BazTech - Yadda

1

Zastosowanie nanodomieszek w materiałach izolacyjnych

Dąda Anna, Błaut Paweł

Przegląd Elektrotechniczny

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2023

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R. 99, nr 1

185--189

PL

Nieustannie rosnące zapotrzebowanie na energię elektryczną o wysokiej jakości wymaga zwiększenia niezawodności jej przesyłu i dystrybucji, co skutkuje koniecznością poprawy właściwości materiałów izolacyjnych. Obecnie na całym świecie prowadzone są prace badawcze mające na celu uzyskanie nowych, materiałów izolacyjnych o lepszych parametrach, wśród których wymienia się nanokompozyty. Artykuł przedstawia przegląd dotychczasowych osiągnieć w zakresie nanodielektryków oraz aktualnych problemów zastosowania nanodomieszek/ nanowypełniaczy w materiałach izolacyjnych. Opisano właściwości materiałów izolacyjnych, w aspekcie m.in.: modyfikacji przenikalności elektrycznej, wpływu na rozkład ładunku przestrzennego, odporności na narażenia długotrwałe, zwiększenia wytrzymałości elektrycznej oraz optymalizacji interfazy polimer-nanowypełniacz.

EN

The ever-growing demand for high-quality electricity requires increasing the reliability of its transmission and distribution, which results in the need to improve the properties of insulating materials. Currently, research is carried out all over the world to obtain new, insulation materials with better parameters, including nanocomposites. The article presents an overview of the current achievements in the field of nanodielectrics and the current problems of using nanoparticles / nanofillers in insulation materials. The properties of insulating materials were described in terms of, among others: modification of permittivity, influence on the distribution of space charge, resistance to long-term stresses, increased electrical strength and optimization of the polymer-nanofiller interphase.

2

Experimental study of nano-composite materials on vibration responses

Mobark Haidal Faisal Helal, Fahdel Essam Z., Hussein Mustafa Turki, Mohamad Barhm

Diagnostyka

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2023

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Vol. 24, No. 3

art. no. 2023312

EN

This paper present of experimental and numerical study of nano Al2O3 cantilever beam for forced vibration, addressing an unexplored area in the existing literature. The proposed nano composite cantilever beam is modeled with hole and crack. The study is based on history loading calculation and composite morphology a global parameter, the transverse crack in nano composite cantilever beam was studied and analyzed experimentally using a four-channel dynamic signal acquisition (NI 9234) module for making high-accuracy measurements and its ideal for vibration applications. The relationship between the dispersion and interaction of the alumina nanoparticles within the cantilever beam and morphology of the solid, hole and crack composite has been identified. Furthermore, the influence of particles Al2O3 at different concentrations (0%, 1%, 3% and 4%) have been studied respectively. Supporting results proved that the crack and hole depth increases with increases of history loading. Nanoparticles dispersed within the specimen can increase energy dissipation during vibration, leading to improved damping characteristics. For future work, it is recommended to utilize statistical frequency domain input, such as Power Spectral Density (PSD), for assessing the structural response instead of employing time history loading.

3

Comparative performance assessment of nano-composite cathode of lmso-bscmf for low temperature solid oxide fuel cell applications

Subhashini P.V.C.K., Rajesh K.V.D.

Composites Theory and Practice

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2023

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R. 23, nr 4

235--238

EN

The development of novel cathode materials for low temperature solid oxide fuel cell (SOFC) applications is one of the significant research areas in materials engineering. In the current work, composite cathode materials were prepared by two different modes and the fuel cell performance was assessed using a gadolinium-doped ceria (GDC) electrolyte. Nanocomposite cathodes were fabricated using a lanthanum strontium manganite oxide (LSMO) powder of a 50-100 nm particle size and Ba0.5Sr0.5(Co0.2Mg0.8)0.2Fe0.8O3 (BSCMF) powder of a 1 μm particle size. The cathodes were prepared as layered composites and mixed composites. The electrochemical performance of the symmetric cells was investigated by electrochemical impedance spectroscopy (EIS) at the intermediate temperature of 700°C using air atmosphere. The cathode film coating on the electrolyte was sintered at three different temperatures (900, 950 and 1000°C) and the cell performance was assessed at 700°C. Lower polarization resistance (RP) values were recorded for the cell produced at 900°C. The RP of the nano-composite cathodes was measured as lower (2.72 Ω-cm2 for the layered composites and 1.76 Ω-cm2 for the mixed composites) compared with LSMO. Hence, the results demonstrate the potential of using an LSMO-BSCMF composite in the mixed mode as a cathode for low temperature SOFCs to achieve a lower polarization potential.

