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  1. 25 Materials Science Poland
  2. 22 Polimery
  3. 21 Elektronika : konstrukcje, technologie, zastosowania
  4. 18 Przemysł Chemiczny
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  1. 14 Jakubowska M.
  2. 13 Słoma M.
  3. 12 Czerwosz E.
  4. 12 Iskra A.
  5. 12 Kałużny J.
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  1. 1 2024
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1
Content available Screw Extrusion as a Scalable Technology for Manufacturing Carbon Nanotube-Filled Polylactide Composites
Kaczor Daniel, Bajer Krzysztof, Raszkowska-Kaczor Aneta, Domek Grzegorz, Schroeder Paweł
Advances in Science and Technology. Research Journal
|
2024
|
Vol. 18, no 3
99--110
EN
The bottleneck in the widespread use of carbon multiwall nanotube polymer composites is the lack of manufacturing technology that can be used on an industrial scale. In this article, we describe a two-step composite manufacturing technology based on screw extrusion that produces composites characterizing with good dispersion of carbon nanotube filler in polylactide matrix. The first stage involved the fabrication of highly filled masterbatches of 25 wt% of carbon nanotubes. In the second stage, by screw extrusion of the masterbatch mixture with neat polymer, we obtained homogeneous composites with the target filler concentration. The resulting composites with nanotube content ranging from 0.1 to 2 wt%. Mechanical tests including static tension, tensile strength, tensile modulus, three-point bending and impact strength has shown that optimal concentration of the carbon nanotube filler is ranged between 0.5 and 1 wt%. Samples were examined also by SEM, FTIR-ATR, DSC and MFR methods.
2
Content available Morphology and selected properties of NR/BR/CNT nanocomposites – effect of ethanol-assisted mixing
Zhang Juzheng, Gu Zheng, Meng Chao, Wang Jianfa, Sui Jinyong
Polimery
|
2023
|
Vol. 68, nr 5
251--258
EN
Carbon nanotubes (CNT) and ethanol-assisted mixing were used to obtain composites based on a mixture of natural rubber and butadiene rubber (NR/BR 80/20). The structure of the composites was determined by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Thermal aging tests were also carried out and the vulcanization process was characterized. SEM confirmed the homogeneous dispersion of CNTs in the polymer matrix. Improvements in tensile and tear strength as well as thermal stability were also achieved.
PL
Do otrzymywania kompozytów na bazie mieszaniny kauczuku naturalnego i butadienowego (NR/BR 80/20) zastosowano nanorurki węglowe (CNT) i mieszanie wspomagane etanolem. Strukturę kompozytów określono za pomocą spektroskopii w podczerwieni z transformacją Fouriera (FTIR) oraz skaningowej mikroskopii elektronowej (SEM). Przeprowadzono również badania starzenia termicznego oraz scharakteryzowano proces wulkanizacji. Metodą SEM potwierdzono jednorodną dyspersję CNT w osnowie polimerowej. Uzyskano również poprawę wytrzymałości na rozciąganie i rozdzieranie oraz stabilności termicznej.
3
Content available remote Thermoelastic vibration characteristics of asymmetric annular porous reinforced with nano-fillers microplates embedded in an elastic medium: CNTs Vs. GNPs
Arshid Ehsan, Amir Saeed, Loghman Abbas
Archives of Civil and Mechanical Engineering
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2023
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Vol. 23, no. 2
art. no. e100, 2023
EN
Due to the vast usage of metal foam structures in branches of science, reinforcing them with nano-fillers makes them more convenient. Hence, in the current study, vibration characteristics of functionally graded porous nanocomposite (FGPN) annular microplates are taken into consideration. Two kinds of nano-fillers, namely Carbon nanotubes (CNTs) and Graphene nanoplatelets (GNPs), are selected as the reinforcements to analyze and compare their effect on the microstructure’s vibrational response. The mentioned nano-fillers are dispersed according to four patterns which affect various mechanical properties of the structure. Similarly, based on given functions which are called porosity distributions, pores are placed in thickness course of the microstructure. Then, its properties are determined via employing Halpin-Tsai and extended rule of mixture micromechanics models. Using the first-order shear deformation theory (FSDT), modified couple stress theory (MCST), and Hamilton’s principle for dynamic systems, governing motion equations and related boundary conditions are derived in asymmetric state, and then, they are solved, and natural frequencies and corresponding mode shapes are extracted with the help of generalized differential quadrature method (GDQM). By validating the results in simpler conditions, effects of the most important parameters are examined. It is found that GNPs are more effective in reinforcing the structure than CNTs. Also, about 15~18 percent reduction in frequencies is seen by increasing the porosity up to seventy percent.
