Cotton Fabric Coated With Graphene-based Silver Nanoparticles: Synthesis, Modification, and Antibacterial Activity

2021 ◽  
Author(s):  
Nguyen Thi Thuy Linh ◽  
Tran Chau Diep ◽  
Tran Tuong Vy ◽  
Nguyen Minh Dat ◽  
Dinh Ngoc Trinh ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Vitamin C ◽  
Cotton Fabric ◽  
Chemical Reduction ◽  
Dip Coating ◽  
Reducing Agent ◽  
X Ray ◽  
Antibacterial Performance ◽  
Two Samples ◽  
Significant Difference

Abstract In this study, silver immobilizing onto graphene oxide (Ag/GO) was synthesized by the in-situ method. Subsequently, silver immobilizing reduced graphene oxide cotton fabric (Ag/rGO/cotton) was made by the dip-coating method in Ag/GO suspension followed by the chemical reduction with the presence of vitamin C as an environmentally friendly reducing agent. The characteristics of Ag/GO, Ag/GO/cotton, and Ag/rGO/cotton were investigated by Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy, transmission electron microscopy, scanning electron microscope, and energy-dispersive X-ray spectroscopy. The results showed that AgNPs were uniformly distributed on the surface of GO sheets with an average size of 10–15 nm. Regarding Ag/rGO/cotton, the fiber surface was evenly covered by Ag/rGO materials. Besides, there was no significant difference between the two samples of Ag/GO/cotton and Ag/rGO/cotton, indicating the reduction reaction possessed no effect on the cotton structure. Moreover, the Ag/rGO/cotton also exhibited effective hydrophobicity with a wetting angle of 103.85 ± 0.75 o. The antibacterial performance of Ag/GO, Ag/GO/cotton, and Ag/rGO/cotton against the Gram-positive (Staphylococcus aureus-S. aureus) and Gram-negative (Pseudomonas aeruginosa-P. aeruginosa) bacteria were determined via the diameter zone of inhibition. The results indicated that the appropriate reducing agent is L-ascorbic acid-vitamin C (VC) with the conditions: the VC:Ag/GO mass ratio of 1:1, the reducing temperature of 140 oC, and the reducing time of 120 min showed the highest antibacterial effect against two types of bacteria. All results of the study confirmed that Ag/rGO/cotton possesses significant potential for several antibacterial applications such as protective equipment.

Investigation of the Influences of Reaction Temperature and Time on the Chemical Reduction of Graphene Oxide by Conventional Method Using Vitamin C as a Reducing Agent

2017 ◽  
Vol 909 ◽  
pp. 225-230
Author(s):  
Chaval Sriwong ◽  
Kittisak Choojun ◽  
Samart Kongtaweelert
Keyword(s):  
Graphene Oxide ◽  
Vitamin C ◽  
Reaction Temperature ◽  
Chemical Reduction ◽  
Aqueous Suspension ◽  
Heating Time ◽  
Reducing Agent ◽  
Conventional Heating ◽  
Vis Spectroscopy ◽  
Ft Ir

The aim of this work is to investigate the synthesis of reduced graphene oxide (rGO) aqueous suspension by a conventional heating method using vitamin C as a reducing agent. The influences of reaction temperatures (70, 90 and 100 °C) and heating times (30, 45 and 60 min) on the chemical reduction of graphene oxide (GO) were studied. Then, the obtained rGO samples were characterized by FT-IR, Raman and UV-Vis spectroscopy. The FT-IR and Raman results showed that the reduction degree of GO to rGO was increased with the rising of the reaction temperature and time. Moreover, the UV-Vis spectra demonstrated that the absorption band at around 230 nm (π-π*) of pristine GO had shift to the longer wavelength upon the chemical reduction, indicating that GO is reduced to rGO. The optimal condition of the chemical reduction of GO to achievable rGO was the temperature of 90 °C with the 45 min of heating time. This condition yielded the rGO black aqueous suspension with the high quality and stability. Thus, this method of synthesis has an advantage of the rGO dispersion which led to many potential applications.

