Citric-acid-coated magnetite nanoparticles for biological applications

Racuciu, M.; Creangă, Dorina; Airinei, Anton

doi:10.1140/epje/i2006-10051-y

Cited by 219 publications

(128 citation statements)

References 16 publications

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“…We observed that for the synthesis in which we use the solvent, the surfactant can be removed better compared to syntheses without solvent -but not totally. As we do not want risk the increase of the particle size by thermal treatment for the removal of organic residues, we tested another 'washing' method called "ligand exchange" [30][31][32]. For this ligand exchange, we start by collecting the material first by using centrifugation after the synthesis.…”

Section: Washing Procedures Of Limnpo 4 Nanoparticlesmentioning

confidence: 99%

Enhanced electrochemical performance of <30 nm thin LiMnPO4 nanorods with a reduced amount of carbon as a cathode for lithium ion batteries

Kwon

Fromm

2012

Electrochimica Acta

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5-10 nm thin rod shaped LiMnPO 4 nanoparticles are synthesized by an improved thermal decomposition method. The synthesis parameters such as the concentration of surfactants, reaction temperature and time, as well as the presence of a solvent play a critical role in the formation of spherical, thin or thick nanorods, and needle-shaped particles of LiMnPO 4 . A washing procedure to efficiently eliminate the surfactants attached to the surface of LiMnPO 4 nanoparticles is presented, avoiding thermal treatment at high temperatures. A nanocomposite LiMnPO 4 electrode provides a discharge capacity of 165 mAh/g at 1/40 C and 66 mAh/g at 1 C with only 10 wt% of total carbon additive. The characteristics of as-synthesized and low amount of carbon coated LiMnPO 4 are described as well as their electrochemical properties.

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Section: Washing Procedures Of Limnpo 4 Nanoparticlesmentioning

confidence: 99%

Enhanced electrochemical performance of <30 nm thin LiMnPO4 nanorods with a reduced amount of carbon as a cathode for lithium ion batteries

Kwon

Fromm

2012

Electrochimica Acta

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“…CA can prevent the aggregation of magnetic particles effectively owning to the steric and electrostatic repulsive barrier of the ionized layer of citrate coating on magnetite or maghemite [19][20][21][22][23][24]. In general, empirical doses, sometimes huge amounts [19,20,24] are simply added to magnetite just after precipitating nanoparticles. Our adsorption study showed that the high affinity limit is reached at ∼0.1 mmol CA on 1 g magnetite (Fig.…”

Section: Humate and Citrate Adsorption On Magnetite Nanoparticlesmentioning

confidence: 99%

Surface charging, polyanionic coating and colloid stability of magnetite nanoparticles

Hajdú

Illés

Tombácz

et al. 2009

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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a b s t r a c tThe formation of small and large molecular polyanionic coating on the surface of magnetite (Fe 3 O 4 ) nanoparticles and their role in the stability enhancement of aqueous magnetic fluids are compared. Magnetite was synthesized and stabilized with citric (CA) and humic (HA) acids. The macromolecular HA, a notable fraction of the natural organic matter (NOM), contains mainly carboxylic groups similarly to the CA, and both acids are able to form surface complexes on the ≡Fe-OH sites of iron oxides. The pHdependent charge state of particles and their aggregation were quantified, and the enhanced salt tolerance of stabilized systems was studied. The dynamic light scattering (DLS) method was used to characterize colloidal stability under different conditions. The average particle size and electrophoretic mobility were measured, and the electrolyte tolerance was tested in coagulation kinetic measurements. The colloidal stability of magnetite dispersions depends sensitively on the pH and the concentration of organic acids present. The trace amount of HA neutralizes the positive charges on magnetite surface under acidic condition only in part, and so it promotes the aggregation between the particles having both positive sites and negative humate patches on the surface. Above the adsorption saturation, the surface becomes completely covered causing the reversal of charge sign and overcharging of nanoparticles. The magnetite nanoparticles become stabilized in a way of combined steric and electrostatic effects. The thicker layer of macromolecular HA provides better electrosteric stability than that of CA coating. However, in the presence of either CA or HA, the dissolution of magnetite is enhanced due to the complexation of iron ions in the aqueous medium.

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“…Magnetic nanoparticles sources were consistent with magnetite stabilized with citric acid (CA) and respectively sodium oleate (SO), that were supplied as adequate volumes from various dilutions of the corresponding aqueous magnetic fluids (CA-MF and SO-MF) [15][16]. The dilutions (in distilled water), that favored the magnetite reversible complexation with the drug molecules, were: C1 = 1 ml CA-MF + 9 ml water; C2 = 2 ml CA-MF + 8 ml water; C3 = 4 ml CA-MF + 6 ml water for magnetitecitric acid complexation with rifampicin; C4 = 5.0 ml SO-MF + 5.0 ml water; C5 = 2.5 ml SO-MF + 7.5 ml water; C6 = 1.25 ml SO-MF + 8.75 ml water for magnetite-sodium oleate complexation with sodium diclofenac.…”

Section: Methodsmentioning

confidence: 99%

Experimental investigation on blood magnetic contamination in the presence of drug molecules

Creangă

Iacob

Nădejde

2009

J. Phys.: Conf. Ser.

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Abstract. The purpose of the present project was to study the interference of magnetic nanoparticles with drug molecules -rifampicin, used in lung infectious disease and respectively, sodium diclofenac, an antiinflammatory steroid. The controlled magnetic contamination was accomplished using colloidal nanoparticles supplied from diluted magnetic fluids. Various concentrations of diluted aqueous magnetic fluids, based on magnetite cores coated with citric acid and respectively sodium oleate, were tested. The experiment was focused on the capacity of the magnetic nanoparticles to form reversible complexes with the drug molecules, as well as on the monitoring of the nanoparticle-drug complex dynamics, under the action of external magnetic field. The level of released rifampicin ranged between 4 mg/100 ml and 7 mg/100 ml for the magnetic exposure of 20 mT, while the sodium diclofenac decomplexation level was not higher than 2.5 mg/100 ml under magnetic exposure of 60 mT. The experimental arrangement was proved to be an adequate model for the dynamical study of magnetite reversible complexation with drug molecules, evidencing certain specific values of drug concentration and magnetic field induction that favour such interactions.

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Citric-acid-coated magnetite nanoparticles for biological applications

Cited by 219 publications

References 16 publications

Enhanced electrochemical performance of <30 nm thin LiMnPO4 nanorods with a reduced amount of carbon as a cathode for lithium ion batteries

Enhanced electrochemical performance of <30 nm thin LiMnPO4 nanorods with a reduced amount of carbon as a cathode for lithium ion batteries

Surface charging, polyanionic coating and colloid stability of magnetite nanoparticles

Experimental investigation on blood magnetic contamination in the presence of drug molecules

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