4

Leading-edge polymer/carbonaceous nano-reinforcement nanocomposites — opportunities for space sector

Kausar Ayesha, Ahmad Ishaq

Advances in Materials Science

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2023

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Vol. 23, nr 4(78)

99--122

EN

Carbonaceous or nanocarbon nano-reinforcement nanocomposites have been found as emergent candidates for aerospace industry. Consequently, the multifunctional nanocomposites have been fabricated using marvelous nanocarbon nanostructures like graphene, carbon nanotube, fullerene, carbon black, etc. Manufacturing techniques have also been engrossed for the formation of high performance engineering nanocomposites having fine strength, heat stability, flame resistance, and other space desired features. These practices include solution, in situ, and melt procedures, on top of specific space structural design techniques, for the formation of aerospace structures. The aerospace related material property enhancements using various carbonaceous nano-reinforcements depends upon the type of nanocarbon, dimensionality, as well as inherent features of these nanostructures (in addition to the choice of manufacturing methods). Furthermore, carbon nano-reinforcements have been filled, besides carbon fibers, in the epoxy matrices. Nanocarbon coated carbon fibers have been filled in epoxy resins to form the high performance nanomaterials for space structures. The engineering features of these materials have been experiential appropriate for the aerospace structures. Further research on these nanomaterials may be a key towards future opportunities in the aero systems. Additionally, the explorations on structure-property relationships of the carbonaceous nanocomposites have been found indispensable for the development of advanced aerospace structures.

5

Combined axial and lateral stability behavior of random checkerboard reinforced cylindrical microshells via a couple stress-based moving Kriging meshfree model

Liu Hongwei, Safaei Babak, Sahmani Saeid

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 1

art. no. e15, 2022

EN

In this investigation, a size-dependent numerical solution methodology is devised to analyze nonlinear buckling and postbuckling of cylindrical microsized shells made of checkerboard randomly reinforced nanocomposites subjected to a combination of axial and lateral compressions. To accomplish this purpose, the modified couple stress elasticity continuum is formulated within the third-order shear flexible shell model. Using a probabilistic-based homogenization plan in conjunction with the Monte-Carlo simulation, the effective mechanical parameters of the randomly reinforced nanocomposites are captured. The established size-dependent problem is then numerically solved via using the moving Kriging meshfree technique having the ability to enforce the required boundary conditions straightly at the associated nodes without using any type of penalty technique. By tracing the nonlinear stability paths, it is revealed that for the both axial dominated and lateral dominated loading cases, the stiffening feature related to the rotation gradient tensor causes that the microshell endures higher shortening before the buckling phenomenon occurs. In addition, it is found that by increasing the length to width ratio of graphene nanofillers, the effect of combination of axial or lateral load increases a bit.

6

Investigating the effects of alumina nanoparticles on the impact resistance of polycarbonate nano-composites

Alavi Nia Ali, Amirchakhmaghi Saeed

Archive of Mechanical Engineering

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2022

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LXIX, nr 3

431--454

EN

In this project, two types of treated and untreated alumina nanoparticles with different weight percentages (wt%) of 0.5, 1 and 3% were mixed with polycarbonate matrix; then, the impact ballistic properties of the nano-composite targets made from them were investigated. Three types of projectile noses -cylindrical, hemispherical, and conical, each with the same mass of 5.88 gr – were used in the ballistic tests. The results highlighted that ballistic limit velocities were improved by increasing the percentage of alumina nanoparticles and the treatment process; changing the projectile’s nose geometry from conical to blunt nose increases the ballistic limit velocity, and ultimately, by increasing the initial velocity of conical and hemispherical nosed projectiles, the failure mechanism of the targets changed from dishing to petalling; whereas for the cylindrical projectile, the failure mode was always plugging.

7

Research on dielectric parameters of epoxy resin based nanocomposites using the impedance spectroscopy method

Dąda Anna, Błaut Paweł

Przegląd Elektrotechniczny

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2021

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R. 97, nr 12

234--237

EN

Due to the modern requirements regarding the reliability of electrical devices operation, research on improving the parameters of materials and insulation systems, in particular high-voltage ones, used in the production, transmission and distribution of electricity is still valid. One of the research directions is the development and application of insulating materials modified with nanofillers. The paper presents the results of stability studies of selected dielectric properties of samples of insulation materials based on epoxy resin modified with titanium dioxide TiO2 nanopowders. Changes in parameters caused by different wt% nanofiller content and their long-term stability after 10,000 hours from manufacturing are compared and analyzed.