Well-Aligned Graphene Oxide Nanosheets Decorated with Zinc Oxide Nanocrystals for High Performance Photocatalytic Application

2015 ◽  
Vol 14 (03) ◽  
pp. 1550007 ◽  
Author(s):  
K. Kaviyarasu ◽  
C. Maria Magdalane ◽  
E. Manikandan ◽  
M. Jayachandran ◽  
R. Ladchumananandasivam ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Graphene Oxide ◽  
High Performance ◽  
Chemical Reduction ◽  
Visible Region ◽  
Single Layer ◽  
Single Layer Graphene ◽  
Graphene Oxides ◽  
X Ray ◽  
Nanoscale Structures

Graphene oxide (GO) nanosheets modified with zinc oxide nanocrystals were achieved by a green wet-chemical approach. As-obtained products were characterized by XRD, Raman spectra, XPS, HR-TEM, EDS, PL and Photocatalytic studies. XRD studies indicate that the GO nanosheet have the same crystal structure found in hexagonal form of ZnO . The enhanced Raman spectrum of 2D bands confirmed formation of single layer graphene oxides. The gradual photocatalytic reduction of the GO nanosheet in the GO : ZnO suspension of ethanol was studied by using X-ray photoelectron (XPS) spectroscopy. The nanoscale structures were observed and confirmed using high resolution transmission electron microscopy (HR-TEM). The evolution of the elemental composition, especially the various numbers of layers were determined from energy dispersive X-ray spectra (EDS). PL properties of GO : ZnO nanosheet were found to be dependent on the growth condition and the resultant morphology revealed that GO nanosheet were highly transparent in the visible region. The photocatalytic performance of GO : ZnO nanocomposites was performed under UV irradiation. Therefore, the ZnO nanocrystals in the GO : ZnO composite could be applied in gradual chemical reduction and consequently tuning the electrical conductivity of the graphene oxide nanosheet.

Shape-Controlled Synthesis and Formation Mechanism of Cobalt Nanopowders by a PVP-Assisted Method

2010 ◽  
Vol 654-656 ◽  
pp. 1186-1189 ◽  
Author(s):  
Bing Cong Zhang ◽  
Hong Ying Yu ◽  
Dong Bai Sun
Keyword(s):  
Hydrazine Hydrate ◽  
Chemical Reduction ◽  
Reducing Agent ◽  
Soft Template ◽  
Basic Solution ◽  
X Ray Diffraction ◽  
Mechanism Of Formation ◽  
X Ray ◽  
Nucleation Sites ◽  
Shape Controlled

Three different kinds of morphologies including spherical, chainlike and wirelike cobalt nanopowders, have been synthesized by chemical reduction of coblat chloride solution with hydrazine hydrate in basic solution. The products were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). It was revealed that the morphologies of the nanopowders depend on the concentration of Co2+ and the way of adding reducing agent (hydrazine hydrate). These two features affected the nucleation sites and the number of nucleuses. When the concentration of Co2+ was low, nucleuses formed in the soft template, while the reducing of the reducing agent added drop wise, a little number of nucleuses was formed. Based on that, a mechanism of formation, as a basis of gram-scale syntheses, was proposed.

scholarly journals Gamma-Irradiation Induced Functionalization of Graphene Oxide with Organosilanes

2019 ◽  
Vol 20 (8) ◽  
pp. 1910 ◽  
Author(s):  
Kabiru Musa Aujara ◽  
Buong Woei Chieng ◽  
Nor Azowa Ibrahim ◽  
Norhazlin Zainuddin ◽  
Chantara Thevy Ratnam
Keyword(s):  
Raman Spectroscopy ◽  
Graphene Oxide ◽  
Thermogravimetric Analysis ◽  
Gamma Ray ◽  
Chemical Interaction ◽  
Chemical Reduction ◽  
Contact Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir

Gamma-ray radiation was used as a clean and easy method for turning the physicochemical properties of graphene oxide (GO) in this study. Silane functionalized-GO were synthesized by chemically grafting 3-aminopropyltriethoxysilane (APTES) and 3-glycidyloxypropyltrimethoxysilane (GPTES) onto GO surface using gamma-ray irradiation. This established non-contact process is used to create a reductive medium which is deemed simpler, purer and less harmful compared conventional chemical reduction. The resulting functionalized-GO were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis (TGA), and Raman spectroscopy. The chemical interaction of silane with the GO surface was confirmed by FT-IR. X-ray diffraction reveals the change in the crystalline phases was due to surface functionalization. Surface defects of the GO due to the introduction of silane mioties was revealed by Raman spectroscopy. Thermogravimetric analysis of the functionalized-GO exhibits a multiple peaks in the temperature range of 200–650 °C which corresponds to the degradation of chemically grafted silane on the GO surface.

scholarly journals Effect of Microwave Treatment in a High Pressure Microwave Reactor on Graphene Oxide Reduction Process—TEM, XRD, Raman, IR and Surface Electron Spectroscopic Studies

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5728
Author(s):  
Beata Lesiak ◽  
Grzegorz Trykowski ◽  
József Tóth ◽  
Stanisław Biniak ◽  
László Kövér ◽  
...  
Keyword(s):  
High Pressure ◽  
Graphene Oxide ◽  
Chemical Reduction ◽  
Reduction Process ◽  
Microwave Treatment ◽  
Spectroscopic Studies ◽  
Reducing Agent ◽  
Vacancy Defects ◽  
Microwave Reactor ◽  
Oxygen Groups

