 °C and 9.13 °C maximum surface temperature reduction (below ambient) during the day and night, respectively. The samples with the commercial substrate achieved a mean reduction of 3.72 °C below ambient temperature. Although the aluminum samples did not achieve subambient cooling throughout the entire day, the emissive layer reduced the sample's surface temperature by an average of 1.7 °C. The PMSQ radiative cooling materials show great potential for future building applications. Suitability under different climates and experimental settings should be done to test broad applicability. The materials development in this research received a grant from the Government of Navarre "Convocatoria proyectos I + D 2019" file number 0011-1365-2019-000051; and financial support from Alonso Hernandez & asociados arquitectura, S. L.

Funding Information: This work made use of the Aalto University Otanano and RAMI infrastructures. The authors also thank Dr. Hannu Revitzer for performing AAS measurements. Financial support from Business Finland BATCircle (Energy) (no. 2117574) is also greatly acknowledged. Publisher Copyright: © 2021 The Authors. Published by American Chemical Society. Nickel-rich layered oxides, such as LiNi0.6Co0.2Mn0.2O2 (NMC622), are high-capacity electrode materials for lithium-ion batteries. However, this material faces issues, such as poor durability at high cut-off voltages (>4.4 V vs Li/Li+), which mainly originate from an unstable electrode-electrolyte interface. To reduce the side reactions at the interfacial zone and increase the structural stability of the NMC622 materials, nanoscale (

International audience; In Peierls-distorted materials, photoexcitation leads to a strongly coupled transient response between structural and electronic degrees of freedom, always measured independently of each other. Here we use transient reflectivity in the extreme ultraviolet to quantify both responses in photoexcited bismuth in a single measurement. With the help of first-principles calculations based on density-functional theory (DFT) and time-dependent DFT, the real-space atomic motion and the temperature of both electrons and holes as a function of time are captured simultaneously, retrieving an anticorrelation between the A$_{1g}$ phonon dynamics and carrier temperature. The results reveal a coherent, bidirectional energy exchange between carriers and phonons, which is a dynamical counterpart of the static Peierls-Jones distortion, providing validation of previous theoretical predictions.

Surfaces of polycrystalline ferritic Fe–Cr steel with grain sizes of about 13 µm in diameter were investigated with surface sensitive techniques. Thin oxide layers, with a maximum thickness of about 100 nm, were grown by oxidation in air at temperatures up to 450°C and were subsequently characterized using time-of-flight secondary ion mass spectrometry (TOF-SIMS) and atomic force microscopy. Correlative microscopy was applied, which allows for element-specific depth profiles on selected grains with a particular crystal orientation. A strong correlation between the grain orientation and the thickness of the oxide layer was found. The sequence in the oxidation growth rate of ferritic Fe–Cr steel crystal planes is found to be {011} > {111} > {001}, which is unexpectedly opposed to known Fe-based systems. Moreover, for the first time, the Cr/Fe ratio throughout the oxide layer has been determined per grain orientation. A clear order from high to low of {001} > {111} > {011} was detected.

To best catch human eyes in next-generation displays, the updated recommendation 2020 (Rec. 2020) standard has called for ultrapure green emitters to be qualified with a narrow emission of 525-535 nm with a full width at half-maximum (fwhm) below 25 nm. However, it is still challenging to find an emitter which can simultaneously cover these two criteria. Instead of traditional II-VI group semiconductor quantum dots, perovskite nanocrystals (NCs) can render versatile emitting tunability to allow them access to the Rec. 2020 standard. Herein, to realize the critical window of Rec. 2020, we have proposed a scalable, room temperature synthesis route of formamidinium lead bromide (FAPbBr3) NCs using a sole ligand of sulfobetaine-18 (SBE-18). The as-synthesized FAPbBr3 NCs exhibit an ideal emission at 534 nm with an ultranarrow fwhm of 20.5 nm and a high photoluminescence quantum yield of 90.6%, overwhelming the FAPbBr3 nanoplates capped with oleic acid/oleylamine (OA/OAM). Introducing these high quality NCs into backlight displays, an ultrapure green backlight which covers ≈85.7% of the Rec. 2020 standard in the CIE 1931 color space is achieved, signifying the "greenest" backlight till now. Thus, we can foresee perovskite NCs as the most potential candidates for next-generation displays.

