Impact of Different Set of Precipitants on the Formation of BaFe12O19 Phase Nanomaterials

2020 ◽  
Vol 20 (6) ◽  
pp. 3486-3495 ◽  
Author(s):  
S. Balamurugan ◽  
S. P. Resmi ◽  
B. C. Brightlin ◽  
V. Sherly Arputha Kiruba ◽  
A. Reshma

This work deals with the preparation of BaFe12O19 materials by soft chemical co-precipitation method using a different set of precipitants namely, (i) NaOH and Na2CO3, (ii) NH2CONH2 and NH4OH, and (iii) NH4HCO3 and NH4OH. The influence of these precipitants on the different properties is also investigated by various characterizations. The precipitants used in this work considerably affected the phase formation of BaFe12O19 materials. The thermal analyses reveal the thermal decomposition of the intermediate phase as well as the crystallization of BaFe12O19 phase. Due to the amorphous nature, all the co-precipitated products were annealed for 2 h at 1000 °C. Among the different annealed samples, the NaOH and Na2CO3 set of precipitant derived materials exhibit nearly single hexagonal phase of crystalline BaFe12O19 nanomaterials with an average crystalline size of ˜48 nm with a = 0.5888(4) nm and c = 2.320(2) nm. The particle size observed in micrograph was rather much higher than the average crystalline size obtained from XRD for the best sample. The BaFe12O19 nanomaterials studied in the present work have been found potential applications in magneto-optic recording media, biomolecular separations, magnetic carriers for drug targeting, permanent magnet, chip inductors, microwave absorbers, and hyperthermia cancer treatment.

2016 ◽  
Vol 16 (4) ◽  
pp. 3547-3556 ◽  
Author(s):  
Errui Yang ◽  
Guangshe Li ◽  
Yunlong Zheng ◽  
Liping Li

Selective synthesis of specific phased nanomaterials via a green route is a promising yet challenging task. In the present work, the hexagonal and monoclinic phases of BiPO4:Ln3+ (Ln = Sm, Eu, Tb, Dy) were prepared via room temperature co-precipitation method. For adjusting the phase of the products, the prepared mediums selected were the most common solvents, i.e., water and ethanol. It was very important that the prepared mediums could be easily recycled and reused by evaporating the filtrate. The formation mechanisms of hexagonal in water and monoclinic in ethanol were investigated. Interestingly, the growth behaviors of these phases were quite distinct and thus gave rise to distinct morphology and particle size. The hexagonal phase possesses a rod-like morphology with diameters of 50–160 nm and lengths of 65–400 nm while the monoclinic phase consists of almost entirely irregular nanoparticles. Also, it was found that the bending and stretching vibrations of O–H and PO4 tetrahedra were quite different for the products prepared in water and ethanol. Moreover, it was found that the luminescence properties, including emission intensity, lifetime, quantum efficiency, and color, could be readily tailored through controlling the phase structures and microstructures. The results showed that the monoclinic phase exhibited superior luminescent performance to the hexagonal phase. The methodologies reported in this work were fundamentally important, which could be easily extended to large-scale synthesis of other phased nanomaterials for potential applications as electroluminescent devices, optical integrated circuits, or biomarkers.


Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 832
Author(s):  
Edna X. Figueroa-Rosales ◽  
Javier Martínez-Juárez ◽  
Esmeralda García-Díaz ◽  
Daniel Hernández-Cruz ◽  
Sergio A. Sabinas-Hernández ◽  
...  

Hydroxyapatite (HAp) and hydroxyapatite/multi-walled carbon nanotube (MWCNT) composites were obtained by the co-precipitation method, followed by ultrasound-assisted and microwave radiation and thermal treatment at 250 °C. X-ray diffraction (XRD) confirmed the presence of a hexagonal phase in all the samples, while Fourier-transform infrared (FTIR) spectroscopy elucidated the interaction between HAp and MWCNTs. The photoluminescent technique revealed that HAp and the composite with non-functionalized MWCNTs present a blue luminescence, while the composite with functionalized MWCNTs, under UV-vis radiation shows an intense white emission. These findings allowed presentation of a proposal for the use of HAp and HAp with functionalized MWCNTs as potential materials for optoelectronic and medical applications.


