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An extensive analysis of iron–nitrogen-carbon (Fe–N–C) electrocatalysts synthesis and activity is presented concerning synthesis conditions such as initial Fe content, pyrolysis temperature and atmosphere (inert N2, reducing NH3, oxidizing Cl2 and their sequential combinations) and the influence of an external magnetic field on their performance in oxygen reduction reaction (ORR). Thermosetting porous polymers doped with FeCl3 were utilized as the Fe–N–C catalysts precursors. The pyrolysis temperature was varied within a 700–900 °C range. The temperature and atmosphere of pyrolysis strongly affect the porosity and composition of the resultant Fe–N–C catalysts, while the initial amount of Fe precursor shows much weaker impact. Pyrolysis under NH3 yields materials similar to those pyrolyzed under an inert atmosphere (N2). In contrast, pyrolysis under Cl2 yields carbon of peculiar character with highly disordered structure and extensive microporosity. The application of a static external magnetic field strongly enhances the ORR process (herein studied in an alkaline environment) and the enhancement correlates with the Fe content in the Fe–N–C catalysts. The Fe–N–C materials containing ferromagnetic iron phase embedded in N-doped microporous carbon constitute attractive catalysts for magnetic field-aided anion exchange membrane fuel cell technology.

Polyurethane coatings containing copper(II) L-tyrosine and glass microspheres were laser irradiated and underwent electroless metallization. Various sizes of glass microspheres were incorporated into the polyurethane coating matrix in order to examine their effects on surface activation and electroless metallization. The surface of the coatings was activated by using ArF excimer laser emitting ultraviolet radiation (λ = 193 nm) using different number of laser pulses and their fluence. The effects of surface activation and metallization were evaluated mainly based on optical and scanning electron microcopies (SEM), energy-dispersive X-ray spectroscopy (EDX) and photoelectron spectroscopy (XPS). It was found that the presence of glass microspheres enabled the reduction in copper complex content, intensified the ablation process (higher cone-like structures created) and resulted in higher content of copper metallic seeds. On the other hand, the glass microspheres concentration, which was higher for lower size microspheres, was advantageous for obtaining a fully metallized layer.

In this work, low-temperature photoionized plasma, induced in N2 by extreme ultraviolet (EUV) pulses, was used for surface modification of poly(L-lactic acid) (PLLA). Polymer samples were irradiated with 100, 200, and 300 pulses at a 10 Hz repetition rate. The physical and chemical properties of PLLA samples were examined using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The human dermal fibroblast adult cells (NHDF-Ad) were used for the cell culture and viability tests on modified PLLA surfaces. The N2-plasma and EUV treatment caused alteration of the surface morphology resulting in increased surface roughness, incorporation of nitrogen atoms, and appearing of new functional groups on the surface. Cell culture results showed an increase in the number of fibroblasts attached to the modified surfaces compared to the pristine PLLA. The modified surfaces demonstrated high cell viability and no cytotoxic effects were observed.

The morphology and chemical composition of platinum coatings deposited by magnetron-ion sputtering of a platinum target in various modes (stationary, pulsed), and air spraying of platinum black on titanium supporting foils were studied. Metallic platinum subjected to ionic purification was used as a reference sample. It is shown that the composition of coatings in addition to platinum includes its oxides PtO (10–11 at. %) and PtO2 (2–5 at. %). The presence of oxides in the composition of platinum coatings is explained by the high specific surface of platinum in the coating, whereby partial oxidation takes place in the air. It has been found that the mode of magnetron-ion sputtering, as well as the presence of the Nafion® ionomer (5 wt. %) in the air-spraying composition based on platinum black does not affect the phase composition of the coating. Morphological properties of the platinum coatings are influenced by the state of initial platinum source, and by the energy of the sputtered particles.

Surface-enhanced Raman spectroscopy (SERS) is a very promising analytical technique for the detection and identification of trace amounts of analytes. Among the many substrates used in SERS of great interest are nanostructures fabricated using physical methods, such as semicontinuous metal films obtained via electron beam physical vapor deposition. In these studies, we investigate the influence of morphology of semicontinuous silver films on their SERS properties. The morphologies studied ranged from isolated particles through percolated films to almost continuous films. We found that films below the percolation threshold (transition from dielectric-like to metal-like) made of isolated silver structures provided the largest SERS enhancement of 4-aminothiophenol (4-ATP) analyte signals. The substrate closest to the percolation threshold has the SERS signal about four times lower than the highest signal sample.

The results of studies on the fabrication and characterization of silver nanoisland films (SNIFs) using pulsed laser deposition (PLD) and the evaluation of these films as potential surface-enhanced Raman scattering (SERS) substrates are reported. The SNIFs with thicknesses in a range of 4.7 ± 0.2 nm to 143.2 ± 0.2 nm were deposited under different conditions on silicon substrates. Size and morphology of the fabricated silver nanoislands mainly depend on the substrate temperature, and number and energy of the laser pulses. SERS properties of the fabricated films were evaluated by measuring SERS spectra of para-mercaptoaniline (pMA) molecules adsorbed on them. SERS enhancement factors are shown to depend on the SNIF morphology, which is modified by changes of the deposition conditions. The highest enhancement factor in the range of 105 was achieved for SNIFs that have oval and circular silver nanoislands with small distances between them.

