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M Mozaffari - One of the best experts on this subject based on the ideXlab platform.
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synthesis of aqueous ferrofluids of znxfe3 xo4 nanoparticles by citric acid assisted hydrothermal reduction route for magnetic hyperthermia applications
Journal of Magnetism and Magnetic Materials, 2012Co-Authors: Behshid Behdadfar, A Kermanpur, Hojjat Sadeghialiabadi, M P Morales, M MozaffariAbstract:Abstract Superparamagnetic and monodispersed aqueous ferrofluids of Zn substituted magnetite nanoparticles (Zn x Fe 3− x O 4 , x =0, 0.25, 0.3, 0.37 and 0.4) were synthesized via hydrothermal-reduction route in the presence of citric acid, which is a facile, low energy and environmental friendly method. The synthesized nanoparticles were characterized by X ray diffraction (XRD) analysis, Fourier transform infrared (FTIR) spectroscopy, scanning and transmission electron microscopy (SEM and TEM) and the dynamic light scattering (DLS) method. The results showed that a certain amount of citric acid was required to obtain single phase Zn substituted magnetite nanoparticles. Citric acid acted as a modulator and reducing agent in the formation of spinel structure and controlled nanoparticle size and crystallinity. Mean particle sizes of the prepared nanoparticles were around 10 nm. The results that are obtained from XRD, magnetic and power Loss measurements showed that the crystallinity, saturation magnetization ( M S ) and Loss power of the synthesized ferrofluids were all influenced by the substitution of Zn in the structure of magnetite. The Zn substituted magnetite nanoparticles obtained by this route showed a good stability in aqueous medium (pH 7) and hydrodynamic sizes below 100 nm and polydispersity indexes below 0.2. The calculated Intrinsic Loss power (ILP) for the sample x =0.3 (e.g. 2.36 nH m 2 /kg) was comparable to ILP of commercial ferrofluids with similar hydrodynamic sizes.
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synthesis of high Intrinsic Loss power aqueous ferrofluids of iron oxide nanoparticles by citric acid assisted hydrothermal reduction route
Journal of Solid State Chemistry, 2012Co-Authors: Behshid Behdadfar, A Kermanpur, Hojjat Sadeghialiabadi, M P Morales, M MozaffariAbstract:Monodispersed aqueous ferrofluids of iron oxide nanoparticle were synthesized by hydrothermal-reduction route. They were characterized by X-ray diffraction analysis, Fourier transform infrared spectroscopy, scanning and transmission electron microscopy and dynamic light scattering. The results showed that certain concentrations of citric acid (CA) are required to obtain only magnetic iron oxides with mean particle sizes around 8 nm. CA acts as a modulator and reducing agent in iron oxide formation which controls nanoparticle size. The XRD, magnetic and heating measurements showed that the temperature and time of hydrothermal reaction can affect the magnetic properties of obtained ferrofluids. The synthesized ferrofluids were stable at pH 7. Their mean hydrodynamic size was around 80 nm with polydispersity index (PDI) of 0.158. The calculated Intrinsic Loss power (ILP) was 9.4 nHm{sup 2}/kg. So this clean and cheap route is an efficient way to synthesize high ILP aqueous ferrofluids applicable in magnetic hyperthermia. - Graphical abstract: Monodispersed aqueous ferrofluids of iron oxide nanoparticles were synthesized by hydrothermal-reduction method with citric acid as reductant which is an efficient way to synthesize aqueous ferrofluids applicable in magnetic hyperthermia. Highlights: Black-Right-Pointing-Pointer Aqueous iron oxide ferrofluids were synthesized by hydrothermal-reduction route. Black-Right-Pointing-Pointer Citric acid acted as reducing agent andmore » surfactant in the route. Black-Right-Pointing-Pointer This is a facile, low energy and environmental friendly route. Black-Right-Pointing-Pointer The aqueous iron oxide ferrofluids were monodispersed and stable at pH of 7. Black-Right-Pointing-Pointer The calculated Intrinsic Loss power of the synthesized ferrofluids was very high.« less
M P Morales - One of the best experts on this subject based on the ideXlab platform.
