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PL
Korozji, jako procesu korzystnego termodynamicznie, nie można zatrzymać, ponieważ metale występują naturalnie w postaci rud tlenkowych lub soli metali. Dla gospodarki jest to niestety proces kapitałochłonny i niepożądany, jednak z zastosowaniem odpowiednich strategii działania można ograniczyć jego skalę. Niniejszy przegląd literatury, głównie z lat 2018–2020, skupia się na powłokach kompozytowych opartych na polimerze przewodzącym – polipirolu (PPy), wybranych tlenkach metali oraz, ewentualnie, domieszkach surfaktantów i innych związków. Celem pracy jest wykazanie roli polipirolu – polimeru przewodzącego, a przy tym ekologicznego, w ochronie konstrukcji przed korozją metali.
EN
Corrosion cannot be stopped due to its thermodynamically favorable character, since metals occur naturally in the form of oxide ores or metal salts. It is an adverse and capital-intensive process for the economy. However, it can be alleviated by adopting various strategies. This review of the literature, mainly from 2018–2020, focuses on composite coatings based on a conductive polymer – polypyrrole (PPy) and on some metal oxides with the possible use of surfactant admixtures and other compounds. The aim of the study is to emphasize the role of polypyrrole – a conductive and ecological polymer – in the protection of structures against metal corrosion.
2
Content available remote Granular metal-dielectric nanocomposites as an alternative to passive SMD
EN
AC electrical properties of granular metal-dielectric nanocomposites (FeCoZr)x(PbZrTiO3)(100-x) have been examined. The study was carried for frequencies from 50 Hz to 1 MHz and measurement temperatures of 81 K – 293 K. The samples above percolation threshold xc considered to be resistive. Layers subdued to thermal treatment in air atmosphere behave as perfect capacitors, especially for low temperatures. Nanomaterials below xc demonstrate inductive-like properties. Tested samples could provide an alternative to conventional SMD components.
PL
Ziarniste nanokompozyty typu metal-dielektryk o strukturze (FeCoZr)x(PbZrTiO3)(100-x) zbadano pod kątem właściwości elektrycznych w przedziale temperatur pomiarowych 81 K – 293 K oraz częstotliwości pomiarowych 50 Hz – 1 MHz. Materiały powyżej progu perkolacji xc wykazują rezystancyjny charakter, warstwy wygrzane w temperaturze 573 K – typowo pojemnościowy typ, natomiast nanokompozyty poniżej xc poddane obróbce termicznej – właściwości indukcyjne. Badane nanostruktury stanowią alternatywę dla konwencjonalnych elementów SMD.
EN
The impact of the addition of the nanofiller – halloysite – on the mechanical, physicochemical and biological properties of a nanocomposite, in which thermoplastic polyurethane fulfilled the role of the matrix was investigated. The nanocomposite was obtained by extrusion in three variants with 1, 2 and 3 wt % halloysite. The nanostructure of the obtained materials was confirmed using Atomic Force Microscopy (AFM). Based on the mechanical tests carried out, it was proven that the obtained nanocomposites were characterized by a tensile modulus greater than the polyurethane constituting the matrix. The density and hardness of the nanocomposites had changed within error limits compared to unmodified polyurethane. Biological tests showed no cytotoxicity of all the tested materials to normal human dermal fibroblasts (NHDF). Degradation tests were carried out in artificial plasma and showed that samples with 2 wt % halloysite addition had the best ratio of tensile strength and elongation at break to elasticity modulus.
PL
Zbadano wpływ naturalnego nanonapełniacza – haloizytu – na właściwości mechaniczne, fizykochemiczne oraz biologiczne kompozytu wytworzonego na bazie termoplastycznego poliuretanu. Nanokompozyt o zawartości 1, 2 i 3% mas. haloizytu otrzymywano na drodze wytłaczania. Nanostrukturę wytworzonych materiałów potwierdzono za pomocą mikroskopii sił atomowych (AFM). Na podstawie przeprowadzonych badań mechanicznych wykazano, że uzyskane nanokompozyty charakteryzują się modułem sprężystości większym niż poliuretan stanowiący osnowę. Zmiany gęstości i twardości niemodyfikowanego poliuretanu po dodaniu haloizytu mieściły się w granicach błędu pomiaru. Testy biologiczne nie wykazały cytotoksyczności wszystkich badanych materiałów wobec prawidłowych fibroblastów ludzkiej skóry (NHDF). Badania degradacji przeprowadzone w środowisku syntetycznego osocza wykazały, że próbki z dodatkiem 2% mas. haloizytu mają najlepszy stosunek wytrzymałości na rozciąganie i wydłużenia przy zerwaniu do modułu sprężystości.
