scholarly journals Anti-Inflammatory and Antioxidant Properties of Coffea Arabica/Reduced Graphene Oxide Nanocomposite prepared by green synthesis

2021 ◽  
Vol 18 (3) ◽  
pp. 305-317
Author(s):  
D. S. M. Perera ◽  
R. C. L. De Silva ◽  
L. D. C. Nayanajith ◽  
H. C. D. P. Colombage ◽  
T. S. Suresh ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Coffea Arabica ◽  
Antioxidant Properties ◽  
Medical Applications ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Reduced Graphene ◽  
Ft Ir ◽  
Anti Inflammatory ◽  
Near Future

The present study focuses on an efficient eco-friendly method for reducing graphene oxide (rGO) using Coffea arabica leaf extract for bio-medical applications for the first time to the best of our knowledge. The reduction of graphene oxide (GO) using Coffea arabica leaves was verified through Raman, X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM). The XRD peaks corresponding to GO at 2 =10º have dissapeared on reduction of GO to rGO and the formation of rGO was verified through a new broad peak at 2 =26º. FTIR revealed functional group changes in reducing GO to rGO. The SEM images of rGO showed a ribbed form instead of the rigid appearance of the GO flakes. The analysis revealed that the current green method is a feasible method for reducing GO to rGO and formation of the Coffea arabica/rGO nanocomposite. The composite prepared from young coffee leave exhibited higher antioxidant capacity than matured leave against scavenging 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radicals. Fascinatingly, the Coffea arabica/rGO nanocomposite showed an anti-inflammatory activity as well suggesting that the Coffea arabica /rGO nanocomposite is promising candidate for bio-medical applications in near future.

Preparation and Characterization of Mesoporous Sulfated TiO2-Graphene Oxide Composites

2015 ◽  
Vol 815 ◽  
pp. 241-247 ◽  
Author(s):  
Qi Lai ◽  
Shi Fu Zhu ◽  
Xue Ping Luo ◽  
Xing Ping Fan
Keyword(s):  
Graphene Oxide ◽  
Mesoporous Structure ◽  
Electronic System ◽  
X Ray Diffraction ◽  
Sulfated Titania ◽  
Reduced Graphene ◽  
Bet Method ◽  
Photocatalytic Activities ◽  
Ft Ir ◽  
Oxide Composites

Mesoporous sulfated TiO2-graphene oxide composites were prepared by hydrothermal method. The samples were analyzed by using scanning electron microscope (SEM), X-ray diffraction (XRD), FT-IR spectroscopy (IR) and Brunauer-Emmett-Teller (BET) method. photocatalytic activities of sulfated titania-GO samples were evaluated using the photooxidation of methylene blue in aqueous solutions by ultraviolet-visible (UV-via) spectroscopy. The results indicated that oxygen-containing carbonaceous groups in the GO are incorporated into the network of C\O\Ti and coordinated to titania in bidentate model, Sulfur species in the form of sulfate are incorporated into the network of Ti\O\Ti, resulting in the strong inductive effect, large specific surface area, and mesoporous structure. All these are beneficial to improve the photocatalytic activities of the mesoporous sulfated TiO2-graphene oxide composites. The formation mechanism of sulfated mesoporous titania-graphene oxide composites was explored. Joint electronic system of reduced graphene oxide, SO42−and TiO2was also predicted.

scholarly journals Magnetization of Ultraviolet-Reduced Graphene Oxide Flakes in Composites Based on Polystyrene

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2519
Author(s):  
Alexander N. Ionov ◽  
Mikhail P. Volkov ◽  
Marianna N. Nikolaeva ◽  
Ruslan Y. Smyslov ◽  
Alexander N. Bugrov
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Reduction Process ◽  
X Ray Diffraction ◽  
Mesoscopic Structure ◽  
Reduced Graphene ◽  
Study Results ◽  
Edge Defects ◽  
Mesoscopic Level ◽  
Ferromagnetic Hysteresis

This work presents our study results of the magnetization of multilayer UV-reduced graphene oxide (UV-rGO), polymer matrix (polystyrene), and a conjugated composite based on them. The mesoscopic structure of the composites synthesized in this work was studied by such methods as X-ray diffraction, SEM, as well as NMR-, IR- and Raman spectroscopy. The magnetization of the composites under investigation and their components was measured using a vibrating-sample magnetometer. It has been shown that the UV-reduction process leads to the formation of many submicron holes distributed inside rGO flakes, which can create edge defects, causing possibly magnetic order in the graphite samples under investigation on the mesoscopic level. This article provides an alternative explanation for the ferromagnetic hysteresis loop in UV-rGO on the base of superconductivity type-II.

scholarly journals Enhanced apatite precipitation on a biopolymer-coated bioactive glass

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
M. Araújo ◽  
M. Miola ◽  
A. Venturello ◽  
G. Baldi ◽  
J. Perez ◽  
...  
Keyword(s):  
Bioactive Glass ◽  
Body Fluid ◽  
Organic Coating ◽  
Medical Applications ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Ph Measurements ◽  
X Ray ◽  
Ft Ir ◽  
Scanning Electron

