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EN
The research focused on TiO2 nanostructures environmental applications due to the special characteristics that displayed degradation of the organic compounds into environmentally friendly products through exposure to UV light. The protocol behind obtaining the nanostructures involved the use of a Ti material exposed to alkaline treatment and advanced oxidation using NaOH solution and acetone. These studied nanostructures were analyzed extensively by using methods such as scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) for characterizing the elements, compounds and morphological properties of the material. These differences in morphology is attributed to different NaOH solution concentrations. The Ti sheets were immersed into NaOH and acetone mixed solutions for 72 hours. The best results were recorded by using 30% NaOH solution. After obtaining the 3D structures, which improve specific surface and contact area with the environment, the samples were tested under UV light in order to degrade methylene blue in order to determine their photocatalytic performance.
EN
Purpose: The aim of this paper is to develop a functional model for the synthesis of nanostructures of the given quality level, which will allow to effectively control the process of nanopatterning on the surface of semiconductors with tunable properties. Design/methodology/approach: The paper uses the IDEF0 methodology, which focuses on the functional design of the system under study and describes all the necessary processes with an accuracy sufficient for an unambiguous modelling of the system's activity. Based on this methodology, we have developed a functional model for the synthesis of nanostructures of the given quality level and tested its effectiveness through practice. Findings: The paper introduces a functional model for the synthesis of nanostructures on the surface of the given quality level semiconductors and identifies the main factors affecting the quality of nanostructures as well as the mechanisms for controlling the formation of porous layers with tunable properties. Using the example of etching single-crystal indium phosphide electrochemically in a hydrochloric acid solution, we demonstrate that the application of the suggested model provides a means of forming nanostructures with tunable properties, assessing the quality level of the nanostructures obtained and bringing the parameters in line with the reference indicators at a qualitatively new level. Research limitations/implications: Functional modelling using the IDEF0 methodology is widely used when process control is required. In this study it has been applied to control the synthesis of nanostructures of the given quality level on the surface of semiconductors. However, these studies require continuation, namely, the establishment of correlations between the technological and resource factors of synthesis and the acquired properties of nanostructures. Practical implications: This study has a significant practical effect. Firstly, it shows that functional modelling can reduce the time required to form large batches of the given quality level nanostructures. This has made it possible to substantiate the choice of the initial semiconductor parameters and nanostructure synthesis modes in industrial production from the theoretical and empirical perspective. Secondly, the presented methodology can be applied to control the synthesis of other nanostructures with desired properties and to reduce the expenses required when resources are depleted and the cost of raw materials is high. Originality/value: This paper is the first to apply the IDEF0 methodology to control the given quality nanostructure synthesis. This paper will be of value to engineers who are engaged in the synthesis of nanostructures, to researchers and scientists as well as to students studying nanotechnology.
EN
Purpose: The article proposes a methodology for determining the chemical quality criterion of porous layers synthesized on the surface of semiconductors, based on taking into account the chemical parameters of the surface that can affect the properties of nanostructures. Design/methodology/approach: The chemical quality criterion was evaluated in terms of stoichiometry, stability of structures over time, uniformity of distribution over the surface, and the presence of an oxide phase. As an example, a calculation is demonstrated for the por-InP/InP structure synthesized on a mono-InP surface. The results of calculating the chemical quality criterion were evaluated using the Harrington scale to rank samples by quality level. Findings: A chemical criterion for the quality of porous layers synthesized on the surface of semiconductors has been developed. This criterion contains a set of indicators sufficient for a comprehensive assessment of the surface condition and is universal in nature. The studies carried out make it possible to reasonably approach the determination of the modes of electrochemical processing of semiconductors and open up new perspectives in the construction of a model of self-organization of a porous structure. Research limitations/implications: The chemical quality criterion does not allow evaluating the obtained nanostructures in terms of geometric parameters. Therefore, in the future, there is a need to develop a morphological quality criterion and determine a methodology for assessing a generalized quality criterion for nanostructures synthesized on the surface of semiconductors, which may include economic, environmental, technological indicators, and the like. Practical implications: Study results are expedient from a practical point of view, since they make it possible to reasonably approach the determination of the modes of electrochemical processing of semiconductors, synthesize nanostructures with predetermined properties, and create standard samples of nanomaterial composition. Originality/value: Methodology for assessing the quality of porous semiconductors by a chemical criterion has been applied for the first time in engineering science. The article will be useful to engineers, who are engaged in the synthesis of nanostructures, researchers and scientists, as well as specialists in nanometrology.