EN
In manufacturing industries, the selection of machine parameters is a very complicated task in a time-bound manner. The process parameters play a primary role in confirming the quality, low cost of manufacturing, high productivity, and provide the source for sustainable machining. This paper explores the milling behavior of MWCNT/epoxy nanocomposites to attain the parametric conditions having lower surface roughness (Ra) and higher materials removal rate (MRR). Milling is considered as an indispensable process employed to acquire highly accurate and precise slots. Particle swarm optimization (PSO) is very trendy among the nature-stimulated metaheuristic method used for the optimization of varying constraints. This article uses the non-dominated PSO algorithm to optimize the milling parameters, namely, MWCNT weight% (Wt.), spindle speed (N), feed rate (F), and depth of cut (D). The first setting confirmatory test demonstrates the value of Ra and MRR that are found as 1.62 µm and 5.69 mm3/min, respectively and for the second set, the obtained values of Ra and MRR are 3.74 µm and 22.83 mm3/min respectively. The Pareto set allows the manufacturer to determine the optimal setting depending on their application need. The outcomes of the proposed algorithm offer new criteria to control the milling parameters for high efficiency.
EN
The biomaterials, which are the subject of this work, are the dental restorative materials classified as light cured polymer matrix ceramic composites or resin based composites. The dental composite materials are needed for the repairment of human teeth. Fillings and other dental applications are exposed to the biomechanical loading in the chewing process. The wear resistance and hardness are important functional properties. Currently, nanofiller composites play an important role among dental composites. The objective of this paper was to study and analyze the friction, mechanical and wear properties of the surface of polymer matrix ceramic filed nanocomposites. Three material groups were used, one commercial composite Filek Z550 (3M ESPE, USA) and two experimental composites Ex-nano(G) and Ex-flow(G). The microindentation tests were conducted on the Micro Combi Tester device (Anton Paar GmbH, Germany). Rotating sliding ball-on-disc friction tests were performed against an alumina ball on 5 N load at 1 Hz in the bath of artificial saliva at 37°C. The linear wear and friction coefficients were evaluated. In the light of the obtained results of contact and friction strength tests, it was found that the performance depends on the production technology of the polymer-ceramic composites. The test results indicate that the share of filler nanoparticles the in experimental composites is advantageous due to the tribological wear.
EN
The problem of plastic accumulation in the environment requires the development of effective strategies to shift the paradigm of used plastics from wastes to resources. In the present contribution, after an overview of the current plastic management strategies, the possible role of nanotechnology to this emerging field is considered. In particular, the challenges related to the use of nano-additives to improve the properties of recycled plastics is discussed based on the fundamental aspects of colloid stabilisation. Finally, the contribution of nanotechnology to the fabrication of effective catalysts for the depolymerisation of plastics into the constituent monomers is outlined.
PL
Dokonano przeglądu literatury krajowej i światowej, obejmującego również doniesienia i osiągnięcia własne autorek. Przegląd dotyczy stabilności termicznej i ograniczenia palności nanokompozytów polimerów termoutwardzalnych. Analizę termiczną nanokompozytów prowadzono, biorąc pod uwagę rodzaj, ilość i barierowość nanomodyfikatorów, ich strukturę oraz oddziaływanie między nanododatkiem a reaktywnymi grupami polimerów. Wykazano synergizm między nano- i mikrocząstkami a konwencjonalnymi fosforowymi antypirenami oraz ukazano różnice efektywności zastosowanych retardantów palenia wraz z odniesieniem do wymagań obowiązujących w krajach UE z zakresu modyfikacji ogniochronnej materiałów polimerowych.
