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PL
Nanocząstki są niezwykle małymi składnikami materii o rozmiarze nieprzekraczającym wielkości 100 nm w jednym z trzech wymiarów. Powszechnie występują w środowisku w sposób naturalny lub jako produkt celowej albo niezamierzonej działalności człowieka. Kontakt kręgowców z nimi jest więc nieunikniony. Okazuje się, że nanocząstki oddziałują ze składnikami układu immunologicznego tych organizmów. Mogą pobudzać albo hamować składowe wrodzonej i nabytej odporności u kręgowców w zależności od swoich właściwości fizyczno-chemicznych i strukturalnych. Coraz większa jest wiedza dotycząca oddziaływania nanocząstek z białkami układu dopełniacza (komplementu). Nanocząstki mogą oddziaływać ze składnikami kaskady komplementu na różnych etapach aktywacji, tj. od etapu rozpoznania patogenów, przez działanie jego składników, po utworzenie kompleksu atakującego błonę. W tym zakresie oddziałują na komplement hamująco bądź aktywująco, w zależności od właściwości fizyczno-chemicznych. Wpływają również na komórki układu immunologicznego, takie jak makrofagi. Obserwuje się także udział nanocząstek w rozwoju i przebiegu alergii. Dokładne poznanie powyższych oddziaływań daje możliwości zrozumienia wpływu nanocząstek znajdujących się w środowisku na organizmy zwierząt kręgowych i poznania korzyści oraz konsekwencji jakie mogą z tego wynikać.
EN
Nanoparticles are extremely small components of matter not exceeding 100 nm in one of the three dimensions. They commonly occur in the environment naturally or as a product of intentional or unintentional human activity. The contact of vertebrates with them is therefore inevitable. lt turns out that nanoparticles interact with the components of the immune system of these organisms. They can stimulate or inhibit the components of innate and acquired immunity in vertebrates depending on their physicochemical and structural properties. Knowledge about the interaction of nanoparticles with complement proteins is increasing. Nanoparticles can interact with the components of the complement cascade of various stages of activation, i.e. from the pathogen recognition stage, to the action of its components, to the formation of the membrane attack complex. In this regard, they inhibit or stimulate the complement depending on the physicochemical properties. They also affect immune cells such as microphages. The participation of nanoparticles in the development and course of allergies is also observed. A thorough understanding of the above interactions gives the opportunity to understand the impact of nanoparticles in the environment on vertebrate animals and to know the consequences and benefits that may result from this.
PL
W artykule zawarto podstawowe informacje dotyczące ochrony układu oddechowego przed aerozolami zawierającymi nanocząstki. Z nanocząstkami coraz częściej mamy do czynienia nie tylko w pracy zawodowej, na skutek rozwoju nowych technologii, ale również w życiu codziennym. Rosnąca ilość zagrożeń docierających drogą oddechową, związana z rozwojem przemysłu, nowymi technologiami i zanieczyszczeniem środowiska jest sytuacją, z którą coraz częściej musimy się mierzyć. Niezwykle istotna z punktu widzenia zdrowia społeczeństwa jest również rosnąca świadomość użytkowników sprzętu ochrony układu oddechowego odnośnie do istniejących zagrożeń. Przywykliśmy już na ulicach naszych miast do w tłoku osób w półmaskach filtrujących, chroniących przed smogiem. Historia oczyszczania powietrza do oddychania sięga czasów Cesarstwa Rzymskiego, gdzie w pierwszym wieku naszej ery najprawdopodobniej po raz pierwszy zastosowano środek ochrony układu oddechowego. Ochrona poprzez stosowanie indywidualnego sprzętu ochrony układu oddechowego w dzisiejszym świecie staje się zjawiskiem coraz powszechniejszym. Nie dotyczy ona już tylko pracowników, ale również osób prywatnych - obecnie wszyscy chronimy się wszak przed nowym koronawirusem.
