scholarly journals Antimicrobial Activity of Amino Acid-Capped Zinc and Copper Sulphide Nanoparticles

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Thapelo P. Mofokeng ◽  
Makwena J. Moloto ◽  
Poslet M. Shumbula ◽  
Pardon Nyamukamba ◽  
Pierre K. Mubiayi ◽  
...  

The synthesis of polydispersed zinc sulphide and copper sulphide nanocrystals capped with polar L-alanine (Aln) and l-aspartic acid (Asp) molecules is reported. The resulting nanocrystals were characterized by UV-visible spectroscopy (UV-Vis), photoluminescence (PL), X-ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR). UV-Vis absorption spectra of all samples were blue-shifted from the bulk band edges due to quantum confinement effects. PL emission spectrum of the nanoparticles showed peaks at 453 and 433 nm for Aln-capped ZnS and CuS nanoparticles, respectively, while peaks for Asp-capped ZnS and CuS nanoparticles were observed at 455 and 367 nm, respectively. The average particle sizes for Aln-capped ZnS and Asp-capped ZnS nanoparticles synthesized at 35°C were measured to be 2.88 nm and 1.23 nm, respectively. The antibacterial properties were tested using different strains of both positive and negative bacteria and fungi. It was found that capped-copper sulphide nanoparticles were more effective against the bacteria than capped-zinc sulphide nanoparticles. Staphylococcus aureus (ATCC 25923) was the most susceptible one with an MIC of 0.05 mg/mL for uncapped-CuS nanoparticles while Pseudomonas aeruginosa (ATCC 15442) and Cryptococcus neoformans (ATCC 14116) were the least ones with the MIC of 3.125 mg/mL for both uncapped-CuS and Aln-capped CuS.

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Mahmoud Goodarz Naseri ◽  
Elias B. Saion ◽  
Ahmad Kamali

This study reports the simple synthesis of MFe2O4 (where M=Zn, Mn, and Co) nanoparticles by a thermal treatment method, followed by calcination at various temperatures from 723 to 873 K. Poly(vinyl pyrrolidone) (PVP) was used as a capping agent to stabilize the particles and prevent them from agglomeration. The characterization studies were conducted by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The average particle sizes were obtained by TEM images, which were in good agreement with the XRD results. Fourier transform infrared spectroscopy (FT-IR) confirmed the presence of metal oxide bands for all the calcined samples. Magnetic properties were demonstrated by a vibrating sample magnetometer (VSM), which displayed that the calcined samples exhibited superparamagnetic and ferromagnetic behaviors.


2011 ◽  
Vol 228-229 ◽  
pp. 639-644 ◽  
Author(s):  
Jian Lin Xu ◽  
Shu Hua Yang ◽  
Li Hui Zhang ◽  
Zhao Kang ◽  
Qiang Guo

The nano-antimony particles with different shape, size and stability are prepared by electrochemical method under the dilute hydrochloric acid electrolyte including the surface dispersant OP-10 and different current densities. The influences of current density on the shape and size of nanometer antimony particles prepared by electrochemical method are analyzed by using X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR). The results show that nano-antimony powder can be prepared by electrochemical method, and the antimony powder possesses the crystal structure with orthorhombic hexahedron. The current density has a significant impact on the agglomeration, shape and size of antimony powder. The size and shape of antimony powder are determined by the nucleation rate of nano-antimony and combination capacity of antimony ions and OP-10 surface dispersing agents affected by current density. When the current density is 25mA/cm2, the average particle size is 12nm or so, the shape is spherical, and the nano-antimony particles are well dispersed and no agglomeration.


Author(s):  
Harish Kumar ◽  
Renu Rani

ZnO nanoparticles were synthesized by microemulsion route in W/S ratio of 5 at room temperature. X-ray diffraction (XRD) pattern reveals wurtzite structure of ZnO nanoparticles. Rod shape of ZnO nanoparticles of average particle size 10.0 to 12.0 nm were observed by transmission electron microscopy. FT-IR spectra confirmed the adsorption of surfactant molecules at the surface of ZnO nanoparticles and presence of Zn-O bonding. Thermal studies were carried out by the differential scanning calorimeter (DSC) techniques. In addition, UV-Visible spectra were employed to estimate the band gap energy of ZnO nanoparticles.


Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 456
Author(s):  
Fahad A. Alharthi ◽  
Hamdah S. Alanazi ◽  
Amjad Abdullah Alsyahi ◽  
Naushad Ahmad

This study demonstrated the hydrothermal synthesis of bimetallic nickel-cobalt tungstate nanostructures, Ni-CoWO4 (NCW-NPs), and their phase structure, morphology, porosity, and optical properties were examined using X-ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Scanning electron microscopy- energy dispersive X-ray spectroscopy (SEM-EDS), high resolution Transmission electron microscopy (HR-TEM), Brunauer-Emmett-Teller (BET) and Raman instruments. It was found that as-calcined NCW-NPs have a monoclinic phase with crystal size ~50–60 nm and is mesoporous. It possessed smooth, spherical, and cubic shape microstructures with defined fringe distance (~0.342 nm). The photocatalytic degradation of methylene blue (MB) and rose bengal (RB) dye in the presence of NCW-NPs was evaluated, and about 49.85% of MB in 150 min and 92.28% of RB in 90 min degraded under visible light. In addition, based on the scavenger’s study, the mechanism for photocatalytic reactions is proposed.


2012 ◽  
Vol 600 ◽  
pp. 174-177 ◽  
Author(s):  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
Fu Qiang Zhu ◽  
...  

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.