4
Pozytywne efekty dodania nanorurek węglowych do zaprawy
Kostrzanowska-Siedlarz Aleksandra
Magazyn Autostrady
|
2022
|
Nr 3
24--28
PL
Celem badań przedstawionych w artykule jest poszukiwanie pozytywnych efektów dodania wielościennych nanorurek węglowych do zapraw podczas modyfikacji właściwości reologicznych, cech wytrzymałościowych oraz analiza bibliometryczna ujawniająca pozytywny wpływ nanorurek na kinetykę hydratacji.
EN
The paper presents research which aim is to search for the positive effects of adding multi-wall carbon nanotubes to mortar during the modification of rheological properties, strength properties and bibliometric analysis in order to look for the influence of nanotubes on the hydration kinetics.
5
Content available remote Zawiesina nanorurek z surfaktantem, a właściwości reologiczne zapraw cementowych
Goldmann Eryk, Kostrzanowska-Siedlarz Aleksandra, Górski Marcin, Klemczak Barbara
Cement Wapno Beton
|
2022
|
R. 27, nr 4
275--284
PL
Dodatek nanomateriałów węglowych wpływa na szereg właściwości kompozytów cementowych. Pomimo wielu badań na temat właściwości stwardniałych materiałów cementowych, wpływ nanorurek węglowych [MWCNT, ang. Multiwall Carbon Nanotube] na właściwości reologiczne zapraw cementowych, wciąż nie jest wystarczająco opisany. Badania wykazały, że właściwości reologiczne zapraw z MWCNT, oznaczone Viskomatem NT, okazały się bardzo zależne od czasu sonikacji i ilości MWCNT. Wraz ze wzrostem czasu sonikacji zawiesiny z MWCNT i surfaktantem oraz wraz ze zmniejszeniem zawartości MWCNT płynność zaprawy jest większa, tym samym zmniejsza się zarówno granica płynięcia jak i lepkość plastyczna.
EN
The addition of carbon nanomaterials influences the variety of properties, of cementitious composites. Despite the multiple researches in the topic of properties of the hardened cement materials the influence of the Mutiwall Carbon Nanotubes [MWCNT] on rheological parameters of the cement mortars is not sufficiently described. Research shows that rheological properties of cement mortars with the MWCNTs, determined with the use of Viscometer NT, proved to be strongly dependent on the sonication time and amount of MWCNT, added. Increase of sonication time of MWCNT suspension with surfactant and decrease of amount of MWCNT caused increment in fluidity while yield stress parameter and plastic viscosity parameter decreased.
6
Content available Influence of the Interface of Carbon Nanotube-Reinforced Aluminum Matrix Composites on the Mechanical Properties – a Review
Li Rong, Pan Zhilin, Zeng Qi, Xiaoli Ye
Archives of Foundry Engineering
|
2022
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Vol. 22, iss. 1
23--36
EN
Carbon nanotubes (CNTs) are a good reinforcement for metal matrix composite materials; they can significantly improve the mechanical, wear-resistant, and heat-resistant properties of the materials. Due to the differences in the atomic structure and surface energy between CNTs and aluminum-based materials, the bonding interface effect that occurs when nanoscale CNTs are added to the aluminum alloy system as a reinforcement becomes more pronounced, and the bonding interface is important for the material mechanical performance. Firstly, a comparative analysis of the interface connection methods of four CNT-reinforced aluminum matrix composites is provided, and the combination mechanisms of various interface connection methods are explained. Secondly, the influence of several factors, including the preparation method and process as well as the state of the material, on the material bonding interface during the composite preparation process is analyzed. Furthermore, it is explained how the state of the bonding interface can be optimized by adopting appropriate technical and technological means. Through the study of the interface of CNT-reinforced aluminum-based composite materials, the influence of the interface on the overall performance of the composite material is determined, which provides directions and ideas for the preparation of future high-performance CNT-reinforced aluminum-based composite materials.
