scholarly journals Synthesis of Hydroxyapatite and ZnO Nanoparticles via Different Routes and its Comparative Analysis

2016 ◽  
Vol 13 (1) ◽  
pp. 07-13 ◽  
Author(s):  
P. Mahapatra ◽  
Shreya Kumari ◽  
Simran Simran ◽  
Shruti Sharma ◽  
K. Gaurav ◽  
...  

Hydroxyapatite (HAp) was prepared from egg shells by various routes using hexane and acetic acid followed by heat treatment. HAp has a wide application in water treatment by removal of metal ions. XRD of the samples showed use of acetic acid followed by high temperature sintering leads to formation crystalline phases of HAp. Strong evidence of CaCO3 in calcite phase was obtained in other samples. Zinc oxide nanoparticles have also been synthesized by different methods such as sol-gel, co- precipitate and green synthesis. The effect of different synthesis methods were investigated using X-Ray Diffraction (XRD). The structural properties of nanoparticles including particle size were calculated from XRD data. The XRD reveals that the prepared ZnO samples were highly crystalline, having wurtzite crystal structure. The comparative analysis shows variations in particle size with different synthesis methods.

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3876
Author(s):  
Jesús Valdés ◽  
Daniel Reséndiz ◽  
Ángeles Cuán ◽  
Rufino Nava ◽  
Bertha Aguilar ◽  
...  

The effect of microwave radiation on the hydrothermal synthesis of the double perovskite Sr2FeMoO6 has been studied based on a comparison of the particle size and structural characteristics of products from both methods. A temperature, pressure, and pH condition screening was performed, and the most representative results of these are herein presented and discussed. Radiation of microwaves in the hydrothermal synthesis method led to a decrease in crystallite size, which is an effect from the reaction temperature. The particle size ranged from 378 to 318 nm when pH was 4.5 and pressure was kept under 40 bars. According to X-ray diffraction (XRD) results coupled with the size-strain plot method, the product obtained by both synthesis methods (with and without microwave radiation) have similar crystal purity. The Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) techniques showed that the morphology and the distribution of metal ions are uniform. The Curie temperature obtained by thermogravimetric analysis indicates that, in the presence of microwaves, the value was higher with respect to traditional synthesis from 335 K to 342.5 K. Consequently, microwave radiation enhances the diffusion and nucleation process of ionic precursors during the synthesis, which promotes a uniform heating in the reaction mixture leading to a reduction in the particle size, but keeping good crystallinity of the double perovskite. Precursor phases and the final purity of the Sr2FeMoO6 powder can be controlled via hydrothermal microwave heating on the first stages of the Sol-Gel method.


PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244511
Author(s):  
Fernando Gordillo-Delgado ◽  
Jakeline Zuluaga-Acosta ◽  
Gonzalo Restrepo-Guerrero

In this work, the effect of the inoculation of silver-incorporated titanium dioxide nanoparticles (Ag-TiO2 NPs) in spinach seeds was evaluated on certain growth, physiology and phytotoxicity parameters of the plants. This is an important crop for human consumption with high nutritional value due to their low calorie and fat content, providing various vitamins and minerals, especially iron. These NPs were obtained by means of the sol-gel method and heat treatment; the resulting powder material was characterized using X-ray diffraction and scanning electron microscopy and the influence of these NPs on plants was measured by estimating the germination rate, monitoring morphological parameters and evaluating phytotoxicity. The photosynthetic activity of the spinach plants was estimated through the quantification of the Ratio of Oxygen Evolution (ROE) by the photoacoustic technique. Samples of TiO2 powder with particle size between 9 and 43 nm were used to quantify the germination rate, which served to determine a narrower size range between 7 and 26 nm in the experiments with Ag-TiO2 NPs; the presence of Ag in TiO2 powder samples was confirmed by energy-dispersive X-ray spectroscopy. The analysis of variance showed that the dependent variable (plant growth) could be affected by the evaluated factors (concentration and size) with significant differences. The statistical trend indicated that the application of the Ag-TiO2 NPs suspension of lowest concentration and smallest particle size could be a promoting agent of the growth and development of these plants. The inoculation with NPs of 8.3 nm size and lowest concentration was related to the highest average ROE value, 24.6 ± 0.2%, while the control group was 20.2 ± 0.2%. The positive effect of the Ag-TiO2 NPs treatment could be associated to the generation of reactive oxygen species, antimicrobial activity, increased biochemical attributes, enzymatic activity or improvements in water absorption.


