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Content available Synteza i zastosowanie modyfikowanych nanorurek TiO2
EN
Heterogeneous photocatalysis in the presence of semiconductor materials, especially TiO2, is increasingly studied due to its potential application in hydrogen generation, carbon dioxide conversion, and pollutant degradation. TiO2, known for its cost-effectiveness, stability, and safety, is particularly effective in its nanometric form, with nanotubes standing out for their structure that improves light absorption and charge carrier mobility. One approach to improve the properties of TiO2 for its application in photocatalytic processes involves its modification. Modifications of TiO2 nanotubes aim to reduce the rate of recombination of photogenerated charge carriers, increase photocatalytic activity in the UV range, extend its activity to the visible radiation range, and enhance reaction selectivity. Enhancing TiO2 photocatalytic efficiency involves modifications such as doping, creating heterojunctions, and introducing structural defects. The objective of this mini-review is to present selected methods of modifying TiO2 nanotubes obtained through anodic oxidation, leading to the enhancement of their photocatalytic properties.
EN
With the development of manufacturing processes, an increase in the importance of metal-fibre composites in materials engineering is observed. These are materials consisting of appropriately arranged layers of metal and various types of fibres. The very wide use of composite materials in the construction of machine and equipment components means they are often exposed to work in variable temperature conditions. The aim of this article was analysis of the thermal expansion of typical composites: carbon fibre-reinforced polymer, glass fibre-reinforced polymer, glass-reinforced aluminium laminate and carbon-fibre reinforced aluminium laminate. EN AW-6060 aluminium alloy was used as the reference material. The aim of the dilatometric tests was to determine the coefficient of thermal expansion and the dimensional stability of composite materials at elevated temperatures up to 100 °C. The EN AW-6060 aluminium alloy was characterized by the highest linear expansion coefficient (20.27×10−6 1/K). Composites containing glass fibres were characterized by the lowest positive linear thermal expansion coefficient. Among the composite materials tested, CARALLs exhibit the lowest thermal expansion coefficient.
PL
Wraz z rozwojem techniki, możemy zaobserwować wzrost znaczenia kompozytów metalowo-włóknistych w inżynierii mechanicznej. Są to materiały składające się z odpowiednio ułożonych warstw metalu oraz różnego rodzaju włókien. Bardzo szerokie zastosowanie materiałów kompozytowych w budowie elementów maszyn i urządzeń powoduje, że niejednokrotnie są one narażone na pracę w warunkach zmiennych temperatur. Celem tego artykułu była analiza rozszerzalności cieplnej typowych materiałów kompozytowych wzmocnionych włóknami węglowymi i szklanymi oraz laminatów typu GLARE i CARALL. Jako materiał referencyjny wykorzystano stop aluminium EN AW-6060. Celem badań dylatometrycznych było określenie rozszerzalności cieplnej i stabilności wymiarowej materiałów kompozytowych w podwyższonych temperaturach do 100°C z szybkością nagrzewania 5°C/min. Największym współczynnikiem rozszerzalności liniowej (20,27×10−61/K) charakteryzował się stop aluminium EN AW-6060. Najmniejszym dodatnim liniowym współczynnikiem rozszerzalności cieplnej charakteryzowały się kompozyty zawierające włókna szklane. Spośród materiałów kompozytowych, najmniejszym współczynnikiem rozszerzalności cieplnej charakteryzował się kompozyt typu CARALL.
EN
This article presents a description of the properties of basalt fibers and polymer composites containing basalt fibers. Basalt fibers are seen as a potentially beneficial component in composite development, especially for vehicles in transport applications. The article also presents the results of the mechanical properties investigation of the glass-epoxy and basalt-epoxy composites. The composites for testing were prepared using the popular hand lay-up method. The samples were cut from prepared plates using abrasive water jet methods. The obtained samples were tested to evaluate their flexural strength and interlaminar sharing strength. The achieved mechanical properties were compared.