7
Content available remote Buckling analysis of composite conical shells reinforced by agglomerated functionally graded carbon nanotube
Eskandary K., Shishesaz Mohammad, Moradi Shapour
Archives of Civil and Mechanical Engineering
|
2022
|
Vol. 22, no. 3
art. no. e132
EN
This study primary objective is to analyze the effect of agglomeration of carbon nanotubes on the buckling behavior of functionally graded carbon nanotube-reinforced composite conical shells (FG-CNTCS). Considering the first-order shear deformation theory, the differential equations of buckling behavior are obtained. Subsequently, the buckling load was derived utilizing Galerkin methods. A parametric study is established to consider the influence of characteristic parameters on the buckling behavior of the FG-CNTCS. The results reveal that agglomeration of CNTs substantially reduces the buckling load. Considering that, the effect of high volume fractions of carbon nanotubes on increasing buckling load is overly inconsiderable, it is suggested to use low volume fractions of nanoparticles in producing this type of nanocomposites, which reduces the probability of agglomeration phenomenon and also cut down the manufacturing costs.
8
Content available Effects of carbon nanotubes and graphene on the structure and properties of natural rubber
Sui Jinyong, Gu Zheng, Zhang Xiaoyi, Li Zhenxu, Song Lining, Yang Lina, Wang Ning
Polimery
|
2021
|
T. 66, nr 4
217--223
EN
Natural rubber (NR) is an important strategic material for national defense industry. It is also used in the food industry and medicine. However, due to the unsaturated double bond, its aging resistance, mechanical properties and solvent resistance are very poor. In order to improve these properties, carbon nanotubes (CNTs) and reduced graphene oxide (rGO) were used, added at 1 : 1 ratio. The NR/CNTs/rGO nanocomposites were obtained by mechanical mixing aft er adding 1, 2, 3 and 4 phr of fi ller. The infl uence of the fi ller content on the structure (TEM), vulcanization properties, abrasion and solvent resistance, mechanical properties, dynamic mechanical properties (DMA) and thermal properties (TGA) of nanocomposites was investigated. Increasing the content of CNTs/rGO increased the crosslinking density of the composites. TEM studies showed that CNTs and graphene sheets were evenly dispersed throughout the NR matrix. They also had good compatibility with the rubber matrix. The addition of CNTs and graphene increased the abrasion and solvent resistance as well as improved the mechanical properties. TGA analysis showed that the nanocomposites had excellent thermal stability. The best properties were obtained with the CNTs/rGO content of 2 phr.
PL
Kauczuk naturalny (NR) stanowi ważny materiał strategiczny dla przemysłu obronnego. Znajduje również zastosowanie w przemyśle spożywczym i medycynie. Jednak obecność w cząsteczce nienasyconych podwójnych wiązań powoduje osłabienie jego odporności na starzenie, pogorszenie wytrzymałości mechanicznej i odporności na działanie rozpuszczalników. W celu poprawy tych właściwości do kauczuku naturalnego wprowadzono nanorurki węglowe (CNTs) i zredukowany tlenek grafenu (rGO), dodawane w stosunku 1 : 1. Nanokompozyty NR/CNTs/rGO otrzymywano metodą mechanicznego mieszania NR z 1, 2, 3 lub 4 phr napełniacza (CNTs/rGO). Zbadano wpływ zawartości dodatku na strukturę (TEM), właściwości wulkanizacyjne, właściwości mechaniczne, odporność na ścieranie i działanie rozpuszczalnika, dynamiczne właściwości mechaniczne (DMA) i właściwości termiczne (TGA) wytworzonych kompozytów. Zwiększenie udziału CNTs/rGO powodowało zwiększenie gęstości usieciowania kompozytów. Z badań TEM wynika, że cząstki CNTs i grafenu były równomiernie rozproszone w osnowie NR i wykazywały dobrą kompatybilność z kauczukiem naturalnym. Dodatek CNT i grafenu zwiększył odporność na ścieranie i działanie rozpuszczalników oraz poprawił właściwości mechaniczne naturalnego kauczuku. Na podstawie analizy TGA stwierdzono, że nanokompozyty charakteryzowały się doskonałą stabilnością termiczną. Najlepszymi właściwościami użytkowymi odznaczały się kompozyty NR zawierające 2 phr CNTs/rGO.
