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1

Low-temperature powder paint modified with graphene oxide

Pojnar Katarzyna, Pilch-Pitera Barbara, Roś Natalia, Florczak Łukasz

Ochrona przed Korozją

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2024

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nr 2

30--39

EN

The aim of this study was to obtain low temperature polyurethane powder paint based on a thermosetting acrylic resin modified with graphene oxide (GO) and to investigate the protective properties of the coatings. The acrylic resin was synthesised by the radical copolymerisation reaction of 2-hydroxyethyl methacrylate (HEMA), methyl methacrylate (MMA) and n-butyl acrylate (BA). Graphene oxide was added to the resin at the synthesis stage in appropriate amounts by weight (so-called in situ method). An optimal amount of added graphene oxide of 0.5 wt% had a significant effect on the final result. Thanks to the use of a commercial crosslinker (VESTANAT B 1358/100), the coatings cured at a relatively low temperature (160°C). The curing process of the coatings was studied by differential scanning calorimetry (DSC). The cross-linked coatings were examined for appearance, physical and chemical properties, and resistance to corrosive media by electrochemical impedance spectroscopy (EIS). The presence of a modifier in the form of graphene oxide increased the hardness, scratch resistance, ductility, contact angle and resistance to corrosive media of the coatings obtained.

PL

Celem badań opisanych w artykule było otrzymanie niskotemperaturowych poliuretanowych powłok proszkowych na bazie termoutwardzalnej żywicy akrylowej modyfikowanej tlenkiem grafenu (GO) oraz określenie właściwości ochronnych powłok. Żywica akrylowa została zsyntezowana w reakcji kopolimeryzacji wolnorodnikowej metakrylanu 2-hydroksyetylu (HEMA), metakrylanu metylu (MMA) i akrylanu n-butylu (BA). Tlenek grafenu został dodany do żywicy na etapie syntezy w odpowiednich ilościach wagowych (metodą in situ). Istotny wpływ na wynik końcowy miała optymalna ilość dodanego tlenku grafenu – na poziomie 0,5% wag. Dzięki zastosowaniu komercyjnego środka sieciującego VESTANAT B 1358/100 powłoki utwardzały się w stosunkowo niskiej temperaturze (160°C). Przebieg procesu utwardzania powłok badano za pomocą różnicowej kalorymetrii skaningowej (DSC). Usieciowane powłoki analizowano pod kątem wyglądu, właściwości fizykochemicznych oraz odporności na media korozyjne, wykonując pomiar metodą elektrochemicznej spektroskopii impedancyjnej (EIS). Obecność modyfikatora w postaci tlenku grafenu zwiększyła twardość, odporność na zarysowanie, tłoczność, kąt zwilżania oraz odporność na media korozyjne otrzymanych powłok.

2

Zinc and graphene oxide composites as new protective coatings for oil and gas pipes

Asghar M. Sajid Ali, Amir Muhammad, Hussain Umer, Sabri Mohammed M.

Polimery

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2023

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Vol. 68, nr 7-8

378--385

EN

A method was developed to obtain a durable coating consisting of zinc and graphene oxide (Zn-GO) in order to reduce the mechanical wear and tear rate of oil and gas pipelines made of steel. Graphene oxide was obtained from graphite by wet chemical oxidation (unmodified and modified Hummers’ method) using potassium permanganate and sulfuric acid. The process was carried out at various temperatures. The steel was covered with an ultrathin layer of Zn-GO using the electrophoretic deposition method. The GO particle size (< 90 nm) was confirmed by XRD and laser analysis. For GO particles obtained by the modified Hummers’ method, a significant correlation was observed in the scratch (R2 = 0.87) and the Vickers microhardness tests (R2 = 0.93), which indicates a lower wear rate of Zn-GO-coated steel.