PL
Artykuł przedstawia koncepcje weryfikacji materiału kompozytowego zbrojonego włóknem szklanym w osnowie epoksydu mogącego znaleźć zastosowanie w nośnej konstrukcji ramy motocyklowej. Poddano analizie występujące typy ram motocyklowych umożliwiających zastosowanie kompozytów. Wytworzono próbki materiału kompozytowego z wykorzystaniem metody trzpieniowej dla wybranej konstrukcji ramy, badając wpływ różnej orientacji włókien szklanych. Próbki kompozytu poddano badaniom fizykochemicznym, określając podstawowe własności wytrzymałościowe, gęstość, pracę zniszczenia oraz przeprowadzono obserwację mikroskopową wykonanych próbek.
EN
The article presents the concept of a glass fiber reinforced composite in an epoxy matrix that can be used in a motorcycle frame. Motorcycle frames types enabling the composites usage were analyzed. Composite material samples with different glass fibers orientations were produced using the pin method. The manufactured composite material was subjected to physicochemical tests to determine basic strength properties, density, work of destruction, and microscopic observation was carried out.
EN
The article presents the main research directions of the project implemented by the consortium under the National Defence and Security Program: "Development of modern, breakthrough technologies for state security and defence", codename "SZAFIR". During the implementation of the project, the possibilities of using terahertz radiation will be examined for diagnostic tests of components crucial for defence and security, such as solid rocket fuels, aramid fibre-based composites (bulletproof vests, helmets, pyrotechnic suits), and polymer composites reinforced with glass and carbon fibres (aircraft elements). As a result of research, the interaction of tetheric radiation with materials of these components will be analysed, followed by the development of a methodology for determining their defects. This will result in creating innovative dedicated stations for non-destructive testing of these components. Neural network-based advanced signal processing and artificial intelligence algorithms will be used for automatic diagnostics of key components, improve the process of their control and therefore increase the safety of people and military equipment.
PL
W artykule przedstawiono główne kierunki badawcze projektu TeraDiag realizowanego przez konsorcjum (WITU, IOE WAT, ITWL oraz LTT) w ramach programu NCBR na rzecz obronności i bezpieczeństwa państwa pn. "Rozwój nowoczesnych, przełomowych technologii służących bezpieczeństwu i obronności państwa” pk. "SZAFIR". W trakcie realizacji projektu zostaną zbadane możliwości zastosowania promieniowania terahercowego do badań diagnostycznych kluczowych dla obronności i bezpieczeństwa komponentów, takich jak stałe paliwa rakietowe, kompozyty na bazie włókien aramidowych (kamizelki kuloodporne, hełmy, kombinezony pirotechniczne), kompozyty polimerowe wzmacniane włóknami szklanymi i węglowymi (elementy statków powietrznych).W wyniku prac badawczych przeprowadzona będzie analiza oddziaływania promieniowania terahercowego anetz materiałami tych komponentów a następnie opracowana metodyka wyznaczania ich defektów. W rezultacie powstaną nowatorskie dedykowane co najmniej dwa stanowiska do badań nieniszczących tych komponentów. Zaawansowane algorytmy przetwarzania sygnałów i sztucznej inteligencji bazujące na sieciach neuronowych pozwolą na automatyczną diagnostykę kluczowych komponentów, przyczynią się do polepszenia procesu ich kontroli, a przez to poprawią bezpieczeństwo ludzi i sprzętu wojskowego.
EN
The non-destructive testing methods (NDT) are gaining significant attention due to their ability to monitor the objects structure without causing their damage. In recent years, studies focused on NDT have been directed towards imaging with the use of the terahertz (THz) waves. The presented study describes terahertz imaging-based NDT method and testing results on selected military-designated materials with intentionally introduced defects. The main aim of the work was to clearly detect various discontinuities in materials interior and thus, to show the possibilities of the newly developed terahertz-based testing method in transmission mode. The results confirmed high applicability of THz waves for monitoring various materials where each implemented flaw was easily distinguished. Therefore, the presented method looks promising for real applications in everyday practice.