9
Content available Composites based on conductive polymer with carbon nanotubes in DMMP gas sensors – an overview
Nurazzi N. M., Harussani M. M., Siti Zulaikha N. D, Norhana A. H., Imran Syakir M., Norli A.
Polimery
|
2021
|
T. 66, nr 2
85--97
EN
A number of recent terrorist attacks make it clear that rapid response, high sensitivity and stability are essential in the development of chemical sensors for the detection of chemical warfare agents. Nerve agent sarin [2-(fluoro-methyl-phosphoryl) oxypropane] is an organophosphate (OP) compound that is recognized as one of the most toxic chemical warfare agents. Considering sarin’s high toxicity, being odorless and colorless, dimethyl methylphosphonate (DMMP) is widely used as its simulant in the laboratory because of its similar chemical structure and much lower toxicity. Thus, this review serves to introduce the development of a variety of fabricated chemical sensors as potential sensing materials for the detection of DMMP in recent years. Furthermore, the research and application of carbon nanotubes in DMMP polymer sensors, their sensitivity and limitation are highlighted. For sorption-based sensors, active materials play crucial roles in improving the integral performances of sensors. The novel active materials providing hydrogen-bonds between the polymers and carbon nanotubes are the main focus in this review.
PL
Przeprowadzone w ostatnich latach liczne ataki terrorystyczne jasno wskazują, że w wypadku czujników do wykrywania chemicznych środków bojowych są niezbędne: ich wysoka czułość, szybka reakcja i stabilność. Środek paralityczno-konwulsyjny sarin (2-fluorometylofosforylooksypropan) to związek fosforoorganiczny (OP) uznawany za jeden z najbardziej toksycznych dostępnych chemicznych środków bojowych. Ze względu na to, że jest on bezwonny, bezbarwny, a ponadto bardzo toksyczny, w badaniach laboratoryjnych szeroko stosuje się jego symulator – metylofosfonian dimetylu (DMMP), o podobnej strukturze chemicznej i znacznie mniejszej toksyczności. W artykule przedstawiono rozwój technologii czujników chemicznych do wykrywania gazu DMMP. Omówiono badania dotyczące wykorzystania kompozytów polimerowych z udziałem nanorurek węglowych w czujnikach gazu DMMP. W wypadku czujników, w których wykorzystuje się zjawisko sorpcji, kluczową rolę w poprawie ich wydajności odgrywają materiały aktywne. W niniejszym przeglądzie skupiono się na nowatorskich materiałach aktywnych, w których występują wiązania wodorowe między polimerem a nanorurkami węglowymi.
10
Content available Carbon nanotubes-based sensor for ammonia gas detection – an overview
Nurazzi N. M., Demon Siti Zulaikha N., Halim Norhana A., Mohamad Syakir I., Abdullah Norli
Polimery
|
2021
|
T. 66, nr 3
175--186
EN
A sensitive, selective and reliable sensing techniques for ammonia (NH3) gas detection have been highly demanded since NH3 is both a commonly utilized gas in various industrial sectors, and considered as a toxic and caustic agent that can threat human health and environment at a certain level of concentrations. In this article, a brief on the fundamental working principles of sensor specifications of the analytes detection techniques relying has been reviewed. Furthermore, the mechanism of NH3 detection and recent progress in the development of advanced carbon nanotubes (CNTs)-based NH3 gas sensors, and their performance towards the hybridization with the conductive polymers was comprehensively reviewed and summarized. Finally, the future outlook for the development of highperformance NH3 sensors was presented in the conclusions part.
PL
Amoniak (NH3) to gaz powszechnie stosowany w różnych sektorach przemysłu, jest toksyczny i żrący, a powyżej określonego poziomu stężeń może zagrozić ludzkiemu zdrowiu i środowisku, dlatego ciągle trwają poszukiwania czułych, selektywnych i niezawodnych metod wykrywania gazów amoniakalnych. W niniejszym artykule dokonano przeglądu specyfikacji i podstawowych zasad działania czujników stosowanych w technikach wykrywania takich analitów. Szczegółowo przeanalizowano też mechanizm wykrywania i niedawny postęp w opracowywaniu zaawansowanych czujników do wykrywania gazu NH3 , opartych na nanorurkach węglowych (CNTs), a także ich modyfikacje obejmujące hybrydyzację z polimerami przewodzącymi. Przedstawiono również perspektywy rozwoju wysoko wydajnych czujników NH3.