2010 ◽  
Vol 123-125 ◽  
pp. 1291-1294 ◽  
Author(s):  
Bin Lü ◽  
Jian Zhong Ma ◽  
Dang Ge Gao ◽  
Lei Hong

Modified rapeseed oil(MRO) was prepared by using rapeseed oil, ethylene diamine and acrylic acid as the raw materials. Modified rapeseed oil/montmorillonite(MRO/MMT) nanocomposite was prepared by using modified rapeseed oil and montmorillonite. The emulsifying properties of MRO and MRO/MMT were determined respectively. Fourier transforms infrared spectrometry (FT-IR) and Transmission Electron microscope (TEM) results showed that MRO/MMT was prepared successfully. X-ray diffraction (XRD) results showed that modified rapeseed oil could smoothly enter the interlayer of montmorillonite, and modified the montmorillonite; with an increase in the amount of montmorillonite, the layer spacing of montmorillonite in the MRO/MMT lower after the first increase. The results of emulsifying properties indicated that emulsifying properties of MRO/MMT was better than MRO.


2017 ◽  
Vol 50 ◽  
pp. 18-31 ◽  
Author(s):  
Rudzani Sigwadi ◽  
Simon Dhlamini ◽  
Touhami Mokrani ◽  
Patrick Nonjola

The paper presents the synthesis and investigation of zirconium oxide (ZrO2) nanoparticles that were synthesised by precipitation method with the effects of the temperatures of reaction on the particles size, morphology, crystallite sizes and stability at high temperature. The reaction temperature effect on the particle size, morphology, crystallite sizes and stabilized a higher temperature (tetragonal and cubic) phases was studied. Thermal decomposition, band structure and functional groups were analyzed by Brunauer-Emmett-Teller (BET), Scanning Electron Microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Thermo-gravimetric analysis (TGA) and Fourier transform infrared (FT-IR). The crystal structure was determined using X-ray diffraction. The morphology and the particle size were studied using (SEM) and (TEM). The shaped particles were confirmed through the SEM analysis. The transmission electron microscopic analysis confirmed the formation of the nanoparticles with the particle size. The FT-IR spectra showed the strong presence of ZrO2 nanoparticles.


2021 ◽  
Author(s):  
Amalanathan.M ◽  
Aravind.M ◽  
Sony Michael Mary.M ◽  
Razan A. Alshgari ◽  
Asma A. Alothman ◽  
...  

Abstract In this work, jasmine flower derived activated carbon were successfully synthesized by hydrothermal carbonization process at the different annealing temperature. The Crystallinity, phase, structural, morphological and optical properties of activated carbon were investigated using X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), Transmission electron microscope (TEM), and UV-visible spectroscopy analysis. The graphitic phase of carbon was obtained from the XRD pattern. Surface morphology reveals irregular-shaped nanoparticles. The photodegradation of methylene blue (MB) was carried out under the visible light irradiation technique to study its photocatalytic activity. The activated carbon obtained at 400oC, 500oC and 600oC shows a photocatalytic degradation efficiency of 86%, 90%, and 94%, respectively. Antibacterial activity of activated carbon was examined against S. Aureus (MTCC-737) and E-Coli (MTCC- 443) microbial pathogens, and their potent antibacterial activity was examined from the zone of inhibition layer.


2021 ◽  
Vol 72 (3) ◽  
pp. 89-101
Author(s):  
Guowei Zeng ◽  
Guihong Wu ◽  
Zhihui Wang ◽  
Xiaonan Li ◽  
Jie Yang ◽  
...  

In this work, K7PW11O39 (abbreviated as PW11) was immobilized on ZrO2 nanofibers and used as an efficient recyclable catalyst in extraction catalytic oxidation desulfurization system (ECODS).The 500 ppm DBT model oil(5mL) can desulphurize completely within 20 min with the catalytic conditions of 50��, 0.010 g 50 wt%- CTAB�C PW11�CZrO2 nanofibers and O/S molar ratio H2O2/DBT molar ratio�� was 2:1. The synthesized catalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and thermo gravimetric analyzer (TGA). The results indicated the PW11�CZrO2 nanofibers were synthesized successfully and the possible catalytic mechanism is also revealed.


Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1725 ◽  
Author(s):  
Xiaohong Liu ◽  
Ming Li ◽  
Xuemei Zheng ◽  
Elias Retulainen ◽  
Shiyu Fu

As a type of functional group, azo-derivatives are commonly used to synthesize responsive materials. Cellulose nanocrystals (CNCs), prepared by acid hydrolysis of cotton, were dewatered and reacted with 2-bromoisobuturyl bromide to form a macro-initiator, which grafted 6-[4-(4-methoxyphenyl-azo) phenoxy] hexyl methacrylate (MMAZO) via atom transfer radical polymerization. The successful grafting was supported by Fourier transform infrared spectroscopy (FT-IR) and Solid magnetic resonance carbon spectrum (MAS 13C-NMR). The morphology and surface composition of the poly{6-[4-(4-methoxyphenylazo) phenoxy] hexyl methacrylate} (PMMAZO)-grafted CNCs were confirmed with Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The grafting rate on the macro-initiator of CNCs was over 870%, and the polydispersities of branched polymers were narrow. The crystal structure of CNCs did not change after grafting, as determined by X-ray diffraction (XRD). The polymer PMMAZO improved the thermal stability of cellulose nanocrystals, as shown by thermogravimetry analysis (TGA). Then the PMMAZO-grafted CNCs were mixed with polyurethane and casted to form a composite film. The film showed a significant light and pH response, which may be suitable for visual acid-alkali measurement and reversible optical storage.


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