2016 ◽  
Vol 875 ◽  
pp. 24-44
Author(s):  
Ming Guo Ma ◽  
Shan Liu ◽  
Lian Hua Fu

CaCO3 has six polymorphs such as vaterite, aragonite, calcite, amorphous, crystalline monohydrate, and hexahydrate CaCO3. CaCO3 is a typical biomineral that is abundant in both organisms and nature and has important industrial applications. Cellulose could be used as feedstocks for producing biofuels, bio-based chemicals, and high value-added bio-based materials. In the past, more attentions have been paid to the synthesis and applications of CaCO3 and cellulose/CaCO3 nanocomposites due to its relating properties such as mechanical strength, biocompatibility, and biodegradation, and bioactivity, and potential applications including biomedical, antibacterial, and water pretreatment fields as functional materials. A variety of synthesis methods such as the hydrothermal/solvothermal method, biomimetic mineralization method, microwave-assisted method, (co-) precipitation method, and sonochemistry method, were employed to the preparation of CaCO3 and cellulose/CaCO3 nanocomposites. In this chapter, the recent development of CaCO3 and cellulose/CaCO3 nanocomposites has been reviewed. The synthesis, characterization, and biomedical applications of CaCO3 and cellulose/CaCO3 nanocomposites are summarized. The future developments of CaCO3 and cellulose/CaCO3 nanocomposites are also suggested.


2019 ◽  
Vol 967 ◽  
pp. 259-266 ◽  
Author(s):  
Muhammad Rizal Fahlepy ◽  
Yuyu Wahyuni ◽  
Muhamma Andhika ◽  
Arini Tiwow Vistarani ◽  
Subaer

This research is about nanoparticles hematite (NPH) synthesized and characterized from natural iron sands using co-precipitation method and its potential applications as extrinsic semiconductor materials type-N. The aims of this study is to determine the process parameters to obtain hematite of high purity degree and to observe its physical characteristics as an extrinsic semiconductor materials type-N. The iron sand was first separated by magnetic technique and then dissolved into HCl solution before conducting the precipitation process. Precipitation was done by dripping ammonium hydroxide (NH4OH). Precipitated powder was dried at 80°C for 2 hours, and then calcined at 500°C, 600°C 700°C for 2 hours respectively. The composition of iron sands, purity degree, hematite mineral grain size, and space group were analyzed by XRF, XRD, FTIR and SEM. The XRF analysis result of raw material, showed that dominant element and composition in the sample is Fe with purity degree is 90.51%. The XRD result before and after precipitation showed Fe3O4 and α-Fe2O3. Fe3O4 purity degree was obtained 85%, and α-Fe2O3 in NPH500, NPH600, NPH700 were 63%, 83%, and 76%, respectively. FTIR spectral showed crystalline hematite characteristics stong band of 472.07 to 559.62 cm-1. SEM image showed the morphology of agglomeration particulates, when the calcinaton temperature increases, the agglomeration will be seperated due to thermal energy. Based on the charaterization results it was found that the natural iron sand synthesized has the potential to be applied as an N-type extrinsic semiconductor material.