EN
In this review, we highlight new insights and place the molecular mechanisms of the biogenesis of nanomaterials such as silicified frustules, coccoliths, magnetosomes and bacterial nanowires in the context of the complex biology of a microbial cell. The silicified frustules are formed by diatoms, which are a widespread group of organisms found in the oceans, fresh water, soil and wet surfaces. They are especially important in the oceans, where it is estimated that they contribute to 45% of total primary ocean production. Coccolith is a collective term that designates all of the biomineralized, calcified scales produced by extant and extinct haptophytes (single-celled algae). The orientation of magnetotactic bacteria is based on the presence of unique organelles, magnetosomes, which are intracellular, membrane-enclosed, nanometre-sized crystals of magnetic iron minerals. The discovery of bacterial conductive structures, called nanowires, has fascinated scientists for almost a decade. Nanowires enable bacteria to transfer electrons over micrometer distances to extracellular electron acceptors such as insoluble metal oxides or electrodes. The possible applications of these extremely interesting nanomaterials in different areas of life is also considered.
EN
Nowadays nanostructures are more and more often designed as carriers for drug delivery, especially to improve the drug pharmacokinetics and pharmaco-dynamics. Numerous kinds of nanostructures are considered a good prospect for medical applications thanks to their small size, acceptable biocompatibility and toxicity. Due to the fact that nanotechnology is a new field of science, every nano-scale product must be thoroughly examined regarding its toxicity to the human body. This study provides new insights into effects of exposing endothelial cells to the selected nanostructures. Dendrimers of the fourth generation (PAMAMs), multi-walled carbon nanotubes (MWCNTs) and silver nanoparticles (SNPs) were used to evaluate nanostructures influence on endothelial cells in vitro. The nanostructures were evaluated via transmission electron microscopy and dynamic light scattering technique. The cells previously exposed to the nanostructures were observed and analyzed via the atomic force microscopy and scanning electron microscopy to obtain a quantitative evaluation of the cells morphology. The presence of multi-walled carbon nanotubes and silver nanoparticles on the cells surface was confirmed by the scanning electron microscopy. Our results confirm that the surface association and/or uptake of nanostructures by the cells resulting from physicochemical and biological processes, affect the cells morphology. Morphological changes can be induced by the membrane proteins interaction with nanomaterials, which trigger a sequence of intracel-lular biological processes.
EN
Nanostructures of copper (II) oxide were synthesized through chemical reduction of copper (II) sulfate pentahydrate using phytochemicals present in leaf extracts of Leucas aspera. The crystalline phases and size were assessed by X-ray diffraction data analysis. From the Bragg reflection peaks, existence of monoclinic end-centered phase of copper (II) oxide along with presence of cubic primitive phase of copper (I) oxide and traces of cubic face centered lattices of zero valent copper was revealed. The three Raman active modes corresponding to CuO phase were identified in the sample with permissible merging of characteristic bands due to nanostructuring and organic capping. The surface topography measurement using field emission scanning electron microscope evidenced the occurrence of cylindrical rod shaped morphological structures along with a number of unshaped aggregates in the sample. The effective crystallite size and lattice strain were estimated from Williamson-Hall analysis of Bragg reflection data. Tauc plot analysis of UV-Vis-NIR absorption data in direct transition mode provided an estimation of band gap, viz. 1.83 eV and 2.06 eV respectively, for copper (II) oxide and copper (I) oxide. Thermal degradation study using thermogravimetric curve analysis could reveal the amount of moisture content, volatile components as well as the polymer capping over nanorods present in the sample. It could be seen that upon heating, inorganic core crystals undergo oxidation process and at temperature above 464 °C, the sample was found to be composed solely of inorganic crystallite phase of copper (II) oxide.
PL
W artykule omówione są różne sposoby przeprowadzania obliczeń dla techniki odbiciowej wysokoenergetycznej dyfrakcji elektronowej, nazywanej zwykle techniką RHEED. Technika ta w chwili obecnej często znajduje zastosowanie m.in. do monitorowania wzrostu cienkich warstw przy użyciu metody PLD, czyli osadzania z wykorzystaniem lasera impulsowego. Artykuł poświęcony jest różnym aspektom teoretycznym opisu dyfrakcji typu RHEED. W przypadku, gdy sieć krystaliczna badanego materiału jest niemal idealna, natężenia wiązek elektronów odbitych od powierzchni powinny być wyznaczane przy użyciu dynamicznej teoria dyfrakcji, czyli z pomocą równań różniczkowych cząstkowych właściwych dla ruchu falowego. W przypadku osadzania cienkich warstw, ułożenie atomów jest jednak zwykle dalekie od idealnego i dlatego stosowanie teorii uproszczonych może być pomocne. W ogólności problem przeprowadzania symulacji komputerowych dla dyfrakcji elektronów, dla częściowo uporządkowanych struktur wciąż jest otwarty.