Polyetheretherketone (PEEK), due to its excellent mechanical and physico-chemical parameters, is an attractive substitute for hard tissues in orthopedic applications. However, PEEK is hydrophobic and lacks surface-active functional groups promoting cell adhesion. Therefore, the PEEK surface must be modified in order to improve its cytocompatibility. In this work, extreme ultraviolet (EUV) radiation and two low-temperature, EUV induced, oxygen and nitrogen plasmas were used for surface modification of polyetheretherketone. Polymer samples were irradiated with 100, 150, and 200 pulses at a 10 Hz repetition rate. The physical and chemical properties of EUV and plasma modified PEEK surfaces, such as changes of the surface topography, chemical composition, and wettability, were examined using atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and goniometry. The human osteoblast-like MG63 cells were used for the analysis of cell viability and cell adhesion on all modified PEEK surfaces. EUV radiation and two types of plasma treatment led to significant changes in surface topography of PEEK, increasing surface roughness and formation of conical structures. Additionally, significant changes in the chemical composition were found and were manifested with the appearance of new functional groups, incorporation of nitrogen atoms up to ~12.3 at.% (when modified in the presence of nitrogen), and doubling the oxygen content up to ~25.7 at.% (when modified in the presence of oxygen), compared to non-modified PEEK. All chemically and physically changed surfaces demonstrated cyto-compatible and non-cytotoxic properties, an enhancement of MG63 cell adhesion was also observed.

In this work, the effect of extreme ultraviolet (EUV) radiation and the combination of EUV radiation and low-temperature nitrogen plasma on the physico-chemical properties of polyetheretherketone (PEEK) surfaces were presented. The laser-plasma EUV source based on a double gas puff target was used in this experiment to irradiate PEEK surfaces with nanosecond pulses of EUV radiation and to produce low-temperature plasma through the photoionization of nitrogen with EUV photons. The changes in surface morphology on irradiated polymer samples were examined using atomic force microscopy (AFM) and scanning electron microscopy (SEM). Chemical changes of the PEEK surfaces were analysed using X-ray photoelectron spectroscopy (XPS). EUV radiation and nitrogen plasma treatment caused significant changes in the topography of modified PEEK&rsquo, s surfaces and an increase in their average roughness. Strong chemical decomposition, appearance of new functional groups as well as incorporation of nitrogen atoms up to ~17 at.% on the PEEK&rsquo, s surface were observed.

Raman spectroscopy has become an essential analytical technique for field detection and identification of illicit or dangerous materials such as explosives, but its main drawback is low signal intensity. This problem can be circumvented by using surface enhanced Raman spectroscopy (SERS), in which scattering signals increase significantly for analytes adsorbed onto or near nanostructured surfaces of the plasmonic materials. However, despite numerous studies, SERS has still not been widely used in real-world applications. The main goal of the studies describe herein was to investigate the possibility of detection of trace amounts of selected explosive materials on various commercial and non-commercial SERS substrates using portable Raman instruments. Our studies have shown that while portable systems suitable for SERS measurement of trace amounts of explosives are readily available, the problem remains in the selection of reliable and reproducible SERS substrates. Among five investigated SERS substrates only two, Klarite 312 and GaN-pillars allowed for trace analysis of all studied explosive materials. In both cases, detected concentrations of explosives ranged from single to hundreds of μg/cm2 depending on the explosive material and the Raman spectrometer used. Based on our findings, it could be concluded that the best SERS substrates for trace analysis of explosives are substrates with hot spots densely and evenly distributed over a whole active area of SERS substrate.

The outstanding properties of carbon materials doped with p-block elements are usually attributed directly to the presence of certain foreign atoms. By using the example of selenium-doped carbon gels, we hereby postulate that in many cases the properties of doped carbon materials are not determined by the presence of the heteroatom itself, but rather by how the element affects the carbon structure during high-temperature synthesis. Se-doped microporous carbogels were obtained via sol-gel polycondensation of resorcinol and 2-formylselenophene followed by pyrolysis at 600–1200 °C. Pyrolysis temperatures above 800 °C result in a decrease in the Se-content accompanied by a distinct increase in ultramicroporosity. A comparative analysis of oxygen-, sulfur- and selenium-doped carbogels shows that chalcogens increase the porosity of carbonaceous materials via the high-temperature oxidation of carbon to corresponding dichalcogenides (CO2, CS2 or CSe2), but their oxidative power diminishes with increasing atomic mass. Consequently, S and Se are more selective carbon oxidants.