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99mtc 90y and 177lu labeled iron oxide nanoflowers designed for potential use in dual magnetic hyperthermia radionuclide cancer therapy and diagnosis
ACS Applied Materials & Interfaces, 2019Co-Authors: Milos Ognjanovic, M P Morales, Magdalena Radovic, Marija Mirkovic, željko Prijovic, Miran Ceh, Sanja Vranjesđuric, Bratislav AnticAbstract:Development of a complex based on iron oxide nanoparticles (IONPs) for diagnosis and dual magnetic hyperthermia/radionuclide cancer therapy accomplishing high yields of radiolabeling and great magnetic heat induction is still a challenge. We report here the synthesis of citric acid, poly(acrylic acid) (PAA) and poly(ethylene glycol) coated IONPs and their labeling with three radionuclides, namely, technetium (99mTc), yttrium (90Y), and lutetium (177Lu), aiming at potential use in cancer diagnosis and therapy. Polyol-synthesized IONPs are a flowerlike structure with 13.5 nm spherically shaped cores and 24.8 nm diameter. PAA-coated nanoparticles (PAA@IONP) showed the best characteristics such as easy radiolabeling with very high yields (>97.5%) with all three radionuclides, and excellent in vitro stabilities with less than 10% of radionuclides detaching after 24 h. Heating ability of PAA@IONP in an alternating external magnetic field showed Intrinsic Loss power value of 7.3 nH m2/kg, which is one of higher ...
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synthesis of aqueous ferrofluids of znxfe3 xo4 nanoparticles by citric acid assisted hydrothermal reduction route for magnetic hyperthermia applications
Journal of Magnetism and Magnetic Materials, 2012Co-Authors: Behshid Behdadfar, A Kermanpur, Hojjat Sadeghialiabadi, M P Morales, M MozaffariAbstract:Abstract Superparamagnetic and monodispersed aqueous ferrofluids of Zn substituted magnetite nanoparticles (Zn x Fe 3− x O 4 , x =0, 0.25, 0.3, 0.37 and 0.4) were synthesized via hydrothermal-reduction route in the presence of citric acid, which is a facile, low energy and environmental friendly method. The synthesized nanoparticles were characterized by X ray diffraction (XRD) analysis, Fourier transform infrared (FTIR) spectroscopy, scanning and transmission electron microscopy (SEM and TEM) and the dynamic light scattering (DLS) method. The results showed that a certain amount of citric acid was required to obtain single phase Zn substituted magnetite nanoparticles. Citric acid acted as a modulator and reducing agent in the formation of spinel structure and controlled nanoparticle size and crystallinity. Mean particle sizes of the prepared nanoparticles were around 10 nm. The results that are obtained from XRD, magnetic and power Loss measurements showed that the crystallinity, saturation magnetization ( M S ) and Loss power of the synthesized ferrofluids were all influenced by the substitution of Zn in the structure of magnetite. The Zn substituted magnetite nanoparticles obtained by this route showed a good stability in aqueous medium (pH 7) and hydrodynamic sizes below 100 nm and polydispersity indexes below 0.2. The calculated Intrinsic Loss power (ILP) for the sample x =0.3 (e.g. 2.36 nH m 2 /kg) was comparable to ILP of commercial ferrofluids with similar hydrodynamic sizes.