1998 ◽  
Vol 13 (2) ◽  
pp. 451-456 ◽  
Author(s):  
C. Vázquez-Vázquez ◽  
P. Kögerler ◽  
M. A. López-Quintela ◽  
R. D. Sánchez ◽  
J. Rivas

The study of submicroscopic particles in already known systems has resulted in a renewed interest due to the large differences found in their properties when the particle size is reduced, and because of possible new technological applications. In this work we report the preparation of LaFeO3 particles by the sol-gel route, starting from a solution of the corresponding metallic nitrates and using urea as gelificant agent. Gels were decomposed at 200 °C and calcined 3 h at several temperatures, T, in the range 250–1000 °C. The samples were structurally characterized by x-ray diffraction (XRD) showing that the orthoferrite crystallizes at T as low as 315 °C. From the x-ray diffraction peak broadening, the particle size was determined. The size increases from 60 to 300 nm as the calcination T increases. Infrared spectroscopy was used to characterize gels and calcined samples. From these studies a mechanism for the gel formation is proposed. Study of the magnetic properties of LaFeO3 particles shows the presence of a ferromagnetic component which diminishes as the calcination temperature increases, vanishing at T = 1000 °C.


2013 ◽  
Vol 1 (1) ◽  
pp. 11-14
Author(s):  
N. Sahu ◽  
◽  
R. K. Duchaniya ◽  

The ZnO-CdO nanocomposite was prepared by sol-gel method by using their respective nitrates. It is a simple and low cost method to prepare nanocomposites. The drying temperature and drying period of prepared gel was varied during the synthesis process. The prepared samples were characterized by using scanning electron microscope (SEM), particle size analysis (PSA), X-ray diffraction (XRD) and photoluminescence spectroscopy (PL) to get surface morphology, idea of getting particle of nanosized range so that further characterizations can be done, to study the optical property of synthesized nanocomposite and measure the band gap . The grain size determined by Scherrer’s formula was found to be between 30-50 nm.


Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1955 ◽  
Author(s):  
Karina del Ángel-Sánchez ◽  
César I. Borbolla-Torres ◽  
Luis M. Palacios-Pineda ◽  
Nicolás A. Ulloa-Castillo ◽  
Alex Elías-Zúñiga

This paper focuses on developing, fabricating, and characterizing composite polycaprolactone (PCL) membranes reinforced with titanium dioxide nanoparticles (NPs) elaborated by using two solvents; acetic acid and a mixture of chloroform and N,N-dimethylformamide (DMF). The resulting physical, chemical, and mechanical properties of the composite materials are studied by using experimental characterization techniques such as scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) analysis, contact angle (CA), uniaxial and biaxial tensile tests, and surface roughness measurements. Experimental results show that the composite material synthesized by sol-gel and chloroform-DMF has a better performance than the one obtained by using acetic acid as a solvent.


2012 ◽  
Vol 727-728 ◽  
pp. 9-13
Author(s):  
Suzana Arleno S. Santos ◽  
Eduardo Sousa Lima ◽  
Luis Henrique Leme Louro ◽  
Célio Albano da Costa

This study aimed to produce nanometric powders of alumina by sol-gel route. Six samples were produced by varying the amount of water for dilution of aluminum nitrate and the calcination temperature. The final products were evaluated by thermogravimetric analysis, scanning electron microscopy, X-ray diffraction and particle size. It could be noticed that, beyond the time of gelation and calcination temperature, the addition of water also influenced the average size of the clusters.