Polylactide (PLA) composites containing flax fibre strands (20 wt%) and various content of triallyl isocyanurate (TAIC) as crosslinking agent were prepared by extrusion and injection moulding processes. The composites were modified by electron beam (EB) irradiation at dose values of 0, 10, 20, 30 and 40 kGy. The effects of EB and TAIC on the mechanical and structural properties of the composites were studied using tensile and impact tests, dynamic mechanical analysis (DMA), gel fraction measurement, differential scanning calorimetriy (DSC) and thermogravimetry (TG). However, the main attention was paid to biodegradation effects. Composites were biodegraded by means of enzymatic treatment and industrial composting. The composites were examined using mass loss analysis, DSC and photoelectron spectroscopy (XPS) in order to determine structural changes induced by biodegradation. Application of TAIC and EB at dose of 40 kGy led to the increase of tensile strength of about 20%. Besides crosslinking branching of PLA macromolecules was of significant importance. EB irradiation intensified enzymatic and composting degradation, however, when TAIC was applied, the composite was much more resistant to these processes.

Self-aligned and equal-space SnO2 nanotubes (NTs) with external diameters ranging from ca. 124 to ca. 325 nm and wall thickness of around 30 nm were synthesized by AAO template-assisted atomic layer deposition. The bulk and surface structure of the SnO2 nanostructures were studied in detail by XRD and XPS techniques, respectively. The SnO2 NTs were polycrystalline with an average crystallite size of ca. 3 nm. The structure analysis has revealed that the SnO2 NTs are composed of the rutile-type SnO2. The SnO2 nanotube arrays with the smaller external diameters emitted green light centered at around 520 nm. The emission was ascribed to the radiative recombination between electrons trapped in shallow donor levels and holes at the intrinsic surface states, associated with the oxygen deficient sites near surface region. The PL intensity diminished with the nanotube diameter and spacing. With increasing external diameter of the SnO2 nanotubes and decreasing the distance between the neighboring nanotubes, the emission become progressively weaker. The results demonstrate that the structure, morphology and arrangement of SnO2 nanotubes play an important role in their luminescent properties.

The aim of present study was to determine the hemocompatibility, cellular response of endothelial cells and bacterial adhesion to a new polyester nanocomposite. The carbon nanoparticle nanocomposite was prepared via in situ polymerization of monomers to obtain material of hardness 55 Sh D similar to polyurethanes used in medical applications, for example, in heart-assisting devices. The carbon nanoparticle-containing polyester exhibits markedly reduced bacterial colonization, as compared to commercially available polyurethanes. Further the nanocomposite possesses markedly improved hemocompatibility, as determined by flow cytometry, and robust endothelialization. Possible explanations for these beneficial properties include surface nanoroughness of carbon nanoparticle-containing nanocomposites and presence of fatty acid sequences within polymer structure.

Self-aligned and equal-spaced zinc oxide (ZnO) nanotube arrays were fabricated with anodic aluminum oxide (AAO)-assisted growth and the ALD technique. The near band-edge (NBE) emission was strongly affected by the nanotube's geometrical parameters, such as a packing density and thickness of the nanotube walls. The NBE emission was further enhanced with Al2O3 coating. The effect was analyzed by X-ray photoelectron spectroscopy (XPS) and ascribed to the surface defect passivation and a ZnAl2O4 spinel formation. The NBE emission enhancement was greater in ZnO nanotubes with thicker walls. A smaller UV enhancement factor was explained by less uniform and integral Al2O3 coverage of the ZnO nanotubes with thinner walls; this, possibly induced a variation of the Al2O3 refractive index along the nanotubes. As a result, the optical conditions at the ZnO/Al2O3/air interfaces was changed and the light extraction efficiency was reduced in the latter samples.

Inorganic hollow spheres find a growing number of applications in many fields, including catalysis and solar cells. Hence, a simple fabrication method with a low number of simple steps is desired, which would allow for good control over the structural features and physicochemical properties of titania hollow spheres modified with noble metal nanoparticles. A simple method employing sol–gel coating of nanoparticles with titania followed by controlled silver diffusion was developed and applied for the synthesis of Ag-modified hollow TiO2 spheres. The morphology of the synthesized structures and their chemical composition was investigated using SEM and X-ray photoelectron spectroscopy, respectively. The optical properties of the synthesized structures were characterized using UV–vis spectroscopy. Ag–TiO2 hollow nanostructures with different optical properties were prepared simply by a change of the annealing time in the last fabrication step. The synthesized nanostructures exhibit a broadband optical absorption in the UV–vis range.

The paper presents the results of laser modification as a method of surface layer preparation to autocatalytic metallization of polylactide. Laser modification was performed using an ArF excimer laser with a fluence of 15, 30 or 60 mJ/cm2. The number of 10, 50, 100, 500 and 1000 laser pulses were used. The effects of laser modification on the geometrical structure, surface wettability, surface energy and chemical composition of polylactide surface layer have been studied. Copper plating was conducted to determine the effectiveness of laser modification as a surface preparation method prior autocatalytic metallization. Studies have shown that the best quality of copper layer was obtained for a sample modified with 10 laser pulses with fluence of 15 mJ/cm2. For the remaining samples modified with higher laser fluence or more pulses deposited layers were inferior quality or did not deposit at all.

