Oleic acid-coated cobalt ferrite nanoparticles were synthesized using the chemical co-precipitation route and characterized by standard techniques for structure, morphology, and magnetic properties ...analysis. The Rietveld refined X-ray diffraction (XRD) pattern of CoFe2O4 nanoparticles indicated the formation of a cubic-spinel single-phase structure with the Fd3̅m space group. The average crystallite size (∼12 nm) confirmed the nanocrystalline appearance of the prepared CoFe2O4 nanoparticles. Transmission electron microscopy (TEM) images revealed the spherical nature of both (CoFe2O4) and (OA-CoFe2O4) samples. The absorption bands in the Fourier transform infrared (FT-IR) spectrum at ∼3418, 3026, 1628, 1404, 1068, 845, 544, and 363 cm–1 affirmed the spinel ferrite formation and OA attachment. The M–H curve recorded at room temperature showed the superparamagnetic nature of the CoFe2O4 nanoparticles with moderate saturation magnetization (∼78 emu/gm). The blocking temperature of the prepared CoFe2O4 nanoparticles obtained from the field-cooled and zero-field-cooled (FC–ZFC) curve was estimated to be 144 K. Further, the characterized surface-modified CoFe2O4 was then added in ethylene glycol/water with various concentrations and characterized by the induction heating technique for the evaluation of their self-heating characteristics. A series of temperature versus time measurements were made by varying the ethylene glycol/water proportion for better understanding of the self-heating characteristics of the prepared CoFe2O4 nanoparticles. All of the findings display the applicability of the surface-modified CoFe2O4 nanoparticles in magnetic fluid hyperthermia toward noninvasive cancer treatment and other bio-applications.
Magnetic nanofluids (commonly known as ferrofluids) have captured the great attention of the researchers due to their various kinds of applications such as heat transfer, hyperthermia treatments, ...targeted drug delivery etc. The present experimental investigations deal with the thermoacoustic behaviour of the water based nanofluids of nickel ferrites. The magnetic nickel ferrite nanoparticles were produced by the simple and inexpensive chemical co-precipitation route. The prepared nanoparticles were exposed to different characterization tools for structural, morphological, compositional and magnetic properties analysis. X-ray diffraction analysis with Rietveld refinement confirmed the single phasic nature with nanometric crystallite size of the prepared nanoparticles. Scanning electron microscope images revealed the spherical and nanocrystalline morphology of the prepared nanoparticles. The M-H plot recorded at room temperature revealed the superparamagnetic nature of the nanoparticles. Further, the co-precipitated nickel ferrite nanoparticles with different concentrations were utilized for the preparation of the water based magnetic nanofluids. Colloidal stability of the prepared nanofluids was analyzed by UV–Vis spectroscopy technique and it revealed the stability over 11 days without separation in phase. The temperature dependent thermoacoustic properties of the prepared nanofluids were analyzed through Ultrasonic Interferometer. The interaction between particle–particle and particle–fluid are explained on the basis of thermo-acoustic parameters.
As the world is at present confronting tremendous issues concerning the atmosphere, energy, and the environment, catalysis innovations have all the earmarks of being getting critical to energy, ...synthesis process, and environmental areas. In the recent years, transformation of the research on catalytic activities and advanced catalyst was seen with the advancement of nanotechnology. Undoubtedly, the utilization of nanomaterials in catalysis and, all the more especially, inorganic nanoparticles has pulled in many research attempts over the globe to create imaginative and greener conventions. These nanoparticles can be used as the catalyst or as mediator and can encourage the reactant procedure in new medium such as, water. Besides, attributable to their little size and expanded surface area, nano-catalysts have obviously risen as offering an interesting candidate at the interface among homogeneous and heterogeneous catalysis, taking into consideration an expanded response rate. Furthermore, nanoparticles give extra reactant functionalities because of their interesting inherent properties (e.g., nanomagnetism, photocatalytic activity). Along these lines, in this pursuit for eco-friendly and more affordable catalyst, nano-catalysis is turning into a significant field in science, which is applied broadly in the academics and industrial areas. This brief review principally centered around portraying the major comprehension of nano-catalysis, how remarkable catalytic property and other explicit properties of nanomaterials rely upon its size and structure at the nano level.