PL

Współczesne wymagania dotyczące niezawodności pracy urządzeń elektrycznych powodują, że wciąż aktualnymi są badania dotyczące poprawy parametrów materiałów i układów izolacyjnych, w szczególności wysokonapięciowych, stosowanych w wytwarzaniu, przesyle i rozdziale energii elektrycznej. Jednym z kierunków badań jest opracowanie i zastosowanie materiałów izolacyjnych modyfikowanych nanowypełniaczami. Referat przedstawia wyniki badań stabilności wybranych właściwości dielektrycznych próbek materiałów izolacyjnych na bazie żywicy epoksydowej modyfikowanej nanoproszkami tlenku tytanu TiO2. Porównane są i analizowane zmiany parametrów powodowane różną zawartością wt% nanowypełniacza oraz ich stabilność długoczasowa po 10.000 godzin od wytworzenia.

8

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

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2021

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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.

9

Experimental and numerical studies of fatigue properties of carbon/glass fiber/epoxy hybrid composites enhanced with nano TiO2 powder

Hunain Mustafa Baqir, Abass Basim A., Akhudair Jaafar Musa

Diagnostyka

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2021

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Vol. 22, No. 2

75--84

EN

The present work deals with the fatigue behavior of hybrid nanocomposites consisting epoxy strengthen by unidirectional carbon fibres, and/or woven roving glass fiber and TiO2 nanofillers. For this purpose, nanocomposite material was manufactured by mixing TiO2 nanoparticles with the epoxy using an ultrasonic mixer to insure complete dispersion of such particles in the base material. Different particle concentrations (1, 3, and 5) % wt. of TiO2 nanoparticles have been added to the epoxy. Different types of hybrid nano composite materials were manufactured by adding three layers of carbon fibers and/or woven roving glass fiber to the prepared epoxy nanocomposite materials with a constant weight fraction of 30%. The laminated hybrid nanocomposite materials were then prepared using hand lay-up technique using a vacuum device. For experimental purposes tensile and fatigue test specimens have been manufactured according to ASTM-D3039 and ASTM D 3479/D 3479M-96, respectively, while ANSYS19 program was used to analyze the fatigue behavior of such materials numerically. Tensile tests were carried out at room temperature while fatigue tests has been carried out at constant stress ratio (R=-1). Scanning electron microscope (SEM) was used to identify the underlying mechanisms for fatigue failure and the progressive of damage growth. For each test, three specimens were tested and the average magnitude for each property was taken. The results obtained indicated that the hybrid nanocomposite (EP+C/C/C+3% TiO2) has the highest fatigue limit and tensile strength in comparison with the other tested material, while the SEM results showed that the composite failed by a brittle way. It has been also generally observed that the addition of (TiO2) nanoparticles has a positive effect on the fatigue behaviour of the such materials.

10

Influence of montmorillonite nanoparticles on thermal and mechanical properties of carbon-carbon hybrid composites based on phenolic-formaldehyde resin

Kateusz Filip, Korzec Tomasz, Zambrzycki Marcel, Cherniushok Oleksandr, Gubernat Maciej

Composites Theory and Practice

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2021

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R. 21, nr 3

96--101

EN

In this study, the effect of the addition of K-10 montmorillonite (MMT) nanoparticles on the mechanical and thermal properties of carbon-carbon composites were investigated. The composites were obtained using self-made prepregs with plain and twill 2/2, 600 g/m2 carbon fabric and phenolic-formaldehyde resin. The composites were obtained by the hot pressing technique, followed by carbonization in an inert argon atmosphere. Modified samples of the composites contained 5 wt.% MMT, homogenously dispersed in the ceramic carbon matrix. The mechanical properties, thermal conductivity and thermal capacity of the composites were determined. Raman spectroscopy and Fourier transform infrared spectroscopy were used to investigate the carbon matrix composition and structure. The results show that the addition of MMT nanoparticles increased Young’s modulus by 48%, Kirchoff’s modulus by 80.2%, but did not change the interlaminar shear strength nor the bending strength. The MMT influenced the carbon microstructure, changed the ID//IG Raman ratios, as well as the matrix composition. The addition of MMT also increased the low temperature regime of thermal conductivity and diffusivity of the samples.