Biocompatible antimicrobial coatings may enhance the function of many orthopedic implants by combating infection. Hydroxyapatite is a choice mineral for such a coating as it is native to bone and silver would be a possible antimicrobial agent as it is also commonly used in biomedical applications. The aim of the research is to develop a silver-containing calcium phosphate (Ag/Ca-P) coating via electrochemical deposition on titanium substrates as this allows for controlled coating buildup on complex shapes and porous surfaces. Two different deposition approaches are explored: one-step Ag/Ca-P(1) deposition coatings, containing silver ions as microsized silver phosphate particles embedded in the Ca-P matrix; and via a two-step method (Ag/Ca-P(2)) where silver is deposited as metallic silver nanoparticle on the Ca-P coating. The Ag/Ca-P(1) coating displays a bacterial reduction of 76.1 +/- 8.3% via Ag-ion leaching. The Ag/Ca-P(2) coating displays a bacterial reduction of 83.7 +/- 4.5% via contact killing. Interestingly, by preincubation in phosphate-buffered saline solution, bacterial reduction improves to 97.6 +/- 2.7 and 99.7 +/- 0.4% for Ag/Ca-P(1) and Ag/Ca-P(2) coatings, respectively, due to leaching of formed AgClx(x-1)- species. The biocompatibility evaluation indicates that the Ag/Ca-P(1) coating is cytotoxic towards osteoblasts while the Ag/Ca-P(2) coating shows excellent compatibility. The electrochemical deposition of highly bactericidal coatings with excellent biocompatibility will enable us to coat future bone implants even with complex or porous structures.

International audience; The binding energy of oxygen and fluorine on the InSb(111) surface is investigated as a function of the termination of the latter using the projector augmented-wave method. It is shown that fluorine adsorption on the In-terminated surface leads, depending on the fluorine concentration, to the complete or partial elimination of the surface states induced by oxygen adsorption from the forbidden gap. The penetration of both adsorbates into the subsurface layers leads to the breaking of In–Sb bonds and the formation of chemical bonds of fluorine and oxygen with surface substrate atoms, which is the initial stage of the formation of a fluorine-containing anodic oxide layer. On the Sb-terminated InSb(111) surface, oxygen adsorption facilitates a decrease in the surface-state density in the forbidden gap. General trends in the variation in the electronic structure of the (111) surface upon fluorine and oxygen coadsorption in III–V semiconductors are discussed.

To investigate the roles of macrophages in material-instructed bone formation, two calcium phosphate (TCP) ceramics with the same chemistry but various scales of surface topography were employed in this study. After being implanted subcutaneously in FVB mice for 8 weeks, TCPs (TCP ceramics with submicron surface topography) gave rise to bone formation, while TCPb (TCP ceramics with micron surface topography) did not, showing the crucial role of surface topography scale in material-instructed bone formation. Depletion of macrophages with liposomal clodronate (LipClod) blocked such bone formation instructed by TCPs, confirming the role of macrophages in material-instructed bone formation. Macrophage cells (i.e. RAW 264.7 cells) cultured on TCPs in vitro polarized to tissue repair macrophages as evidenced by gene expression and cytokine production, while polarizing to pro-inflammatory macrophages on TCPb. Submicron surface topography of TCP ceramics directed macrophage polarization via PI3K/AKT pathways with the synergistic regulation of integrin beta 1. Finally, the tissue repair macrophage polarization on TCPs resulted in osteogenic differentiation of mesenchymal stem cells in vitro. At early implantation in FVB mice, TCPs recruited more macrophages which polarized towards tissue repair macrophages with time. The present data demonstrate the important roles of macrophage polarization in bone formation instructed by calcium phosphate ceramics.

Methodological constraints have limited our ability to study protein corona formation, slowing nanomedicine development and their successful translation into the clinic. We determined hard and soft corona structural properties along with the corresponding proteomic compositions on liposomes in a label-free workflow: surface plasmon resonance and a custom biosensor for in situ structure determination on liposomes and corona separation, and proteomics using sensitive nanoliquid chromatography tandem mass spectrometry with open-source bioinformatics platforms. Undiluted human plasma under dynamic flow conditions was used for in vivo relevance. Proof-of-concept is presented with a regular liposome formulation and two light-triggered indocyanine green (ICG) liposome formulations in preclinical development. We observed formulation-dependent differences in corona structure (thickness, protein-to-lipid ratio, and surface mass density) and protein enrichment. Liposomal lipids induced the enrichment of stealth-mediating apolipoproteins in the hard coronas regardless of pegylation, and their preferential enrichment in the soft corona of the pegylated liposome formulation with ICG was observed. This suggests that the soft corona of loosely interacting proteins contributes to the stealth properties as a component of the biological identity modulated by nanomaterial surface properties. The workflow addresses significant methodological gaps in biocorona research by providing truly complementary hard and soft corona compositions with corresponding in situ structural parameters for the first time. It has been designed into a convenient and easily reproducible single-experiment format suited for preclinical development of lipid nanomedicines.