The use of biodegradable polymers derived from renewable sources may in the future be a solution to the problem of environmental pollution with polymer waste. By using natural fillers and additives in addition to the biodegradable matrix, we are able to obtain truly eco-fiendly green materials. The paper presents the result of selected properties of polylactide films containing natural coffee, cocoa or cinnamon extracts which primarily were proposed as natural antioxidants. The focus was on properties relevant to the packaging industry such as color and transparency, surface roughness, wettability, surface energy, friction coefficient, adhesion strength and gas permeability. It was found that the extracts used at the appropriate contents have a beneficial effect on the studied properties. The obtained results were often better not only than the values ​​obtained for pure polymer, but also better than the values ​​obtained for the film containing a synthetic anti-aging compound. It can therefore be concluded that the proposed plant extracts have a positive effect not only on the aging resistance of polylactide, but also other properties of this polymer. They can be therefore an alternative to synthetic additives.

Surface modification of polymers is often required to make the material suitable for specific application. Physical and chemical properties can be altered using a number of well developed techniques, such as plasma treatment, excimer lasers, chemical treatment, surface coating, plasma immersion ion implantation-deposition and laser surface structuring. Extreme ultraviolet radiations have limited penetration depth as they are readily absorbed even in low dense medium. However, their interaction with polymer surfaces is very strong due to high energy level of these photons. Therefore, EUV photons can be used to induce surface modifications in the polymer surfaces. This study is focused on the use of EUV photons for chemical surface modification of Polyethylene terephthalate (PET) films to incorporate nitrogen atoms. Nitrogen doping is often desirable in biomaterials to enhance the biocompatibility. EUV treated PET films in the presence of nitrogen and helium environments were studied using X-ray photoelectron spectroscopy (XPS) to examine the EUV induce chemical modifications.Surface modification of polymers is often required to make the material suitable for specific application. Physical and chemical properties can be altered using a number of well developed techniques, such as plasma treatment, excimer lasers, chemical treatment, surface coating, plasma immersion ion implantation-deposition and laser surface structuring. Extreme ultraviolet radiations have limited penetration depth as they are readily absorbed even in low dense medium. However, their interaction with polymer surfaces is very strong due to high energy level of these photons. Therefore, EUV photons can be used to induce surface modifications in the polymer surfaces. This study is focused on the use of EUV photons for chemical surface modification of Polyethylene terephthalate (PET) films to incorporate nitrogen atoms. Nitrogen doping is often desirable in biomaterials to enhance the biocompatibility. EUV treated PET films in the presence of nitrogen and helium environments were studied using X-ray photoelectr...

In this work copper(II) L-tyrosine was firstly reported as effective precursors for laser-induced selective activation and electroless metallization of polyurethane coating. The compound in the form of powder was mixed at amount of 20 wt% with polyurethane resin to form the coating on the polycarbonate substrate. The coating was irradiated with excimer ArF laser which generated UV radiation of about 193 nm wavelength. Various laser fluences and number of laser pulses were applied to determine physicochemical changes of the coating surface layer. After irradiation coatings were electrolessly metallized. It was found that laser irradiation resulted in formation of cone-like surface geometrical structure. The high of the cones was dependent on the dose of irradiation, whereas their tops were covered with copper. The external surface layer of precipitated copper was oxidized. This, however, did not affect the possibility of the surface to be electrolessly metalized. The irradiated coatings was effectively metallized and thus deposited copper layer characterized with high adhesion strength.

Raman spectroscopy has become a standard tool for identification of hazardous materials by first responders. However, despite many advantages of this technique, it has also a limitation, which is low sensitivity. This limitation could be overcome by Surfaced Enhanced Raman Spectroscopy, technique which still waits for real-world applications. In this paper, we present an overview of both methods, Raman and SERS spectroscopies, and examples of their uses for detection and identification of biological, chemical and explosive materials.

Nanoporous anodic aluminum oxide was formed in sulfuric acid with addition of indigo carmine. During anodizing, the organic dye was incorporated into the porous oxide walls. X-ray photoelectron spectroscopy revealed the presence of nitrogen and sulfur in the anodic aluminum oxide. Two types of incorporated sulfur were found: belonging to the sulfate anions SO42 − of the electrolyte and belonging to the C-SO3− side groups of the indigo carmine. Raman spectroscopy confirmed the incorporation and showed that the inorganic–organic hybrid material inherited optical properties from the indigo carmine. Typical modes from pyrrolidone rings, unique for indigo carmine in the investigated system (650 and 1585 cm− 1), were found to be the strongest for the greatest anodizing voltages used. Despite the indigo carmine incorporation, the morphology of the oxide is still nanoporous and its geometry is still tuned by the voltage applied during aluminum anodization. This work presents an inexpensive and facile approach to doping an inorganic oxide material with organic compounds.