11
Content available Wpływ nanorurek węglowych (CNTs) na parametry mechaniczne kamieni cementowych w warunkach HPHT
Kędzierski Miłosz, Rzepka Marcin, Kremieniewski Marcin
Nafta-Gaz
|
2021
|
R. 77, nr 2
106--117
PL
Artykuł przedstawia wyniki badań wpływu nanorurek węglowych (CNTs) na parametry mechaniczne kamieni cementowych w warunkach HPHT. W badaniach zastosowano wielościenne nanorurki węglowe (MWCNTs) o średnicy zewnętrznej 10–20 nm i długości 10–30 µm. Do zaczynów dodawano 0,1% nanorurek węglowych. Receptury cementowe opracowane zostały w Laboratorium Zaczynów Uszczelniających Instytutu Nafty i Gazu – Państwowego Instytutu Badawczego. Badania przeprowadzono w warunkach podwyższonego ciśnienia i temperatury w zakresie temperatur 60–130C i zakresie ciśnień 25–80 MPa. W przypadku temperatury 60C jako spoiwo wiążące zastosowano cement portlandzki CEM I 42,5R oraz cement wiertniczy G. Zaczyny dla temperatur od 80C do 130C sporządzono na osnowie cementu wiertniczego G. Przy opracowywaniu receptur kierowano się wymaganiami, jakie powinien spełniać zaczyn cementowy użyty do cementowania rur okładzinowych w warunkach występowania bardzo wysokich temperatur oraz ciśnień złożowych. Zaczyny po- siadały gęstość od około 1840 kg/m3 (zaczyny dla temperatury 60C) do około 2250 kg/m3 (zaczyny z dodatkiem hematytu). Badania wytrzymałości na ściskanie i przyczepności do rur prowadzono po 2, 7, 14 i 28 dniach. Opracowano receptury o bardzo dobrych parametrach technologicznych, które po utwardzaniu (po okresie 28 dni hydratacji) posiadały bardzo wysokie wartości wytrzymałości na ściskanie, osiągające nawet do 44 MPa. Uzyskano również wysokie wartości przyczepności kamienia cementowego do rur, dochodzące do około 8 MPa po 28 dniach hydratacji, oraz wytrzymałości na zginanie, wynoszące około 11 MPa. Przeprowadzone badania ujawniają pozytywny wpływ dodatku nanorurek węglowych na wytrzymałość kamieni cementowych z ich dodatkiem. Zmodyfikowane w ten sposób kamienie charakteryzują się wysokimi wartościami wytrzymałości na ściskanie oraz wysokimi przyczepnościami do rur stalowych. Konieczne są jednak dalsze badania w kierunku określenia wpływu nanorurek węglowych na mikrostrukturę stwardniałych zaczynów cementowych. Niezbędne jest również kontynuowanie badań nad określeniem optymalnych ilości tych środków oraz doborem najbardziej kompatybilnych dodatków do zaczynów cementowych działających w sposób optymalny w połączeniu z nanocząsteczkami.
EN
The article presents the results of testing the influence of carbon nanotubes on the mechanical parameters of cement stones under HPHT conditions. Multi-walled carbon nanotubes (MWCNTs) with an external diameter of 10–20 nm and a length of 10–30 μm were used for testing. 0.1% of carbon nanotubes was added to the cement slurry. Laboratory tests of cement slurries were carried out at Oil and Gas Institute – National Research Institute. The tests were carried out under conditions of increased pressure and temperature in the temperature range of 60–130C and the pressure range of 25–80 MPa. CEM I 42.5R Portland cement and Class G drilling cement were used to make the slurries at temperature of 60o C. Cement slurries for temperatures from 80o C to 130o C were prepared on the basis of class G drilling cement. The recipes were developed on the basis of the requirements to be met by cement slurry for the cementing of casing under conditions of very high temperatures and reservoir pressures. The densities of tested slurries ranged from 1,840 kg/m3 (slurries at a temperature of 60C) to 2.250 kg/m3 (slurries with the addition of hematite).Compressive strength tests and adhesion measurements were carried out after 2, 7, 14 and 28 days. Cement slurry recipes with very good technological parameters were developed, which after curing (after 28 days of hydration) showed very high values of compressive strength, reaching up to 44 MPa. Cements were characterized by high values of adhesion to pipes reaching up 8 MPa after 28 days and flexural strength of about 11 MPa. The test results show that the addition of carbon nanotubes has a positive effect on the mechanical strength of cement stones with their addition. The stones modified in this way are characterized by high compressive strength and high adhesion to steel pipes. Further research is needed to determine the influence of carbon nanotubes on the microstructure of hardened cement slurries. It is also necessary to conduct further research on the determination of the optimal amounts of these agents and the selection of the most compatible additives for cement slurries that work optimally in combination with nanoparticles.
