scholarly journals Precipitation of Zinc Oxide Nanoparticles in Bicontinuous Microemulsions

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Liliana E. Romo ◽  
Hened Saade ◽  
Bertha Puente ◽  
Ma. Luisa López ◽  
Rebeca Betancourt ◽  
...  

Zinc oxide nanoparticles were obtained directly, avoiding the calcination step, by precipitation at 70°C in bicontinuous microemulsions stabilized with a mixture of surfactants sodium bis (2-ethylhexyl) sulfosuccinate/sodium dodecyl sulfate (2/1, wt./wt.) containing 0.7 M zinc nitrate aqueous solution. Two concentrations of aqueous solution of precipitating agent sodium hydroxide were used under different dosing times on microemulsion. Characterization by X-ray diffraction and electron microscopy allowed us to identify particles with an acicular rod-like morphology and a hexagonalwurtzitecrystal structure as small as 8.5 and 30 nm in average diameter and length, respectively. Productivities much higher than those typical in the preparation of zinc oxide nanoparticles via reverse microemulsions were obtained. Particle size was the same at the two studied sodium hydroxide concentrations, while it increases as dosing time of the precipitant agent increases. It is believed that the surfactant film on the microemulsion channels restricts the particle diameter growth.

2020 ◽  
Vol 12 (10) ◽  
pp. 1231-1235
Author(s):  
V. Sorna Gowri ◽  
Raj Kumar Sen ◽  
Sunil Kumar Sanghi ◽  
Avanish Kumar Srivastava

A series of novel Zinc Oxide (ZnO) copolymer composites films with different Zinc Oxide concentration were prepared through incorporation of pre-made Zinc Oxide particle in to copolymer epoxy poly(dimethyl acrylamide). The copolymer epoxy poly(dimethyl acrylamide) was synthesized by free radical polymerization to disperse the Zinc Oxide nanoparticles. The Zinc Oxide nanoparticles with the diameter of 19 nm–35 nm were synthesized from zinc nitrate via a wet chemical method. The aim of the work is to develop a new method/process/material for the dispersion of Zinc Oxide nanoparticles and testing the performance of these composites films. Thermo gravimetric analysis show that Zinc Oxide nanoparticles were successfully incorporated into the polymer matrix and the Zinc Oxide copolymer composites have a good thermal stability. The micro structural analysis also show newly synthesized polymer disperse the nanoparticles well as evidenced by Scanning Electron Microscopy (SEM) analysis. The uniformly dispersed Zinc Oxide nanoparticle in the polymer matrix and the particles almost remained in their original shape and size even after incorporation in the polymer matrix. Fourier transform infrared spectroscopy (FT-IR) shift of the copolymer adsorbed Zinc Oxide nanoparticles confirmed that polymer molecules chain was anchored on the surface of the nanoparticles.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Nattanan Panjaworayan T-Thienprasert ◽  
Jiraroj T-Thienprasert ◽  
Jittiporn Ruangtong ◽  
Thitiradsadakorn Jaithon ◽  
Pattana Srifah Huehne ◽  
...  

Fungicides have been extensively used to control fungal diseases that affect several crops including ornamental crops. However, concerns have arisen due to a development of fungicide resistance and increasing incidences of fungicide toxicity effects on nontarget organisms. As zinc oxide nanoparticles (ZnO NPs) have demonstrated effective antimicrobial activity, this study is therefore aimed at synthesizing ZnO NPs from banana peels using a green chemistry method in a large scale and determines their physical properties including their inhibitory effects against a plant pathogen fungus causing anthracnose in orchids, Colletotrichum sp. Results from X-ray diffraction and scanning electron microscope indicated that the synthesized ZnO NPs were obtained without other crystalline impurities, and they were spherical in shape with the average diameter of 256 ± 40   nm , respectively. The absorption peak was found to be centered at ~370 nm with the optical band gap value approximately 2.8 eV. Fourier transform infrared spectroscopy analysis confirmed the presence of several functional groups on synthesized ZnO NPs. The total amount of synthesized ZnO NPs was obtained about 170 g for a synthesis reaction. By performing the antifungal activity assay, high doses of green synthesized ZnO NPs significantly inhibited growth of isolated Colletotrichum sp. (KUFC 021) on culture plates. Under greenhouse conditions, high doses of synthesized ZnO NPs also significantly reduced anthracnose symptoms on inoculated orchid leaves with the Colletotrichum sp. (KUFC 021).


2017 ◽  
Vol 62 ◽  
pp. 346-354 ◽  
Author(s):  
L. Khezami ◽  
Kamal K. Taha ◽  
Ezzeddinne Amami ◽  
med Ghiloufi ◽  
Lassaad El Mir

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