Extreme ultraviolet (EUV) surface modification of polytetrafluoroethylene (PTFE) was performed in order to enhance the degree of biocompatibility. Polymer samples were irradiated by different number of EUV shots using a laser–plasma based EUV source in the presence of nitrogen gas. The physical and chemical properties of EUV modified PTFE samples were studied using Atomic Force Microscopy, X-ray photoelectron spectroscopy and water contact angle (WCA) methods. Pronounced wall type micro and nano-structures appeared on the EUV treated polymer surfaces resulting in increased surface roughness and hydrophobicity. Stronger cell adhesion and good cell morphology were observed on EUV modified surfaces by in-vitro cell culture studies performed using L929 fibroblasts.

Polycaprolactone (PCL) is a biodegradable and biocompatible polyester whose low melting point facilitates production of 3D porous scaffolds with precisely defined dimensions and internal architecture by rapid prototyping techniques. To improve the suitability of such PCL scaffolds for bone regeneration applications, they were coated with inorganic layers of calcium phosphate (CaP) and CaP doped with 0.6% w/v magnesium (CaP+Mg) using pulsed laser deposition (PLD) and characterized in vitro using osteoblast-like Saos-2 cells. Saos-2 cells were able to adhere to all scaffolds. CaP+Mg coatings significantly increased activity of alkaline phosphatase (ALP), an early differentiation marker, after 7 days. However, gene expression of ALP after 7 days was markedly lower on the same scaffolds. These data show the feasibility of coating PCL with CaP layers by PLD and the possibility of influencing osteoblastic differentiation by magnesium doping of the CaP coating.

In this work experimental results are presented and analyzed for catalytic platinum films of ultra-low thickness of 0.09–3.47 nm and Pt loading of 0.18–7.44 μg cm−2 deposited using the PLD method with an ArF excimer laser (λ = 193 nm) at room temperature. For Pt deposited on the surface of the Nafion® membrane (electrolyte), in a fuel cell with PLD Pt working as oxygen cathode the peak power density is obtained equal to 59.36 mW cm−2 for the Pt loading of 1.24 μg cm−2. In the case of Pt deposition on the gas-diffusion layer (as cathode), a much higher maximum power density of 106.36 mW cm−2 at the same loading and a maximum of 188.44 mW cm−2 at the 7.44 μg cm−2 loading is observed. Experiments are also presented of Nafion® modification before the deposition of Pt on the Nafion®, in which the surface of the membranes is enlarged by bombarding with Ar ions from a plasma generator of RF 13.56 MHz. The electrochemical activity of the elements prepared by PLD is assessed in a H2/Pt/Nafion®/Pt/O2 PEMFC. The structure and morphology of the surface layers is examined by AFM and SEM microscopy.

Boron nitride coatings have been deposited onto high-speed steel substrates using pulsed laser deposition technique combined with RF-discharge. In order to improve adhesion and reduce internal stresses, substrates were subjected to gas nitriding. The structure and morphology of coatings were investigated applying atomic force microscopy (AFM) and FTIR spectroscopy. Nanohardness and elastic modulus were examined employing a nanoanalyzer (CETR). On the basis of the conducted experiments, stable, crystalline, multiphase coatings have been obtained. It has been proved that morphology, structure and mechanical properties strongly depend on the parameters of the PLD process; in particular, the temperature of the substrate has a crucial influence on the properties of BN coatings.

In this study, surface modification of fluoropolymer Polyvinyl fluoride (PVF) films was performed using Extreme Ultraviolet (EUV) radiations to induce patterned structures on surface and to provide control over the surface wettability. Specially developed laser produced plasma based EUV source was used for surface structuring. The double stream gas-puff target was produced by injection of krypton and xenon (KrXe) gas mixture into a hollow stream of helium. Commercially available EKSPLA Nd:YAG 1.06 micron laser was used to irradiate the KrXe gas puff target with 3 nanosecond pulse duration having 0.8 J energy. The PVF films were irradiated with 50 and 200 EUV pulses. The surface characterisation of the pristine and EUV modified PVF polymer films was performed by Atomic Force Microscopy (AFM) for morphological modifications. To investigate chemical modifications, X-ray Photoelectron Spectroscopy was used. The wettability of the sample surfaces was examined by Water Contact Angle (W CA) measurements. EUV surface modification of PVF films resulted in formation of wall type rippled structures on the polymer surfaces. The surface roughness of the EUV treated surfaces was increased up to 287 nm and 21° reduction was observed in the WCA of the PVF films. Successful surface structuring and wettability control was obtained using EUV surface modification of PVF films.

In this work we compare two InAs/GaSb superlattice samples grown in MBE VIGO/MUT laboratory on 2 inch (001) GaAs substrate, using MBE technique. Both samples have the same architecture, however their growth processes were conducted at different temperatures. For sample A the growth temperature was equal 668 K (395°C), for sample B 588 K (315°C). Photoluminescence measurements were performed at 30 K. For sample A there is no photoluminescence signal, while spectrum for sample B consists of two peaks: bandgap peak at 0.5 eV and deep state peak at 0.25 eV. X-ray diffraction (XRD) measurements indicate that sample A has better crystallographic quality than sample B. Raman spectra consists of low energy peaks (20-100 cm-1) which confirm the existence of superlattice for both samples [4]. Additionally, for sample A there are peaks related to Sb precipitates. It suggests that except the InAs/GaSb superlattice there is an additional Sb layer which may disturb band structure of superlattice and cause the disappearance of photoluminescence for sample A.