2013 ◽  
Vol 678 ◽  
pp. 163-167 ◽  
Author(s):  
D. Amaranatha Reddy ◽  
G. Murali ◽  
N. Madhusudhana Rao ◽  
R.P. Vijayalakshmi ◽  
B.K. Reddy

Undoped and Cr doped ZnS nanoparticles with Cr concentrations of 3.0 at.% were prepared by a chemical co-precipitation method for the fist time, using 2-Mercaptoethanol as the capping agent and annealed the synthesized particles at 600°C for 3h in air. The effect of annealing on morphological, structural and optical properties of ZnS and ZnS:Cr have been studied and compared with as prepared samples. EDAX measurements confirmed the presence of Cr in the ZnS lattice and it also confirms the conversion of ZnS into ZnO after annealed at 600 0C/3h. Surface morphologies of all samples were characterized using scanning electron microscopy (SEM). XRD spectra of as synthesized nanoparticles of ZnS and ZnS:Cr exhibited cubic phase. After annealing, the cubic phase is transformed into hexagonal phase. The particle sizes of the ZnS:Cr powders were increased from 5 to 30 nm when the powders were annealed at 600°C. A stable blue emission peak at 445 nm is observed from the as prepared samples (pure ZnS and Cr doped ZnS) but annealed at 600 0C the PL peaked at 500 nm for pure ZnS and Cr doped ZnS nanoparticles exhibited PL peak at 500 nm as well as 654 nm. The emission intensity decreased in annealed particles compared to as synthesized samples.


2018 ◽  
Vol 55 (1B) ◽  
pp. 7 ◽  
Author(s):  
Dai Hai Nguyen

The objective of this study is to prepare biodegradable iron oxide nanoparticles with gelatin (GEL) for paclitaxel (PTX) delivery. In detail, Fe3O4 nanoparticles were prepared and then coated them with GEL (Fe3O4@GEL) conjugate by co–precipitation method. Furthermore, the formation of Fe3O4@GEL was demonstrated by Fourier transform infrared (FT–IR) and powder X–ray diffraction (XRD). The superparamagnetic property of Fe3O4@GEL was also showed by hysteresis loop analysis, the saturation magnetization reached 20.36 emu.g–1. In addition, size and morphology of Fe3O4@GEL nanoparticles were determined by transmission electron microscopy (TEM). The results indicated that Fe3O4@GEL nanoparticles were spherical shape with average diameter of 10 nm. Especially, PTX was effectively loaded into the coated magnetic nanoparticles, 86.7 ± 3.2 % for drug loading efficiency and slowly released up to 5 days. These results suggest that the potential applications of Fe3O4@GEL nanoparticles in the development of stable drug delivery systems for cancer therapy.


Author(s):  
R. M. Rosnan ◽  
Zulkafli Othman ◽  
A. A. Ati

This study evaluates the morphology and structural properties of Ni-Mg substituted Cobalt ferrite samples prepared through the co-precipitation method. The nominal composition of Co0.5Ni0.5−xMgx Fe2O4 in the range x = 0.1 have been synthesized and then were sintered at temperature 700 and 1000°C for 10 hour with a heating rate of 5°C/min. The prepared nano-ferrites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM). XRD confirmed formation of single phase spinel ferrite with average crystalline size in the range of 40–120 nm. Further information about the structure and morphology of the nanoferrites was obtained from FESEM and results are in good agreement with XRD.


2010 ◽  
Vol 63 ◽  
pp. 152-157 ◽  
Author(s):  
Kien Seng Lew ◽  
Radzali Othman ◽  
Fei Yee Yeoh

Among the porous media, hydroxyapatite (HA) possesses good biocompatibility and bioactivity properties with respect to bone cells and tissues, due to its similarity with the hard tissues of the body. In this study, mesoporous HA was synthesized using a soft-templating technique via a self-assembly between HA and cationic surfactant decyltrimethylammonium bromide (C10TAB), which is analogous to the synthesis of mesoporous silica MCM-41. This co-precipitation method involved formation of hexagonal-phase micelle template by the surfactant and the precipitation of HA surrounding the micelle. After ageing, calcination was carried out to remove the templates, revealing the pores as well as to produce more crystalline and more stable HA structure. This study showed that instead of hexadecyltrimethylammonium bromide (C16TAB) which was conventionally used, C10TAB could also be used to synthesize single-phase mesoporous HA with pore size ca. 3 nm. Ageing temperature of 120 °C, for 24 hours was found sufficient for the formation of mesoporous HA. The adsorption properties of mesoporous HA was able to be improved by increasing the water content of C10TAB-phosphate solution and by constant pH adjustment during the mixing of solutions.


