scholarly journals Reinforced Epoxy Composites Modified with Functionalized Graphene Oxide

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 338
Author(s):  
Anton Mostovoy ◽  
Andrey Shcherbakov ◽  
Andrey Yakovlev ◽  
Sergey Arzamastsev ◽  
Marina Lopukhova

The possibility of using graphene oxide as a modifying additive for polymer fiber-reinforced composites based on epoxy resin and basalt roving has been studied. The content of graphene oxide in the system has been experimentally selected, which has the best effect on the physico-mechanical properties of the obtained polymer composite material. The efficiency of the modification of the graphene oxide surface with APTES finishing additives and aminoacetic acid, which provides chemical interaction at the polymer matrix–filler interface, has been considered. The influence of graphene oxide and functionalizing additives on the polymer curing process was investigated using the thermometric method and differential scanning calorimetry.

2019 ◽  
Vol 55 (4) ◽  
pp. 1436-1450 ◽  
Author(s):  
Jan Broda ◽  
Marcin Baczek ◽  
Janusz Fabia ◽  
Dorota Binias ◽  
Ryszard Fryczkowski

Abstract During the investigations, functionalization of graphene oxide synthesized using modified Hummers’ method and its reduced form was performed. Mixtures of graphene oxide and reduced graphene oxide with pimelic acid and calcium hydroxide were prepared for functionalization. During the reaction, the molecules of pimelic acid were attached to the surface of graphene sheets. By forming links between the carboxylic groups of pimelic acid and graphene oxide, the durable connection was achieved. The functionalized graphene oxide and the reduced graphene oxide were used as additives in isotactic polypropylene crystallization. The influence of additives on crystallisation in non-isothermal conditions was examined using polarized optical microscopy and differential scanning calorimetry. The effect of the additives on the polypropylene structure was analysed using wide-angle X-ray scattering. For both functionalized compounds, the nucleating ability towards β-form of polypropylene was detected. Both additives showed the increase in the nucleation rate and promotion of growth of the β-form crystals. Nucleation efficiency similar to other nucleating agents used in the crystallization of the β-form of polypropylene was revealed.


2017 ◽  
Vol 231 (11-12) ◽  
Author(s):  
Tianlin Cao ◽  
Fanyu Zhao ◽  
Zulin Da ◽  
Fengxian Qiu ◽  
Dongya Yang ◽  
...  

AbstractIn this work, an amino-functionalized graphene oxide (AFGO) was synthesized by graphene oxide (GO) and ethylene diamine. A novel amino-functionalized graphene oxide/azobenzene polyimide (AFGO/ACPI) was synthesized with AFGO, azobenzene chromophore and pyromellitic dianhydride (PMDA). The structure, mechanical and thermal property of AFGO/ACPI were characterized and measured by fourier transform infrared, UV-visible spectroscopy, near-infrared spectrum, thermogravimetric analysis and differential scanning calorimetry. To obtain the refractive index of AFGO/ACPI at different temperature and wavelength (532 nm, 650 nm and 850 nm), the attenuated total reflection (ATR) method was used to measure, and thermo optic coefficients (dn/dT) were −7.22×10


2019 ◽  
Vol 814 ◽  
pp. 96-101
Author(s):  
Kun Yan Wang

Poly (trimethylene terephthalate) (PTT)/functionalized graphene oxide (fGO) nanocomposites were prepared by melt compounding. The crystalline morphology and crystallization behavior of PTT/fGO with different amounts of fGO were investigated by differential scanning calorimetry (DSC) and polarizing optical microscope (POM). The results show that the crystallization peak shifts to higher temperature after adding fGO, indicating that fGO have a nucleating effect on PTT. The crystallization temperature of nanocomposites increases with increasing content of fGO. The XRD pattern of PTT/fGO nanocomposites almost no change that indicated the degree of crystallinity of the PTT matrix remained unaffected by the addition of fGO. The nanocomposite revealed integrated Maltese crossed spherulitic morphologies. When adding 1% fGO to the PTT, big-sized PTT spherulites occurred and small-sized PTT spherulites were formed around the big-sized PTT spherulites which indicated that the mechanism of nucleation is changed.


2020 ◽  
Vol 90 (19-20) ◽  
pp. 2322-2335 ◽  
Author(s):  
Jan Broda ◽  
Marcin Baczek ◽  
Janusz Fabia ◽  
Ryszard Fryczkowski

Pimelic acid and calcium hydroxide were used to attach calcium pimelate to the surface of graphene oxide. The additive was mixed with isotactic polypropylene granulate. Neat polypropylene and polypropylene with functionalized graphene oxide was extruded into fibers under laboratory conditions. The gravity spun fibers containing different concentration of the additive and the fibers taken at various velocities were obtained. Morphology and elemental composition of functionalized graphene oxide were studied by means of scanning electron microscopy and energy dispersive X-ray spectroscopy. The structure of fibers was examined by means of differential scanning calorimetry and wide-angle X-ray scattering. The ability of calcium pimelate supported on the surface of the graphene oxide to nucleate the β-form of polypropylene was revealed. A considerable amount of the β-form crystals was obtained in the gravity spun fibers. In the fibers taken at moderate and higher velocities the β-form disappeared. The structure of the fibers extruded with the additive was similar to the structure of the fibers extruded from neat polypropylene. At moderate velocities, the content of mesophase in the structure was high. At higher velocities, the crystalline structure built only from α-form crystals was obtained. The paper presents a discussion of the changes observed in the fiber structure in connection with polypropylene nucleation.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Joo Hyung Lee ◽  
Seong Hun Kim

Abstract Incorporation of nanofillers into polyurethane (PU) is a promising technique for enhancing its thermal and mechanical properties. Silane grafting has been used as a surface treatment for the functionalization of graphene oxide (GO) with numerous reactive sites dispersed on its basal plane and edge. In this study, amine-grafted GO was prepared using silanization of GO with (3-aminopropyl)triethoxysilane. The functionalized graphene oxide (fGO) was characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy. Next, it was introduced in PU fabricated using polycaprolactone diol, castor oil, and hexamethylene diisocyanate. The fGO–PU nanocomposites were in turn characterized by FT-IR, X-ray diffraction, scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and a universal testing machine. The results obtained from these analyses showed changes in structural thermal properties, as well as improved thermal stability and mechanical properties because of the strong interfacial adhesion between the fGO and the PU matrix.