In this work we compare two superlattices: InAs/GaSb (sample A) and InAs/InAsSb (sample B). Both samples were grown in MBE VIGO/ MUT laboratory on 2 inch (001) GaAs substrate using MBE technique. We characterized quality and thickness of the samples using three methods: photoluminescence, X-ray diffraction (XRD) and Raman scattering. Period of superlattice layers was obtained using Raman scattering and XRD measurements. For sample A it was equal 5.3 nm and 4.76 nm for InAs and GaSb layers respectively, for sample B 8.3 nm and 9.4 nm. Photoluminescence spectrum for sample A exhibits two peaks: band gap peak at 0.5 eV and deep state peak at 0.25 eV. Spectrum for sample B consists of one band gap peak at 0.17 eV.

The use of porous titanium-based implant materials for bone contact has been gaining ground in recent years. Selective laser melting (SLM) is a rapid prototyping method by which porous implants with highly defined external dimensions and internal architecture can be produced. The coating of porous implants produced by SLM with ceramic layers based on calcium phosphate (CaP) remains relatively unexplored, as does the doping of such coatings with magnesium (Mg) to promote bone formation. In this study, Mg-doped coatings of the CaP types octacalcium phosphate and hydroxyapatite (HA) were deposited on such porous implants using the pulsed laser deposition method. The coated implants were subsequently implanted in a rabbit femoral defect model for 6 months. Uncoated implants served as a reference material. Bone-implant contact and bone volume in the region of interest were evaluated by histopathological techniques using a tri-chromatographic Masson-Goldner staining method and by microcomputed tomography (µCT) analysis of the volume of interest in the vicinity of implants. Histopathological analysis revealed that all implant types integrated directly with surrounding bone with ingrowth of newly formed bone into the pores of the implants. Biocompatibility of all implant types was demonstrated by the absence of inflammatory infiltration by mononuclear cells (lymphocytes), neutrophils, and eosinophils. No osteoclastic or foreign body reaction was observed in the vicinity of the implants. µCT analysis revealed a significant increase in bone volume for implants coated with Mg-doped HA compared to uncoated implants.

Polycarbonate Polymer Surface Modi cation by Extreme Ultraviolet (EUV) Radiation I.U. Ahada,b,∗, B. Budner, B. Korczyc, H. Fiedorowicz, A. Bartnik, J. Kostecki, S. Burdy«ska and D. Brabazon Institute of Optoelectronics, Military University of Technology, S. Kaliskiego 2, 00-908 Warszawa, Poland Advanced Processing Technology Research Centre, School of Mechanical and Manufacturing Engineering Faculty of Engineering & Computing, Dublin City University, Dublin 9, Ireland

The photoluminescence (PL) properties of tin oxide nanostructures are investigated. Three samples of different morphology, induced by deposition process and various geometrical features of nanoporous anodic aluminum oxide (AAO) substrate, are analyzed. X-ray photoelectronic spectroscopy (XPS) analysis reveals the presence of two forms of tin oxide on the surface of all studied samples: SnO and SnO 2 . The former form is typical for reduced surface with bridging oxygen atoms and every other row of in-plane oxygen atoms removed. The oxygen defects give rise to a strong emission in visible region. Two intense PL peaks are observed centered at about 540 (band I) and 620 (band II) nm. The origin of these bands was ascribed to the recombination of electrons from the conduction band (band I) and shallow traps levels (band II) to the surface oxygen vacancy levels. Upon deposition of Au nanoparticles on the top of tin oxide nanostructures the emission at 540 and 620 nm disappears and a new band (band III) occurs in the range >760 nm. The PL mechanism operating in the studied systems is discussed. The tin oxide/Au nanocomposites can be used as efficient multi-band light emitters in a wide (from visible to near infrared) wavelength range.

In this work the quality, arrangement, composition, and regularity of nanoporous AAO formed on the low-purity (AA1050) and high-purity aluminum during two-step anodization in a mixture of sulfuric acid solution (0.3 M), water and glycol (3:2, v/v), at various voltages (15, 20, 25, 30, 35 V) and at temperature of −1 °C, are investigated. The electrochemical conditions have allowed to obtain pores with the size ranging from 30 to 50 nm, which are much larger than those usually obtained by anodization in a pure sulfuric acid solution (

A simple method to produce highly ordered carbon nanostructures by combustion synthesis is presented. Graphite-encapsulated magnesium oxide, iron carbide nanoparticles and carbon nanobelts were synthesized by the one-step reduction of iron pentacarbonyl with magnesium. High-resolution transmission electron microscopy analysis of the products revealed nanocrystalline MgO and Fe 3 C particles surrounded by a well-crystallized, tight graphite film. The possible formation mechanism is presented and discussed.