2019 ◽  
Vol 9 (2) ◽  
pp. 278-284
Author(s):  
Mohammad Sabet ◽  
Marziyeh Mohammadi ◽  
Fatemeh Googhari

Background: Due to unique chemical and physical properties and potential application in many fields, nanostructured materials have attracted many attentions. Cadmium sulfide (CdS) is a semiconductor that has a wide band gap of 2.42 eV at room temperature and can be served in solar cells and photoluminescence devices. Cadmium sulfide (CdS) is a kind of attractive semiconductor material, and it is now widely used for optoelectronic applications. CdS nano and microstructures can be synthesized via different chemical methods such as microwave-solvothermal synthesis, surfactant-ligand coassisting solvothermal method and hydrothermal route. Also different morphologies of this semiconductor such as dendrites, nanorods, sphere-like, flakes, nanowires, flower-like shape triangular and hexagonal plates, were synthesized. Methods: To synthesis of the nanocomposite, a simple co-precipitation method was served. In briefly, 0.1 g of Pb(NO3)2 was dissolved in the distilled water (Solution 1). Also different aqueous solutions were made from dissolving different mole ratio of Cd(NO3)2.6H2O respect to the lead source in the water (Solution 2). Two solutions were mixed together under vigorous stirring and then S2- solution (0.02 g thiourea in the water) was added to the Pb2+/Cd2+ solution. After that 0.1 g of CTAB as surfactant was added to the final solution. Finally to the synthesis of both sulfide and oxide nanostructures, NaOH solution was added to the prepared solution to obtain pH= 10. Distilled water and absolute ethanol were used to wash the obtained precipitate and then it dried at 80 °C for 8 h. Results: From the XRD pattern it was found that the peaks placed at 24.9°, 27°, 44.1°, 48°, 52°, 54°, 57.8°, 66.8°, 71.2° are associated to CdS compound with hexagonal phase (JCPDS=00-001-0780) that belong to (100), (002), (110), (103), (112), (201), (202), (203), (211) Miller indices respectively. The Other peaks belong to PbS with hexagonal phase (JCPDS=01-078-1897), and CdO with cubic phase (JCPDS=00-001-1049). From SEM images, it was found by choosing the mole ratio to 1:1, very small and uniform particles were achieved. By increasing Pb2+/Cd2+ mole ratio to 1:2, very tiny particles aggregated together were achieved. Conclusion: The results showed that the product can adsorb extra 80% of heavy metal ions from the water. So it can be said that the nanocomposite can be used in the water treatment due to its high photocatalytic and surface adsorption activities. In other words, it can remove heavy metals from the water and also decompose organic pollutions.


2013 ◽  
Vol 678 ◽  
pp. 234-238 ◽  
Author(s):  
Vishwanath D. Mote ◽  
Babasaheb N. Dole

Nanosized Mn doped ZnO samples were synthesized by co-precipitation method using Polyethylene glycol (PEG) as a capping agent. X- ray diffraction patterns confirm that the pure and Mn doped ZnO nanocrystals have wurtzite structure without any seconadary phases. Lattice parameters of pure and Mn doped ZnO nanocrystals increase slightly with increasing Mn concentration. The average crystalline size of pure and Mn doped ZnO nanocrystals are in the range of 14-18 nm. The X-ray density for pure and Mn doped ZnO sample is calculated using lattice parameters. It is found that almost static for Mn doped ZnO samples. In the Zn1-xMnx samples, room temperature magnetic hysteresis is observed and the saturation magnetization increases with increasing Mn content. However, these samples show room temperature ferromagnetic in nature. Result of the present investigation compared without PEG.


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