PL
W prezentowanej pracy opisano zastosowanie metody obrazowania nieniszczącego przy wykorzystaniu promieniowania terahercowego. Badaniom poddano wybrane grupy materiałów kompozytowych znajdujących zastosowanie w wojsku, które miały celowo wprowadzone defekty. Głównym celem pracy było wyraźne wykrycie różnych nieciągłości we wnętrzu materiałów kompozytowych, a tym samym pokazanie możliwości nowo opracowanej metody testowania opartej na zastosowaniu promieniowania terahercowego w trybie transmisyjnym. Metoda terahercowa w trybie transmisyjnym, gdzie generator promieniowania i detektor znajdowały się po przeciwnej stronie próbki. W wyniku badań wykryte zostały wszystkie defekty celowo wprowadzone do analizowanych materiałów kompozytowych, wśród których wyróżniono: kompozyty wzmocnione włóknem aramidowym, gazogenerator, wkład do kamizelki kuloodpornej. W ramach tej pracy przedstawiono przykłady efektywnego wykorzystania promieniowania terahercowego jako metody badań nieniszczących oraz potencjalne zastosowanie w monitorowaniu materiałów o przeznaczeniu wojskowym. Wyniki dowiodły, że metoda terahercowa jest w stanie wykryć wady ukryte w kompozytach wzmocnionych włóknami aramidowymi, gazogeneratorze i wkładzie do kamizelki kuloodpornej. Wyniki przedstawione w postaci zdjęć cechowała wyższa jakość w odniesieniu do danych literaturowych.
EN
The effect of nanocellulose (3 or 5 wt%) on the PLA properties was investigated. Moreover, the possibility of using such composites as an expansion joint material was considered. Nanocellulose was obtained from wastepaper by mechano-chemical treatment. The structure, impact strength, tensile strength of the composites and the adhesion to the cement were studied. It was observed that with the increasing nanocellulose content, the impact strength and tensile strength decreased because of weak interactions at the interface and formation of agglomerates.
PL
W pracy zbadano wpływ nanocelulozy (3 oraz 5% mas.) na właściwości PLA. Dodatkowo rozważono możliwość zastosowania tego typu kompozytów jako materiału dylatacyjnego. Nanocelulozę otrzymano z makulatury poprzez obróbkę mechano-chemiczną. Zbadano strukturę, udarność i wytrzymałość kompozytów na rozciąganie oraz adhezję do cementu. Zaobserwowano, że wraz ze wzrostem zawartości nanocelulozy udarność i wytrzymałość na rozciąganie zmniejszały się jako efekt słabych oddziaływań na granicy faz i tworzenia się aglomeratów.
EN
Adhesion between the polymer matrix and fillers is an important factor influencing the properties of the obtained composites. One way to improve interactions at the interface is to modify the filler with coupling agents, e.g., silanes. The article presents the effect of modifying the surface of the mineral filler with a new type of silane [triethoxy(ketoimino)silane] on the mechanical properties of polyester resin based composites. Composites with triethoxy(ketoimino)silane-modified filler had similar mechanical properties to composites obtained with commercial silanes, with slightly lower water absorption.
PL
Adhezja między osnową polimerową i napełniaczami jest istotnym czynnikiem wpływającym na właściwości otrzymanych kompozytów. Jednym ze sposobów poprawy oddziaływań na granicy faz jest modyfikacja napełniacza środkami sprzęgającymi, np. silanami. W artykule przedstawiono wpływ modyfikacji powierzchni napełniacza mineralnego przy użyciu nowego typu silanu [triethoksy(ketoimino)silan] na właściwości mechaniczne kompozytów na bazie żywicy poliestrowej. Kompozyty z udziałem napełniacza modyfikowanego triethoksy(ketoimino)silanem miały podobne właściwości mechaniczne do kompozytów otrzymanych z udziałem silanów handlowych, przy nieco mniejszej chłonności wody.
EN
The effect of compatibilizer – ethylene-n-octene copolymer grafted with maleic anhydride (EOC-g-MAH) used in the amount of 3 wt% on tensile and flexural properties and impact strength of bioPET with the addition of 10 wt% filler derived from organic waste (egg and mollusc shells, coffee grounds) was investigated. EOC-g-MAH slightly decreased tensile strength, flexural strength, and modulus of elasticity, while significantly increasing impact strength (up to 426%). Moreover, ability of bioPET-based composites to dissipate mechanical energy was improved.