Surface roughness control of polymeric materials is often desirable in various biomedical engineering applications related to biocompatibility control, separation science and surface wettability control. In this study, Polyethylene terephthalate (PET) polymer films were irradiated with Extreme ultraviolet (EUV) photons in nitrogen environment and investigations were performed on surface roughness modification via EUV exposure. The samples were irradiated at 3 mm and 4 mm distance from the focal spot to investigate the effect of EUV fluence on topography. The topography of the EUV treated PET samples were studied by AFM. The detailed scanning was also performed on the sample irradiated at 3 mm. It was observed that the average surface roughness of PET samples was increased from 9 nm (pristine sample) to 280 nm and 253 nm for EUV irradiated samples. Detailed AFM studies confirmed the presence of 1.8 mm wide period U-shaped channels in EUV exposed PET samples. The walls of the channels were having FWHM of about 0.4 mm. The channels were created due to translatory movements of the sample in horizontal and transverse directions during the EUV exposure. The increased surface roughness is useful for many applications. The nanoscale channels fabricated by EUV exposure could be interesting for microfluidic applications based on lab-on-a-chip (LOC) devices.

The modification induced in polylactide (PLA) by the ArF excimer laser radiation has been investigated. Various fluences and numbers of laser pulses were applied to modify surface properties. The contact angles of test liquids (water and diiodomethane) were measured with use of a goniometer while the surface energy (SE) was calculated by the Owens–Wendt method. Changes in the chemical composition of the PLA surface layer were studied using the X-ray photoelectron spectroscopy (XPS). Analysis of the morphological changes in the polymer surface layer was performed via the atomic force microscopy (AFM). It was found that the surface energy change was affected by surface oxidation as well as by surface roughness resulted from laser irradiation. The influence of laser induced surface oxidation and roughness on SE depended on applied fluence and the number of laser pulses.

The InAs1–xSbx ternary alloy band gap nonlinearly depends on the composition, which gives the opportunity to use this material in devices operating in a wide range of infrared radiation. We present experimental results for InAs1–xSbx samples for Sb composition from 0.1 to 0.8. Raman spectrum of InAs and InSb in the range of 20 - 250 cm-1 exhibits two main peaks: LO peak and 2TA peak. On the other hand in the same range for InAsSb in Raman spectra two additional peaks (round 44 cm-1 and round 130 cm-1) appear, while they are not existing neither in pure InAs nor in InSb. Energies of 44 cm-1 and 130 cm-1 are close to phonon energy for momentum equals K and L for InAs. This type of peaks are usually called DALA and DATA and it is commonly accepted that they come from disorder in crystal field. We propose other explanation-existence of zone folding in phonon dispersion curves as a result of CuPt unit cell of InAsSb being twice larger than typical ZB unit cell.

The anti-reflective properties of amorphous silicon (a-Si) films deposited directly on Al nanoconcave arrays with various interpore distances ( D c ) were studied. The Al anodized at 195 V ( D c =456.7 nm) and covered by a 277-nm a-Si layer demonstrated the best light- trapping efficiency. It absorbed up to ~86% of incident light. Average reflectivity under AM1.5 solar spectrum is strongly correlated to height alteration at the a-Si front surface. Further optimization found that D c and film thickness of 450–500 nm and 250–300 nm, respectively, take full advantage of the excellent optical properties of this simple, low cost material suitable for large scale production.

The aim of the presented study was an analysis of two apatite coatings: hydroxyapatite (HA) and octacalcium phosphate (OCP) as coatings materials for metallic implants. Both layers were deposited by means of the PLD method. As a target material, synthetic, powdered and pressed hydroxyapatite was used. HA was deposited on 316L steel substrate in two temperature ranges for obtaining different coatings: 150±30°C and 430±30°C for OCP and HA, respectively. As an intermediate layer, the nanocrystalline diamond layer (NCD) was deposited. Examined calcium phosphate layers were tested for adhesion of osteoblast cell culture (MG-63). Analytical methods (AFM, FTIR) showed the usefulness of the PLD method for deposition of the apatite layers on metallic implants. Both examined layers showed biocompatibility with human osteoblast cells and presented favorable conditions for their proliferation.

Tungsten and SiC are candidates for the structural materials of the nuclear fusion reactor walls, while CVD poly-crystal diamond is candidate for the window material under the hazardous fusion stresses. We measured the surface endurance strength of such materials with commercial displacement sensors and our recent evaluation method. The pulsed high thermal input was put into the material surfaces by UV lasers, and the surface erosions were diagnosed. With the increase of the total number of the laser shots per position, the crater depth increased gradually. The 3D and 2D pictures of the craters were gathered and compared under various experimental conditions. For example, the maximum crater depths were plotted as a function of shot accumulated numbers, from which we evaluated the threshold thermal input for the surface erosions to be induced. The simple comparison-result showed that tungsten was stronger roughly two times than SiC. Then we proposed how to monitor the surface conditions of combined samples with such diamonds coated with thin tungsten layers, when we use such samples as parts of divertor inner walls, fusion chamber first walls, and various diagnostic windows. We investigated how we might be able to measure the inner surface erosions with the same kinds of displacement sensors. We found out the measurable maximum thickness of such diamond which is useful to monitor the erosion. Additionally we showed a new scheme of fusion reactor systems with injectors for anisotropic pellets and heating lasers under the probable use of W and/or SiC.