PL

Opracowano metodę otrzymywania trwałej powłoki składającej się z cynku i tlenku grafenu (Zn-GO) w celu zmniejszenia zużycia mechanicznego rurociągów naftowo-gazowych wykonanych ze stali. Tlenek grafenu pozyskano z grafitu metodą mokrego utleniania chemicznego (niezmodyfikowana i zmodyfikowana metoda Hummersa) z użyciem nadmanganianu potasu i kwasu siarkowego. Proces prowadzono w różnej temperaturze. Stal powlekano ultra cienką warstwą Zn-GO techniką osadzania elektroforetycznego. Metodą XRD i analizą laserową potwierdzono wielkość cząstek GO (≤ 90 nm). Dla cząstek GO otrzymanych zmodyfikowaną metoda Hummersa zaobserwowano znaczącą korelację w teście zarysowania (R2 = 0.87) i mikrotwardości Vickersa (R2 = 0.93), co świadczy o mniejszym stopniu zużycia stali pokrytej powłoką Zn-GO.

3

Wpływ nanocząstek FeNi3/SiO2/GO na właściwości mechaniczne i trwałość betonu

Shandiz Afshin Charani, Honarbakhsh Amin, Zhiani Rahele, Amarloo Fatemeh

Cement Wapno Beton

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2023

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R. 28, nr 4

255--267

PL

Najnowsze badania wskazują na to, że nanomateriały mogą częściowo zastąpić cement w kompozytach cementowych. Ostatnio zaproponowanym zamiennikiem cementu w betonie są nanokompozyty tlenku grafenu. W związku z tym, w tym badaniu laboratoryjnym, zsyntetyzowano nanocząstki FeNi3/SiO2/GO [NFSG] oraz nanocząstki SiO2 [NS] i potwierdzono za pomocą analiz FTIR, SEM i TEM ich właściwości. Następnie zastąpiono nimi częściowo cement w ilości 1, 2 i 3% jego masy i określono ich wpływ na właściwości mechaniczne i trwałość próbek w wieku 7, 28 i 90 dni. Wyniki sugerują, że składy o najlepszych właściwościach mechanicznych przyniosły najlepsze rezultaty. W betonach tych wprowadzono 2% NFSG i 2% NS jako zamienniki cementu. Po 28 dniach beton zawierający NFSG zwiększył wytrzymałość na ściskanie o 15% i wytrzymałość na rozciąganie przy rozłupywaniu o 13%. Widma FTIR wykazały, że próbka zawierająca 2% NFSG wytworzyła więcej żelu C-S-H, poprawiając mikrostrukturę betonu, a tym samym jego właściwości.

EN

Recent research in the construction industry supports the idea that nanomaterials can partially replace cement. A recently suggested material as a suitable substitute for cement in concrete is graphene oxide nanocomposite. As a result, in this laboratory study, FeNi3/SiO2/GO nanoparticles [NFSG] and SiO2 nanoparticles [NS] partially replace cement by 1, 2, and 3% by mass after their synthesis and confirmation by FT-IR, SEM and TEM analyses and their impact on the mechanical and durability characteristics of the specimens at ages 7, 28, and 90 days were examined. The findings imply that the designs with the highest mechanical properties tests produced the best results. These designs used 2% of NFSG and 2% of NS substituting cement. After 28 days, NFSG-containing concrete increased compressive strength by 15% and splitting tensile strength by 13%. FTIR spectra demonstrated that specimen containing 2% of NFSG produced more C-S-H [calcium silicate hydrate] gel, improving the microstructure of concrete and subsequently its properties.

4

Ocena skuteczności filtracji półmasek filtrujących wobec nanoaerozolu zredukowanego tlenku grafenu