Funding: RBJ acknowledges the UK's Engineering and Physical Sciences Research Council (EPSRC) for partial funding for this activity (EP/H020055/1) as well as The EC's Horizon 2020 Programme for support from the “GREENDIAMOND” project (ID: 640947). This work was supported by the Research Council of Norway through its Centres of Excellence funding scheme, Project No. 262633, “QuSpin”, and through the Fripro program, Project No. 250985 “FunTopoMat” and 262339 “NEAT”. This work was supported by the Danish Council for Independent Research, Natural Sciences under the Sapere Aude program (Grants No. DFF-4002-00029 and DFF-6108-00409) and by VILLUM FONDEN via the Centre of Excellence for Dirac Materials (Grant No. 11744) and the Aarhus University Research Foundation. Using angle-resolved photoelectron spectroscopy, we compare the electronic band structure of an ultrathin (1.8 nm) δ-layer of boron-doped diamond with a bulk-like boron doped diamond film (3 μm). Surprisingly, the measurements indicate that except for a small change in the effective mass, there is no significant difference between the electronic structure of these samples, irrespective of their physical dimensionality, except for a small modification of the effective mass. While this suggests that, at the current time, it is not possible to fabricate boron-doped diamond structures with quantum properties, it also means that nanoscale boron doped diamond structures can be fabricated which retain the classical electronic properties of bulk-doped diamond, without a need to consider the influence of quantum confinement. Publisher PDF

The paper presents a fragment of on-going investigations directed on creation of optimal information environment that ensures an access to the R&D publications from the known scientific journals and other scientific serials which are necessary for qualitative execution of scientific and technological activities on priority areas in highway engineering. A citation analysis has been applied while using data of Journal Citation Reports for selection of world scientific publications which are necessary for execution of investigations on heat and mass transfer in road dressings. Their deformations occur under various climatic conditions due to heat and mass transfer processes, interaction of transport flows and road surface that leads to crack formation in depth and on the surface of road dressings. Structure of constructive layers especially which are created with the help of technogenic wastes (asphalt-, reinforced concrete, concrete, brick scrap and products of their recycling, various wastes of production etc.) exerts an influence on heat and mass transfer. The paper presents results of investigations on heat flows, boundary layers according to viscosity, air velocity, geometric characteristics, permeability, capillary pressures in materials. It has been shown that calculations based on principles of complex number usage have specific features in engineering practice: it is required to observe their accuracy in approaches, calculation reduction due to some accuracy degradation as a consequence of transition from complex numbers to their modules with exclusion of phase shift account and related with propagation of thermal waves. In this respect calculations of heat resistance without phase shifts are considered as rather important if they are in agreement with principles based on the fact that a complexity is characterized by thermal absorptivity of the material in a great number of calculations. The investigations have been supported by Henan Center for Outstanding Overseas Scientists, Grant Number GZS 2018006 (People’s Republic of China, Henan Province).

Polymer brushes are typically densely grafted assemblies of polymer chains that are tethered via one end group to a solid substrate. Anchoring linear polymer chains via both end groups to a surface results in loop-type polymer brushes. Although loop polymer brushes have been shown to be able to outperform their linear, single-chain-end tethered analogues, for example, with respect to the prevention of biofouling or reducing friction, this brush architecture has received only relatively limited attention. Loop-type polymer brushes are mostly prepared following grafting-onto approaches using alpha,omega-heterobifunctional polymers. Grafting-from strategies, so far, have been rarely explored, but could further expand the range of accessible polymer molecular weights and brush grafting densities and allow the preparation of surface-attached polymer loops from a wider scope of monomers. This manuscript reports an alternative grafting-from strategy for the preparation of loop-type poly(methyl methacrylate) (PMMA) brushes. The strategy presented here starts with the preparation of linear polymer grafts using conventional surface-initiated atom transfer radical polymerization. The free chain-ends of the linear PMMA grafts are modified with an allyl group and subsequently subjected to a metathesis reaction to induce loop closure. The formation of the loop PMMA brushes was monitored by gel permeation chromatography analysis after cleavage of the polymer from the silica nanoparticles.