EN
This article provides basic information about protection of respiratory system from aerosols that contain nanoparticles. Nanoparticles, with which we are increasingly dealing not only in work, as a result of the development of new technologies, but also in everyday life. The growing number of hazards absorbed through the respiratory system, related to the development of industry, new technologies and pollution of the environment in which we live, is nowadays a situation that we must face more and more often. The growing awareness of users of respiratory protective devices regarding existing hazards is also extremely important from the point of view of public health. We have already got used to the image of people in filtering masks on the streets of our cities, protecting against smog. The history of purifying air for breathing goes back to the Roman Empire, where in the first century AD most probably the first time a respiratory protection was used. Respiratory protection through the use of individual solutions in the form of respiratory protection equipment, in today's world is becoming a more common phenomenon. It no longer applies only to employees but also to private individuals.
EN
The progress of medicine and cosmetology corresponds to the increase in the need for new drug design and delivery methods, due to the already common cancer risk, as well as other diseases, which are still difficult for curing. Regardless of the type of active substance and its final application, the selection and synthesis of the appropriate carrier is crucial to provide the pharmaceutics to the target with the controlled release for a set period of time, including the intelligent activity. Depending on the way the bioactive substance is bound to carriers in the drug delivery systems (DDS) they are classified onto: carriers that physically encapsulate them inside i.e. liposomes, solid lipid nanoparticles, nanostructural lipid carriers, nanoparticles (nanocapsules, nanospheres), micelles, and carriers that chemically bind the active substance, i.e. conjugates, polyplexes. The current studies are emphasized to achieve the most perfect improvement, which concerns the efficiency of encapsulation, the ability to deliver several compounds simultaneously or sequentially, the productive release, the elimination of side products, the replacement of synthetic polymers by natural, biodegradable, biocompatible and non-toxic polymers. These carriers are also developed in terms of sensitivity to stimuli (one or several simultaneously or sequentially activated) and adapted for combined therapy. Although the subject of active substance delivery with the use of carriers is already widely studied, these are still a needs for the designing of new or the enhancement of the already known DDS. Working on this issue there is hope that today still incurable diseases, neoplastic diseases, as well as the diagnosis of these diseases themselves, will be possible to control and treat in the future. This report presents the current state of the knowledge in the area of DDS, focusing on newly developed solutions in the last years.
EN
The present investigation was aimed to study the cytotoxic response induced by molybdenum disulfide in nano- (MoS2-NPs) and micro- (MoS2-MPs) size of particle in human bronchial (BEAS-2B) and alveolar (A549) cells. The cells were exposed with different particle size of MoS2 in concentrations range 1-200 μg/mL for 24, 48, and 72 h, and then the cytotoxicity assays (MTT and NRU) was performed. Afterwards, long-term toxicity was assessed by colony forming efficiency assay (CFEA) during 10 days exposure of the cells. Both MoS2-NPs and MoS2-MPs showed similar, weak cytotoxic effects on BEAS-2B and A549 cells assessed by MTT assay, that is reduction of cell viability to approx. 60-70% at concentrations of 2.5 and 5 μg/mL. The percentage viability remained relatively constant at this level across all concentrations above 5 μg/mL. In long-term exposure, both MoS2 inhibited colony formation in a wider range of concentrations to 200 μg/mL. MoS2-NPs were slightly more cytotoxic than MoS2-MPs. The data suggest the low potential hazardous nature of both MoS2 tested with an indication of higher toxicity of MoS2-NPs.
PL
Celem badań była ocena cytotoksycznego działania nano- (MoS2-NPs) i mikrometrycznego (MoS2-MPs) disiarczku molibdenu na ludzkie komórki nabłonka oskrzelików (BEAS-2B) i pęcherzyków (A549) płuc. Komórki narażano na różnej wielkości cząstki MoS2 w zakresie stężeń 1-200 μg/ml przez 24, 48 i 72 h. Badano wpływ obu rodzaju cząstek MoS2 na integralność błon komórkowych (test NRU) oraz aktywność metaboliczną komórek (test MTT). Oceniano również zdolność komórek do proliferacji po długotrwałym (10 dni) narażeniu na podstawie testu efektywności formowania kolonii (CFEA). Oba MoS2 powodowały podobne, słabe działanie cytotoksyczne na komórki oceniane testem MTT, tj. obniżenie przeżywalności komórek do ok. 60-70% w stężeniach of 2,5 and 5 μg/mL po 24 h, które w niewielkim stopniu nasilało się z czasem narażenia, natomiast nie obserwowano wzrostu cytotoksyczności ze wzrostem stężenia. Po długotrwałej ekspozycji (10 dni) oba MoS2 hamowały zdolność tworzenia kolonii w szerszym zakresie stężeń tj. do 200 μg/mL, przy czym MoS2-NPs wykazywały silniejsze działanie ograniczające zdolność komórek do proliferacji niż MoS2-MPs. Dane wskazują na niski potencjał toksyczny obu badanych MoS2 ze wskazaniem wyższej toksyczności MoS2-NP.
