Influence of PEG20000 on Ultrafine ZnO Flowers

2011 ◽  
Vol 239-242 ◽  
pp. 1743-1746 ◽  
Author(s):  
Xiao Yi Shen ◽  
Yi Sun ◽  
Yuan Liang ◽  
Yu Chun Zhai ◽  
Zhi Qiang Ning

With zinc acetate and sodium hydroxide used as raw materials, while polyethylene glycol employed as dispersant agent, ultrafine zinc oxide flowers were successfully synthesized by hydrothermal method. The influence of the concentration of PEG20000 on the morphologies of ZnO flowers was discussed. The as-synthesized ZnO flowers consisted of microrods with hexagonal morphologies. The crystal structure and ultraviolet absorbing performance of ZnO flowers were also characterized using XRD, UV-VIS absorption spectrum. The results indicate that ZnO flowers are hexagonal wurtzite structure with high purity. There is a strong excition absorption peak at 300 nm in UV-VIS absorption spectrum and blue shift existed obviously.

2011 ◽  
Vol 284-286 ◽  
pp. 759-762 ◽  
Author(s):  
Xiao Yi Shen ◽  
Yuan Liang ◽  
Yi Sun ◽  
Yu Chun Zhai

With zinc acetate used as raw material and polyethylene glycol employed as dispersant, ultrafine ZnO flower-like powder was successfully synthesized by hydrothermal method using NaOH and NH3·H2O as precipitants. The influences of the precipitants on the morphology of the ZnO powder were discussed. The as-synthesized ZnO flower-like powder was composed of lots of microrods with hexagon figure. The ZnO flower-like structures synthesized using NaOH were more regular and uniform than that obtained using NH3·H2O. The ZnO flower-like powder was hexagonal wurtzite structure with high purity. The exciton absorptions of the two ZnO flower-like powder both appeared at 300 nm in UV-VIS spectrum.


2014 ◽  
Vol 852 ◽  
pp. 36-39
Author(s):  
Qun Shan Liu ◽  
Jun Xia Yan

By using scrap miscellaneouszinc materialas raw materials, a new technology with the help of two distillationsby fire method to produce zinc oxide was invented.The scrap miscellaneous zinc materialshave complex sources, containing dust, stone, iron and steel parts and other impurities, and zinc content is more than 15% over a wide range. The presence of zinc is in the form of pure metallic state, alloy state and oxidation state.Distillation process has two steps, the primary for removing the principal impurities and the second for zinc oxide purification. With less investment, low cost, simple equipment, easy operation, environmental protection and other advantages, this method is fit for production of high-purity zinc oxide and can also be used for the production of nanoscale high purity zinc oxide.


2007 ◽  
Vol 553 ◽  
pp. 252-256 ◽  
Author(s):  
Mehran Vafaee ◽  
Hossein Youzbashizade

In the recent years, many researchers have been interested in nanoparticles because of their unique properties. In this study, a method for producing ZnO nanoparticle colloids is proposed. The colloids were characterized by spectroscopic analyzer. By absorption spectrum study, we found out that colloids were consisted of nanoparticles with less than 10 nanometer size. The quantum confinement effect in these spectrums was recognized through blue shift of onset absorption wavelengths. These wavelengths shift from 370 nm to 340 nm by decreasing the particles size. Transmittion electron micrographs showed formation of zinc oxide nanoparticles.


2012 ◽  
Vol 602-604 ◽  
pp. 209-213
Author(s):  
Yan Wei Li ◽  
Guang Sun ◽  
Feng Xiao Qi ◽  
Nai Teng Wu ◽  
Jian Liang Cao ◽  
...  

ZnO hierarchical microstructures with uniform sea urchin-like morphology have been successfully synthesized through a facile and reliable ultrasound irradiation route by using Zn(CH3COO)2•2H2O and KOH as raw materials. The ZnO sample is investigated with XRD, SEM, TEM and HRTEM. Results indicate that the as-prepared sea urchin-like ZnO microstructures are assembled by numerous needle-like nanocrystals with the size about 2µm in length and about 100nm in diameter. The preferred growth orientation of these ZnO nanoneedles are along [101] direction. A blue shift in UV-vis absorption spectrum of the as-prepared ZnO sample is observed.


2020 ◽  
Vol 17 (3) ◽  
pp. 0787
Author(s):  
Atheel Alwash

In this study, the zinc oxide NPs have been synthesized from the fresh pomegranate peels extract using the precipitation method. The ZnO nanoparticles were produced from the reaction of fresh peels extract with zinc acetate salt which was used as zinc source in the presence of 2 M NaOH. The green synthesized nanoparticles were characterized through X-ray diffraction (XRD), UV-Vis diffuse reflection spectroscopy, Fourier transform infrared spectroscopy (FTIR), and Atomic force microscopy (AFM). The XRD patterns confirm the formation of hexagonal wurtzite phase structure for ZnO synthesized using pomegranate peels extract with average crystalline size of 28 nm. FTIR spectra identify the presence of many active functional groups for the pomegranate extract which is ideal to bind with zinc acetate to produce the ZnO nanoparticles during the preparation method. The reflection spectra of green synthesis ZnO with pomegranate extract observed a blue shift towards lower wavelength with (8 nm) difference compared to ZnO without the addition of any extract.  The provenance of such blue shift towards shorter wave length was due to the quantum size effect. The Atomic force microscopic (AFM) result shows average roughness value for ZnO nanoparticles of 6.26 nm. The decolorization efficiency of the methylene blue dye was investigated using the ZnO nanoparticles under sun light irradiation and it was compared with the bare ZnO synthesized without the addition of extract. The catalytic activity was about 88% after 60 min of sunlight irradiation for both prepared catalyst however, the decolorization efficiency of ZnO with the addition of extract was higher at the first 16 min compared to bare ZnO.