EN
A review, with 44 refs. of fillers used as nano- or microretardants in polymer-matrix composites.
PL
Przedstawiono bieżące kierunki badań stabilności termicznej polimerów, ze szczególnym uwzględnieniem nowatorskich układów polimerowych: kompozytów i nanokompozytów, polimerów biodegradowalnych, biocydowych i do zastosowań specjalnych. Opisano ogólny mechanizm degradacji termicznej zachodzącej podczas przetwórstwa i podstawowe aspekty kinetyczne tego procesu. Omówiono przykłady badań właściwości termicznych wybranych tworzyw na bazie poliuretanów, żywic epoksydowych, kopolimerów kwasu akrylowego i poliestrów.
EN
The article presents current trends in the studies of thermal stability of polymers, with particular emphasis on novel polymeric systems: composites and nanocomposites, biodegradable and biocidal materials as well as polymers for special applications. The general mechanism of thermal degradation occurring during polymer processing and the basic kinetic aspects of this process are briefly described. Exemplary studies of thermal properties of selected plastics based on polyurethanes, epoxy resins, copolymers of acrylic acid and polyesters are also discussed.
EN
This paper aims to study the degradation rate of sugar palm nanofibrillated cellulose (SPNFCs) and sugar palm starch (SPS). SPNFCs were isolated from sugar palm fiber, while SPS is extracted from sugar palm trunk. The SPNFCs were reinforced with SPS biopolymer as biodegradable reinforcement materials of different diameter/length based on the number of passes of high pressurize homogenization process (5, 10 and 15 passes represented by SPS/SPNFCs-5, SPS/SPNFCs-10, and SPS/SPNFCs-15). These SPNFCs were incorporated into SPS plasticized with glycerol and sorbitol via solution casting method. Soil burial experiment performed on SPS and SPS/SPNFCs bionanocomposites showed that SPS was degraded more rapidly by losing 85.76% of its mass in 9 days compared to 69.89% by SPS/SPNFCs-15 bionanocomposite. The high compatibility between SPNFCs nanofiber and SPS biopolymer matrices can be observed through field emission scanning electron microscopy (FE-SEM).
PL
Zbadano szybkość degradacji nanowłóknistej celulozy wyizolowanej z palmy cukrowej (Arenga pinnata) (SPNFCs) oraz skrobi wydzielonej przez ekstrakcję z rdzenia pnia tej palmy (SPS). SPNFCs uzyskiwano z włókien palmy cukrowej, poddawanych homogenizacji pod wysokim ciśnieniem w 5, 10 lub 15 cyklach, otrzymując nanowłókna celulozy o różnej długości i średnicy. SPNFCs wprowadzano do SPS uplastycznionego mieszaniną (1 : 1) glicerolu isorbitolu. Metodą odlewania z roztworu wytwarzano błony nanokompozytowe SPS/SPNFCs-5, SPS/SPNFCs-10 i SPS/SPNFCs-15. Test glebowy procesu biodegradacji wykazał, że SPS ulegało szybszej degradacji, tracąc 85,76% swojej masy w ciągu 9 dni, w porównaniu z ubytkiem masy 69,89% w wypadku bionanokompozytu SPS/SPNFCs-15. Na podstawie analizy metodą skaningowej mikroskopii elektronowej z emisją polową (FE-SEM) stwierdzono dużą kompatybilność między nanowłóknami SPNFCs i biopolimerową osnową SPS.
EN
This work presents a theoretical study for the distribution of nanocomposite structure of plasmonic thin-film solar cells through the absorber layers. It can be reduced the material consumption and the cost of solar cell. Adding nanometallic fillers in the absorber layer has been improved optical, electrical characteristics and efficiency of traditional thin film solar cells (ITO /CdS/PbS/Al and SnO2/CdS/CdTe/Cu) models that using sub micro absorber layer. Also, this paper explains analysis of J-V, P-V and external quantum efficiency characteristics for nanocomposites thin film solar cell performance. Also, this paper presents the effect of increasing the concentration of nanofillers on the absorption, energy band gap and electron-hole generation rate of absorber layers and the effect of volume fraction on the energy conversion efficiency, fill factor, space charge region of the nanocomposites solar cells.