Extreme ultraviolet (EUV) is an ionizing radiation strongly absorbed in any kind of mater. In case of polymers absorption depth is of the order of 100 nm. Interaction of EUV photons with polymer chains results in chain scission and formation of low weight fractions. In this work interaction of intense EUV pulses with poly(vinylidene fluoride) (PVDF) was investigated. Mass spectroscopy was employed to investigate the ablation products indicating emission of numerous molecular species of C-containing fragments of the polymer chain. Chemical surface changes after irradiation were investigated using X-ray photoelectron spectroscopy (XPS). The XPS spectra obtained for PVDF, samples irradiated with low and high EUV fluence, indicate significant differences between chemical structures in near-surface layers. It was shown that irradiation with low fluence results in defluorination and thus carbon enrichment in near-surface layer. In contrary, irradiation with high fluence leads to intense material ablation and hardly modifies the chemical structure of the remaining material. Additionally chemical modification of the PVDF surface by EUV irradiation in a presence of ionized nitrogen was investigated. The nitrogen gas, injected into an interaction region, was ionized and excited by the EUV radiation from a laser-plasma source. An ionization degree and excited states of nitrogen were investigated using an EUV spectrometry and the corresponding spectra are presented. Chemical modification of the polymer after combined EUV and ionized nitrogen treatment was investigated using an X-ray photoelectron spectroscopy. Significant contribution of the nitrogen atoms in the polymer near-surface layer after the treatment was demonstrated.

The new method to estimate the erosion threshold of various material surfaces with high power pulsed electron beam was extended to the surface erosions with various pulsed laser lights. We are interested in the erosions of candidate materials to be useful under very severe eovironmental conditions with various laser lights, including ArF and Nd:YAG laser lights.

Gradient structures are very important for sensors, laser and wave-guide techniques, telecommunications and other techniques which employ radiation propagation and conversion. By varying admixture concentration, the stress occurring in the structure may increase or reduce, which is vital for charge carrier movement velocity. We discusse two kind of gradient structures of thin TiNx layer with a total thickness of approximately 22 nm deposited on the Si(100) substrate and multi-layer structures with a Si-Pd and Si-Mg bi-layer periods. The gradient structures were deposited using a laser ablation of target-compound materials. A Lambda Physics excimer laser (model LPX 305i; t ~ 15 ns, λ = 193 nm) with f = 5 Hz operating frequency was used for layer depositing. The analyses confirmed the presence of the gradient distribution of deposited materials. The gradient structures proved highly sensitive to both thermal effects and strong adsorption of ambient gases. The usefulness of titanium-containing structures for gas, especially hydrogen and oxygen, sensors was confirmed. Due to the strong gas adsorption, the gradient structures used in radiation conversion or waveguide technology should be adequately protected against ambient conditions.

The most recent fundamental research results to investigate surface erosions of nuclear fusion candidate chamber materials are described in short. We used a commercial surface profiler with a red semiconductor laser. Various material surfaces ablated and eroded by a rather short pulse electron beam and a short pulse ArF laser light were measured with this surface profiler and the associated three-dimensional analysis software. Threshold input levels for various sample surface erosions with electron and laser beams were clearly decided for the first time with our new method in this article. After the above fundamental results were gathered, the methods to inspect inner surface conditions of nuclear fusion reactor chambers were newly proposed with various kinds of laser displacement sensors. The first one is the erosion monitor with the above profiler, and the second one is the laser induced ultrasonic wave detection method to inspect deeper surface layers than the first one.

Carbon thin films are often called in the literature, “diamond-like carbon” films. They consist of two basic allotropic forms of carbon, which are graphite and diamond. Carbon atoms with sp bonds form after deposition of a graphite-like phase. Atoms with sp bonds form a diamond-like phase. Diamond-like crystallites are built into a graphite-like phase matrix. In this paper there are presented experimental results of deposition of carbon films by the magnetron sputtering method and the results of analysis of the surface and phase structures of the deposited films. The amorphous carbon films were deposited from graphite targets on 316L steel substrates. The films were deposited at room temperature, in vacuum. The deposition time was 3 h; the depositions were conducted at two different distances between the substrate and the magnetron target.

The main aim of this work was to assess the ability of thermogravimetric method to predetermine the surface activation properties of the coatings intended for laser-assisted electroless metallization. In this technique of metallization, surface of polymer material has to be activated before immersing in electroless metallization bath. Surface activation may consist in compositional modification of polymer material and in laser irradiation. In this work, polyurethane or epoxy coatings containing copper(I) oxide and copper(II) acetylacetonate or copper hydroxide were laser irradiated and then electrolessly metallized. Surface activation properties are evaluated usually by means of optical imaging, scanning electron microscopy, energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. In this work, an attempt was made to evaluate these properties based on thermogravimetric measurements.