2014 ◽  
Vol 29 (10) ◽  
pp. 1039
Author(s):  
TAN Man-Lin ◽  
WANG Yan-Tao ◽  
ZHANG Wei-Li ◽  
FU Dong-Ju ◽  
LI Dong-Shuang ◽  
...  

2008 ◽  
Vol 368-372 ◽  
pp. 683-685
Author(s):  
Cheng Wei Hao ◽  
Bo Lin Wu ◽  
Ji Yan Li

Ammonium aluminium carbonate hydroxide (AACH), with a small quantity of γ-AlOOH, was synthesized through solid-state reaction at room temperature using AlCl3·6H2O and NH4HCO3 as raw materials and polyethylene glycol (PEG-10000) as the dispersant. After calcined at 1100°C for 1.5h, α-Al2O3 powders with primary particle sizes of 20~30nm were obtained. The crystal phase, particle size and morphology of the high-purity ultrafine α-Al2O3 were characterized. The results showed that a small quantity of γ-AlOOH in the AACH decomposed and formed crystal seeds. The presence of crystal seeds reduced the nucleation activation energy and therefore reduced the phase transformation temperature.


2014 ◽  
Vol 906 ◽  
pp. 66-71
Author(s):  
Zhen Quan Li ◽  
Qiang Zhen ◽  
Ya Li Wang

High purity ZrSiO4 powder were synthesized using Si (C2H5O)4 and ZrOCl2·8H2O as raw materials by the sol-gel method, LiCl was added as mineralizer to promote crystallization of zircon. The influences of molar ratio of Zr:Si, calcined time and calcined temperature on the synthesis of ZrSiO4 powder were investigated. XRD, SEM and TEM were used to characterize the powders. It was found that when the molar ratio of Zr:Si was 1:1.2, the calcined temperature was 1600°C and the calcined time was 4h, the high purity ZrSiO4 ultrafine powder was obtained. The ZrSiO4 formation began at 1300°C and when the gel was calcined at 1600°Cfor 4 h, the formation rate of ZrSiO4 was up to 95%. SEM and TEM studies reveal a homogeneous product with particle sizes on the order of 0.1-1μm. The IR emissivity of ultrafine ZrSiO4 is 0.892 at the whole wavelength range, and that is up to 0.951 at the wavelength range of 8-14 μm.


2012 ◽  
Vol 82 ◽  
pp. 32-37 ◽  
Author(s):  
Malgorzata Plonska ◽  
Wojciech A. Pisarski ◽  
Beata Wodecka-Dus ◽  
Lukasz Cienki

In the present work the influence of neodymium concentration (0-1at-%) and sintering conditions on 8/65/35 PLZT:Nd3+ ceramics were studied. All ceramic powders were synthesized by MOM technique from high purity raw materials (>99,9%), and subsequently sintered by free sintering and hot uniaxial pressing method. To analyze the powders and ceramics more the XRD, EDS SEM, and ferroelectric measurements were performed. Optical spectra were examined for all prepared samples, and their optical properties were analyzed using reflectance, excitation and luminescence measurements. The study gives a detailed account of the relationships between doping and preparing conditions on the basic physical and dielectric and optical properties of obtained ceramic materials.


2017 ◽  
Vol 896 ◽  
pp. 167-174 ◽  
Author(s):  
Zhi Yuan Yang ◽  
Zhuo Yue Meng ◽  
Zhi Hua Li ◽  
Si Tong Wang

Polyethylene glycol (PEG-200) and itaconic acid (IA) were used as raw materials to compound macromer through esterification reaction. A new type of specialized water-coke slurry dispersant was synthesized by copolymerization of microware, sodium methallyl sulfonate (SMAS) and maleic anhydride (MA). The experiment showed that the concentration of slurry could be reached to 63% with the dosage of 0.2%, and the apparent viscosity was 1140.3 mPa∙s. Through the analysis of the infrared, the dispersant was confirmed to have polyethylene glycol branched chain and hydrophilic functional groups such as carboxyl or sulfonic group. When the concentration of dispersant was 30 g/L, the surface tension of water could be decreased from 72.70 mN/m to 45.50 mN/m. Furthermore, when the solution pH value was 9, the Zeta potential of semi-coke powder surface could also be decreased from-13.38 mV to-25 mV with the addition of dispersant. Thus, this dispersant could increase electronegativity of semi-coke powder surface, enhance steric-hindrance effect and prevent the phenomenon of powder flocculation and gather. Meantime, it also could reinforce the semi-coke hydrophilic by reducing the surface tension of water effectively. And then, the high performance water-coke slurry could be obtained.


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