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synthesis of high Intrinsic Loss power aqueous ferrofluids of iron oxide nanoparticles by citric acid assisted hydrothermal reduction route
Journal of Solid State Chemistry, 2012Co-Authors: Behshid Behdadfar, A Kermanpur, Hojjat Sadeghialiabadi, M P Morales, M MozaffariAbstract:Monodispersed aqueous ferrofluids of iron oxide nanoparticle were synthesized by hydrothermal-reduction route. They were characterized by X-ray diffraction analysis, Fourier transform infrared spectroscopy, scanning and transmission electron microscopy and dynamic light scattering. The results showed that certain concentrations of citric acid (CA) are required to obtain only magnetic iron oxides with mean particle sizes around 8 nm. CA acts as a modulator and reducing agent in iron oxide formation which controls nanoparticle size. The XRD, magnetic and heating measurements showed that the temperature and time of hydrothermal reaction can affect the magnetic properties of obtained ferrofluids. The synthesized ferrofluids were stable at pH 7. Their mean hydrodynamic size was around 80 nm with polydispersity index (PDI) of 0.158. The calculated Intrinsic Loss power (ILP) was 9.4 nHm{sup 2}/kg. So this clean and cheap route is an efficient way to synthesize high ILP aqueous ferrofluids applicable in magnetic hyperthermia. - Graphical abstract: Monodispersed aqueous ferrofluids of iron oxide nanoparticles were synthesized by hydrothermal-reduction method with citric acid as reductant which is an efficient way to synthesize aqueous ferrofluids applicable in magnetic hyperthermia. Highlights: Black-Right-Pointing-Pointer Aqueous iron oxide ferrofluids were synthesized by hydrothermal-reduction route. Black-Right-Pointing-Pointer Citric acid acted as reducing agent andmore » surfactant in the route. Black-Right-Pointing-Pointer This is a facile, low energy and environmental friendly route. Black-Right-Pointing-Pointer The aqueous iron oxide ferrofluids were monodispersed and stable at pH of 7. Black-Right-Pointing-Pointer The calculated Intrinsic Loss power of the synthesized ferrofluids was very high.« less
Behshid Behdadfar - One of the best experts on this subject based on the ideXlab platform.
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synthesis of aqueous ferrofluids of znxfe3 xo4 nanoparticles by citric acid assisted hydrothermal reduction route for magnetic hyperthermia applications
Journal of Magnetism and Magnetic Materials, 2012Co-Authors: Behshid Behdadfar, A Kermanpur, Hojjat Sadeghialiabadi, M P Morales, M MozaffariAbstract:Abstract Superparamagnetic and monodispersed aqueous ferrofluids of Zn substituted magnetite nanoparticles (Zn x Fe 3− x O 4 , x =0, 0.25, 0.3, 0.37 and 0.4) were synthesized via hydrothermal-reduction route in the presence of citric acid, which is a facile, low energy and environmental friendly method. The synthesized nanoparticles were characterized by X ray diffraction (XRD) analysis, Fourier transform infrared (FTIR) spectroscopy, scanning and transmission electron microscopy (SEM and TEM) and the dynamic light scattering (DLS) method. The results showed that a certain amount of citric acid was required to obtain single phase Zn substituted magnetite nanoparticles. Citric acid acted as a modulator and reducing agent in the formation of spinel structure and controlled nanoparticle size and crystallinity. Mean particle sizes of the prepared nanoparticles were around 10 nm. The results that are obtained from XRD, magnetic and power Loss measurements showed that the crystallinity, saturation magnetization ( M S ) and Loss power of the synthesized ferrofluids were all influenced by the substitution of Zn in the structure of magnetite. The Zn substituted magnetite nanoparticles obtained by this route showed a good stability in aqueous medium (pH 7) and hydrodynamic sizes below 100 nm and polydispersity indexes below 0.2. The calculated Intrinsic Loss power (ILP) for the sample x =0.3 (e.g. 2.36 nH m 2 /kg) was comparable to ILP of commercial ferrofluids with similar hydrodynamic sizes.
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synthesis of high Intrinsic Loss power aqueous ferrofluids of iron oxide nanoparticles by citric acid assisted hydrothermal reduction route
Journal of Solid State Chemistry, 2012Co-Authors: Behshid Behdadfar, A Kermanpur, Hojjat Sadeghialiabadi, M P Morales, M MozaffariAbstract:Monodispersed aqueous ferrofluids of iron oxide nanoparticle were synthesized by hydrothermal-reduction route. They were characterized by X-ray diffraction analysis, Fourier transform infrared spectroscopy, scanning and transmission electron microscopy and dynamic light scattering. The results showed that certain concentrations of citric acid (CA) are required to obtain only magnetic iron oxides with mean particle sizes around 8 nm. CA acts as a modulator and reducing agent in iron oxide formation which controls nanoparticle size. The XRD, magnetic and heating measurements showed that the temperature and time of hydrothermal reaction can affect the magnetic properties of obtained ferrofluids. The synthesized ferrofluids were stable at pH 7. Their mean hydrodynamic size was around 80 nm with polydispersity index (PDI) of 0.158. The calculated Intrinsic Loss power (ILP) was 9.4 nHm{sup 2}/kg. So this clean and cheap route is an efficient way to synthesize high ILP aqueous ferrofluids applicable in magnetic hyperthermia. - Graphical abstract: Monodispersed aqueous ferrofluids of iron oxide nanoparticles were synthesized by hydrothermal-reduction method with citric acid as reductant which is an efficient way to synthesize aqueous ferrofluids applicable in magnetic hyperthermia. Highlights: Black-Right-Pointing-Pointer Aqueous iron oxide ferrofluids were synthesized by hydrothermal-reduction route. Black-Right-Pointing-Pointer Citric acid acted as reducing agent andmore » surfactant in the route. Black-Right-Pointing-Pointer This is a facile, low energy and environmental friendly route. Black-Right-Pointing-Pointer The aqueous iron oxide ferrofluids were monodispersed and stable at pH of 7. Black-Right-Pointing-Pointer The calculated Intrinsic Loss power of the synthesized ferrofluids was very high.« less
Paul Southern - One of the best experts on this subject based on the ideXlab platform.