12
Content available remote The preparation of CNT/PMMA composite film on SiO2 substrates
Li Jian
Materials Science Poland
|
2021
|
Vol. 39, No. 4
639--645
EN
Microelectromechanical system (MEMS) has been highly valued since the size of the MEMS structure is miniaturized, the spacing between the components is in the nanometer range, and the behaviors of friction and adhesion greatly affect the reliability of MEMS. An atomic force microscope (AFM) was used to observe the surface morphology of carbon nanotube (CNT)/polymethyl methacrylate (PMMA) film, and X-ray photoelectron spectroscopy (XPS) was used to analyze the chemical state of typical elements on the surface of the film. The friction and wear properties of composite nano-films under macroscopic conditions were systematically studied. The research results show that the composite nano-film has excellent anti-friction and anti-wear properties.
13
Nanorurki węglowe - innowacyjne sorbenty w technikach przygotowywania próbek do oznaczania pozostałości farmaceutyków w wodzie
Godlewska Klaudia, Paszkiewicz Monika, Stepnowski Piotr
Laboratorium - Przegląd Ogólnopolski
|
2021
|
nr 1
41--47
PL
Nanorurki węglowe w ciągu ostatnich kilku dekad niezmiennie przyciągają uwagę w wielu dziedzinach zastosowań, w tym w chemii analitycznej. Wielu badaczy i naukowców wykazało ogromne zainteresowanie rozwojem metod ekstrakcji, zwłaszcza w przypadku oznaczania zanieczyszczeń wodnych występujących na bardzo niskich poziomach stężeń, jak np. farmaceutyki. Dzięki swoim wyjątkowym właściwościom nanorurki węglowe zostały niewielokrotnie użyte jako innowacyjne sorbenty w różnych technikach przygotowywania próbek do analizy instrumentalnej, w tym: ekstrakcji do fazy stałej oraz dyspersyjnej ekstrakcji do fazy stałej itp. Z tego względu w niniejszej pracy skupiono się na właściwościach adsorpcyjnych nanorurek węglowych oraz możliwości ich wykorzystania jako sorbentu w technikach przygotowywania próbek wody do oznaczania pozostałości farmaceutyków.
EN
Over the past few decades, carbon nanotubes have consistently attracted attention in many fields of application, including analytical chemistry. Many researchers and scientists have shown great interest in the development of extraction methods, especially for the determination of water contaminants present at very low concentration levels, such as pharmaceuticals. Due to their unique properties, carbon nanotubes have been repeatedly used as innovative sorbents in various techniques of sample preparation for instrumental analysis, including solid phase extraction and dispersive solid phase extraction, etc. For this reason, this paper focuses on the adsorption properties of carbon nanotubes and the possibility of their use as a sorbent in the techniques of preparing water samples for the determination of pharmaceutical residues.
14
Content available Effect of Modified Carbon Nanotubes Epoxy on the Mechanical Properties of Concrete Reinforced with FRP Sheets
Kazemi Hamid, Heydari Mostafa, Bamoharam Fateme Farash
Civil and Environmental Engineering Reports
|
2021
|
Vol. 31, no. 3
177--196
EN
Today, using Fiber Reinforced Polymer (FRP) sheets is one of the conventional methods in retrofitting concrete structures. Some factors affecting FRP sheets proper performance include mechanical properties, surface specifications, connector’s material and connecting approach in concrete elements. Previous studies showed that FRP epoxy resin and its basic surface have a significant impact on the ultimate bearing capacity. In line with the development of nanotechnology in recent years, this paper presents an experimental study to show the effects of adding the best percentage of nano-carbons to adhesive resin and evaluate the ultimate axial, shear and bending strengths in concrete samples. The results show that using FRP with carbon nanotube reinforced resins will significantly increase stiffness and ductility by 100%; moreover, it shows an effective increase of almost 13% in axial and flexural strengths of specimens.