11

Synteza nowych nanokompozytów chitozan/modyfikowany zeolit i ich wpływ na właściwości mechaniczne zapraw cementowych

Karakuş Selcan, Karapınar Işıl Sanrı, Pehlivan Ahmet Onur, Özsoy Özbay Ayşe Elif, Yazgan Utku

Cement Wapno Beton

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2021

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R. 26, nr 6

531--544

PL

W pracy przedstawiono nowy nanokompozyt zawierający biodegradowalny chitozan [CS] i modyfikowany zeolit [mZeo] jako eko-nanododatek do cementu oraz oceniono jego wpływ na właściwości mechaniczne zapraw cementowych. Proponowany nanokompozyt otrzymano dzięki synergicznej metodzie sonikacji mikrofalowej, a morfologię powierzchni i skład chemiczny nanokompozytów mZeo i CS/mZeo określono za pomocą SEM, FTIR, XRF i BET. Zbadano wytrzymałość na ściskanie i zginanie zapraw cementowych zawierających mZeo i CS/mZeo w ilości 0, 0,2, 0,5, 1 i 2 % masy cementu. Wyniki badań doświadczalnych wykazały poprawę wytrzymałości zapraw zawierających proponowany nanokompozyt. W niniejszej pracy po raz pierwszy podjęto próbę zastosowania zeolitu w nanoskali w kompozytach cementowych, a uzyskane dotychczas wyniki są bardzo obiecujące. Stwierdza się zatem, że proponowany nanokompozyt ma duży potencjał do zastosowania jako alternatywny eko-nanododatek do kompozytów cementowych.

EN

In this paper, a novel nanocomposite containing biodegradable chitosan [CS] and modified zeolite [mZeo] was introduced as a cement eco-nano additive and its effects on the mechanical properties of cement mortars were evaluated. The proposed nanocomposite was prepared by using a synergistic sonication-microwave method. The surface morphology and chemical compositions of mZeo and CS/mZeo nanocomposites were determined using SEM, FTIR, XRF, and BET. Compressive and flexural strength of cement mortars containing mZeo and CS/mZeo in ratios of 0%, 0.2%, 0.5%, 1% and 2% by mass, were investigated. Experimental results showed a significant improvement in the mechanical properties of mortars containing the proposed nanocomposite. The use of nanoscale zeolite in cementitious composites was attempted for the first time within this study and the results so far have been very promising. Therefore, it is concluded that the proposed nanocomposite has great potential to be used as an alternative eco-nano additive, for cementitious composites.

12

Characteristic of low-density polyethylene reinforcement with nano/micro particles of carbon black: a comparative study

Sabr O.H., Al-Mutairi N.H., Layla A.Y.

Archives of Materials Science and Engineering

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2021

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Vol. 110, nr 2

49--58

EN

Purpose: Low density polyethylene is commonly used polymer in the industry because of its unique structure and excellent overall performance. LDPE, is relatively low mechanical properties and thermal stability can sometimes limit its application in industry. Therefore, the development of particulate reinforced polymer composites is one of the highly promising methodologies in the area of next generation engineering products. Design/methodology/approach: Nano and Micro composite from low density polyethylene LDPE reinforced with different weight fraction of carbon black particles (CB) (2, 4 and 8)% prepared by first dispersion Nano and Micro carbon black particles CB in solvent and then mixing manually with low density polyethylene LDPE pellet and blended by twin-screw extruder, the current research study the mechanical properties (tensile strength, elastic modulus,and hardness), FTIR, DSC,and thermal conductivity of prepared nano and micro composites using two methodes and the morphological properties of nano-micro composites. Findings: The tensile strength of the LDPE/CB nano and micro composites improved at 2% and 4%, respectively, and decreasing at 8%, addition of carbon black nanoparticles led to increase the tensile strength of pure low-density polyethylene from 13.536 MPa to 19.71 MPa, and then dropping to 11.03 MPa at 8% percent,while the elastic modulus of LDPE/ CB nano and miro composites shows an improvement with all percentages of CB. The results show that the mechanical properties were improved by the addition carbon black nanoparticles more than addition micro- carbon black . FTIR show that physical interaction between LDPE and carbon black. The thermal conductivity improvement from 0.33 w/m.k for pur LDPE to 0.62234 w/m.k at 2% CB microparticle content and the reduced to 0.18645 w/m.k and 0.34063 w/m.k at (4 and 8)% micro-CB respectively , The thermal conductivity of LDPE-CB nano-composites is low in general than that the LDPE-CB microcomposite. DSC result show improvement in crystallization temperature Tc, melting temperature and degree of crystallization with addition nano and micro carbon black. Morever, SEM images revealed to uniform distribution and good bonding between LDPE and CB at low percentages and the precence of some agglomeration at high CB content. Research limitations/implications: This research studied the characteristics of both nano and micro composite materials prepared by two steps: mixing CB particles with solvent and then prepared by twin extruder which can be used packaging material, but the main limitation was the uniform distribution of nano and micro CB particles within the LDPE matrix. In a further study, prepare a blend from LDPE with other materials and improve the degradation of the blend that used in packaging application. Originality/value: LDPE with nanocomposites are of great interest because of their thermal stability, increased mechanical strength, stiffness, and low gas permeability, among other properties that have made them ideal for applications in the packaging and automotive industries. LDPE reinforcements nano-sized carbon black can have better mechanical and thermal properties than micron, resulting in less material being needed for a given application at a lower cost.