PL
Zbadano wpływ kompatybilizatora – kopolimeru etylen-n-okten szczepionego bezwodnikiem maleinowym (EOC-g-MAH) użytego w ilości 3% mas. na właściwości mechaniczne przy rozciąganiu i zginaniu oraz udarność bioPET z dodatkiem 10% mas. napełniacza pochodzącego z odpadów organicznych (skorupki jaj i mięczaków, fusy z kawy). EOC-g-MAH nieznacznie obniżył wytrzymałość na rozciąganie, zginanie i moduł sprężystości, jednocześnie znacznie zwiększył udarność (aż do 426%). Ponadto zwiększyła się zdolność kompozytów na bazie bioPET do rozpraszania energii mechanicznej.
EN
The useful properties of PVC-based composites intended for the production of a new type of pro-ecological acoustic screens for use in road construction as soundproof covers for urban housing estates, bridges and railway tracks were examined. The composites were obtained by melt mixing using a counter-rotating twin-screw extruder. PVC-based composites are characterized by high Charpy notch impact strength (> 12 kJ/m2), high Rockwell hardness (> 78 N/mm2), high oxygen index (50%), good resistance to UV radiation. An important advantage of these composites is the high content of agri-food waste (30 wt%), which makes the materials environmentally friendly.
PL
Zbadano właściwości użytkowe kompozytów na osnowie PVC przeznaczonych do wytwarzania nowego typu proekologicznych ekranów akustycznych do zastosowań w drogownictwie jako osłony dźwiękoszczelne osiedli miejskich, mostów i torów kolejowych. Kompozyty otrzymano metodą mieszania w stanie stopionym przy użyciu przeciwbieżnej wytłaczarki dwuślimakowej. Kompozyty na osnowie PVC charakteryzują się wysoką udarnością z karbem Charpy’ego (> 12 kJ/m2), dużą twardością wg Rockwella (> 78 N/mm2), wysokim indeksem tlenowym (50%), dobrą odpornością na działanie promieniowania UV. Istotną zaletą tych kompozytów jest duża zawartość odpadów rolno-spożywczych (30% mas.), co czyni materiały przyjaznymi dla środowiska.
EN
This work focuses on the study of red brick doped with reed fibers. These properties have been studied using characterizations techniques. In this context, we used Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis on the stability configuration, chemical structures and surface properties (morphology and porosity). The synthesis protocol is followed according to the manufacturing process of bricks on an industrial scale with well-defined standards and specifications. SEM and XRD experimental results showed that doping of clay fibers could effectively increase pore size and grain size as an indication of the removal of non-crystalline cellulosic materials from the fibers. The benefits of using fiber additives in clay bricks are then confirmed from a performance and environmental point of view.
EN
In recent years, metal halide perovskites have gained significant attention due to their unique optical and electronic properties of semiconductor materials, which make them ideal for use in sustainable and energy-efficient devices. These devices include solar cells, lasers, and light-emitting diodes. Therefore, this review aims initially to provide an overview of the most important characteristics of metal halide perovskites, including their engineering development in various types, such as those based on lead or lead-free materials, like tin or germanium. Additionally, perovskites made from purely inorganic compounds like caesium bromide, chloride, or iodide, as well as hybrids mixed with organic compounds like formamidinium and methylammonium halides will be discussed. The goal is to improve their stability and efficiency. Secondly, some of the studies have proposed technologies combining electronic and mechanical characteristics of flexibility or rigidity as required, promoting their synthesis with different materials such as polymers (poly methyl methacrylate, polyvinylidene fluoride), biopolymers (starch, cyclodextrin, polylactic acid, and polylysines), among others. Finally, the subject of this work is to establish the main purpose of the research carried out so far, which is to develop simpler and more scalable processes at industrial level to achieve greater efficiency and duration in storage, exposure to visible light, critical environments, humid or high temperatures.