PL
Artykuł stanowi przegląd literatury dotyczącej wytwarzania, struktury i właściwości membran preparowanych z roztworów polimerowych modyfikowanych nanocząstkami. Dodatek nanomateriałów wpływa na budowę strukturalną i właściwości fizykochemiczne, a także właściwości transportowo-separacyjne wytworzonych membran. Przedstawiono stan najnowszej wiedzy na temat membran nanokompozytowych wytwarzanych za pomocą inwersji faz.
EN
Preparation, structure and properties of nanocomposite membranes prepared by phase inversion The article is a review of the literature related to the techniques of preparation, structure and properties of the membranes obtained from polymer solutions modified with nanoparticles. The incorporation of nanomaterials influences the structure and physicochemical properties as well as transport and separation characteristics of the produced membranes. The current state-of-the-art in the field of polymer nanocomposite membranes prepared by phase inversion is presented.
PL
Nowa norma międzynarodowa ISO 21083 definiuje metodę badania materiałów filtracyjnych podczas filtracji nanocząstek o kształcie zbliżonym do kulistego. Opisana procedura może być stosowana do wyznaczania parametrów operacyjnych materiałów filtracyjnych dowolnych klas. Skuteczność filtracji jest wyznaczana na podstawie uśrednionych wyników uzyskanych dla próbek badanego materiału w stanie wyjściowym oraz po neutralizacji ładunku w oparach 2-propanolu. Norma nie wprowadza podziału na klasy filtrów, a w raporcie końcowym z badań są podawane frakcyjne skuteczności zatrzymywania cząstek. Zakres tematyczny artykułu obejmuje zagadnienia zdrowia oraz bezpieczeństwa i higieny środowiska pracy będące przedmiotem badań z zakresu nauk o zdrowiu oraz inżynierii środowiska.
EN
The new international standard ISO 21083 provides a method of testing filter media during the filtration of spherical shaped nanoparticles. The described procedure can be used to determine operating parameters of filtration materials of any classes. The filtration efficiency is determined on the basis of averaged results obtained for samples of the tested material in the initial state and after neutralization of the charge in the 2-propanol vapour. The standard does not introduce a division into filter classes, and in the final report of the tests, fractional particle retention efficiencies are given. This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering.
7
PL
W artykule określono wpływ modyfikacji posadzki cementowej nanocząstkami fluorku cyny(II) na jej wybrane właściwości. Do badań przygotowano jedną próbkę referencyjną oraz trzy różne próbki posadzki cementowej modyfikowanej fluorkiem cyny(II), z zawartością nanocząstek 0,5 ÷ 1,5% co 0,5%, w stosunku do masy cementu. Wykonane posadzki badano pod kątem odporności na ścieranie oraz przypowierzchniowej wytrzymałości na rozciąganie. Na podstawie badania ścieralności wykazano, że wraz ze wzrostem nanocząstek maleje ubytek masy posadzki cementowej. Dodatkowo, większa ilość fluorku cyny(II) w posadzce cementowej pozytywnie wpływa również na jej przypowierzchniową wytrzymałość na rozciąganie.