AbstractIn this work, sintered pellets of a silica-based bioactive glass were dip-coated with a biocompatible natural-derived polymer in order to investigate the influence of the organic coating on the glass bioactivity. After the sintering process optimization, uncoated and coated pellets have been characterized by means of scanning electron microscopy with energy dispersive spectroscopy (SEM, EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and pH measurements, after the immersion in a simulated body fluid (SBF). An increased apatite forming ability and a better control of the pH during soaking of the samples in SBF were observed in the presence of the biopolymer. This result opens a new insight on the simple fabrication of highly bioactive hybrid inorganic-organic materials for medical applications.

scholarly journals Poly(3,4-ethylenedioxythiophene)-reduced graphene oxide/copper-based metal-organic frameworks as a high-performance symmetrical supercapacitor device

2021 ◽  
Author(s):  
Dharshini Mohanadas ◽  
Muhammad Amirul Aizat Mohd Abdah ◽  
Nur Hawa Nabilah Azman ◽  
Thahira B.S.A. Ravoof ◽  
Yusran Sulaiman
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
High Performance ◽  
Metal Organic Framework ◽  
Specific Power ◽  
X Ray Diffraction ◽  
Reduced Graphene ◽  
Metal Organic ◽  
Energy Storage Material ◽  
Organic Framework

Abstract A novel poly(3,4-ethylenedioxythiophene)-reduced graphene oxide/copper-based metal-organic framework (PrGO/HKUST-1) has been successfully fabricated by incorporating electrochemically synthesized poly(3,4-ethylenedioxythiophene)-reduced graphene oxide (PrGO) and hydrothermally synthesized copper-based metal-organic framework (HKUST-1). The field emission scanning microscopy (FESEM) and elemental mapping analysis revealed an even distribution of poly(3,4-ethylenedioxythiophene) (PEDOT), reduced graphene oxide (rGO) and HKUST-1. The crystalline structure and vibration modes of PrGO/HKUST-1 was validated utilizing X-ray diffraction (XRD) as well as Raman spectroscopy, respectively. A remarkable specific capacitance (360.5 F/g) was obtained for PrGO/HKUST-1 compared to HKUST-1 (103.1 F/g), PrGO (98.5 F/g) and PEDOT (50.8 F/g) using KCl/PVA as a gel electrolyte. Moreover, PrGO/HKUST-1 composite with the longest charge/discharge time displayed excellent specific energy (21.0 Wh/kg), specific power (479.7 W/kg) and outstanding cycle life (95.5%) over 4000 cycles. Thus, the PrGO/HKUST-1 can be recognized as a promising energy storage material.

Study on the preparation and properties of polyamide/chitosan nanocomposite fabricated by electrospinning method

2021 ◽  
Author(s):  
Mahyar Fazeli ◽  
Faegheh Fazeli ◽  
Tamrin Nuge ◽  
Omid Abdoli ◽  
Shokooh Moghaddam
Keyword(s):  
Structural Characteristics ◽  
Decomposition Temperature ◽  
X Ray Diffraction ◽  
Good Adhesion ◽  
Sem Images ◽  
Electrospinning Method ◽  
Maximum Current ◽  
The Matrix ◽  
Ft Ir ◽  
Amine Groups

Abstract The principal intention of this work is to fabricate and characterize the polyamide/chitosan nanocomposite by a novel single solvent method through the electrospinning procedure. The thermal properties and morphology of prepared nanocomposite are studied by thermogravimetric analysis (TGA) and field-emission scanning electron microscopy (FE-SEM). TGA exposed that the primary decomposition temperature is reduced with rising of chitosan content in the nanocomposites and origin disintegration temperature for polyamide/chitosan nanocomposites is perceived to be in the range from 300 to 500°C. Also, FE-SEM images demonstrated that the nanofibers of chitosan have good adhesion on the matrix and are well-oriented. Besides, the crystallinity and structural characteristics of the polyamide/chitosan nanocomposites are investigated by using X-ray diffraction (XRD) and Fourier transform-infrared spectroscopy (FT-IR), respectively. The results of XRD proved that the successful blending of chitosan in polyamide is achieved via the electrospinning method. FT-IR results demonstrate that the nanofibers are consist of amine groups. Also, the electrical properties of the nanocomposite improved with the increasing content of chitosan and the conductivity of the polyamide/chitosan 5 wt% demonstrates the maximum current of 0.3 nA. Besides, the sheet resistance of the composite reduced 118 to 20 × 109 Ω with raising the chitosan volume from 0 to 5 wt%.

scholarly journals Reduced Graphene Oxide–Epoxy Grafted Poly(Styrene-Co-Acrylate) Composites for Corrosion Protection of Mild Steel

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 666
Author(s):  
Xinchuan Fan ◽  
Yue Hu ◽  
Yijun Zhang ◽  
Jiachen Lu ◽  
Xiaofeng Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
X Ray Diffraction ◽  
Corrosion Properties ◽  
X Ray ◽  
Transmission Electron ◽  
Reduced Graphene ◽  
Scanning Electron

Reduced graphene oxide–epoxy grafted poly(styrene-co-acrylate) composites (GESA) were prepared by anchoring different amount of epoxy modified poly(styrene-co-acrylate) (EPSA) onto reduced graphene oxide (rGO) sheets through π–π electrostatic attraction. The GESA composites were characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The anti-corrosion properties of rGO/EPSA composites were evaluated by electro-chemical impedance spectroscopy (EIS) in hydroxyl-polyacrylate coating, and the results revealed that the corrosion rate was decreased from 3.509 × 10−1 to 1.394 × 10−6 mm/a.