Makowski Krzysztof, Owczarek Oliwia, Brochocka Agnieszka

Bezpieczeństwo Pracy : nauka i praktyka

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2023

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nr 8

17-21

PL

W artykule przedstawiono skuteczność filtracji półmasek filtrujących klasy FFP2 i FFP3 wobec nanocząstek zredukowanego tlenku grafenu. Sprzęt ochrony układu oddechowego został wybrany spośród wielu produktów powszechnie dostępnych na rynku. Pomiary penetracji przeprowadzono z użyciem 0,02-proc. zawiesiny wodnej zredukowanego tlenku grafenu przy przepływie nanoaerozolu 95 l/min. Wartość penetracji odczytywano dla cząstek o wielkości do 100 nm. Przedstawione wyniki badań pokazują, że stosowana obecnie klasyfikacja półmasek filtrujących według normy EN 149:2001+A1:2009, oparta na standardowych aerozolach testowych, nie ma przełożenia na ochronę przed nanoaerozolami zredukowanego tlenku grafenu. W przypadku zbadanych półmasek filtrujących wartości penetracji nanocząstek zredukowanego tlenku grafenu dla większości próbek przekroczyły dopuszczalny zakres określony we wspomnianej normie. W związku z tym konieczne jest opracowanie wytycznych doboru sprzętu ochrony układu oddechowego przeznaczonego do stosowania w warunkach obecności nanocząstek, w tym zredukowanego tlenku grafenu.

EN

The article presents the assessment of filtration efficiency of filtering half mask FFP2 and FFP3 against nanoparticles of reduced graphene oxide. Respiratory protective devices were selected from among many commonly available on the market. Penetration measurements were carried out with a 0.02% water suspension of reduced graphene oxide at a nanoaerosol flow of 95 l/ min. The penetration value was read for particles up to 100 nm in size. The presented research results show that the currently used classification of filtering respirators according to the EN 149:2001+A1:2009 standard, based on standard test aerosols, does not reflect the protection against reduced graphene oxide nanoaerosols. The penetration values against the graphene nanoparticles of the tested filtering half masks exceeded the admissible range of penetration according to the above-mentioned standard for most of the samples. Therefore, it is necessary to develop guidelines for the selection of respiratory protective equipment intended for use in the presence of nanoparticles, including reduced graphene oxide.

5

Separation of molybdenite from chalcopyrite, using graphene oxide as a novel depressant

Namiranian Afshin, Noaparast Mohammad, Tonkaboni Sied Ziaedin Shafaei

Archives of Mining Sciences

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2023

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Vol. 68, no. 1

71--86

EN

In this research, graphene oxide was introduced as an efficient flotation reagent for the selective separation of molybdenite from chalcopyrite. The performance of graphene oxide and its adsorption mechanism on chalcopyrite were investigated by flotation tests, FTIR spectra, and XPS measurements. First, graphene oxide was synthesised, and then its performance was evaluated by SEM, XRD, and EDX. Flotation tests were carried out in a hallimond flotation cell with a volume of 300 ml. Optimum flotation values were achieved at pH = 9 by adding 250 g/t of PAX (Potassium Amyl Xanthate) as a collector and 50 g/t of A65 (Poly Propylene Glycol) as a frother. The results showed high recovery, around 80% for molybdenite, while chalcopyrite was depressed in high amounts by employing 11 kg/t of graphene oxide as a depressant. Compared to common chalcopyrite depressants such as NaHS, Na2S, and C2H3NaO2S, graphene oxide had a higher potency in depressing, which can be applied as a green-depressant in the separation of molybdenite from chalcopyrite by the flotation process. Also, the validity of the depressing effect on chalcopyrite was verified by XPS and FTIR spectra.

6

Multimodal machine learning approach for exploring the 28-day compressive strength of nanomaterials-reinforced cement composites

Yang Jinlong, Zeng Bowen, Hang Ziyan, Fan Yucheng, Ni Zhi, Feng Chuang, Liu Chuang, Yang Jie

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 3

art. no. e202, 2023

EN

Accurately predicting the 28-day compressive strength (CS) of carbon nanotubes-reinforced cement composites (CNTRCCs) and graphene oxide-reinforced cement composites (GORCCs) is crucial for accelerating their potential application in civil engineering. However, traditional experimental and theoretical modeling methods suffer from problems, including time-consuming, costly, and inefficient. Moreover, it is also challenging to consider the effects of multiple coupling factors. In this work, a multimodal machine learning (ML) approach is proposed as the first attempt to explore the complex relationships between the CS of hybrid system containing both CNTRCCs and GORCCs. The proposed multimodal ML shows great potential in estimating the nanomaterials-reinforced cement composites with a coefficient of determination (R2) of 0.96, surpassing the single-modal ML approaches. The results demonstrate the effectiveness of the developed model in accurately predicting the 28-day CS of hybrid system containing both CNTRCCs and GORCCs. Shapley additive explanations (SHAP) analysis illustrates that the optimal concentration of CNT is approximately 0.5 wt%, and preferred length of CNT and sheet size of GO are within a range of 20–30 μm and below 10 μm, respectively. Additionally, the enhancement effect of a single-layer GO is better than its multilayer counterparts.