EN
The main aim of the article is to describe the influence of modification of cement floor with tin (II) fluoride nanoparticles on its selected properties. To the tests, one reference sample was prepared. Moreover, three cement floor samples were modified with different percentage content of tin(II) fluoride nanoparticles, from 0,5% to 1,5%, every 0,5%, in relation to cement mass. On prepared samples the abrasion resistance and subsurface pull-off strength tests were performed. Based on obtained results, it has been proved that abrasion resistance increases with higher amount of tin(II) fluoride nanoparticles in cement floor. Moreover, higher amount of tin(II) fluoride in modified cement floor has positive impact on its subsurface pull-off strength.
EN
Purpose: Investigate the hydrophobic, superhydrophobic and hydrophilic properties of Alumina (Al2O3) and Magnesium (Mg) nanoparticles. Design/methodology/approach: This research was conducted by SEM-EDX analysis of Magnesium and Alumina nanoparticles, observation of gas bubbles when droplets of water contact with membrane surfaces, measurement of surface roughness and detection of Hydrogen gas production using Gas Chromatography. There are eleven compositions (Al2O3:Mg) membranes used in this study, namely: (0:100; 10:90; 20:80; 30:70; 40:60; 50:50; 60:40; 70:30; 80:20; 90:10; and 100:0). Findings: Successfully found an alloy membrane between Alumina (Al2O3) and Magnesium (Mg) nanoparticles in the composition of Mg:Al2O3 (0:100%) having Hydrophobic properties; Mg:Al2O3 (50:50%) has Superhydrophobic properties and Mg:Al2O3 (100:0%) has hydrophilic properties. Three conditions occur when H2O droplets come in contact with the membrane layer, namely: hydrophobic conditions when the trapped gas pressure is smaller than the droplet pressure. Superhydrophobic conditions when the trapped gas pressure is equal to the droplet pressure. Hydrophilic conditions occur when the trapped gas pressure is greater than the droplet pressure. Research limitations/implications: This research is limited to the hydrophobic nature of Nano Alumina (Al2O3) and Magnesium (Mg) membrane particles. Practical implications: Superhydrophobic properties are very suitable to be applied to membranes that are useful for destiny. Originality/value: The novelty of this study is to find the right mixture of nanoparticles of Alumina and Magnesium in a composition that is capable of creating hydrophobic, superhydrophobic and hydrophilic properties.
EN
Due to the increasing production and development of nanoparticles, it has become necessary to control the exposure to ultrafine particles (aerodynamic diameter < 0.1 μm) when handling nanopaints. The paper deals with the number and mass distribution of particulate matter (PM) in an indoor environment before, during and after the application of paint Protectam FN containing titanium nanoparticles. The size distribution determination was performed by the electrical low-pressure cascade impactor (ELPI+) in the range from 0.006 μm to 9.93 µm. The highest number of particles was observed in the range from 0.006 to 0.0175 μm. The particulate mass concentration ranging from 0.0175 to 0.0307 μm did not represent more than 0.5% of the sum of PM10 during the individual measurements. The particle mass concentration increased in the range of 0.0175 to 0.0307 μm, after application of the coating nanopaint Protectam FN, but it was observed that the total number of particles has decreased. During the days following the application of the nanopaint, the mass concentration in this grain size class was significantly reduced.
PL
W związku z rosnącą produkcją i rozwojem nanocząstek konieczne stało się kontrolowanie ekspozycji na ultradrobne cząstki (średnica aerodynamiczna <0,1 μm) gdy wykorzystuje się farby zawierające nanocząsteczki (nanopaint). Artykuł dotyczy liczby i rozkładu masowego cząstek stałych (PM) w środowisku wewnętrznym przed, w trakcie i po zastosowaniu farby Protectam FN zawierającej nanocząstki tytanu. Określenie rozkładu wielkości przeprowadzono za pomocą elektrycznego impaktora kaskadowego (ELPI +) w zakresie od 0,006 μm do 9,93 μm. Największą liczbę cząstek zaobserwowano w klasie ziarnowej od 0,006 do 0,0175 μm. Udział masowy cząstek w zakresie od 0,0175 do 0,0307 μm nie stanowił więcej niż 0,5% sumy PM10 podczas poszczególnych pomiarów. Stężenie cząstek wzrosło w zakresie od 0,0175 do 0,0307 μm, po nałożeniu powłoki nanopaint Protectam FN, ale zaobserwowano, że całkowita liczba cząstek zmniejszyła się. Z upływem czasu od nałożenia nanopaint, udział tej klasy ziarnowej spadał.