13

Creep Behaviors at 275°C for Aluminum-Matrix Nano-composite under Different Stress Levels

Azadi M., Behmanesh A., Aroo H.

Archives of Foundry Engineering

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2021

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Vol. 21, iss. 3

81--89

EN

Aluminum alloys, due to appropriate strength to weight ratio, are widely used in various industries, including automotive engines. This type of structures, due to high-temperature operations, are affected by the creep phenomenon; thus, the limited lifetime is expected for them. Therefore, in designing these types of parts, it is necessary to have sufficient information about the creep behavior and the material strength. One way to improve the properties is to add nanoparticles and fabricate a metal-based nano-composite. In the present research, failure mechanisms and creep properties of piston aluminum alloys were experimentally studied. In experiments, working conditions of combustion engine pistons were simulated. The material was composed of the aluminum matrix, which was reinforced by silicon oxide nanoparticles. The stir-casting method was used to produce the nano-composite by aluminum alloys and 1 wt.% of nanoparticles. The extraordinary model included the relationships between the stress and the temperature on the strain rate and the creep lifetime, as well as various theories such as the regression model. For this purpose, the creep test was performed on the standard sample at different stress levels and a specific temperature of 275 oC. By plotting strain-time and strain rate-time curves, it was found that the creep lifetime decreased by increasing stress levels from 75 MPa to 125 MPa. Moreover, by comparing the creep test results of nanoparticle-reinforced alloys and nanoparticle-free alloys, 40% fall was observed in the reinforced material lifetime under 75 MPa. An increase in the strain rate was also seen under the mentioned stress. It is noteworthy that under 125 MPa, the creep lifetime and the strain rate of the reinforced alloy increased and decreased, respectively, compared to the piston alloy. Finally, by analyzing output data by the Minitab software, the sensitivity of the results to input parameters was investigated.

14

Experimental study of nanocomposite hybrid adhesive-rivet joints

Nabibi Nabard, Ramezani Shadi

Archives of Civil and Mechanical Engineering

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2021

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Vol. 21, no. 3

337--365

EN

The wide range of rivets usage goes back to the processes of manufacturing and repairing an aircraft fuselage. When it comes to structural joints, adhesive bonding is said to have some merits which overshadow other joining methods, such as bolting, riveting, and welding. Today, the applications of structural adhesives do not end in aerospace, but they also are ideal for the automotive industry, where the need is to join plates of dissimilar adhesives to produce lightweight car bodies. The hybrid joints also are one of the methods of joining different parts of the machine in a durable way in which some benefits such as the significant tensile strength, the dissipated energy, and higher reliability during long-term working stand out. In this research, the effect of rivets layout on strength and failure of nanocomposite rivet and hybrid adhesive-rivet joints through two experimental and numerical methods was evaluated. Also, using the artificial neural networks method, force–displacement curves for specimens were obtained. The results of the experimental tests and the finite element analysis showed that as the number of rivets increased in the joint of the nanocomposite components, the strength of the joint increased. The layout of the rivets has a significant effect on the strength of the rivet joint. According to the performed experiments for achieving the efficient strength in the hybrid joints for the nanocomposite plates, since the strength of the adhesive is very effective, adhesive selection and the appropriate number of rivets are the key factors. The fracture modes in the internal plates of nanocomposite joints (adhesive, rivet, and adhesive-rivet joints) were observed as follows: net-tension, bearing, shear-out, crack propagation, tearing, and shear in adhesive layers. Besides, the numerical model of the work is done using ABAQUS software. The results of software simulation in the numerical model are compatible with the experimental method’s findings. However, the agreement between the results of experimental and neural network methods is higher. Owing to the results of experiments, the polypropylene nanocomposite as well as the appropriate jointing method can be put forward in the structures of the automotive industry.