EN
Different methods of executing calculations for reflection high energy electron diffraction (RHEED) are discussed in the article. Currently, RHEED is often applied among others to monitor preparation of thin films with the use of pulsed laser deposition. The article is devoted to different theoretical aspects of description of the diffraction phenomenon for electrons. For the case of the material with a nearly ideal crystal lattice, intensities of electron beams reflected from the surface should be determined with the employment of the dynamical diffraction theory, i.e. with the use of partial differential equations proper for the wave motion. However, for the case of the deposition of thin films, the arrangement of atoms is usually far from the ideal one and because of this reason the employment of simplified theoretical approaches may be profitable. In general, the problem of the faithful carrying out computer simulations for electron diffraction, for partially ordered structures is still open.
9
EN
Nanotechnology is an interdisciplinary area of science devoted to the production and testing of nanostructures - defined as forms of the matter organizations the size of which does not exceed 100 nm. It is a quickly developing area of science with many applications in different areas of life, for example in engineering, computing, medicine, pharmacy, andagriculture. One of the problems of contemporary oncology is the low specificity of applied therapies. Most currently used chemiopharmaceuticals have systemic effects which not only affect cancer cells but alsohealthy tissues. Complications after chemotherapy observed in many patients are bone marrow deficiency(neutropenin, thrombocytopenia, anemia), damageto the nervous system (neurotoxicity), myocardium(cardiotoxicity) and pulmonary parenchyma. Similarly, in radiotherapy, ionizing radiation destroys the healthy tissues in the irradiation field. The side effects of radiation therapy may include fatigue, skin reactions, and impairment of tissue and organ functions. According to studies, nanostructures are an opportunity to overcome these limitations. The most popular nanostructures used in medicine are liposomes, silver and gold nanoparticles, magnetic nanoparticles, carbonnanotubes, and dendrimers. The purpose of this article is to present the current state of knowledge on the use of available nanotechnology solutions in pharmacology and cancer treatment.
PL
W pracy przedstawiono wyniki badań strukturalnych wykonanych za pomocą skaningowej i transmisyjnej mikroskopii elektronowej, dyfrakcji rentgenowskiej oraz spektroskopii w podczerwieni tlenku miedzi w postaci nanodrutów otrzymanych w procesie termicznego utleniania. Ponadto przeprowadzono eksperymenty oddziaływania promieniowania elektromagnetycznego z nanodrutami CuO.
EN
In this work the results of structural studies, performed by scanning electron microscopy and transmission electron microscopy, X-ray diffraction and infrared spectroscopy of copper oxide in nanorods form obtained in thermal oxidation, were presented. Moreover, interaction between CuO nanorods and electromagnetic radiation was investigated.
EN
In this work, three ceramic composite coatings Al2O3-3TiO2 C, Al2O3-13TiO2 C, and Al2O3-13TiO2 N were plasma sprayed on steel substrates. They were deposited with two conventional powders differing the volume fraction of TiO2 and nanostructured powder. The mechanical and tribological properties of the coatings were investigated and compared. The increase in TiO2 content from 3 wt.% to 13 wt.% in the conventional feedstock improved the mechanical properties and abrasion resistance of coatings. However, the size of the used powder grains had a much stronger influence on the properties of deposited coatings than the content of the titania phase. The Al2O3-13TiO2 coating obtained from nanostructured powder revealed significantly better properties than that plasma sprayed using conventional powder, i.e. 22% higher microhardness, 19% lower friction coefficient, and over twice as good abrasive wear resistance. In turn, the Al2O3-13TiO2 conventional coating showed an increase in microhardness and abrasive wear resistance, 36% and 43%, respectively, and 6% higher coefficient of friction compared to the Al2O3-3TiO2 conventional coating.
PL
Na obecnym etapie rozwoju nanotechnologii najpopularniejsze w praktycznym zastosowaniu są nanomateriały powszechnie stosowane w: przemyśle, medycynie, inżynierii biomedycznej, farmacji, optoelektronice, mikroelektronice, układach biologicznych, jako środki przeciwdrobnoustrojowe oraz coraz częściej w przemyśle żywnościowym. Do najważniejszych zastosowań nanotechnologii w żywności należy zaliczyć nanokapsułki oraz nanododatki poprawiające właściwości produktów oraz opakowań aktywnych. Mimo licznych zalet nanomateriałów należy zwrócić uwagę na zagrożenia płynące z ich zastosowania oraz opracować metody kontroli bezpieczeństwa i jakości produktów wytworzonych z wykorzystaniem nanotechnologii.