PL
W pracy zaprezentowano wyniki badania wpływu ilości domieszki (2% at. oraz 4% at.) oraz temperatury wygrzewania (300°C i 600°C) na zdolność do rozkładu oranżu metylowego przez nanocząstki dwutlenku tytanu domieszkowane cerem (TiO₂:Ce) w wyniku procesu fotokatalizy. Nanocząstki TiO₂ zostały wytworzone metodą zol-żel, przy użyciu TTiP jako prekursora. Zaobserwowano, że lepsze właściwości fotokatalityczne ma próbka domieszkowana mniejszą ilością ceru, co oznacza, że istnieje optymalna zawartość domieszki. Aktywność fotokatalityczna tej próbki wynosiła 16,7%. Wygrzewanie w wysokiej temperaturze miało negatywny wpływ na zdolności próbek do rozkładu barwnika, gdyż aktywność fotokatalityczna żadnej z wygrzanych próbek nie przekroczyła 4%.
EN
This paper presents the results of the investigation of concentration of the dopant (2 at.% Ce and 4 at.% Ce) and high-temperature annealing (300°C i 600°C) on the decomposition of methyl orange by titanium dioxide nanoparticles doped with cerium (TiO₂:Ce) as a result of photocatalysis process. Methyl orange was decomposed by TiO₂:Ce nanoparticles, which were synthesized by sol-gel technique with using TTiP as a precursor. It was observed that the higher photocatalytic activity has been obtained by TiO₂ doped with smaller amount of cerium, which suggests the existence of the optimum dopant concentration. The photocatalytic activity of this nanoparticles was equal to 16.7%. Moreover, high-temperature annealing had a negative effect on TiO₂:Ce nanoparticles on decomposition ability, due to the fact that the photocatalytic activity of all annealed nanoparticles did not achieve 4%.
PL
W artykule przedstawiono sposób syntezy nanokompozytu węglowego z nanocząstkami złota (warstw C-Au), charakteryzację oraz potencjalne możliwości aplikacyjne warstw w oparciu o ich właściwości fotoelektryczne i/lub fototermiczne. Omówione zostały wyniki badań topografii warstw otrzymane metodą skaningowej mikroskopii elektronowej, morfologii - metodą spektrometrii rentgenowskiej z dyspersją energii, budowy krystalicznej - metodą dyfrakcji promieniowania rentgenowskiego i struktury elektronowej - metodą spektroskopii w zakresie światła widzialnego oraz bliskiego ultrafioletu.
EN
In this article the method of synthesis of carbon nanocomposite materials with gold nanoparticles was presented. The characterization and potential application of this films based on their photoelectric and / or photothermal properties were shown. The results of topography studies obtained by scanning electron microscopy, morphology - X-ray spectrometry with energy dispersion, crystal structure - X-ray diffraction and electron structure - visible and near ultraviolet spectroscopy are discussed.
12
Content available remote Silver and gold ions recovery from batch systems using Spirulina platensis biomass
EN
In order to assess ability of Spirulina platensis to recover silver and gold ions from the environment the bioaccumulation of silver and gold ions and their effect on growth, proteins and carbohydrates content of Spirulina platensis biomass was studied. Silver nitrate (AgNO3) in concentration range 0.01-1 mg/dm3 and tetrachloroaurate Na[AuCl4] in concentration range 18.5-370 mg/dm3 were added as component of the Spirulina platensis cultivation medium. In case of silver two cultivation media were studied: standard and Cl-free. The process of silver and gold uptake was traced using neutron activation analysis. Presence of silver ions in standard cultivation medium reduced biomass productivity by 66 %, while in Cl-free biomass productivity was reduced by 11.8 % only. The reduction of proteins content by 30 % in Cl-free medium and by 19 % in standard medium was also observed. The experiments showed that in case of gold ions loading, the biomass productivity and protein content were reduced only at high Na[AuCl4] concentration in the medium. The behaviour of carbohydrates content change was similar under silver and gold loadings: decrease at low metal concentration followed by increase at high metal concentrations. Scanning electron microscopy allowed observation of spherical metal nanoparticles, which were formed extracellularly during silver and gold bioaccumulation. Spirulina platensis can be used for recovery of precious metals as well as metal nanoparticles production.