EN
The article presents the results of the research work, which included aqualitative and quantitative analysis of the selected wooden wastesintended for manufacturing thecomposite materials. Additionally, theexisting solutions related to the processing of wooden waste from power poles and railway sleepers were analysed. In the context of theanalysis, the focus was on the methods for removing carcinogenic substances used for preserving thetelecommunications poles, power poles and railway sleepers, with the aim of obtaining thesafe end product. On this basis, the concept of a technological system for recycling the mentioned wasteshas beendeveloped. The recycling process involves reprocessing them and using as components of thecomposite materials.
EN
The recycling processes for CFRP waste are difficult due to their complex, and multi-material composition. Consequently, there is a need for new solutions to address this issue. The focus of CFRP composite recycling processes is primarily on recovering costly carbon fibers, which are characterized by exceptional mechanical properties. Pyrolysis has been identified as an effective method for the recovery of carbon fibers without significant damage. In this study, recovered carbon fibers (rCF) were used to produce polymer concrete. The fabricated polymer concretes contained carbon fibers of varying lengths (10, 20, and 30 mm) and volume fractions of 1 and 3%. The results showed that the addition of 3% post-pyrolytic carbon fibers resulted in significant improvement in the mechanical properties of the polymer concrete. Specifically, the flexural strength increased by more than 100% compared to the polymer concrete without carbon fibers, while the compressive strength improved by more than 60%. Overall, the study demonstrates that incorporating post-pyrolytic carbon fibers in the production of polymer concretes offers a promising solution to the challenge of CFRP waste. The use of these fibers not only helps in the recovery of valuable resources but also results in significant improvement in the mechanical strength of the final product.
EN
The rapid development of the automotive industry is very beneficial to many aspects of human life, but it is also a very significant environmental burden. The most straightforward impact is related to the generation of exhaust, but the management of post-consumer car parts is also a major challenge. Among them, waste tires are very burdensome due to their enormous numbers. Therefore, it is essential to develop novel, environmentally friendly methods for their disposal, which would reduce their environmental impacts. One of the most promising approaches is shredding, resulting in the generation of ground tire rubber (GTR), which can be introduced into polymeric materials as a filler. The presented work is related to the thermomechanical treatment of GTR in a twin-screw extruder assisted by zinc borate (ZB), whose incorporation is aimed to increase interparticle friction within the extruder barrel. The impact of the treatment conditions on the particle size and Surface development of the GTR/ZB compositions was evaluated. Modified GTR was introduced into flexible polyurethane (PU) foams, and the impact on the static and dynamic mechanical performance of the resulting composites was investigated. Increasing the treatment temperature occurred to have an adverse effect on the tensile performance of the composites due to the agglomeration of GTR particles limiting the efficiency of stress transfer, which was also confirmed by dynamic mechanical analysis. On the other hand, increasing the ZB share in the GTR/ZB compositions limited PU disruptions related to the reactivity of the GTR functional groups with isocyanates, which enhanced the mechanical performance of the composites. It was proven that the proposed method of GTR thermomechanical treatment assisted by ZB might benefit the performance of flexible PU foamed composites, which could broaden the application range of GTR and provide novel ways for its efficient utilization.
EN
This study examined the effects rheological properties of different composition kaolin and kaolin geo-filler in polypropylene composites. Polypropylene composites with varying composition of kaolin geo-filler 0 wt%, 2 wt%, 4 wt%, 6 wt%, 8 wt%, and 10 wt% was prepared and compared with polypropylene composite with raw kaolin. Kaolin is an aluminosilicate based mineral filler was used to prepare geopolymer paste by combining with alkaline activator solution. The polypropylene composite was compounded using a twin-screw extruder and the melt flow index was determined by a constant weight pressure of 2.16 kg at 230°C in 10 min. Knowing the melt flow index is necessary to predict and control the process, the study has demonstrated that the composition of kaolin filler and kaolin geo-filler affects the melt flow, melt density and surface morphology at varies composition. Composites with kaolin geo-filler have demonstrated high melt flow index process and having better distribution and flow.