EN
The most important in whidespread use are nanomaterials commonly used in industry, medicine, biomedical engineering, pharmacy, optoelectronics, microelectronics, biological systems as antimicrobial agents and, increasingly, in food technology. Nanocapsules, nanoadditives improving the quality of the products and nanopackages are the most important applications. Despite the numerous advantages of nanomaterials, it is important to pay attention to the risks arising from their use and to develop methods to control the safety and quality of products made using nanotechnology.
PL
Głównymi funkcjami opakowań do żywności są utrzymywanie jakości produktów spożywczych podczas przechowywania i transportu oraz wydłużenie ich okresu przydatności do spożycia poprzez kontrolowanie przenikania wilgoci, gazów i innych lotnych składników. Jednym z ważnych czynników wpływających na walory smakowe i świeżość wybranych produktów spożywczych jest kwasowość. Zmiana właściwości kwasowozasadowych zachodzi m.in. pod wpływem czynników zewnętrznych, temperatury i warunków przechowywania. Celami pracy były synteza biodegradowalnego kompozytu na bazie półsyntetycznego polisacharydu zawierającego kropki kwantowe (ang. Quantum Dots – QDs) CdS i badanie wpływu kwasowości na właściwości optyczne otrzymanego materiału.
EN
The main function of food packaging is maintaining the quality of food products during their storage and transport and increasing their shelf life by controlling the penetration of moisture and gases. One of the important factors affecting the taste and freshness of selected food products is their acidity. Changes in acid-base properties take place due to the influence of external factors, temperature and storage conditions. The aims of this study have been to synthetize a biodegradable composite based on a semi-synthetic polysaccharide containing CdS quantum dots (QDs) and to analyse the influence of acidity on the optical properties of the obtained material.
14
Content available remote Luminescence of II–VI and III–V nanostructures
EN
Photoluminescence of HgCdTe epitaxial films and nanostructures and electroluminescence of InAs(Sb,P) light-emitting diode (LED) nanoheterostructures were studied. For HgCdTe-based structures, the presence of compositional fluctuations, which localized charge carriers, was established. A model, which described the effect of the fluctuations on the rate of the radiative recombination, the shape of luminescence spectra and the position of their peaks, was shown to describe experimental photoluminescence data quite reasonably. For InAs(Sb,P) LED nanoheterostructures, at low temperatures (4.2–100 K) stimulated emission was observed. This effect disappeared with the temperature increasing due to the resonant ‘switch-on’ of the Auger process involving transition of a hole to the spin-orbit-splitted band. Influence of other Auger processes on the emissive properties of the nanoheterostructures was also observed. Prospects of employing II–VI and III–V nanostructures in light-emitting devices operating in the mid-infrared part of the spectrum are discussed.
EN
Different morphologies of bismuth sulphide (Bi2S3) nanoparticles (NPs) were synthesized at room temperature using wet chemical method. The properties of bismuth sulphide (Bi2S3) nanoparticles can be controlled by different amounts of Mn2+ dopant. The synthesized nanoparticles were characterized by several techniques, such as high resolution scanning electron microscopy (HR-SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), electron diffraction (ED), and energy dispersive X-ray spectroscopy (EDS). The nanoparticles (Bi2S3) were found to have excellent activity for the UV light assisted decolorization of methyl violet dye and also helped to speed up the redox reaction of Fe(CN)3−6 and S2O2−3. The reactions were monitored through UV-Vis spectroscopy.
EN
In this study, physical properties of copper sulfide thin films deposited on glass substrates by spray pyrolysis method at different temperatures (260 °C, 285 °C and 310 °C) were investigated. The influence of annealing time on the physical properties of grown layers was also studied. According to FESEM images, the sizes of the compact copper sulfide grains were varied from about 100 nm to 60 nm. Hall effect and resistivity measurements confirmed that all samples had p-type conductivity. The XRD patterns showed that, together with the dominant digenite phase (Cu1.8S) in all samples, the copper-rich phases also appeared as a result of increasing substrate temperature. The optical UV-Vis spectra analysis showed that due to increasing the substrate temperature, the band gap of the layers was reduced from about 2.4 eV to 2.0 eV. We found that as a result of annealing at 400 °C for 1.5 h in Ar atmosphere, the sample which was initially grown at 310 °C with the highest copper content, totally transformed into the polycrystalline monoclinic chalcocite phase (Cu2S) with 3D nanoporous architecture.