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Author's personal copy Suitability of commercial colloids for magnetic hyperthermia
2020Co-Authors: Mathew Kallumadil, Paul Southern, Masaru Tada, Takashi Nakagawa, Masanori Abe, Quentin A. PankhurstAbstract:a b s t r a c t Commercial nanoparticles supplied by Chemicell, Micromod and Bayer-Schering were characterised with regard to their nanocrystalline diameter, hydrodynamic diameter, total iron content and relative ferrous iron content. Additionally, calorimetric measurements were taken using a 900 kHz AC magnetic field of amplitude 5.66 kA/m. It was found that those samples containing relatively high (418%) ferrous content generated a substantially smaller (12% on average) Intrinsic Loss power (ILP) than those samples with a lower ferrous content. Two nominally identical Chemicell samples that differed only in their production date showed significantly different ILPs, attributed to a variation in batch-to-batch crystallite sizes. The highest ILP values in the cohort, ca. Many research groups are exploring the potential of magnetic nanoparticles (MNPs) in biomedical applications One such case where the goal is the use of MNPs in human therapies is magnetic field hyperthermia -a cancer therapy involving the targeted administration of MNPs into the body, accumulation of those MNPs at sites of cancer, and the local heating of those MNPs with an externally applied AC magnetic field. To date, almost all reports in the literature deal with the heating properties of bespoke MNPs. In this paper, we report on a survey of some commercially available MNPs as possible candidates for hyperthermia applications. We also compare the results obtained with previously published data on bespoke MNPs, using a new design rule parameter -the Intrinsic Loss power (ILP), -which in the case of superparamagnetic nanoparticles, and under certain assumed conditions, allows direct comparison of the particle-heating capabilities of materials recorded in response to different AC field strengths and frequencies. The heat rise rate of a magnetic fluid in an AC magnetic field can be described by the phenomenological Box-Lucas equation: where T is the temperature, t is time, A is the saturation temperature and B is a parameter related to the curvature of the heating curve. The product A Â B at t ¼ 0 is also known as the initial heat rise rate and is equivalent to the ratio DT/Dt used in the specific absorption rate (SAR) formula [2]: SAR
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relating magnetic properties and high hyperthermia performance of iron oxide nanoflowers
Journal of Physical Chemistry C, 2017Co-Authors: Philipp Bender, Lara K. Bogart, Jeppe Fock, Cathrine Frandsen, Mikkel Fougt Hansen, Christoph Balceris, Frank Ludwig, Oliver Posth, Erik Wetterskog, Paul SouthernAbstract:We investigated, in depth, the interrelations among structure, magnetic properties, relaxation dynamics and magnetic hyperthermia performance of magnetic nanoflowers. The nanoflowers are about 39 nm in size, and consist of densely packed iron oxide cores. They display a remanent magnetization, which we explain by the exchange coupling between the cores, but we observe indications for internal spin disorder. By polarized small-angle neutron scattering, we unambiguously confirm that, on average, the nanoflowers are preferentially magnetized along one direction. The extracted discrete relaxation time distribution of the colloidally dispersed particles indicates the presence of three distinct relaxation contributions. We can explain the two slower processes by Brownian and classical Neel relaxation, respectively. The additionally observed very fast relaxation contributions are attributed by us to the relaxation of disordered spins within the nanoflowers. Finally, we show that the Intrinsic Loss power (ILP, ma...
