scholarly journals Surfactant-Assisted Sol-Gel Synthesis of TiO2 with Uniform Particle Size Distribution

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
O. L. Galkina ◽  
V. V. Vinogradov ◽  
A. V. Agafonov ◽  
A. V. Vinogradov

TiO2 materials were prepared from a titanium isopropoxide precursor by sol-gel processing in water media with or without various templates (polyethylenimine or Pluronic P-123). The photocatalytic efficiency of the samples was found to depend strongly on the use of and type of template added. Titania/Pluronic sols resulted in homogeneous anatase TiO2—rutile with uniform particle size distribution after calcination (400°C). Optical properties of the samples were characterized by UV-Vis spectroscopy and crystalline structures by X-ray diffraction. A surfactant-assisted sol-gel process retarded crystallization of the anatase and rutile titania, which resulted in smaller grain sizes and presumably a larger active surface area. The morphology of the surfaces was obtained by AFM techniques. The highest photobleaching rate was found for samples deposited from the sol with the addition of the Pluronic P-123 surfactant, and it was almost twice as high as that for films deposited from sols with polyethylenimine.

2014 ◽  
Vol 670-671 ◽  
pp. 113-116 ◽  
Author(s):  
Xiao Yan Zhang ◽  
Xi Wei Qi ◽  
Zhi Yuan Yang ◽  
Rui Xia Zhong

Multiferroic BiFeO3 powders were synthesized by two methods: sol-gel process and hydrothermal method. The synthesized powders were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (SEM) and particle size distribution analysis. The results obtained by XRD, which is consistent with 86-1518 JCPDS card, show that powders prepared by hydrothermal method are composed of the single phase with the trigonal structure (perovskite-type). It can be found by particle size distribution analysis that the particle size of the samples prepared by sol-gel process is finer and more uniform than that of the samples synthesized by the hydrothermal method. The SEM images of samples depicts that the synthesized BiFeO3 powders are united and the average grain size of hydrothermal processed samples is significantly large as compared to the sol-gel derived sample.


2019 ◽  
Vol 2 (98) ◽  
pp. 81-84
Author(s):  
K. Szmajnta ◽  
M. Szindler

Purpose: The main purpose of this publication is to bring closer method of synthesis and examining basic properties of TiO2, ZnO and NiO nanoparticles (NPs), and investigate their possible biomedical application. Design/methodology/approach: Nanopowders were made with sol-gel method. Surface morphology studies of the obtained materials were made using Zeiss's Supra 35 scanning electron microscope and the structure using S/TEM TITAN 80-300 transmission electron microscope. In order to confirm the chemical composition of observed nanopowders, qualitative tests were performed by means of spectroscopy of scattered X -ray energy using the Energy Dispersive Spectrometer (EDS). The DLS (Dynamic Light Scattering) method was used to analyse the particle size distribution using the AntonPaar Litesizer 500 nanoparticle size analyser. Changes in particle size distribution at elevated temperatures were also observed. The TiO2, ZnO and NiO NPs with spherical shape were successfully produced by sol-gel method. Findings: The diameter of the as prepared nanoparticles does not exceed 25 nm which is confirmed by the TEM analysis. The highest proportion among the agglomerates of the nanoparticles has been shown to show those with a diameter of 80 to 125 nm. The qualitative analysis of EDS confirmed the chemical composition of the material. Practical implications: Nanoparticles (NPs) has been receiving an incrementally increasing interest within biomedical fields researchers. Nanoparticles properties (physical, chemical, mechanical, optical, electrical, magnetic, etc.) are different from the properties of their counterparts with a larger particle size. Originality/value: The nanoparticles were prepared using sol-gel method which allows the particle size to be controlled in a simple way.


2014 ◽  
Vol 1078 ◽  
pp. 31-35
Author(s):  
Liang Zhao ◽  
Qun Hu Xue ◽  
Dong Hai Ding

MgO-Al2O3-ZrO2composite powders with 3 kinds of mass ratio were synthesized by sol–gel method using MgCl2·6H2O, AlCl3·6H2O and ZrOCl2·8H2O as starting materials, and NH3·H2O as a precipitant. The composite powders which match with zirconium oxide particle size and evenly distribute can are advantageous to the formation of metastable t-ZrO2and restrain the grain growth as the additive of modified sizing nozzle. Chemical composition, mineral phase, particle size distribution and micro-morphology of the composite powders were investigated by X-ray fluorescence instrument, X-ray diffractometer, laser particle size analyzer and scanning electron microscope. Research showed that under the process that the concentration of MgCl2solution 0.2 mol/L, AlCl3and ZrOCl2solution concentration 0.5 mol/L, the pH controlled between 10 ~ 11, PEG as the surfactant, drying at 70°C±5°C, heat treatment temperature at 800°C for 3h, particle size distribution of MgO-Al2O3-ZrO2composite powders were: d10= 1.28 μm, d50= 4.65μm, d90= 11.13μm (MgO 10%); d10= 1.15μm, d50= 5.80μm, d90= 15.13μm (MgO 15%);d10= 1.21μm, d50= 6.59μm, d90= 16.87μm (MgO 20%). With the rising of heat treatment temperature, the crystallization degree of composite powders increased, at 800 °C a small amount of t - ZrO2precipitated, meanwhile MgO and Al2O3are still in the amorphous phase. The MgO-A12O3-ZrO2composite powders under this condition have high reactivity and uniform distribution.