EN
The thermo-evolution of the interface obtained by room temperature (RT) deposition of 8.7 ML Ni onto an Ag/Si(111)-√3×√3 surface has been studied with the use of scanning tunneling microscopy. Annealing the surface within RT- 573 K temperature range leads to the increase in surface roughness which is followed by its drop upon annealing at 673 K. The comparison of the images presented here with those published for both submonolayer Ni and 4.2 ML Ni indicates coverage-dependent features.
PL
Ewolucja termiczna interfejsu otrzymanego w wyniku osadzenia 8.7 ML Ni na powierzchni Ag/Si(111)-√3×√3 w temperaturze pokojowej (RT) badana była przy użyciu skaningowej mikroskopii tunelowej. Wygrzewanie powierzchni w zakresie temperatur RT- 573 K prowadzi do wzrostu szorstkości powierzchni, po czym w temperaturze 673 K następuje jej spadek. Porównanie obrazów prezentowanych w niniejszej pracy z obrazami opublikowanymi dla pokryć Ni niższych niż 1 monowarstwa oraz dla pokrycia 4.2 ML wskazuje na występowanie cechy zależnych od pokryć.
18
EN
Nanostructured targets, based on hydrogenated polymers with embedded nanostructures, were prepared as thin micrometric foils for high-intensity laser irradiation in TNSA regime to produce high-ion acceleration. Experiments were performed at the PALS facility, in Prague, by using 1315 nm wavelength, 300 ps pulse duration and an intensity of 1016 W/cm2 and at the IPPLM, in Warsaw, by using 800 nm wavelength, 40 fs pulse duration, and an intensity of 1019 W/cm2. Forward plasma diagnostic mainly uses SiC detectors and ion collectors in time of fl ight (TOF) confi guration. At these intensities, ions can be accelerated at energies above 1 MeV per nucleon. In presence of Au nanoparticles, and/or under particular irradiation conditions, effects of resonant absorption can induce ion acceleration enhancement up to values of the order of 4 MeV per nucleon.
19
Content available remote Fabrication and characterization of nanostructured Ba-doped BiFeO3 porous ceramics
EN
Nanostructured barium doped bismuth ferrite, Bi0.8Ba0.2FeO3 porous ceramics with a relatively high magnetic coercivity was fabricated via sacrificial pore former method. X-ray diffraction results showed that 20 wt.% Ba doping induces a structural phase transition from rhombohedral to distorted pseudo-cubic structure in the final por(o)us samples. Moreover, utilizing Bi0.8Ba0.2FeO3 as the starting powder reduces the destructive interactions between the matrix phase and pore former, leading to an increase in stability of bismuth ferrite phase in the final porous ceramics. Urea-derived Bi0.8Ba0.2FeO3 porous ceramic exhibits density of 4.74 g/cm3 and porosity of 45 % owing the uniform distribution of interconnected pores with a mean pore size of 7.5 mu m. Well defined nanostructured cell walls with a mean grain size of 90 nm were observed in the above sample, which is in a good accordance with the grain size obtained from BET measurements. Saturation magnetization decreased from 2.31 in the Bi0.8Ba0.2FeO3 compact sample to 1.85 A.m2 /kg in urea-derived Bi0.8Ba0.2FeO3 porous sample; moreover, coercivity increased from 284 to 380 kA/m.
PL
W artykule podsumowano ostatnie 25 lat prac badawczych i aplikacyjnych nad laserami półprzewodnikowymi prowadzonych w Zakładzie Fotoniki ITE. Prace te dotyczyły nowej generacji laserów półprzewodnikowych, których działanie opiera się na wykorzystaniu specyficznych zjawisk fizycznych zachodzących w nanostrukturach. Były to prace pionierskie w skali kraju, nawiązujące do aktualnych trendów nauki światowej. Stały się one możliwe dzięki wprowadzeniu do Polski nowych technologii wzrostu struktur półprzewodnikowych, nowych sposobów finansowania prac badawczych i szerokiemu otwarciu na współpracę międzynarodową.
EN
The paper summarizes the last 25 years of research and application works on semiconductor lasers carried at the Department of Photonics at the Institute of Electron Technology. The research dealt with a new generation of semiconductor lasers which operations is based on quantum effects in nanostructures. These were pioneering works in Poland, following actual trends in world science and technology. Their realization became possible due to the advent of new technologies of the growth of semiconductor structures, introduction of new instruments of funding research and opening for international cooperation.
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