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enhancing the magnetic heating capacity of iron oxide nanoparticles through their postproduction incorporation into iron oxide gold nanocomposites
European Journal of Inorganic Chemistry, 2017Co-Authors: Gavin Bell, Lara K. Bogart, Paul Southern, Malini Olivo, Quentin A. Pankhurst, Ivan P. ParkinAbstract:Small variations in the synthesis conditions of iron oxide–gold nanocomposites, made in an aqueous medium by a coprecipitation reaction, have a significant effect on the magnetic‐heating properties of the iron oxide nanoparticles. Citric acid coated magnetite/maghemite (Fe3O4/γ‐Fe2O3) nanoparticles were used as a Turkevich‐style reducing agent and added to varying concentrations of HAuCl4 to form iron oxide–gold nanoparticle composites with Fe/Au molar ratios ranging from ca. 5:1 to ca. 300:1. The magnetic‐heating capacities of the products were measured in a high‐frequency alternating field (peak amplitude 6.6 kA/m, frequency 967 kHz), to determine both the specific absorption rates (SARs) and the Intrinsic Loss powers (ILPs) of the products. The iron oxide (FeOx) precursor presented a moderately high SAR of 33.9 W/gFeOx and an ILP of 0.8 nH m2/kgFeOx, but the iron oxide–gold nanocomposite formed with 0.75 mm HAuCl4 had an almost threefold‐enhanced heating capacity with a SAR of 88.3 W/gFeOx and an ILP of 2.1 nH m2/kgFeOx. This corresponds to an ILP of 3.0 nH m2/kgFe, which is as high as that of any commercially available material to date. This result has implications for the possible postproduction enhancement of the magnetic‐heating capacities of similar iron oxide systems as well as increasing the theranostic potential of such materials through the incorporation of Au nanoparticles, which may act as integrated binding sites for drugs or other beneficial biomolecules.
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on the reliable measurement of specific absorption rates and Intrinsic Loss parameters in magnetic hyperthermia materials
Journal of Physics D, 2014Co-Authors: R R Wildeboer, Paul Southern, Q A PankhurstAbstract:In the clinical application of magnetic hyperthermia, the heat generated by magnetic nanoparticles in an alternating magnetic �耀eld is used as a cancer treatment. The heating ability of the particles is quanti�耀ed by the speci�耀c absorption rate (SAR), an extrinsic parameter based on the clinical response characteristic of power delivered per unit mass, and by the Intrinsic Loss parameter (ILP), an Intrinsic parameter based on the heating capacity of the material. Even though both the SAR and ILP are widely used as comparative design parameters, they are almost always measured in non-adiabatic systems that make accurate measurements dif�耀cult. We present here the results of a systematic review of measurement methods for both SAR and ILP, leading to recommendations for a standardised, simple and reliable method for measurements using non-adiabatic systems. In a representative survey of 50 retrieved datasets taken from published papers, the derived SAR or ILP was found to be more than 5% overestimated in 24% of cases and more than 5% underestimated in 52% of cases.
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suitability of commercial colloids for magnetic hyperthermia
Journal of Magnetism and Magnetic Materials, 2009Co-Authors: Paul Southern, Q A Pankhurst, Mathew Kallumadil, Masaru Tada, Takashi Nakagawa, Masanori AbeAbstract:Commercial nanoparticles supplied by Chemicell, Micromod and Bayer-Schering were characterised with regard to their nanocrystalline diameter, hydrodynamic diameter, total iron content and relative ferrous iron content. Additionally, calorimetric measurements were taken using a 900kHz AC magnetic field of amplitude 5.66kA/m. It was found that those samples containing relatively high (418%) ferrous content generated a substantially smaller (12% on average) Intrinsic Loss power (ILP) than those samples with a lower ferrous content. Two nominally identical Chemicell samples that differed only in their production date showed significantly different ILPs, attributed to a variation in batch-to-batch crystallite sizes. The highest ILP values in the cohort, ca. 3.1nHm 2 /kg, were achieved for particles with hydrodynamic diameters of ca. 70nm and nanocrystalline diameters of ca. 12nm. These compare favourably with most samples prepared in academic laboratories, although they are not as high as the ca. 23.4nHm 2 /kg reported for naturally occurring bacterial magnetosomes.