13
Content available remote Natural flavonoids as potential photosensitizers for dye-sensitized solar cells
EN
Natural flavonoids quercetin, morin, fisetin and luteolin were studied as potential photosensitizers for dye-sensitized solar cells (DSSC). Spectroscopic methods were used to investigate the formation of dye/TiO2 nanoparticles assemblies and the development of their absorption spectra. The results show that the flavonoids adsorb well on TiO2 nanoparticles and this process causes the shift of absorption spectra from the near UV into the visible range of solar light. The mode of binding of the dye molecules on TiO2 surface is analyzed by comparison of spectral absorption properties and with the use of structural differences introduced by fisetin and luteolin for discrimination between several possibilities.
PL
Jednym z kierunków rozwoju technologii materiałowych jest nanotechnologia rozumiana jako dziedzina zajmująca się zastosowaniem nanododatków do wytwarzania nowych materiałów oraz ich wpływem na parametry modyfikowanych materiałów. W ostatnich latach nanotechnologia wkracza do technologii modyfikacji asfaltów stosowanych do wykonania nawierzchni drogowych. W artykule przedstawiono stosowane obecnie w budownictwie drogowym nanododatki oraz ich właściwości.
EN
One of the direction in the development of the material technology is nanotechnology, understood as using nanoadditives to create new materials and the impact of the additives on the properties of modified materials. In recent years nanotechnology is increasingly used in the modification of the bitumen used in the asphalt pavements. The article presents presently used nanoadditives and their properties.
EN
In the recent years industrial applications of carbon allotropes such as carbon nanotubes (CNTs) and graphene have been tested extensively, thus justifying research on the environmental impact these materials have. In the current paper we compare EDS spectroscopy results of a cabin filter used in a car to a filter used in an air purifier inside a residential space. The contaminants adsorbed on the car-bon nanoparticles trapped in both types of filters allows for determining of their source of origin demonstrating clearly the dominant role of non-road emissions in Poland. Finally we present the experimental study on the growth of plants on substrates intentionally enriched with CNTs.
EN
Purpose: The main purpose of this publication is to bring closer method of synthesis and examining basic properties of TiO2, ZnO and NiO nanoparticles (NPs), and investigate their possible biomedical application. Design/methodology/approach: Nanopowders were made with sol-gel method. Surface morphology studies of the obtained materials were made using Zeiss's Supra 35 scanning electron microscope and the structure using S/TEM TITAN 80-300 transmission electron microscope. In order to confirm the chemical composition of observed nanopowders, qualitative tests were performed by means of spectroscopy of scattered X-ray energy using the Energy Dispersive Spectrometer (EDS). The DLS (Dynamic Light Scattering) method was used to analyse the particle size distribution using the AntonPaar Litesizer 500 nanoparticle size analyser. Changes in particle size distribution at elevated temperatures were also observed. The TiO2, ZnO and NiO NPs with spherical shape were successfully produced by sol-gel method. Findings: The diameter of the as prepared nanoparticles does not exceed 25 nm which is confirmed by the TEM analysis. The highest proportion among the agglomerates of the nanoparticles has been shown to show those with a diameter of 80 to 125 nm. The qualitative analysis of EDS confirmed the chemical composition of the material. Practical implications: Nanoparticles (NPs) has been receiving an incrementally increasing interest within biomedical fields researchers. Nanoparticles properties (physical, chemical, mechanical, optical, electrical, magnetic, etc.) are different from the properties of their counterparts with a larger particle size. Originality/value: The nanoparticles were prepared using sol-gel method which allows the particle size to be controlled in a simple way.