7

Graphene oxide - potential use in wood protection based on a review of antibacterial and fungicide properties

Bąk Milena, Lipska Karolina, Betlej Izabela, Krajewski Krzysztof

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2023

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No. 123

51--59

EN

Graphene oxide - potential use in wood protection based on a review of antibacterial and fungicide properties. Graphene oxide is a material that has been generating interest among researchers in recent years. Due to its properties, it can be used in many scientific and industrial fields. Not all of its properties are significantly known, making it a potential subject of research in many different aspects. The topic of this article is to assess the potential applications of graphene oxide in the field of wood science industry. Based on the literature, the antibacterial and fungicidal properties are characterised. The fungicidal effect of graphene oxide, mainly in plant protection, leads to consideration of the potential use of this material in protection against wood-destroying fungi.

PL

Tlenek grafenu – potencjalne wykorzystanie w ochronie drewna na podstawie przeglądu właściwości antybakteryjnych i fungicydowych. Tlenek grafenu jest materiałem, który w ostatnich latach budzi zainteresowanie wśród badaczy. Ze względu na swoje właściwości może być wykorzystywany w wielu dziedzinach nauki i przemysłu. Nie wszystkie jego właściwości są istotnie poznane, przez co może stanowić on przedmiot badań w wielu różnych aspektach. Tematem tego artykułu jest ocena możliwości potencjalnych zastosowań tlenku grafenu w dziedzinie drzewnictwa. Na podstawie literatury przedmiotu dokonano charakterystyki właściwości antybakteryjnych i fungicydowych. Fungicydowe oddziaływanie tlenku grafenu, głównie w ochronie roślin, prowadzi do rozważań nad potencjalnym zastosowaniem tego materiału w ochronie przed grzybami, powodującymi destrukcję drewna.

8

Preparation of rGO/ZnO photoanodes and their DSSCs performance

Li Jiake, Wu Lanxiang, Li Wentao, Chen Ying, Liu Xin, Jiang Hedong, Guo Pingchun, Zhu Hua, Wang Yanxiang

Materials Science Poland

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2022

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Vol. 40, No. 2

170--180

EN

In this study, we report a mild and controllable preparation method for graphene oxide (GO) and ZnO ultrafine powder, respectively. On this basis, reduced graphene oxide (rGO)/ZnO composite powder for the photoanodes of dye-sensitized solar cells (DSSCs) was synthesized by chemical reduction method. Phase composition, microstructure, chemical structure, conductivity, and specific surface area were examined using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), Raman, and Brunauer-Emmett-Teller (BET) method, respectively. Photoelectric performance of DSSCs was studied by the current density-voltage (J-V), electrochemical impedance spectra (EIS) photoelectric test system. As rGO possesses higher adsorption capacity and excellent conductivity, hence it may effectively promote separation of electrons and holes, transmission ability of electrons and holes, and utilization of the light. By contrast, the as-synthesized zinc oxide (ZnO) may increase adsorption capacity of dye molecules, so photoelectric conversion efficiency (PCE) of the solar cells is increased by means of synergistic effects. When adding rGO in the rGO/ZnO composite powder at 1.25 wt%, PCE reaches to 6.27%, an increase of 20.6% more than that of pure ZnO as the photoanode.

9

Optimization of Graphene Oxide Mixed Matrix Membrane for AB-210 Dye Removal

Al-Sultan Ammar A., Kadhim Rana J., Al-Emami Omar H., Alsalhy Qusay F., Majdi Hasan Sh.