The present work reports the structural, thermal, spectral, optical and surface analysis of rare earth metal ion (Gd3+) doped mixed Zn–Mg nano-spinel ferrites. The samples of Gd3+ doped Zn–Mg nano ...ferrites with equi-amount chemical composition i.e. Zn0.5Mg0.5Fe2-xGdxO4 (0.00 ≤ x ≤ 0.10 in step of 0.02) were prepared by self-ignited sol-gel route. The variance in the thermal behaviour and spinel phase development with weight loss percentage in the prepared samples was investigated by TG-DTA technique. The powder X-ray diffraction (P-XRD) patterns ensured the nanocrystalline mono-phasic formation and spinel-cubic structure of all the samples. The trend of increment in lattice constant (a) and decrement in crystallite (t) size was observed with the doping of Gd3+ ions. The appearance of two requisite vibrational stretching modes was affirmed by the FT-IR spectral studies. The UV–Vis optical analysis displayed the augmentation in absorbance and drastic decrement in energy band gap value (1.96 eV–1.83 eV) with Gd3+ doping. The photo-luminescent (PL) studies revealed the broad near band-edge emission in visible wavelength range (523 nm–528 nm) for all the samples. The surface parameters investigation was undertaken with the help of BET isotherms recorded by the N2-physisorption and BJH model. The various surface parameters such as BET surface area, volume and radius of the pores, distribution of the pore sizes etc were construed from the BET data. The enhancement in these surface parameters via Gd3+ doping was noted for all the samples. The outcomes of the present work reflects the influential doping of Gd3+ ions in Zn–Mg nano ferrites, which can be implementable for bio-applications as thermal seeds in magnetic hyperthermia or as contrast enhancer in medical MRI imaging.
The work reports, enhancement in colloidal stability and hyperthermia efficiency of nano-spinel magnesium ferrite (MgFe2O4) by hydrophobic-to-hydrophilic surface transformation via oleic acid (OA) ...coating. The nano-spinel structured MgFe2O4 was prepared by the auto-combustion assisted sol-gel route and consequently, its surface was coated by OA. The uncoated and coated MgFe2O4 were portrayed by various physicochemical characterizations. The XRD analysis assured the unchanged single phasic cubic spinel structure and nanocrystalline nature of both the samples. FT-IR spectral analysis indicated the spinel belonging two vibrational stretching modes and OA attachment over the MgFe2O4 core. FE-SEM images revealed the nano-metric spherical type grain-morphology and visualization of OA coating. The drastic diminishment in contact angle values signifies hydrophobic to hydrophilic surface transition. M − H plots revealed the superparamagnetic appearance of uncoated and coated samples. Physisorption analysis showed the elevated surface area and pore size values. Zeta potential and DLS study displayed the enhancement in fluidic dispersion and hydro-dynamic size. The nano-particle concentration (2–10 mg/mL) dependent hyperthermia analysis was carried out for both the samples. Cell viability studies confirmed the improvement in the bio-friendly nature of MgFe2O4 via OA coating. All the outcomes show the superiority of the surface transformed MgFe2O4 nanoparticles in nano-magnetic hyperthermia treatments.
•Hydrophobic to hydrophilic surface transformation of nanoscale MgFe2O4 by oleic acid (OA) coating was done successfully.•Effect of OA coating on the structural, morphological, surface, magnetic and colloidal stability properties were studied.•Systematic investigations of magnetic hyperthermia properties and cytotoxicity analysis were carried out.•Enhancement in the colloidal stability and particle size distribution by OA coating was observed.•OA coated MgFe2O4 shows potentiality in hyperthermia therapies for cancer treatment and other biomedical applications.
Surface‐functionalized superparamagnetic Zn‐Mg ferrite (Zn0.4Mg0.6Fe2O4) nanoparticles are prepared by sol‐gel self‐combustion route. The surface‐modified Zn‐Mg Ferrite nanoparticles are ...characterized by standard techniques. XRD pattern of the prepared sample ensures the nanocrystalline single phasic cubic spinel structure. FT‐IR spectra reveals the presence of vibrational frequency‐modes belonging to spinel structure and successful coating of oleic acid (OA) over Zn‐Mg Ferrite. The nano‐size spherical grains with some agglomeration and OA coating over Zn‐Mg Ferrite are visualized in FE‐SEM images. The hydrophilic surface of Zn‐Mg Ferrite is confirmed by water contact‐angle measurements. The BET surface‐area is evaluated by recording N2‐isotherms. The M‐H plots confirm the superparamagnetic nature of the prepared sample. The colloidal stability and distribution of particle sizes are estimated by Zeta potential and DLS measurements. Magnetic hyperthermia studies are carried out for different concentrations (2, 4, and 6 mg mL–1) of the prepared sample. The biocompatible nature for the prepared sample is studied by cell‐viability studies. All these results ensure the implementation of OA‐coated Zn‐Mg Ferrite nanoparticles with minimum dose rate (6 mg mL–1) in magnetic hyperthermia therapies for noninvasive cancer treatment.