EN
This paper proposes two new methods of measuring the viscoelastic parameters of materials. The methods are based on the composite beams’ resonant frequencies measurement. The Young moduli and loss factors of the components are determined by measuring the frequency response of a composite beam twice, each time with different layer thickness ratios. A system of two equations is obtained, from which Young’s moduli of the composite components are calculated. Similarly, two obtained equations determine the loss factors. The results obtained by the proposed methods are compared with those obtained by standard methods and then validated by experiments and FEM simulations. It was noted that the developed models, as well as the standard ones, are highly sensitive to the precision of the samples (material trimming and the way of joining the composite elements). The proposed methods prove to have an advantage over the standard ones in the matter of more frequent measurement criterion fulfilment. The acknowledged criterion represents the existence of a sensible solution insensitive to measurement errors. This criterion, which assures that the results are not prone to errors (for example negative loss factors) is met in 100% of cases in one of the methods, compared to 65% for standard methods.
EN
The subject of the work are modern composite materials with increased wear resistance intended for elements of machines operating in difficult conditions in the construction and mining industries. The study determined the effect of zone reinforcement of GX120Mn13 cast steel with macroparticles (Al2O3+ZrO2) on the corrosion resistance and abrasion wear of the composite thus obtained. SEM studies have shown that at interface between two phases, and more precisely on the surface of particles (Al2O3+ZrO2) a durable diffusion layers are formed. During the corrosion tests, no significant differences were found between the obtained parameters defining the corrosion processes of GX120Mn13 cast steel and GX120Mn13 with particles (Al2O3+ZrO2) composite. No intergranular corrosion was observed in the matrix of the composite material, nor traces of pitting corrosion at both phases interface. This is very important in terms of tested material’s service life. Reinforcement of cast steel with particles (Al2O3+ZrO2) resulted in a very significant improvement in the abrasion resistance of the composite – by about 70%. After corrosion tests, both materials were subjected to further operational investigations. These examinations consisted in determining the impact of corrosion processes on the durability of the composite in terms of abrasion. The obtained results indicate that corrosion processes did not significantly deteriorate the wear resistance of both the cast steel and the composite.
EN
One of the basic trends in the automotive industry today is to achieve the most acceptable ratio between the total weight of the car to its overall performance and utility properties. Reducing the weight of cars is largely due to the use of new materials, where composite materials offer a wide space for their application. Composite materials have their specific properties which is very beneficial in reducing the total weight. Another advantages is strength, stiffness, low fiber density, the ability to form them into any shape based on the required applications. One of the challenges associated with the use of composite materials is the search for new technological possibilities of joining composite materials with metals. These include technologies as for example riveting, ultrasonic welding, but especially gluing. Bonding is currently one of the most preferred ways of joining composite materials. The paper deals with testing of technology of bonding composite materials with metals used in the manufacture of automobiles and a comparison of individual results obtained from the experiment.
EN
The aim of this study is to determine the effect of environmental factors in the form of UV radiation and temperature on the amplitude-frequency behaviour of polymer composites (prepregs) based on a framework of thermosetting epoxy resin reinforced with high-strength R-glass fibres. Two series of composites with different fibre arrangements were prepared. The series had fibres arranged at angles of 30°, 45°, and 60°, at symmetric and asymmetric orientations in relation to the central layer. The composites were subjected to conditioning which simulated a six-month period of use in the spring and summer in the temperate warm transitional climate of Central and Eastern Europe. An UV QUV/SPRAY/RP accelerated aging chamber manufactured by Q - Lab Corporation was used for this purpose, and UV-A 340 lamps were used to simulate daylight. In addition, varying loads caused by sudden temperature changes were simulated using the Thermal Shock Chamber T/60/V2 Weisstechnik. Conditioned samples were tested using a TIRAvib 50101 electromagnetic exciter in combination with an LMS Scadias III controller and Test.Lab software. The results of the tests, in the form of amplitude-frequency diagrams in resonance regions, indicated that certain changes occurred as a result of the conditioning, which is a new development in the area of material tests. The results shed light on the effects of environmental conditions on the stiffness characteristics of composites, causing dynamic nonlinearities when operating at resonant frequencies.
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