Journal of Ecological Engineering

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2022

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Vol. 23, nr 9

115--127

EN

This research aimed to find the best-operating conditions for incorporating the GO material into PES/GO membranes for the NF applications. Organic dye molecules may foul GO-NP/PES membranes. The improved model aimed to reduce the energy lost while maintaining a high system discharge throughout the treatment process in order to face the technical problems that the membranes are exposed to. To create a particular amount of flux above the intended values, an optimization approach was used to find the optimal values for several important parameters in the process. To enhance the process effectiveness on a broader scale, mathematical and statistical studies, such as response surface methodology and statistical analysis of the parameters (ANOVA), were applied. The impact of operational factors, like the pH values of the dye feeding (3–11), GO weight content (0–2 wt.%), dye concentration (10–100 ppm) of AB-210, and the interfaces for these factors with the PES/GO membrane permeability was examined. The PES membrane had the best performance, with a result of 131.2338 L·m-2·h-1·bar-1. The pH did not influence the AB-210 dye reaction, and the Pareto chart of the standardized effects on dye permeation flux using statistical comparison at the 5% significance level supports these findings.

10

Self-healing epoxy/PDMS/graphene oxide nanocomposites for anti-corrosive applications

Moorthi Krishna, Saxena Vishesh, Prasanna Sanka R.V. Siva, Rana Sravendra

Chemical and Process Engineering

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2022

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Vol. 43, nr 2

137–-145

EN

This study discusses the synthesis, characterization and development of self-healing nanocomposite of amino-terminated PDMS (Polydimethylsiloxane), Epoxy (EPON828 ̧ Diethylenetriamine (DETA)), and Graphene Oxide (GO). GO was prepared using a modified Hummer’s method and was incorporated into the PDMS-Epoxy composite in various ratios (0.1 wt.%, 0.3 wt.%, and 0.5 wt.%) using toluene as the dispersing medium. Fourier Transform Infrared Spectroscopy was used for confirming the presence of the designed/prepared structures, and thermo-mechanical analysis was performed to test the change in glass transition temperature and initiation temperature of self-healing process. The composite resins were coated on mild steel substrates by curing freshly prepared resins over the substrates at elevated temperatures. The corrosion behavior of mild steel in 3.5 wt.% NaCl solution before and after the coatings was studied using Tafel Electrochemical Polarization test. The self-healing properties of the materials were also studied by applying cuts on the material and letting them heal under elevated temperatures, and the results showed that the prepared coating demonstrated an effective corrosion resistance for mild steel for various marine applications

11

Regenerated Cellulose/Graphene Composite Fibers with Electroconductive Properties

Kulpinski Piotr, Jeremiasz K. Jeszka, Malolepszy Artur, Stobinski Leszek

Autex Research Journal

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2022

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Vol. 22, no. 2

177--183

EN

Conductive cellulose fibers may find application in producing antistatic materials and fibrous electronic elements for smart textiles (textronics). In this paper, we present a method of fabrication of cellulose fibers modified with the reduced graphene oxide (rGO) and graphene oxide (GO). The fibers were obtained by using N-methylmorpholine-N-oxide (NMMO) as a direct solvent, adding dispersion of GO during the cellulose dissolution process. In the next step, the GO enclosed in the fibers was reduced for ca. half an hour at 90°C with the excess of water solution of hydrazine to obtain fibers containing rGO. The viscosity of the spinning solution increased when GO was added; however, the difference is important at low shearing rates but decreases at high shearing rates, similar to that used in the process of fiber spinning. Cellulose fibers containing 3, 4, 6, and 10% w/w of rGO were obtained. Fiber morphology was studied using electron microscopy. The results of the electrical properties’ measurements showed that the conductivity of modified fibers strongly depends on the concentration of rGO. At 10% rGO conductivity was 9 x 10−3 S/cm. The mechanical properties of the obtained fibers were slightly changed by the presence of GO and rGO. Tenacity and elongation at break decreased with the increase in the content of GO and rGO in the fibers but remain at an acceptable level from the textiles processing point of view.

12

Characterisation of nano-thin film GO/TiO2 layers for Kretschmann-based surface plasmon resonance visible sensing using FDTD method

Khairulazdan N. B., Mohamed R., Berhanuddin D. D., Menon P. S.