15
Content available Silicon nitride/carbon nanotube composites: preparation and characterization
Mikuśkiewicz Marta
Bulletin of the Polish Academy of Sciences. Technical Sciences
|
2021
|
Vol. 69, nr 5
art. no. e138234
EN
This paper investigates the preparation of silicon nitride composites with multi-walled carbon nanotubes (MWCNTs). Samples containing 1–10 wt% MWCNTs were ultrasonically processed in non-aqueous suspensions, dried, pressed, and then subjected to non-pressure sintering at 1600 °C for 2 h. The preliminary results showed that the mixture of activated silicon nitride and covered MWCNTs could be sintered. The porosity of the obtained samples ranged from 0.27 to 36.94 vol.%. The microstructure was observed by scanning electron microscopy (SEM), and the mechanical properties (hardness and fracture toughness) were also determined. Good hardness values were obtained for samples prepared by sintering the mechanically activated precursor under a flowing nitrogen atmosphere using the lowest fraction of CNTs. Residual activator reduced the densification of the composites.
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Content available Multiobjective Performance Investigation of CNT Coated HSS Tool Under the Response Surface Methodology Platform
Chandru Manivannan, Selladurai Velappan, Venkatesh Chenrayan
Archives of Metallurgy and Materials
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2021
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Vol. 66, iss. 2
627--635
EN
The present research employs the statistical tool of response surface methodology (RSM) to evaluate the machining characteristics of carbon nanotubes (CNTs) coated high-speed steel (HSS) tools. The methodology used for depositing carbon nanotubes was Plasma-Enhanced Chemical Vapor Deposition (PECVD). Cutting speed, thickness of cut, and feed rate were chosen as machining factors, and cutting forces, cutting tooltip temperature, tool wear, and surface roughness were included as machining responses. Three-level of cutting conditions were followed. The face-centered, Central Composite Design (CCD) was followed to conduct twenty number of experiments. The speed of cutting and rate of feed have been identified as the most influential variables over the responses considered, followed by the thickness of cut. The model reveals the optimized level of cutting parameters to achieve the required objectives. The confirmation experiments were also carried out to validate the acceptable degree of variations between the experimental results and the predicted one.
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Content available remote New generation of semipermeable membranes with carbon nanotubes for water and wastewater treatment : Critical review
Bodzek Michał, Konieczny Krystyna, Kwiecińska-Mydlak Anna
Archives of Environmental Protection
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2021
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Vol. 47, no. 3
3-27
EN
Environmental applications of carbon nanotubes (CNTs) have recently attracted worldwide attention due to their excellent adsorption capacities and promising physical, chemical and mechanical properties, as well as the preparation of novel membranes with attractive features for water purification. This paper critically reviews the recent progress on the preparation and applications of CNT based membranes in water and wastewater treatment. Various synthesis techniques for the preparation of CNT based membranes are discussed. The functionalization of CNTs, which involves chemical/physical modification of pristine CNTs with different types of functional groups, improves the capabilities of CNT for water and wastewater treatment and/or removal of waterborne contaminants. The CNT-based membrane applications are found to possess a variety of advantages, including improving water permeability, high selectivity and antifouling capability. However, their applications at full scale are still limited by their high cost. Finally, we highlight that CNT membranes with promising removal efficiencies for respective contaminants can be considered for commercialization and to achieve holistic performance for the purpose of water treatment and desalination. This paper may provide an insight for the development of CNT based membranes for water purification in the future. With their tremendous separation performance, low biofouling potential and ultra-high water flux, CNT membranes have the potential to be a leading technology in water treatment, especially desalination.
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Content available remote Properties of flame spraying coatings reinforced with particles of carbon nanotubes
Czupryński A., Mele C.