EN
The exponential increase in the potential applications of graphene has forced its inclusion in composites. Presently, composites containing graphene have been manufactured by many conventional processes. Since 3D printing (additive manufacturing) offers a wide range of advantages for manufacturing, researchers from the composite industry are now adopting novel techniques to manufacture graphene based composites via additive manufacturing. When selecting materials for composites, polymers stand out as the top choice for manufacturers because polymers require a low temperature to mold their shape and they are easy to handle when compared to ceramics and metals. Hence, substantial focus of the composite industry is now shifting towards manufacturing graphene based polymer matrix composites. In this regard, this paper provides a brief review of the 3D printing (additive manufacturing) processes which to date have been adopted to manufacture ‘graphene based polymer matrix composites’. The promising physical properties of graphene based polymer matrix composites and the future prospects of functionalizing graphene in polymer based composites is also highlighted.
EN
Constantly developing nanotechnology provides the possibility of manufacturing nanostructured composites with a polymer matrix doped with ceramic nanoparticles, including ZnO. A specific feature of polymers, i.e. ceramic composite materials, is an amelioration in physical properties for polymer matrix and reinforcement. The aim of the paper was to produce thin fibrous composite mats, reinforced with ZnO nanoparticles and a polyvinylpyrrolidone (PVP) matrix obtained by means of the electrospinning process and then examining the influence of the strength of the reinforcement on the morphology and optical properties of the composite nanofibers. The morphology and structure of the fibrous mats was examined by a scanning electron microscope (SEM) with an energy dispersive spectrometer (EDS) and Fourier-transform infrared spectroscopy (FTIR). UV –Vis spectroscopy allowed to examine the impact of zinc oxide on the optical properties of PVP/ZnO nanofibers and to investigate the width of the energy gap.
EN
The paper presents the results of research on nanocomposite nickel/graphene oxide (Ni/GO) coatings produced by electrochemical reduction method on a steel substrate. Discussed is the method of manufacturing composite coatings with nickel matrix and embedded graphene oxide flakes. For comparative purposes, the studies also included a nanocrystalline Ni coating without embedded graphene oxide flakes. Graphene oxide was characterized by Raman spectroscopy, infrared spectroscopy (FTIR) and transmission (TEM) and scanning (SEM) electron microscopy. Results of studies on the structure of nickel and composite Ni/GO coatings deposited in a bath containing different amount of graphene oxide are presented. The coatings were characterized by scanning electron microscopy, light microscopy, Raman spectroscopy and X-ray diffraction. The adhesion of the prepared coatings to the substrate was examined by the scratch method. The microhardness of the coatings was measured using the Vickers method on perpendicular cross-sections to the surface. Corrosion tests of the coatings were investigated using the potentiodynamic method. The influence of graphene oxide on the structure and properties of composite coatings deposited from baths with different content of graphene oxide was determined.
EN
The dispersion of nanoparticles in the host matrix is a novel approach to enhance the thermoelectric performance. In this work, we incorporate the TiC (x = 0, 1 and 2 wt.%) nanoparticles into a p-type Bi0.5Sb1.5Te3 matrix, and their effects on microstructure and thermoelectric properties were systematically investigated. The existence of TiC contents in a base matrix was confirmed by energy dispersive X-ray spectroscopy analysis. The grain size decreases with increasing the addition of TiC content due to grain boundary hardening where the dispersed nanoparticles acted as pinning points in the entire matrix. The electrical conductivity significantly decreased and the Seebeck coefficient was slightly enhanced, which attributes to the decrease in carrier concentration by the addition of TiC content. Meanwhile, the lowest thermal conductivity of 0.97 W/mK for the 2 wt.% TiC nanocomposite sample, which is ~16% lower than 0 wt.% TiC sample. The maximum figure of merit of 0.90 was obtained at 350 K for the 0 wt.% TiC sample due to high electrical conductivity. Moreover, the Vickers hardness was improved with increase the addition of TiC contents.