Optica Applicata

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2021

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Vol. 51, nr 4

579--587

EN

Kretschmann-based surface plasmon resonance (K-SPR) is suitable for biomolecular sensing which provides label-free and quick detection results with real-time analysis. In this work, we have investigated the effect of graphene oxide (GO) with titanium dioxide (TiO2) thin films that are placed in hybrid above metal layers such as gold (Au), silver (Ag) and copper (Cu) with the presence of chromium (Cr) as an adhesive layer. The thickness of the Au, Ag and Cu metal thin films were optimized to 40, 30 and 30 nm, respectively, with a fixed thickness of GO of 2 nm and TiO2 of 1.9 nm. The sensing was evaluated for SPR excitation at three different visible wavelengths of 633, 670 and 785 nm. The performance of sensing was analyzed based on the reflectance intensity and full-width at half-maximum (FWHM) of the spectrum using the finite-difference time-domain (FDTD) method. The sensitivity was calculated for analyte sensing in dielectric mediums of air versus water. The sensitivity increment percentage (%∆S ) was determined when comparing analyte detection using Cr/metal and Cr/metal/GO/TiO2 sensor structures. The highest sensitivity of 94.51 deg/RIU was achieved for Cr/Cu/GO/TiO2 K-SPR sensor at 633 nm wavelength.

13

Effect of addition of non-functionalized graphene oxide in a commercial epoxy resin used as coating

Varela Caselis Jenaro Leocadio, Santamaría Juárez Juana Deisy, Galicia Aguilar José Alberto, Domínguez Alcalá María Fernanda, Rubio Rosas Efraín, Mendoza Hernández José Carlos, Sánchez Cantú Manuel

Materials Science Poland

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2021

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Vol. 39, No. 4

467--477

EN

The paper studies the effect of incorporating graphene oxide (GO) without surface functionalization on a commercial epoxy resin. GO was dispersed in a commercial epoxy resin at concentrations of 0 wt.%, 0.1 wt.%, 0.5 wt.%, 1 wt.%, and 3 wt.%. The resultant materials were deposited on carbon steel substrates, followed by the use of a 5 wt.% aqueous NaCl electrolyte, to evaluate the effectiveness of their anticorrosive coating function. Scanning electron microscopy (SEM) analysis showed that the GO was homogenously dispersed in the polymer matrix, resulting in flat and smooth surfaces. The X-ray diffraction (XRD) results showed that although GO was highly dispersed in the polymer matrix, multilayer graphene was also obtained after curing. The anticorrosive properties were evaluated by electrochemical impedance spectroscopy (EIS) at various exposure periods. Analysis of the prepared samples indicated that the best anticorrosion performance among them was available with the 0.5 wt.% GO coating. The obtained results indicate that GO–polymer matrix composites provide improved corrosion protection properties even after 500 h exposure to the NaCl solution.

14

Wpływ dodatku tlenku grafenu na poprawę właściwości betonu

Wydra Małgorzata, Szulc Hubert

Cement Wapno Beton

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2021

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R. 26, nr 4

294--306

PL

Celem przeprowadzonych badań było wyjaśnienie, w jaki sposób dodanie tlenku grafenu do betonu wpływa na jego wybrane właściwości, a mianowicie: wytrzymałość na ściskanie, rozciąganie oraz zginanie, przepuszczalność powietrza, sorpcyjność, nasiąkliwość, mrozoodporność i przewodnictwo ciepła. W analizowanych seriach próbek stwierdzono, że dodatek tlenku grafenu w większości przypadków zmniejszał wytrzymałość na ściskanie. Jednak równocześnie poprawiał wybrane właściwości, a przede wszystkim wytrzymałość na zginanie – poprawa o 7%, i na rozciąganie – poprawa o 6%, w przypadku betonu z dodatkiem 0,005% tlenku grafenu. Jako planowany zakres badań zaproponowano analizy mieszanek betonowych o większej płynności i metody uśredniania mieszanek.

EN

The aim of the research was to explain how the addition of graphene oxide [GO] to concrete influences performance parameters such as compressive, tensile, and flexural strength, air permeability, sorptivity, absorbability, frost resistance, and thermal conductivity. It was found that the addition of GO in most cases decreased the compressive strength. Nevertheless, an improvement of selected parameters has been observed, eg, an increase in flexural strength by 7% and a split tensile strength by 6% for concrete with GO in the content of 0.005%. Concrete mixes with higher fluidity and improvement of homogenization procedures are suggested for future research areas.