Advances in Materials Science
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2021
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Vol. 21, nr 1(67)
57--76
EN
The article presents the results of the preliminary research of tribological properties of flame sprayed nickel and aluminum coatings reinforced with carbon nanotubes made on the structural steel S235J0 substrate. The carbon material – carbon nanotubes Nanocyl NC 7000 (0.5 wt.% and 1 wt.%) was used for structural reinforcement. The properties evaluation was made by the use of optical microscopy, scanning electron microscopy, Raman spectroscopy, microhardness measurements, and by means of abrasion and erosion resistance laboratory tests. The obtained results were compared with pure nickel powder coatings 2N5 (Ni 99.5%) and with pure aluminum powder coatings (EN AW 1000 series). It was proved that the flame spraying of nickel and aluminum coatings reinforced with particles carbonaceous material can be an effective alternative for other more advanced surfacing technology. The preliminary test results will be successively extended by further experiments to contribute in the near future to develop innovative technologies, that can be implemented in the aviation industry and the automotive. The presented research is a continuation of the work previously published.
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Content available remote Microstructure and mechanical properties of laser surface-treated Ti13Nb13Zr alloy with MWCNTs coatings
Majkowska-Marzec Beata, Sypniewska Joanna
Advances in Materials Science
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2021
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Vol. 21, nr 4(70)
5--18
EN
Laser surface modification of titanium alloys is one of the main methods of improving the properties of titanium alloys used in implantology. This study investigates the microstructural morphology of a laser-modified surface layer on a Ti13Nb13Zr alloy with and without a carbon nanotube coating deposited by electrophoretic deposition. Laser modification was performed for samples with and without carbon nanotube coating for two different laser powers of 800 W and 900 W and for different scan rates: 3 mm/s or 6 mm/s at 25 Hz, and the pulse duration was 2.25 ms or 3.25 ms. A scanning electron microscope SEM was used to evaluate the surface structure of the modified samples. To observe the heat-affected zones of the individual samples, metallographic samples were taken and observed under an optical microscope. Surface wettability tests were performed using a goniometer. A surface roughness test using a profilograph and a nanoindentation test by NanoTest™ Vantage was also performed. Observations of the microstructure allowed to state that for higher laser powers the surfaces of the samples are more homogeneous without defects, while for lower laser powers the path of the laser beam is clearer and more regular. Examination of the microstructure of the cross-sections indicated that the samples on which the carbon nanotube coating was deposited are characterized by a wider heat affected zone, and for the samples modified at 800 W and a feed rate of 3 mm/s the widest heat affected zone is observed. The wettability tests revealed that all the samples exhibit hydrophilic surfaces and the samples with deposited carbon nanotube coating increase it further. Surface roughness testing showed a significant increase in Ra for the laser-modified samples, and the presence of carbon nanotubes further increased this value. Nanoindentation studies showed that the laser modification and the presence of carbon coating improved the mechanical properties of the samples due to their strength.
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Content available remote Determination of organochlorine pesticides in water using GC combined with dispersive solid-phase extraction with single-walled carbon nanotubes
Sun Peng, Cui Yanhong, Yan Rui, Lian Yongfu
Acta Chromatographica
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2021
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Vol. 33, no. 2
202--207
EN
In this study, single-walled carbon nanotubes (SWNTs) were used to determine organochlorine pesticides (chlorothalonil and pentachloronitrobenzene) in water using dispersive solid-phase extraction (DSPE), followed by gas chromatography (GC). The optimal adsorption conditions were determined by analyzing the effect of adsorbent dosage, adsorption time, eluent type and volume, and elution time. Under the optimal conditions, a good linearity was obtained at concentrations from 10 to 400 μg L−1 with correlation coefficients ranging from 0.9991 to 0.9986. The limits of detection (LOD) for the two organochlorine pesticides were 0.025 and 0.049 μg L−1, and the limits of quantification (LOQ) were 0.080 and 0.156 μg L−1, respectively. The accuracy of the proposed method was evaluated by measuring the recovery of the spiked samples, which ranged from 82.5% to 110.5% at spiking levels of 0.5–10 μg L−1 with relative standard deviations lower than 5.6% (n = 6). This method was successfully applied to determine the target analytes in canal water, drinking water, and water taken from the inlets and outlets of a wastewater treatment plant. The results demonstrate that the developed method has great potential for determining the two organochlorine pesticides in water samples.
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