Summary Although tremendous efforts have been devoted to investigating the analogy between the surface plasmon polariton and its spoof counterparts, it remains elusive that a single thin spoof plasmonic metalens realizes wide-angle focusing and wide field-of-view (FOV) imaging. Here, we propose a spoof plasmonic metasurface that can impart arbitrary phase with high transmittance, which comprises two-dimensional (2D) gradient spoof-insulator-spoof waveguides. With the developed catenary field and dispersion theory, their intrinsic physics is theoretically analyzed. As a proof of concept, a spoof plasmonic metalens with a thickness of 0.15λ has been elaborately designed and experimentally demonstrated for wide-angle (∼170°) focusing and wide FOV (∼40°) imaging. To the best of our knowledge, it is the first experimental demonstration of wide FOV imaging of a 2D object with single thin and planar metalens in the microwave regime. The proposed method offers a promising solution to compact cameras, integrated imaging, and detection systems., Graphical Abstract, Highlights • Thin spoof metalens has been developed • A satisfactory qualitative description through catenary dispersion theory • Wide-angle microwave focusing (170°) and wide FOV (40°) imaging of 2D objects, Optical Imaging; Electromagnetic Waves; Surface

We report on influence of the surface functionalization on the properties of highly oriented pyrolytic graphite. The samples were processed in nitric acid and characterized by XPS, Raman and EDX spectroscopies, AFM, SEM and optical microscopy. It is shown that interaction of nitric acid with the surface of HOPG leads to two types of reactions: oxidation of the graphite and intercalation of the nitrate ions at the blistered areas.

Plasmon-polaritons are among the most promising candidates for next generation optical sensors due to their ability to support extremely confined electromagnetic fields and empower strong coupling of light and matter. Here we propose quantum plasmonic immunoassay sensing as an innovative scheme, which embeds immunoassay sensing with recently demonstrated room temperature strong coupling in nanoplasmonic cavities. In our protocol, the antibody-antigen-antibody complex is chemically linked with a quantum emitter label. Placing the quantum-emitter enhanced antibody-antigen-antibody complexes inside or close to a nanoplasmonic (hemisphere dimer) cavity facilitates strong coupling between the plasmon-polaritons and the emitter label resulting in signature Rabi splitting. Through rigorous statistical analysis of multiple analytes randomly distributed on the substrate in extensive realistic computational experiments, we demonstrate a drastic enhancement of the sensitivity up to nearly 1500% compared to conventional shifting-type plasmonic sensors. Most importantly and in stark contrast to classical sensing, we achieve in the strong-coupling (quantum) sensing regime an enhanced sensitivity that is no longer dependent on the concentration of antibody-antigen-antibody complexes -- down to the single-analyte limit. The quantum plasmonic immunoassay scheme thus not only leads to the development of plasmonic bio-sensing for single molecules but also opens up new pathways towards room-temperature quantum sensing enabled by biomolecular inspired protocols linked with quantum nanoplasmonics., Just Accepted Manuscript, Nano Letters 2019

A simplified Cu(In, Ga)Se-2 (CIGS) solar cell structure based on a 500 nm thin CIGS layer is presented. The absorber layers are grown with a single-stage coevaporation process, and various KF post-deposition treatments (KF-PDT) are performed. The KF-PDT leads to an efficiency increase from 7% to 12%. For all cells an increase in open circuit voltage (V-oc) and fill factor is measured, which is attributed to an improved pn junction. By changing the annealing conditions, an additional V-oc increase is measured. This increase is attributed to the reduction of light-induced defects at the CIGS/CdS interface in addition to the improved pn junction. A reduction of defects is confirmed by reduced sub band gap emission in the photoluminescence spectra, an increased decay time, and increased quasi Fermi level splitting. With SCAPS the results are simulated, and it is concluded that after KF-PDT the V-oc is limited to 640 mV due to recombination at the back contact. A higher V-oc can then only be achieved by applying a passivation layer at the back. There are no indications that the single-stage process is limiting the efficiency, revealing the potential of the proposed simplified CIGS structure and the importance of interfaces for ultrathin CIGS solar cells. J. de Wild, D.G. Buldu, T. Kohl, G. Birant, and B. Vermang received funding from the European Union’s H2020 research and innovation program under grant agreement no. 715027.