2011 ◽  
Vol 10 (04n05) ◽  
pp. 571-576 ◽  
Author(s):  
M. CHAITANYA VARMA ◽  
A. MAHESH KUMAR ◽  
K. H. RAO

Cobalt substituted nickel zinc ferrite nanoparticles ( Ni 0.65–x Co x Zn 0.35 Fe 2.0 O 4) X varying from 0.0 to 0.65 in steps of 0.15 have been produced using sol–gel method, with PVA as chelating agent. The phase formation of the sintered ferrite was confirmed by X-ray diffraction studies. The lattice parameter a(A°) has been calculated using Nelson–Riley method. The crystallite size has been estimated by the Williamson–Hall method using the full width at half-maximum (FWHM) of the line broadening of all the peaks. Mössbauer spectroscopy (MS) of the samples showed the clear presence of two sextets and distribution of iron over the two sites has been given. Increase in saturation magnetization with cobalt concentration with a slight decrease for x = 0.15 has been observed with the vibrating sample magnetometry study. The observed value of magnetization for Ni0.65Zn0.35Fe2O4 with a particle size of 43.5 nm has been 71 emu/gm at room temperature, which is higher than that reported for samples prepared using chemical methods of the same composition. The results have been explained on the basis of the particle size and cation distribution among various sites.


1986 ◽  
Vol 73 ◽  
Author(s):  
J. Covino ◽  
F. G. A. De Laat ◽  
R. A. Welsbie

ABSTRACTLithium Aluminum Silicate (LAS) glass-ceramic compositions with and without phosphorous have been synthesized by Sol-Gel techniques. Resulting LAStype powders are herein designated as NZ and NZP. X-Ray analysis, thermogravimetric analysis (TGA), particle size measurements, and thermal dilatometric shrinkage measurements have been performed on these samples. The NZ and NZP powders in calcined form, as well as commercially-available LAS glass-ceramic produce x-ray diffraction pattern very similar to the pattern of Virgilite LixAlxSi3−xO6 (x=0.5–1.0). There is little difference between powders with and without phosphorous in the diffuse reflectance spectra (DRS). Preliminary results show that the material can be easily processed into glass ceramics.


2021 ◽  
Vol 10 (4) ◽  
pp. xx-xx
Author(s):  
Dung Le Thi ◽  
Loan Nguyen Quynh ◽  
Thang Nguyen Duc ◽  
Son Le Thanh ◽  
Duc Pham Tien

The present study investigated adsorption of 2,4-dichorophenoxy acetic acid(2,4-D) on titania (TiO2) nanoparticles with surface modification by cationic surfactant, cetyltrimethylammonium bromide (CTAB). Titania nanoparticles which were successfully synthesized by sol-gel method, were characterized by X-ray diffraction (XRD) and Transmission electron microscopy (TEM). Surface modification of TiO2 with CTAB enhanced the removal of 2,4-D significantly. Some effective conditions affect to the removal of 2,4-D using CTAB modified TiO2 such as pH and adsorbent dosage were systematically studied and found to be 5 and 10 mg/mL, respectively. Adsorption mechanisms of 2,4-D onto CTAB modified TiO2 was suggested based on the change in surface charge after adsorption. 


2013 ◽  
Vol 747 ◽  
pp. 83-86
Author(s):  
Jutharatana Klinkaewnarong ◽  
Ekaphan Swatsitang

Nanocrystalline hydroxyapatite (HAp) powders were successfully synthesized by natural biopolymers based sol-gel technique. The biopolymers were extracted from the leaves of Yanang (Tiliacora triandra), Krueo Ma Noy (Cissampelos pareira) and Konjac (Amorphophallus konjac). To obtain HAp powders, the prepared precursors were calcined in air at 600, 700, and 800 °C for 2 h. The phase composition of the calcined samples was studied by X-ray diffraction (XRD) technique. The XRD results confirmed the formation of HAp phase with a small trace of β-tricalcium phosphate (β-TCP). The crystalline sizes of the samples were found to be 20-50 nm as evaluated by the XRD line broadening method. TEM investigation revealed that the synthesized HAp samples consisted of nanoparticles with a particle size in the range of 50-100 nm in diameter. The corresponding selected area electron diffraction (SAED) analysis further confirmed the formation of hexagonal structure of HAp.


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