In this concise survey, we have introduced overview and features on biomedical utilizations of a class of metal nanoparticles including magnetic nanoparticles. Their most significant related ...materials are additionally examined for biomedical applications for treating different cancer like diseases. At present, physicochemical techniques have been demonstrated fruitful to orchestrate, shape, control, and produce metal and oxide based homogeneous frameworks, e.g., nano and micro scale particles. In this way, we have principally centred around useful magnetic nanoparticles for nano-medication as a result of their high bio-flexibility to the organs inside human body. Here, bio-conjugation procedures are extremely urgent to interface nanoparticles with customary medications, nano-drugs, bio-particles or polymers for biomedical applications. Bio-functionalization of tailored nanoparticles for biomedicine is demonstrated separate to in vitro and in vivo investigation conventions that commonly incorporate medication conveyance, hyperthermia treatment, magnetic resonance imaging (MRI). The last can be particularly applied utilizing magnetic nanoparticles, for example, spinel ferrite oxide nanoparticles for diagnostic and treatment of malignancies. Significantly, nano scale-frameworks or micro scale-frameworks or half breed micro-nano scale frameworks are shortly brought into nano-medication.
Poly(ethylene glycol) (PEG)‐coated superparamagnetic MnFe2O4 ferrite nanoparticles are of great interest for application in magnetic fluid hyperthermia (MFH) due to their heat generation capability ...in an external alternating magnetic field, besides biocompatibility, and surface properties. MFH has emerged as a promising therapeutic approach for cancer treatment and is based on controlled heating tumor tissue through the accumulation of MnFe2O4 ferrite nanoparticles within cancer cells. In the present work, MnFe2O4 superparamagnetic ferrite nanoparticles via the chemical combustion method are synthesized. The preparation of PEGylated MnFe2O4 ferrite nanoparticles, which involves the attachment of such molecules at the surface, without the need for coupling agents or prior modification on the species involved. The conjugation of folate onto MnFe2O4 ferrite nanoparticles is confirmed by FTIR spectroscopy. The MnFe2O4 ferrite nanoparticles are colloidal stable. The obtained targeted PEGylated MnFe2O4 ferrite nanoparticles show superparamagnetic behavior with a saturation magnetization of 78.68 emu·g−1 at 300 K. Their specific absorption rate (SAR) ranged from 43.2 to 19.5 W g−1 in an alternating magnetic field of 5—20 kA m−1. The heat generated is sufficient to raise the sample temperature to the therapeutic range used in MFH establishing this system as promising candidates for use in MFH treatment.
A facile and cost-effective preparation of nanoscale TiO2 with enhanced surface area was achieved through gel-combustion technique assisted via glycine as a fuel. X-ray diffraction studies confirmed ...the anatase phase and nanocrystalline formation of TiO2 nanoparticles (NPs). Using N2 adsorption-desorption curve, the enhanced surface area (54.3m2g−1) of TiO2 NPs was noted. Visible light driven photocatalytic activity of the TiO2 NPs for the degradation of Methylene Blue (MB) dye was studied. The complete degradation of MB dye under sunlight irradiation was achieved in 120min. All the outcomes show that prepared TiO2 nanoparticles have excellent visible light driven photocatalytic activity for the active degradation of MB dye.
Stable magnetic nanofluids of cobalt ferrite nanoparticles were synthesized by chemical co-precipitation method. The structural, morphological and magnetic properties were characterized by the X-ray ...diffraction (XRD), Transmission Electron Microscopy (TEM), and Vibrating Sample Magnetometer (VSM) respectively. The XRD study revealed the spinel structure of the prepared cobalt ferrite nanoparticles with Fd-3m space group. Prepared nanoparticles were found to be spherical in nature with average particles size of 10 nm. The prepared cobalt ferrite nanoparticles were exhibit near superparamagnetic behavior. These superparamagnetic cobalt ferrite nanoparticles used for the preparation of the magnetic nanofluids in ethylene glycol with various volume fraction concentrations viz. 0.2%, 0.4%, 0.6%, 0.8%, and 1%. The thermal conductivity of the ethylene glycol was significantly enhanced by dispersing the cobalt ferrite nanoparticles. The thermal conductivity of the prepared cobalt ferrite / ethylene glycol (COEG) magnetic nanofluid were also responded to the magnetic field intensity and shows increasing trend with increasing magnetic field intensity.
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