15

Badanie właściwości mechanicznych i trwałości betonu zawierającego nanocząstki Fe3O4/SiO2/tlenek grafenu i tlenku grafenu

Saliani Mehdi, Honarbakhsh Amin, Zhiani Rahele, Mojtaba Movahedifar Seyed, Motavalizadehkakhky Alireza

Cement Wapno Beton

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2021

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R. 26, nr 1

67--82

PL

Najnowsze badania w przemyśle materiałów budowlanym uzasadniają częściowe zastąpienie cementu nanomateriałami. Nanokompozyt tlenku grafenu jest materiałem, który został ostatnio zaproponowany jako dodatek do betonu. Brak jest jednak badań nad zastosowaniem tych syntetycznych związków w betonie, a także niewiele wiadomo o wpływie tych materiałów na właściwości mechaniczne i trwałość betonu. Dlatego w niniejszej pracy laboratoryjnej, przeprowadzeniu syntezy nanocząstek Fe3O4/SiO2/ tlenek grafenu i nanocząstek tlenku grafenu oraz potwierdzono je wynikami analiz spektroskopii w podczerwieni oraz za pomocą skaningowej i trasmisyjnej mikroskopii elektronowej. Nanocząstki te dodawano do betonu jako zamiennik cementu w ilości 1, 2, 3 i 4% masy cementu i zbadano ich wpływ na właściwości mechaniczne i trwałość próbek po 7, 28 i 90 dniach. Wyniki badań wykazują, że najlepsze wyniki w badaniach właściwości mechanicznych uzyskały mieszanki, w których cement zastąpiono odpowiednio 2% nanocząstek Fe3O4/ SiO2/tlenek grafenu oraz 3% nanocząstek tlenku grafenu. Beton zawierający nanocząstki Fe3O4/SiO2/tlenek grafenu zwiększył wytrzymałość na ściskanie o 14% i wytrzymałość na rozciąganie przy rozłupywaniu o 12% po 28 dniach utwardzania. Również w próbce zawierającej 2% nanocząstek Fe3O4/SiO2/tlenek grafenu zaobserwowano największą odporność na środowisko kwasowe najmniejszą przepuszczalność. Natomiast w teście ultradźwiękowym stwierdzono największą prędkość przejścia fali ultradźwiękowej w porównaniu z próbkami zawierającymi nanocząstki tlenku grafenu i z próbką wzorcową.

EN

Recent research in the construction industry justifies the partial replacement of cement by nanomaterials. Graphene oxide nanocomposite is a material that has been recently proposed as a suitable alternative for part of cement in concrete. However, there is no research on the addition of these synthetic compounds to concrete, and little is known about the effect of these materials on the mechanical and durability properties of concrete. Therefore, in this laboratory study, the synthesis of Fe3O4/SiO2/GO and GO nanoparticles was performed and confirmed with FT-IR, SEM, TEM analyses. These nanoparticles partially replaced cement by 1, 2, 3, and 4 % by mass of the cement, and their effect on mechanical and durability properties of concrete at the ages of 7, 28, and 90-day, were investigated. The results suggest that mixtures in which 2% Fe3O4/SiO2/GO and 3% GO substituted cement yielded the best results in the mechanical properties tests. Concrete containing Fe3O4/SiO2/GO nanoparticles enhanced compressive strength by 14% and splitting tensile strength by 12% after 28-days of curing. Also, concrete containing 2% Fe3O4/SiO2/GO, had the highest resistance to an acidic environment, the lowest permeability, and the highest transient pulse velocity in the ultrasonic test, compared to the specimen containing GO nanoparticles and the control sample.