Study on Magnetic Properties of Na-Doped rGO Prepared from Coconut Shells

2020 ◽  
Vol 855 ◽  
pp. 160-165
Author(s):  
Deril Ristiani ◽  
Niken Sylvia Puspitasari ◽  
Retno Asih ◽  
Fahmi Astuti ◽  
Malik Anjelh Baqiya ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Mixing Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reduced Graphene ◽  
Naoh Solution ◽  
Na Ions ◽  
Diffraction Peaks ◽  
Coconut Shells

Na-doped reduced graphene oxide (Na-rGO) was prepared by wet mixing process of the reduced graphene oxide (rGO) in NaOH solution. The results showed that the rGO doped with Na ions can increase its magnetization approximately 2 times greater than that in rGO without doping. Saturation magnetization (Ms) for rGO and Na-rGO samples are 0.017 emu/g and 0.037 emu/g, respectively. The increasing value of magnetization is suggested to be due to defect presented in the Na-rGO samples. Both samples, rGO and Na-rGO, have the similar XRD (X-ray Diffraction) spectra that is marked by two characteristic diffraction peaks of rGO, which are associated with [002] and [10] planes, followed by the increasing inter-planar distance in Na-rGO samples which might be due to Na ions intercalation into rGO sheets, confirmed by the energy-dispersive X-ray (EDX) result revealing the presence of Na atoms in rGO.

Characterization of Electrospun Poly(Lactic Acid)/polyaniline Blend Nanofibers

2011 ◽  
Vol 332-334 ◽  
pp. 317-320 ◽  
Author(s):  
Hui Qin Zhang
Keyword(s):  
Lactic Acid ◽  
Composite Nanofibers ◽  
Weight Ratio ◽  
Electrospinning Process ◽  
Poly Lactic Acid ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Ft Ir

In this study, composite nanofibers of polyaniline doped with dodecylbenzene sulfonic acid (PANI-DBSA) and Poly(lactic acid) (PLA) were prepared via an electrospinning process. The surface morphology, thermal properties and crystal structure of PLA/PANI-DBSA nanofibers are characterized using Fourier transform infrared spectroscopy (FT-IR), wide-angle x-ray diffraction (WAXD) and scanning electron microscopy (SEM). SEM images showed that the morphology and diameter of the nanofibers were affected by the weight ratio of blend solution.

scholarly journals X-ray diffraction investigations of nanostructured ZnO coated with reduced graphene oxide.

2019 ◽  
Vol 1292 ◽  
pp. 012011 ◽  
Author(s):  
I Boukhoubza ◽  
M Khenfouch ◽  
M Achehboune ◽  
B M Mothudi ◽  
I Zorkani ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reduced Graphene

scholarly journals Influence of Ionic Liquids Assisted Synthesis on Morphology and Photocatalytic Properties of Bi4O5Br2

Proceedings ◽  
2019 ◽  
Vol 16 (1) ◽  
pp. 26
Author(s):  
Patrycja Wilczewska ◽  
Aleksandra Bielicka-Giełdoń ◽  
Agnieszka Fiszka Borzyszkowska ◽  
Aleksandra Pieczyńska ◽  
Ewa Maria Siedlecka
Keyword(s):  
Ionic Liquids ◽  
Photoelectron Spectroscopy ◽  
Photocatalytic Properties ◽  
X Ray Diffraction ◽  
Sem Images ◽  
New Thought ◽  
X Ray ◽  
Chromium Vi ◽  
Ft Ir ◽  
Adsorption Desorption

A series of Bi4O5Br2 photocatalysts were prepared via an innovation method of synthesis with ionic liquids (ILs). The crystal structures were investigated by X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR). The Field Emission Scanning Electron Microscope (FE-SEM) images illustrated the unique structure of prepared photocatalysts. The photocatalysts were also characterized by N2 adsorption-desorption analysis, X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectra (UV-vis/DRS) and photoluminescence spectra (PL). The role of ILs in synthesis of Bi4O5Br2 on morphology and photocatalytic properties were investigated. Rhodamine B, 5-fluorouracil and chromium (VI) were used as the model micropollutants to evaluated adsorption capacity, photooxidation and photoreduction ability of prepared Bi4O5Br2 under artificial solar light. This work provided a new thought for enhanced photocatalytic activity of bismuth oxybromide photocatalysts.

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