15

The analysis of surface morphology, band gaps and optical properties of PAN/GO thin films

Matysiak W., Adamczyk K.

Archives of Materials Science and Engineering

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2020

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Vol. 101, nr 2

49--56

EN

Purpose: PAN/GO nanocomposites are gaining more and more interest from research and industrial environments. According to theoretical studies and experimental tests, PAN/ GO exhibits excellent properties such as tensile strength, good thermal and electrical conductivity, excellent thermal and tribological properties. Thanks to this property, the composite is considered the ideal successor to the nanocomposites used so far. The PAN/GO nanocomposite has great potential in the filtration, automotive, electrical and photovoltaic industry. Design/methodology/approach: The spin-coating process is used to produce thin layers by centrifuging a liquid substance on flat surfaces. The advantages of the spin- coating process are simplicity and ease with which the process can be carried out. Due to the ability to high spin speeds, high airflow leads to fast drying time, which in turn results in high consistency in both macroscopic and nanometre scales. The spin-coting method is usually the starting point and reference point for most academic and industrial processes that require a thin and uniform coating. The use of spin coating has a wide spectrum. This technique can be used to coat small substrates (from a few square mm) up to the coating of flat displays, e.g. TV sets, which may have a meter or more in diameter. Findings: Among the existing methods for producing thin layers, including physical and chemical methods for gas phase deposition or the self-assembly process, the spin-coating process makes it possible to produce uniform thin nanocomposite layers in an easy and cheap way. Spin coating is usually the starting point and reference point for most academic and industrial processes that require a thin and uniform coating. The advantage of the method is the wide spectrum of use. It is used for coating substrates with everything from photoresists, insulators, organic semiconductors, synthetic metals, nanomaterials, metal precursors and metal oxides, transparent conductive oxides and many other materials. Often, spin coating is used to unravel polymer layers or photoresist on semiconductor substrates. Research limitations/implications: Due to the ongoing research on the potential applications of PAN/GO thin layers, including electronics, automotive and photovoltaics, it is worth trying to optimize the parameters of the spin-coiling process such as rotational speed or duration of the process. It is also worth trying to optimize the concentration of GO in the nanocomposite. Practical implications: Despite mixing the solution with an ultrasonic homogenizer to disperse the nanoparticles, the particles dispersed to form a rough surface. Originality/value: Low-cost, easy to carry out method of producing thin nanocomposite layers, having significant application in laboratory environments.

16

Production and investigation of mechanical properties and electrical resistivity of cement-matrix nanocomposites with graphene oxide and carbon nanotube reinforcements

Najafishad S., Manesh H. D., Zebarjad S. M., Hataf N., Mazaheri Y.

Archives of Civil and Mechanical Engineering

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2020

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Vol. 20, no. 2

397--409

EN

In this study, two groups of the cement-matrix nanocomposites (CMNC) were produced. The first group was reinforced with either carbon nanotubes (CNT) or graphene oxide (GO), where the equivalent weight% of cement equaled 0.05, 0.1, and 0.15. The second group was reinforced with the hybrid CNT–GO, where the equivalent weight% of cement equaled 0.05 CNT–0.1 GO and 0.1 CNT–0.05 GO. Before producing nanocomposites, the distribution of the nanoreinforcement in water had been investigated using spectrophotometric analysis, scanning electron microscopy, and transmission electron microscopy. The physical and mechanical behaviors of different samples of the produced nanocomposites were evaluated by electrical resistivity and compressive strength tests. The effects of the types and the percentages of the nanoreinforcements on the electrical and mechanical properties of the produced nanocomposites were measured. The results showed that the electrical resistivity of the produced composites decreased with increasing the percentage of CNT, whereas the compressive strength of the cement paste initially increased and then decreased. Also, with increasing the percentage of GO, the compressive strength of the produced composites increased, while the electrical resistivity decreased. Moreover, in comparison with the composites reinforced with either CNT or GO, by using the hybrid reinforcement (CNT/GO), the compression strength increased, while the electrical resistivity decreased.