Calcium phosphate (Ca P) coatings were electrochemically deposited on titanium substrates. By increasing the electrodeposition time (from 1 to 30 min), the coating thickness increases but also the surface morphology of the Ca P coatings is greatly affected going from smooth to plate-like, featuring elongated plates, ribbon-like and finally sharp needle structures. Micro-stretch tests reveal that, regardless of the coating morphology and thickness, the electrodeposited Ca P coatings have strong adhesion with the titanium substrates and their failure mode is cohesive failure. The effects of different morphologies on cellular behavior such as adhesion, viability, proliferation, and osteogenic gene expression were studied. The surface morphology of Ca P coatings has a remarkable effect on cell attachment, proliferation, and viability. A smooth surface results in better adhesion of the cells, whereas the presence of sharp needles and ribbons on rough surfaces restricts cell adhesion and consequently cell proliferation and viability. The improved cell adhesion and viability on the smoother surface can be attributed to the higher contact area between the cell and the coating, while the needle-like morphology inflicts damage to the cells by physically disrupting the cell wall. There is no significant difference in the level of osteoblast gene expression when osteosarcoma cells are cultured on coatings with different morphologies. Our study provides crucial insights into the optimum electrodeposition procedures for Ca P coating formation leading to both good cell-material interaction and sufficient mechanical properties. This can be achieved with relatively thin coatings produced by short electrodeposition times.

Summary This paper reports a new method to generate stable and high-brightness electroluminescence (EL) by subsequently growing large/small grains at micro/nano scales with the configuration of attaching small grains on the surfaces of large grains in perovskite (MAPbBr3) films by mixing two precursor solutions (PbBr2 + MABr and Pb(Ac)2·3H2O + MABr). Consequently, the small and large grains serve, respectively, as passivation agents and light-emitting centers, enabling self-passivation on the defects located on the surfaces of light-emitting large grains. Furthermore, the light-emitting states become linearly polarized with maximal polarization of 30.8%, demonstrating a very stable light emission (49,119 cd/m2 with EQE = 11.31%) and a lower turn-on bias (1.9 V) than the bandgap (2.25V) in the perovskite LEDs (ITO/PEDOT:PSS/MAPbBr3/TPBi[50 nm]/LiF[0.7 nm]/Ag). Therefore, mixing large/small grains with the configuration of attaching small grains on the surfaces of large grains by mixing two precursor solutions presents a new strategy to develop high-performance perovskite LEDs., Graphical Abstract, Highlights • Small grains are attached to the surfaces of large grains in perovskite films • Ions can passivate grain boundary defects to enable self-passivation in PeLEDs • Light-emitting states become linearly polarized upon self-passivation • Turn-on voltage is lower than bandgap in perovskite LEDs under self-passivation, Materials Characterization; Optical Materials; Surface

The properties of ligand protected gold nanoparticles are determined by the synergistic interplay of their structural components, including the metal core, the ligand shell, and the solvation layer. However, the simultaneous characterization of all these components remains a major challenge given their disparate chemical nature. In the case of mixed ligand nanoparticles, this task becomes daunting due to the presence of intercorrelated additional parameters such as the ligand ratio, ligand spatial distribution, and solvation of the heterogeneous ligand shell. Here we show that small angle neutron scattering (SANS) is a tool capable of simultaneously characterizing the core and the ligand shell of monodisperse mixed ligand gold nanoparticles. We systematically examine how each parameter (e.g., the core size, the thickness, composition and the spatial heterogeneity of the ligand shell) affects nanoparticles' scattering profile. Quantitative information on these parameters is retrieved using analytical fitting as well as 3D modeling. Importantly, we show that SANS can evaluate the solvation degree of mixed ligand protected gold nanoparticles, a challenging task for any other characterization methods.

We investigate the growth of gas bubbles in a water solution at rest with a supersaturation level that is generally associated with diffusive mass transfer. For $\text{CO}_{2}$ bubbles, it has been previously observed that, after some time of growing in a diffusive regime, a density-driven convective flow enhances the mass transfer rate into the bubble. This is due to the lower density of the gas-depleted liquid which surrounds the bubble. In this work, we report on experiments with different supersaturation values, measuring the time $t_{conv}$ it takes for convection to dominate over the diffusion-driven growth. We demonstrate that by considering buoyancy and drag forces on the depleted liquid around the bubble, we can satisfactorily predict the transition time. In fact, our analysis shows that this onset does not only depend on the supersaturation, but also on the absolute pressure, which we corroborate in experiments. Subsequently, we study how the depletion caused by the growth of successive single bubbles influences the onset of convection. Finally, we study the convection onset around diffusively growing nitrogen $\text{N}_{2}$ bubbles. As $\text{N}_{2}$ is much less soluble in water, the growth takes much longer. However, after waiting long enough and consistent with our theory, convection still occurs as for any gas–liquid combination, provided that the density of the solution sufficiently changes with the gas concentration.