EN
A series of nanocomposite graphene/CoFe2 O4 and graphene/NiFe2 O4 hybrid materials was synthesized via facile, one-pot solvothermal route. The materials were obtained using two pressure methods: synthesis in the autoclave and synthesis in the microwave solvothermal reactor. The use of a microwave reactor enabled to significantly shorten the synthesis time up to 15 min. All the syntheses were carried out in a solution of ethanol. The effect of processing conditions and composite composition on the physicochemical properties and electric conductivity was studied. The specific surface area, density, morphology, phase composition, thermal properties and electric conductivity of the obtained composites were investigated. The results of studies of composites obtained in an autoclave and in a microwave reactor were compared.
EN
The addition of hard ceramic particles of nc-(Ti, Mo)C in carbon network into Ti matrix has been proved to be an efficient way to enhance their properties. The purpose of this work was to analyze the corrosion, tribological, mechanical and morphological effects of combining nc-(Ti, Mo)C/C with titanium metal, to create a unique composite via selective laser melting technique (SLM). Composites with different weight percentage (5, 10 and 20 wt%) of ceramic phase were produced. The samples of pure Ti and Ti-6Al-4V alloy were also tested, as a reference. These composites were examined for corrosion resistance in body fluid (artificial saliva solution). Moreover, the properties of titanium composites reinforced with nc-TiC powders were compared. It was stated that mechanical properties were significantly improved with increasing amount of nc-(Ti, Mo)C/C in Ti matrix. In terms of corrosion resistance, the composites showed worse properties compared to pure titanium and Ti-6Al-4V alloy, but better than TiC-reinforced composites.
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.
PL
W niniejszej pracy zaprezentowano stan badań na podstawie przeglądu literatury dotyczącej właściwości nanocząstek srebra (nano-Ag). Szczegółowo opisano właściwości korzystne z punktu widzenia zakładanych zastosowań, a także niekorzystne, powodujące wzrost zagrożenia związanego z cytotoksycznością i ekotoksycznością nano-Ag. Zaprezentowano przegląd literatury dotyczącej modyfikacji nano-Ag tlenkami metali oraz w kompleksowy sposób opisano różne metody wytwarzania nanomateriałów z tej grupy oraz układy wieloskładnikowe bioszkieł. Potwierdzono, że metoda zol-żel jest nie tylko mało skomplikowana z technologicznego punktu widzenia, ale także bardzo elastyczna, poprzez możliwość zastosowania różnych rodzajów prekursorów ceramiki i szerokiego wachlarza warunków prowadzonych procesów. Dane wskazują, że modyfikacje nanocząstek Ag tlenkiem glinu z wykorzystaniem metody zol-żel prowadzą do otrzymania ciekawych właściwości biologicznych, często znacząco różnych w porównaniu do wolnych nanocząstek Ag. Wciąż jednak trudnością pozostaje kontrola morfologii produktu końcowego i powtarzalność procesów zol-żel, ze względu na występujące zjawisko dyfuzji i transportu masy, które powoduje często rozrost wielkości wytwarzanych cząstek, a także powstawanie aglomeratów.
EN
This paper presents a review of the literature on the properties of silver nanoparticles (nano-Ag). Properties that are beneficial from the point of view of the intended applications have been described in detail, as well as undesired properties that increase the risk associated with the cytotoxicity and ecotoxicity of nano-Ag. A review of the literature concerning the modification of nano-Ag with metal oxides was also presented. Various methods for the production of nanomaterials from this group, as well as multi-component systems of bioglass, have been described in a comprehensive way. It was shown that the sol-gel method is not only not very complicated from a technological point of view, but also very flexible, through the possibility of using different types of ceramic precursors and a wide range of conditions of the processes. Data indicate that modifications of Ag with alumina particles using the sol-gel method lead to the production of interesting biological properties, often significantly different compared to free Ag nanoparticles. However, it is still difficult to control the final product morphology and the repeatability of the sol-gel processes because of the phenomenon of diffusion and mass transport often results in the size increase of the produced particles as well as the formation of agglomerates.
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