17

Nanocomposites Based on Polyamide and Montmorillonite Obtained from a Solution

Krasinskyi Volodymyr, Suberlyak Oleh, Kochubei Viktoria, Jachowicz Tomasz, Dulebova Ludmila, Zemke Viktoria

Advances in Science and Technology. Research Journal

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2020

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Vol. 14, no 3

192--198

EN

This work deals with the development of a method for obtaining polyamide and montmorillonite based nanocomposite, which was modified with polyvinylpyrrolidone by mixing in a formic acid solution. The structure and thermophysical properties of the obtained nanocomposites were investigated by means of the X-ray, differentialthermal, thermogravimetric and IR spectroscopic analyses. It was found that nanomodified polycaproamide has a higher crystallinity and higher thermal stability than the original PA-6, and is characterized by considerably higher melt fluidity. The presence of polyvinylpyrrolidone and exfoliated montmorillonite in the nanocomposite structure was confirmed experimentally.

18

Multifunctional biodegradable polymer/clay nanocomposites with antibacterial properties in drug delivery systems

Rapacz-Kmita Alicja, Szaraniec Barbara, Mikołajczyk Maciej, Stodolak-Zych Ewa, Dzierzkowska Ewa, Gajek Marcin, Dudek Piotr

Acta of Bioengineering and Biomechanics

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2020

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Vol. 22, no. 2

83--92

EN

Purpose: The aim of this study was to investigate the possibility of intercalation of gentamicin and neomycin in montmorillonite (MMT) nanofillers, as well as to study the in vitro antimicrobial properties of nanocomposite films containing a small amount of thus obtained nanofillers. Methods: The polylactide matrix (PLA) nanocomposite films with drug-intercalated montmorillonite fillers were obtained by casting after intercalation of drugs in aqueous solutions. The efficiency of intercalation has been confirmed by X-ray diffraction (XRD) and Zeta potential measurements. The materials were studied for surface wettability, roughness and mechanical properties during 6 weeks of incubation in phosphate buffer saline, and their bactericidal activity was tested against Escherichia coli bacteria before and after 6 weeks of incubation in distilled water at 37 C. The presence of antibiotics during the incubation was monitored by conductivity and pH measurements. Results: The results indicate that nanocomposite polylactide films with montmorillonite filler intercalated with gentamicin and neomycin tend to degrade faster that their counterparts with non-intercalated fillers, which affects their mechanical properties. However, drug intercalation provided an antibacterial activity, which was confirmed by the presence of zones inhibiting the growth of Gram-negative bacteria for both antibiotics. It was also confirmed that the interaction of antibiotics with clay and polymer matrix did not adversely affect this bactericidal effect. Conclusions: Montmorillonite can be successfully intercalated with both gentamicin and neomycin, and then used as active filler for polylactide films having very good antibacterial properties, therefore their use in biomedical applications can be significantly expanded.

19

Nanokompozytowe materiały węglowe z nanocząstkami złota : synteza, charakteryzacja, zastosowania

Rymarczyk Joanna, Czerwosz Elżbieta

Elektronika : konstrukcje, technologie, zastosowania

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2019

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Vol. 60, nr 12

14--18

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.

20

Photocatalytic degradation of pharmaceuticals using TiO2 based nanocomposite catalyst - review

Fawzi Suleiman Khasawneh Omar, Palaniandy Puganeshwary

Civil and Environmental Engineering Reports

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2019

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Vol. 29, no. 3

1--33

EN

The occurrence of contaminants of emerging concern (CECs) such as pharmaceutical compounds (PhACs) is becoming a major global issue due to the persistence, bioaccumulation, and toxicity of these pollutants. Human and animal consumption was recognized as the major sources for pharmaceutical pollution. Existent conventional treatment processes have shown low degradation efficiencies towards PhACs. In this regard, TiO2 based nanocomposite photocatalysis process has presented effective degradation towards PhACs. Operational parameters such as dopant content, catalyst loading, and initial pH were the major factors in the photocatalysis system. In this review, we discuss the recent studies that have employed TiO2 based nanocomposite for the degradation of PhACs. Future research recommendations have also been elaborated.