International audience; The surface properties of five kaolinites of various origins were analyzed using potentiometric titration, electrokinetic measurements and low-pressure gas adsorption associated to derivative isotherm summation (DIS) modeling. The data show that sample structure is important in determining the surface properties. The combined analytical results clearly shows the existence of a permanent negative layer charge for all the samples. The general features that could be observed for the five kaolinites are: the titration curves are shifted to lower pH with increasing ionic strength due to the layer charge; the amount of consumed proton is influenced by the permanent layer charge; although low, the permanent charge determines the electrokinetic behavior. The shape anisotropy and the charge distribution on the basal and edge surfaces are crucial parameters to understand the behavior of kaolinite particles in aqueous media. The Cameroonian sample of the set exhibits a significant permanent charge together with large specific surface area associated to fine particle size and considerable shape anisotropy.

Made available in DSpace on 2019-10-06T16:17:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-05-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) In the current study, the size and surface of ZnO nanoparticle (ZnO NP) suspensions and powders were finely controlled to evaluate their influence on the ZnO antibacterial activity against Staphylococcus aureus and Escherichia coli. The ZnO NP were prepared by the sol-gel method with different reaction times for NP size control and followed by the addition of (3-glycidyloxypropyl) trimethoxysilane (GPTMS) as a surface modifier. The ZnO NP were characterized by different techniques and the antibacterial activity was assessed through the minimum inhibitory concentration assay (MIC), minimum bactericidal concentration assay (MBC) and scanning electron microscopy (SEM). The ZnO NP exhibited significant antibacterial activity against Staphylococcus aureus. The NP size highly influenced the antibacterial activity, which increased with decreasing particle size. The small ZnO NP presented bactericidal activity whereas the largest showed bacteriostatic activity. The use of GPTMS, in general, led to increase of MIC and MBC. The formation of holes in the cell wall of Staphylococcus aureus was evidenced by SEM after contact between the bacteria and ZnO NP. The cytotoxicity assay showed that ZnO NP did not cause a loss of cell viability in the human keratinocyte cell line (HaCat) at the maximum concentration assessed. Thus, this study indicated that 5 nm ZnO NP modified by GPTMS has great potential for use as an inorganic antibacterial material. São Paulo State University (UNESP) School of Pharmaceutical Sciences Department of Drugs and Medicines, Highway Araraquara-Jaú Department of Biological and Health Sciences Universidade de Araraquara UNIARA São Paulo State University (UNESP) School of Pharmaceutical Sciences Department of Drugs and Medicines, Highway Araraquara-Jaú

In this work we successfully synthesized degradable microgels based on poly(N-vinylcaprolactam) (PVCL) with hydrophobic pockets for the uptake/release of poorly water-soluble molecules. The degradability as well as the presence of hydrophobic pockets in the microgel structure are ensured by incorporation of a star-shaped acrylate-functionalised poly(e-caprolactone) (starPCL) crosslinkers. Microgels with variable amount of star PCL crosslinker, narrow size distribution and a hydrodynamic radius of 200–400 nm were obtained by miniemulsion polymerisation. The microgel size and size distribution was characterised by means of dynamic light scattering (DLS), field emission scanning electron microscopy (FESEM) and sedimentation analysis. The obtained microgels undergo enzymatic degradation in aqueous medium as evidenced by DLS, nuclear magnetic resonance (NMR) and FESEM. Additionally, the uptake of hydrophobic molecules like the dye Nile-Red (model system) and the drug Ibuprofen into the starPCL-based microgels was proven by ultraviolet–visible spectroscopy (UV/Vis). The experimental data indicate that the solubilisation ability of microgels can be regulated by the amount of crosslinker in the microgel structure.