Reduced graphene oxide (rGO) was prepared by chemical reduction of graphene oxide (GO) (with a modified Hummers method) in aqueous solutions of hydrazine (N2H4), formaldehyde (CH2O), formic acid (HCO2H) accompanied by a microwave treatment at 250 °C (MWT) by a high pressure microwave reactor (HPMWR) at 55 bar. The substrates and received products were investigated by TEM, XRD, Raman and IR spectroscopies, XPS, XAES and REELS. MWT assisted reduction using different agents resulted in rGOs of a large number of vacancy defects, smaller than at GO surface C sp3 defects, oxygen groups and interstitial water, interlayer distance and diameter of stacking nanostructures (flakes). The average number of flake layers obtained from XRD and REELS was consistent, being the smallest for CH2O and then increasing for HCO2H and N2H4. The number of layers in rGOs increases with decreasing content of vacancy, C sp3 defects, oxygen groups, water and flake diameter. MWT conditions facilitate formation of vacancies and additional hydroxyl, carbonyl and carboxyl groups at these vacancies, provide no remarkable modification of flake diameter, what results in more competitive penetration of reducing agent between the interstitial sites than via vacancies. MWT reduction of GO using a weak reducing agent (CH2O) provided rGO of 8 layers thickness.

Proximate Composition and Sensory Evaluation Between Artificially Ripened and Naturally Ripened Pineapples (Ananas comosus)

2022 ◽  
Author(s):  
Rahat Bin Robbani ◽  
Rasel Talukder ◽  
Md. Abu Zubair ◽  
SHUMSUZZAMAN KHAN
Keyword(s):  
Vitamin C ◽  
Calcium Carbide ◽  
Titratable Acidity ◽  
Growth Hormones ◽  
Ananas Comosus ◽  
Arsenic Content ◽  
Physicochemical Changes ◽  
Two Samples ◽  
Significant Difference ◽  
Lower Vitamin

The number of artificially ripened pineapples is outnumbered than the naturally ripened pineapples. However, there is a lack of understanding between artificially ripened and naturally ripened pineapples. Thus the inquiry was anticipated to explore the physicochemical changes and organoleptic acceptability of the naturally ripened and artificially ripened pineapples. Farmers used different chemicals such as calcium carbide, ethylene, besides growth hormones to reduce production loss. Here we evaluated the content of moisture, ash, protein, fat, crude fiber, reducing sugar, total sugar, titratable acidity, sucrose, and vitamin C in both naturally ripened and artificially ripened pineapples. Artificially ripened pineapples showed a significantly lower vitamin C than naturally ripened ones, but arsenic content was nil in both samples. In the case of color and appearance, there was no significant difference between the two samples, but in case of the other organoleptic properties, such as flavor, sweetness, sourness, the natural one was more acceptable. Thus naturally ripened pineapples are more beneficial to consumers than artificially ripened ones.

Efficient reduction of graphene oxide nanosheets using Na2C2O4 as a reducing agent

2015 ◽  
Vol 08 (02) ◽  
pp. 1550026 ◽  
Author(s):  
Mohamad Fahrul Radzi Hanifah ◽  
Juhana Jaafar ◽  
Madzlan Aziz ◽  
A. F. Ismail ◽  
M. H. D. Othman ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Chemical Reduction ◽  
Single Layer ◽  
Reduction Process ◽  
Atomic Ratio ◽  
Reducing Agent ◽  
Sodium Oxalate ◽  
Transmission Electron ◽  
Efficient Reduction

The efficient synthesis of reduced graphene oxide (RGO) nanosheets via chemical reduction process of exfoliated graphene oxide (GO) nanosheets was performed by introducing sodium oxalate ( Na 2 C 2 O 4) as a reducing agent. To study the effects of the reduction time on the synthesized RGO, the GO was reduced within -1/2, 1 and 2 h for RGO-1, RGO-2 and RGO-3, respectively. The C/O atomic ratio of the synthesized RGO-3 has increased from 2.16 to 6.32 after reduction as determined by X-ray photoelectron spectroscopy (XPS). The morphology analysis of the RGO-3 was determined by high-resolution transmission electron microscopy (HRTEM) almost revealed the formation of single layer. The number of RGO layers decreases as the time of the reduction increases. Based on these analysis results, sodium oxalate plays an important role in the efficient removal of the oxygen containing groups in the GO to produce high quality of RGO.

scholarly journals Antibacterial Performance of a Mussel-Inspired Polydopamine-Treated Ag/Graphene Nanocomposite Material