16

The Fabrication of Cassava Silk Fibroin-Based Composite Film with Graphene Oxide and Chitosan Quaternary Ammonium Salt as a Biodegradable Membrane Material

Zhao Shuqiang, Ma Pibo, Wan Ailan, Huang Jiwei, Yu Houyong, Lai Enping, Lin Haitao, Miao Xuhong, Yue Xinxia

Autex Research Journal

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2021

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Vol. 21, no. 4

459--466

EN

A novel and excellent composite film was fabricated by simply casting cassava silk fibroin (CSF), chitosan quaternary ammonium salt (HACC), and graphene oxide (GO) in an aqueous solution. Scanning electron microscope images showed that when GO was dispersed in the composite films, the surface of CSF-based composite film became rough, and a wrinkled GO structure could be found. When the content of GO was 0.8%, the film displayed a higher change with respect to the breaking strength and elongation, respectively, up to 97.69 ± 3.69 and 79.11 ± 1.48 MPa, keeping good thermal properties because of the incorporation of GO and HACC. Furthermore, the novel CSF/HACC/GO composite film demonstrates a lower degradation rate, implying the improvement of the resistance to the enzyme solution. Especially in the film with 0.8 wt% GO, the residual mass arrived at 64.35 ± 1.1% of the primary mass after 21 days compared with the CSF/HACC film. This would reclaim the application of silk-based composite films in the biomaterial field.

17

Effect of graphene oxide additive on the structure of composite cellulose fibers

Gabryś Tobiasz, Ślusarczyk Czesław

Polimery

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2020

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T. 65, nr 9

646--650

EN

The paper presents results of investigations on the effect of the addition of graphene oxide (GO) on the structural properties of composite cellulose fibers (CEL). GO/CEL fibers were obtained from a solution of CEL in ionic liquid – 1-ethyl-3-methylimidazole acetate – with the addition of GO dispersion in DMF. A classic wet spinning method was used using water and methanol as coagulants. Results have shown that the addition of GO increases the crystallinity of fibers to 31–40.8%. Moreover, these results indicate a significant impact of the coagulant used in the fiber forming process. Methanol coagulated fibers have greater porosity and larger pore sizes than water coagulated fibers.

PL

Przedstawiono badania wpływu dodatku tlenku grafenu (GO) na właściwości strukturalne kompozytowych włókien celulozowych (CEL). Włókna GO/CEL otrzymywano z roztworu CEL w cieczy jonowej – octanie 1-etylo-3-metyloimidazolu – z dodatkiem dyspersji GO w DMF. Zastosowano klasyczną metodę formowania włókien na mokro z zastosowaniem wody oraz metanolu jako koagulantów. Badania wykazały, że dodatek GO wpływa na wzrost stopnia krystaliczności włókien do wartości 31–40,8%. Ponadto wyniki te wskazują na znaczny wpływ koagulantu stosowanego w procesie formowania włókien na ich strukturę. Włókna koagulowane metanolem mają większą porowatość i większe rozmiary porów niż włókna koagulowane wodą.

18

Tlenek grafenu - nanomateriał do wytwarzania półprzepuszczalnych membran

Bodzek Michał, Konieczny Krystyna

Instal

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2020

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nr 1

40--44

PL

W artykule przedstawiono metody syntezy membran kompozytowych opartych na grafenie, ich właściwości i możliwości aplikacyjne. Omówiono również funkcje chemiczne i fizyczne pochodnych grafenu, które wpływają na efektywność odsalania wody i właściwości anty-foulingowe. Przedstawiono metody funkcjonalizacji grafenu i jego pochodnych, zwiększające stabilność warstwy aktywnej, retencję soli, przepuszczalność wody, oraz mechanizm transportu jonów i zmniejszania foulingu. Membrany wykonane z tych materiałów pozwalają na osiągnięcie znacznie wyższego strumienia wody/permeatu niż stosowane obecnie poliamidowe cienkowarstwowe membrany kompozytowe.

EN

In this paper methods of synthesis of membranes containing graphene and its derivatives, their properties and application areas are discussed. Chemical and physical functions of graphene and graphene oxide influencing water desalination efficiency and antifouling properties are also described. The article shows the methods of graphene functionalization and its derivatives, increasing the stability of the active layer, salt retention, permeability of water and the ion transport mechanism and reduction of fouling. Membranes made of these materials enable to obtain significantly higher water/permeate fluxes than in the case of currently used thin film composite polyamide membranes.

19

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.

20

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.