We studied the adsorption geometry and bonding of mono- and tetraphosphonic-acid-functionalized tetraphenylporphyrin molecules on rutile TiO2(110) surfaces. The investigation was carried out by means of X-ray photoelectron spectroscopy and near edge X-ray absorption fine structure (NEXAFS) measurements. We found that the molecules bind covalently to the surface in a mixed monodentate and bidentate mode implying deprotonation of one or two phosphonate hydroxyl groups. Our NEXAFS data suggest that molecules containing one functional phosphonic acid group are on average tilted further away from the surface than molecules with four functional groups. The highest occupied electronic state of both molecules is in the band gap at 2.1 eV below the Fermi level. Our results demonstrate that the number of functional phosphonic acid groups determine the adsorption geometry of tetraphenylporphyrins. Fil: Fernández, Cynthia Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina Fil: Wechsler, Daniel. Universitat Erlangen-Nuremberg; Alemania Fil: Rocha, Tulio C. R.. Brazilian Center for Research on Energy and Materials ; Brasil Fil: Steinrück, Hans-Peter. Universitat Erlangen-Nuremberg; Alemania Fil: Lytken, Ole. Universitat Erlangen-Nuremberg; Alemania Fil: Williams, Federico José. Universitat Erlangen-Nuremberg; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina

Mesoporous silicon (PSi) is biocompatible and tailorable material with high potential in drug delivery applications. Here, we report of an evaluation of PSi as a carrier platform for theranostics by delivering a radioactive ion beam- (RIB-) based radioactive lanthanoid into tumors in a mouse model of prostate carcinoma. Thermally hydrocarbonized porous silicon (THCPSi) wafers were implanted with 159Dy at the facility for radioactive ion beams ISOLDE located at CERN, and the resulting [159Dy]THCPSi was postprocessed into particles. The particles were intratumorally injected into mice bearing prostate cancer xenografts. The stability of the particles was studied in vivo, followed by ex vivo biodistribution and autoradiographic studies. We showed that the process of producing radionuclide-implanted PSi particles is feasible and that the [159Dy]THCPSi particles stay stable and local inside the tumor over seven days. Upon release of 159Dy from the particles, the main site of accumulation is in the skeleton, which is in agreement with previous studies on the biodistribution of dysprosium. We conclude that THCPSi particles are a suitable platform together with RIB-based radiolanthanoids for theranostic purposes as they are retained after administration inside the tumor and the radiolanthanoid remains embedded in the THCPSi.

Polycrystalline diamond (PCD) grown by chemical vapor deposition (CVD) is an intrinsic semiconductor particularly attractive for high power/high temperature devices. Nevertheless, the physical models for injection and transport of electrical carriers are remarkable complex and depend on the microstructure and composition of carbon species in the film. In this work, free-standing CVD PCD films were deposited by microwave plasma CVD (MPCVD) and were characterized by Raman spectroscopy. Gold and aluminum circular contacts were deposited on the growth surface in order to fabricate a planar diode. The current-voltage characteristics were measured at different temperatures. The application of a non-homogeneous barrier model to fit the current-voltage characteristics reveals the existence of two barriers related with the grain/electrode and grain boundary/electrode interfaces. Small signal analysis was performed at room temperature to understand the nature of electrical process involved in the injection and carrier transport. The existence of parallel channels through with charge flows was confirmed and the fittings suggest the existence of a nearly equipotential surface at the interface diamond/electrode. The physical origin of the inclusion of a constant phase element in the equivalent circuit model is discussed. The results obtained are of particular importance to further devices fabrication. Prime novelty: An equivalent circuit model for the diamond Schottky diode is proposed the physical origin of the constant phase element included in the model is discussed. European Regional Development Fund (FEDER), through the Regional Operational Program of Centre (CENTRO 2020) of the Portugal 2020 framework [017942 (CENTRO-01-0247-FEDER-017942)]

Introduction Maximizing osteointegration potential of three-dimensionally-printed porous titanium (3DPPT) is an ongoing focus in biomaterial research. Many strategies are proposed and tested but there is no weighted comparison of results. Methods We systematically searched Pubmed and Embase to obtain two pools of 3DPPT studies that performed mechanical implant-removal testing in animal models and whose characteristics were sufficiently similar to compare the outcomes in meta-analyses (MAs). We expanded these MAs to multivariable meta-regressions (moderator analysis) to verify whether statistical models including reported scaffold features (e.g., “pore-size”, “porosity”, “type of unit cell”) or post-printing treatments (e.g., surface treatments, adding agents) could explain the observed differences in treatment effects (expressed as shear strength of bone-titanium interface). Results “Animal type” (species of animal in which the 3DPPT was implanted) and “type of post-treatment” (treatment performed after 3D printing) were moderators providing statistically significant models for differences in mechanical removal strength. An interaction model with covariables “pore-size” and “porosity” in a rabbit subgroup analysis (the most reported animal model) was also significant. Impact of other moderators (including “time” and “location of implant”) was not statistically significant. Discussion/conclusion Our findings suggest a stronger effect from porosity in a rat than in a sheep model. Additionally, adding a calcium-containing layer does not improve removal strength but the other post-treatments do. Our results provide overview and new insights, but little narrowing of existing value ranges. Consequent reporting of 3DPPT characteristics, standardized comparison, and expression of porosity in terms of surface roughness could help tackle these existing dilemmas. Graphical abstract