Hojjat Sadeghialiabadi - One of the best experts on this subject based on the ideXlab platform.
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synthesis of aqueous ferrofluids of znxfe3 xo4 nanoparticles by citric acid assisted hydrothermal reduction route for magnetic hyperthermia applications
Journal of Magnetism and Magnetic Materials, 2012Co-Authors: Behshid Behdadfar, A Kermanpur, Hojjat Sadeghialiabadi, M P Morales, M MozaffariAbstract:Abstract Superparamagnetic and monodispersed aqueous ferrofluids of Zn substituted magnetite nanoparticles (Zn x Fe 3− x O 4 , x =0, 0.25, 0.3, 0.37 and 0.4) were synthesized via hydrothermal-reduction route in the presence of citric acid, which is a facile, low energy and environmental friendly method. The synthesized nanoparticles were characterized by X ray diffraction (XRD) analysis, Fourier transform infrared (FTIR) spectroscopy, scanning and transmission electron microscopy (SEM and TEM) and the dynamic light scattering (DLS) method. The results showed that a certain amount of citric acid was required to obtain single phase Zn substituted magnetite nanoparticles. Citric acid acted as a modulator and reducing agent in the formation of spinel structure and controlled nanoparticle size and crystallinity. Mean particle sizes of the prepared nanoparticles were around 10 nm. The results that are obtained from XRD, magnetic and power Loss measurements showed that the crystallinity, saturation magnetization ( M S ) and Loss power of the synthesized ferrofluids were all influenced by the substitution of Zn in the structure of magnetite. The Zn substituted magnetite nanoparticles obtained by this route showed a good stability in aqueous medium (pH 7) and hydrodynamic sizes below 100 nm and polydispersity indexes below 0.2. The calculated Intrinsic Loss power (ILP) for the sample x =0.3 (e.g. 2.36 nH m 2 /kg) was comparable to ILP of commercial ferrofluids with similar hydrodynamic sizes.
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synthesis of high Intrinsic Loss power aqueous ferrofluids of iron oxide nanoparticles by citric acid assisted hydrothermal reduction route
Journal of Solid State Chemistry, 2012Co-Authors: Behshid Behdadfar, A Kermanpur, Hojjat Sadeghialiabadi, M P Morales, M MozaffariAbstract:Monodispersed aqueous ferrofluids of iron oxide nanoparticle were synthesized by hydrothermal-reduction route. They were characterized by X-ray diffraction analysis, Fourier transform infrared spectroscopy, scanning and transmission electron microscopy and dynamic light scattering. The results showed that certain concentrations of citric acid (CA) are required to obtain only magnetic iron oxides with mean particle sizes around 8 nm. CA acts as a modulator and reducing agent in iron oxide formation which controls nanoparticle size. The XRD, magnetic and heating measurements showed that the temperature and time of hydrothermal reaction can affect the magnetic properties of obtained ferrofluids. The synthesized ferrofluids were stable at pH 7. Their mean hydrodynamic size was around 80 nm with polydispersity index (PDI) of 0.158. The calculated Intrinsic Loss power (ILP) was 9.4 nHm{sup 2}/kg. So this clean and cheap route is an efficient way to synthesize high ILP aqueous ferrofluids applicable in magnetic hyperthermia. - Graphical abstract: Monodispersed aqueous ferrofluids of iron oxide nanoparticles were synthesized by hydrothermal-reduction method with citric acid as reductant which is an efficient way to synthesize aqueous ferrofluids applicable in magnetic hyperthermia. Highlights: Black-Right-Pointing-Pointer Aqueous iron oxide ferrofluids were synthesized by hydrothermal-reduction route. Black-Right-Pointing-Pointer Citric acid acted as reducing agent andmore » surfactant in the route. Black-Right-Pointing-Pointer This is a facile, low energy and environmental friendly route. Black-Right-Pointing-Pointer The aqueous iron oxide ferrofluids were monodispersed and stable at pH of 7. Black-Right-Pointing-Pointer The calculated Intrinsic Loss power of the synthesized ferrofluids was very high.« less