EN
The paper deals with the problems of nanoparticles and nanomaterials applied in technical practice. The research on the use of nanoparticles has at present a great development. Their potential has a large of use. Particles of nano-size, i.e. below 100 nm exhibit other properties than larger particles and because this area is being explored in all possible sectors. The effect of adding these particles at different mechanical properties in coatings on various surfaces neat (separated on a band saw, milling work, ground roughness 800 and 80 polished) dependent on quality prepared nanoparticles by different conditions of milling. One of the possibilities for an extension of the duty cycle of tyre production molds is applying a protective coating. Due to the functionality of the desktop is needed a very thin coating layer. A suitable type of coating is thus a PTFE coating, which prolongs the service life of hundreds of percent. Better possibility how to improve an extension of the duty cycle is the addition of the coating titanium dioxide particles into the PTFE medium. This is the way how to create nanocomposite directly on the mold surface.
EN
In this study, melting of a phase changing material enriched with nanoparticles in a circular ring-rectangular enclosure was investigated and the results were analyzed. At the beginning of the melting process in the absence of a natural displacement, the mechanism of conduction heat transfer around the hot cylinder is the dominant mechanism. Over time, natural displacement gradually appears and deforms the melting boundary above the cylinder. Over time, when the thickness of the liquid phase grows, the thermal resistance increases, this can be verified by reviewing the Nusselt chart. So this phenomenon reduces the rate of melting and temperature changes. The results show that increasing the nanoparticle volume fraction due to increased conductivity and decreasing latent heat causes an increase in the melting rate and the amount of energy absorbed. From the study of various volume fractions, it can be concluded that the use of a higher volume fraction of 3% is more appropriate both in terms of energy and in terms of the melting rate. However, it should be taken into account that if the melting rate exceeds this value, it may cause agglomeration and deposition of nanoparticles and reducing system efficiency.
EN
Among the large family of metallic oxides, there is a considerable group possessing excellent semiconducting properties. What follows, they are promising materials for applications in the field of optoelectronics and photonics. Thanks to the development of nanotechnology in the last few decades, it is now possible to manufacture a great variety of different nanostructures. By controlling their size, shape, composition and crystallinity, one can influence such properties as band gap, absorption properties, surface to volume ratio, conductivity, and, as a consequence, tune the material for the chosen application. The following article reviews the research conducted in the field of application of the metallic oxide nanoparticles, especially ZnO, TiO2 and ITO (Indium-Tin Oxide), in such branches of optoelectronics as solid-state lightning, photodetectors, solar-cells and transparent conducting layers.
EN
Nanomaterials are the latest group of materials which owes its special features thanks to their nanosize. The most characteristic properties include the large surface area, strong chemical reactivity and tendency to agglomerate. Nanomaterials have wide applications in several disciplines, i.e. materials engineering, medicine and food technology. These materials have high potential in biomedical engineering thanks to increased biological activity when compared with the bulk material. Recent advances in nanotechnology are currently mostly focused on improvement of effective synthesis methods. Sonochemical irradiation is an effective technique for the synthesis nanoparticles. This method is widely used for inorganic nanoparticles production in contrast to organic ones, which could open powerful possibilities of creating bioactive, therapeutic or self-cleaning surfaces. In principle, the introduction of a strong acoustic field into an aqueous solution induces acoustic cavitation. The nucleation, growth and collapse of the bubble during acoustic cavitation are graphically shown in Figure 1. When the bubble reaches a certain size it become resonant with ultrasonic radiation and rapidly increase in size. Then, the bubble becomes unstable and violently collapses. The collapse of microbubbles produces extremely high localized pressures and temperatures (hundreds bar and thousands K) which lead to hot spot. Conditions of sonochemistry are rather radical in comparison to other chemical processes. Moreover, the synthesis and simultaneously embedding nanoparticles into polymer surfaces are possible. This paper constitutes a review of the recent literature in sonochemical synthesis of organic, bioactive nanoparticles. The introduction will focus on a short overview of sonochemistry, the next part will present the mechanism of formation nanoparticles using ultrasounds. Also, some advantages of sonochemistry as a tool for nanomaterials fabrication is presented. In the next section some examples of bioactive nanoparticles prepared in sonochemical reaction are listed and advantages of sonochemical synthesis are discussed.
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