We use \textit{ab initio} molecular dynamics simulations to investigate the properties of the dry surface of pure silica and sodium silicate glasses. The surface layers are defined based on the atomic distributions along the direction ($z-$direction) perpendicular to the surfaces. We show that these surfaces have a higher concentration of dangling bonds as well as two-membered (2M) rings than the bulk samples. Increasing concentration of Na$_2$O reduces the proportion of structural defects. From the vibrational density of states, one concludes that 2M rings have a unique vibrational signature at a frequency $\approx850$~cm$^{-1}$, compatible with experimental findings. We also find that, due to the presence of surfaces, the atomic vibration in the $z-$direction is softer than for the two other directions. The electronic density of states shows clear the differences between the surface and interior and we can attribute these to specific structural units. Finally, the analysis of the electron localization function allows to get insight on the influence of local structure and the presence of Na on the nature of chemical bonding in the glasses.

The skin microbiome has become a hot field of research in the last few years. The emergence of next-generation sequencing has given unprecedented insights into the impact and involvement of microbiota in skin conditions. More and more cosmetics contain probiotics or bacteria as an active ingredient, with or without scientific data. This research is also acknowledged by the textile industry. There has been a more holistic approach on how the skin and textile microbiome interacts and how they influence the pH, moisture content and odour generation. To date, most of the ingredients have a broad-spectrum antibacterial action. This manuscript covers the current research and industry developments in the field of skin and textiles. It explores the nature of antimicrobial finishing in textiles which can disrupt the skin microbiome, and the benefits of more natural and microbiome friendly therapies to combat skin conditions, malodour and skin infection.

In this paper, a quick nanosecond laser micro structuring process was employed to change the surface wettability of Ti6Al4V alloy. The same laser structuring method was used throughout, but with varying input fluence. The laser processing parameters resulted in high surface melting. After laser treatment, four post-processing methods were used, namely high vacuum, low temperature annealing, storage in a polyethylene bag, and storage in ambient air. Subsequently, the water droplet contact angle was measured over a long time period of 55 days. The results show that the sample stored in ambient air remained hydrophilic. On the other hand, the sample post-processed in a vacuum chamber behaved hydrophobically with a contact angle of approximately 150°. Other post-processing did not lead to specific wettability behavior. After wettability testing, all samples were cleaned ultrasonically in distilled water. This cleaning process led to annulation of all obtained properties through post-processing. In summary, this paper shows that it is more important to study surface chemistry than topography in terms of effects on wettability. Moreover, surface wettability can be controlled by laser structuring, post-processing, and surface cleaning.

Hybrid nanoparticles composed of an efficient nonlinear optical core and a gold shell can enhance and tune the nonlinear optical emission thanks to the plasmonic effect. However the influence of an incomplete gold shell, i.e., isolated gold nano-islands, is still not well studied. Here LiNbO3 (LN) core nanoparticles of 45 nm were coated with various densities of gold nano-seeds (AuSeeds). As both LN and AuSeeds bear negative surface charge, a positively-charged polymer was first coated onto LN. The number of polymer chains per LN was evaluated at 1210 by XPS and confirmed by fluorescence titration. Then, the surface coverage percentage of AuSeeds onto LN was estimated to a maximum of 30% using ICP-AES. The addition of AuSeeds was also accompanied with surface charge reversal, the negative charge increasing with the higher amount of AuSeeds. Finally, the first hyperpolarizability decreased with the increase of AuSeeds density while depolarization values for Au-seeded LN were close to the one of bare LN, showing a predominance of the second harmonic volumic contribution. ispartof: NANOMATERIALS vol:11 issue:4 ispartof: location:Switzerland status: published

Neural electrodes are key tools for achieving a successful brain-computer interface and the electrodes should be small to minimize damage to neural tissue and obtain good spatial selectivity such as single unit recording. Here we show conventional platinum/tungsten neural probes can be coated with nanoporous Pt. Thanks to nanoporous Pt with the extremely small and uniform pores, L-2-ePt, the electrode impedance could be reduced by more than 2 orders of magnitude while the apparent area was almost the same. L-2-ePt coating enhanced neuronal recording of local field potential in monkeys, leading to facilitating implanted electrical devices in the nervous system.