2021 ◽  
Vol 13 (2) ◽  
pp. 199-208
Author(s):  
Qiang Zhao ◽  
Si Ouyang ◽  
Gang Chen ◽  
Yiqing Deng ◽  
Mengxiao Chen ◽  
...  

To improve the overall performance of polyurea, linear diamines with three different chain lengths (1,2-ethylenediamine (EDA) and amino-terminated polyoxypropylenes D230 and D2000) were reacted with graphene oxide (GO) by reaction of amines with carboxyl groups, and three different amino-functionalized graphene oxide (AGO) nanosheets (EDA-GO, D230-GO and D2000-GO) were prepared. Subsequently, an AGO flake was bonded to a polyurea (PUA) substrate by an in situ chemical process. Analytical tests, including X-ray photoelectron spectroscopy (XPS), showed that diamines were attached to the GO flake. The reinforcement properties of the nanocomposites were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and tensile testing. AGO nanosheets, especially EDA-GO, result in a certain degree of enhancement in the thermal and mechanical properties of nanocomposites formed with polyurea. The TGA and DSC results indicated that the T5% and Tg of the nanocomposites at low AGO loading were increased compared with those of pure polyurea. Meanwhile, the elongation at break of the nanocomposite film with 0.1 wt% EDA-GO loading was 240% higher than that of pure polyurea, and tensile strength was increased by 80% over that of pure polyurea. We provide a new approach to the chemical conversion of GO/PUA nanocomposites by preparing AGO and complexing it with polyurea.


2017 ◽  
Vol 21 (03) ◽  
pp. 179-188 ◽  
Author(s):  
Xia Li ◽  
Kezhen Li ◽  
Dandan Wang ◽  
Jie Huang ◽  
Chunyong Zhang ◽  
...  

In this paper, graphene oxide (GO) sheets covalently functionalized with (5,10,15,20-tetraphenyl) porphinato manganese(III) (MnTPP) has been successfully synthesized and tested as a photocatalyst for hydrogen evolution from water under UV-vis light irradiation. The obtained sample was systematically characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis, Fourier transform infrared (FTIR), and Raman spectroscopy. The results show that the MnTPP moiety has been successfully grafted on the graphene oxide surface to form MnTPP modified GO (GO-MnTPP). The fluorescence quenching and photocurrent enhancement of GO-MnTPP confirm that the rapid electrons transfer from photoexcited the MnTPP moiety to the GO sheets. The platinized GO-MnTPP exhibits enhanced photocatalytic activity for water reduction to produce hydrogen. Moreover, with the assistance of polyvinyl pyrrolidone (PVP), the photocatalytic activity is further improved because of aggregation prevention of the GO-MnTPP nanocomposite. This study provides a facile method to build porphyrin-graphene-based photocatalysts for solar energy conversion.


2020 ◽  
Vol 44 (15) ◽  
pp. 5995-6002 ◽  
Author(s):  
Bingxu Qian ◽  
Fei Wang ◽  
Dongsheng Li ◽  
Yongxin Li ◽  
Bo Zhang ◽  
...  

In this study, a series of Pickering emulsions for catalysis of Knoevenagel condensations of malononitrile with aldehydes were prepared by surface modification of amine-functionalized graphene oxide (GO-NH2) with trimethoxymethylsilane (MTMS).


Author(s):  
Meena K. S. ◽  
Sonia K ◽  
Alamelu Bai S

In order to develop the efficiency and the specificity of anticancer drug delivery, we have designed an innovative nanocarrier. The nanocarrier system comprises of a multifunctional graphene oxide nanoparticle-based drug delivery system (GO-CS-M-DOX) as a novel platform for intracellular drug delivery of doxorubicin (DOX). Firstly, graphene oxide (GO) was synthesized by hummer’s method whose surface was functionalized by chitosan (CS) in order to obtain a more precise drug delivery, the system was then decorated with mannose (M). Further conjugation of an anti-cancer drug doxorubicin to the nanocarrier system resulted in GO-CS-M-DOX drug delivery system. The resultant conjugate was characterized for its physio-chemical properties and its biocompatibility was evaluated via hemolysis assay. The drug entrapment efficiency is as high as 90% and in vitro release studies of DOX under pH 5.3 is significantly higher than that under pH 7.4. The anticancer activity of the synthesized drug delivery system was studied by 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay against MCF-7 cell line. These results stated that the pH dependent multifunctional doxorubicin- chitosan functionalized graphene oxide based nanocarrier system, could lead to a promising and potential platform for intracellular delivery and cytotoxicity activity for variety of anticancer drugs.   


2015 ◽  
Vol 19 (18) ◽  
pp. 1828-1837 ◽  
Author(s):  
George V. Theodosopoulos ◽  
Panayiotis Bilalis ◽  
Georgios Sakellariou

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