2015 ◽  
Vol 1108 ◽  
pp. 67-72 ◽  
Author(s):  
Najwa Adni Ibarahim ◽  
Nafisah Osman ◽  
Mohd Azlan Mohd Ishak

Ceramics powder of BaCe0.54Zr0.36Y0.1O2.95 (BCZY) was synthesized using three different methods namely sol-gel (SG), supercritical fluid (SC) and sol-gel assisted supercritical fluids (SGSF).The respective prepared samples were denoted as S1, S2 and S3. The calcined powder (T= 1100 °C) was analyzed using particle size analyzer (PSA), Pcynometer and scanning electron microscope (SEM). PSA showed a single particle size distribution (PSD) for all samples except for S3 which exhibits bimodial particle distribution. PSD of the samples were in the range of 295-396 nm for the primary powder and 712-820 nm for secondary powder. High relative powder density for S1, S2, S3 were recorded at 95 %, 93 % and 99 %, respectively. Morphology of the calcined powders by SEM micrograph revealed that S1 is in spherical shape, S2 is in cubic structure and S3 showed a mixture of spherical and rod-like structure. It was found that SG and SC produce a single shape of powder with lower density compared with SGSF.


2014 ◽  
Vol 70 (5) ◽  
Author(s):  
Sheen-Jeff Teh ◽  
Yew-Keong Sin ◽  
Kah-Yoong Chan ◽  
Tai-Wenn Law

In this paper, zinc oxide (ZnO) colloidal spheres structures were prepared by sol-gel method which is simple, effective and less costly. The scanning electron microscopy (SEM) images illustrated the ZnO colloidal spheres structures with diameter size ranging between 200–700 nm. The particle size distribution of colloidal spheres was determined by the added amount of supernatant in dehydration process. 3 mL and 6 mL of added supernatant were resulted particle size distribution dominant in the range of 250–400 nm and 150–250 nm, respectively. Transmission spectra demonstrated the photonic band gap (PBG) of colloidal spheres prepared with different amounts of colloidal suspension coating sample were near ultraviolet and violet region. The thermal annealing process was introduced to narrow the PBG width of colloidal spheres based on Bragg’s law. Current-voltage measurement of ZnO colloidal spheres based thin film with particles size in the range of 150–250 nm showed that the resistivity of the thin film is 4.5 x 106 Ωcm.


2012 ◽  
Vol 05 ◽  
pp. 559-567
Author(s):  
H. Abdizadeh ◽  
Y. Vahidshad ◽  
H. R. Baharvandi ◽  
M. Akbari Baseri

In the water-in-oil (W/O) microemulsions based on anionic (AOT) surfactants, the ω value (molar ratio of water to surfactant), precursor, and surfactant could remarkably affect the synthesis of CuO - ZrO 2 nanocomposite and the morphologies of the sol-gel products simultaneously. In this study, CuO - ZrO 2 nanoparticles are synthesized using microreactors made of surfactant/water/n-hexane microemulsions and discusses the effect of different microemulsion variables on the particle size and particle size distribution by water-to-surfactant molar ratio. The obtained powders are characterized by DTA, XRD, SEM, EDS, and TEM and their physical properties are compared. For AOT surfactant the particle size increased with increasing the water to surfactant molar ratio. The particles size of CuO - ZrO 2 nanocomposite in sample with anionic surfactant with molar ratio of 6 that calcined at 600°C is between 15-20 nm.


2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Shahram Moradi ◽  
Parviz Aberoomand Azar ◽  
Sanaz Raeis Farshid ◽  
Saeed Abedini Khorrami ◽  
Mohammad Hadi Givianrad

TiO2/ZnO nanocomposites were prepared by the sol-gel method with and without addatives such as carboxy methyl cellulose (CMC), poly(ethylene glycol) (PEG), polyvinylpyrrolidon, (PVP), and hydroxylpropylcellulose (HPC). The characteristics of the prepared TiO2/ZnO nanocomposites were identified by IR spectra, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) methods. The additives have a significant effect on the particle size distribution and photocatalytic activity of TiO2/ZnO nanocomposites. The photocatalytic activity of the synthesized nanocomposites was investigated for decolorization of methyl orange (MO) in water under UV-irradiation in a batch reactor and the results showed that the photocatalytic activity of the nanocomposites have been increased by CMC, PEG, PVP, and HPC, respectively. SEM has shown that the particle size distribution of TiO2/ZnO nanocomposite in the presence of HPC was better than the other samples.


2013 ◽  
Vol 872 ◽  
pp. 94-105
Author(s):  
Mayra C. Ramirez-Camacho ◽  
Inga Tuzovskaya ◽  
Nina Bogdanchikova ◽  
Alexey Pestryakov ◽  
Arturo Susarrey-Arce ◽  
...  

Au nanoparticles (NPs) functionalized with L-cysteine (Cys) and cysteine-glycine (Cys-Gly) were synthetized. The AuNPs were prepared using sodium citrate as reducing agent. The influence of the molar concentrations of Cys and Cys-Gly, as well as the sodium citrate is studied on particle size and particle size distribution. TEM measurements revealed the formation of AuNPs with diameter in the range 5-35 nm which corresponds to nontoxic sizes [we should add a reference here, perhaps number one]. The optimal particle size for biomedical application along with narrow particle size distribution was observed for samples prepared with molar ratio of CAu:Ccitrate = 1:10. The results of UV-Vis spectroscopy revealed the interaction of the AuNPs with Cys and Gly-Cys demonstrated by a visible change in the absorption intensities of the plasmon peak located at 520 nm after AuNP functionalization and a slight shifting of this gold nanoparticles plasmon peak. Thus, any dielectric shell on surface of particles with more refraction index (and, correspondingly, dielectric function) can produce the particles with the red shift. Such effect of the surface shell with red-shift in the range of few nanometers observed for the AuNPs functionalized with Cys and Cys-Gly (Fig. 4) can be interpreted as thin or discontinuous layer of aminoacid molecules according to the data of optical spectra simulation.


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