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3360
Author(s):  
Jianming Liao ◽  
Shuaiming He ◽  
Shasha Guo ◽  
Pengcheng Luan ◽  
Lihuan Mo ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Antibacterial Properties ◽  
Great Promise ◽  
X Ray ◽  
Antibacterial Performance ◽  
Reduced Graphene ◽  
Wide Range ◽  
Graphene Nanocomposite

Graphene-based nanocomposites have attracted tremendous attention in recent years. In this study, a facile yet effective approach was developed to synthesize reduced graphene oxide and an Ag–graphene nanocomposite. The basic strategy involved in the preparation of reduced graphene oxide includes reducing graphene oxide with dopamine, followed by in situ syntheses of the Ag-PDA-reducing graphene oxide (RGO) nanocomposite through adding AgNO3 solution and a small amount of dopamine. The nanocomposite was characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD), FTIR spectra, Raman spectra, ultraviolet-visible (UV-vis), and X-ray photoelectron spectroscopy (XPS), results indicated that a uniform PDA film is formed on the surface of the GO and GO is successfully reduced. Besides, the in situ synthesized Ag nanoparticles (AgNPs) were evenly distributed on the RGO surface. To investigate antibacterial properties Ag-PDA-RGO, different dosages were selected for evaluating the antibacterial activity against Gram-positive bacteria Staphylococcus aureus and Gram-negative bacteria Escherichia coli. The Ag-PDA-RGO nanocomposites displayed excellent antibacterial property. The antibacterial ratio reached 99.9% against S. aureus and 90.9% against E. coli when the dosage of 100 mg/L Ag-PDA-RGO nanocomposites was 100 μL. The novel Ag-PDA-RGO nanocomposite prepared by a facile yet effective, environmentally friendly, and low-cost method holds great promise in a wide range of modern biomedical applications.

PRODUCTION OF STABLE DISPERSIONS OF REDUCED GRAPHENE OXIDE USING INDOLE AS A REDUCTION AGENT

NANO ◽  
2013 ◽  
Vol 08 (02) ◽  
pp. 1350017 ◽  
Author(s):  
YING HUANG ◽  
PANBO LIU ◽  
LEI WANG
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Large Scale ◽  
Analytical Techniques ◽  
Cost Effective ◽  
Reducing Agent ◽  
X Ray ◽  
Force Microscopy ◽  
Reduced Graphene

Stable dispersions of reduced graphene oxide (RGO) have been prepared by indole as a previously unreported reducing agent without employing any external stabilizing reagents. The obtained RGO can be individually dispersed in ethanol, N, N-dimethylformamide (DMF), N-methylpyrrolidone (NMP), dimethylsulfoxide (DMSO), tetrahydrofuran (THF) and isopropanol. Several analytical techniques including Atomic force microscopy, X-ray diffraction, UV-Vis spectra, Raman spectroscopy and X-ray photoelectron spectroscopy indicate that a significant fraction of the oxygen-containing functional groups are removed, yields a C/O ratio as high as 7.4. The conductivity of RGO is 21.2 S/m and the thickness of RGO increases to 1.7 nm. Furthermore, this new reducing agent is of low toxicity, which makes the reduction much safer than hydrazine and this method is cost-effective to produce single-layered RGO on a large scale.

scholarly journals Green Synthesis of Reduced Graphene Oxide Using Lime Juice Reductor From Citrus aurantifolia

Elkawnie ◽  
2019 ◽  
Vol 5 (2) ◽  
pp. 139
Author(s):  
Said Ali Akbar ◽  
Fitriya Nanda ◽  
Nispi Mawaddah ◽  
Mima Yuriati
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Vibrational Mode ◽  
Reducing Agent ◽  
Hydroxyl Group ◽  
Polar Solvents ◽  
Lime Juice ◽  
X Ray ◽  
Three Samples ◽  
Reduced Graphene

In this study, the reduced graphene oxide (rGO) synthesized by using lime juice as an environmentally friendly reducing agent and inexpensive cost. The synthesis was carried out by oxidizing graphite with the Hummer method to form graphene oxide (GO) was formed, then the GO was reduced by using lime as the natural reducing agent. X-ray analysis shown a vital diffraction pattern for graphite at 2θ = 26.4°, for graphene oxide appears around 2θ = 10° and 43o, and rGO at 2θ = 23.8°. Furthermore, the infrared spectrum of the three samples showed the peak of the hydroxyl group at 3412 cm-1, which appeared on graphene oxide, but was not observed in rGO. The vibrational mode of carbonyl (C=O) at 1723 cm-1 was also observed with high intensity on graphene oxide. This information showed that GO has a large number of oxygen-containing groups. Then, in the dissolution test shown that the GO was more soluble in polar solvents such as water than ethanol.

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