Colloidal dispersions of monodisperse magnetite nanoparticles modified with poly(ethylene glycol)

Barrera, Carola; Herrera, Adriana; Rinaldi, Carlos

doi:10.1016/j.jcis.2008.09.071

Cited by 128 publications

(93 citation statements)

References 51 publications

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“…Hydrophilic molecules are usually polymeric [e.g., poly(ethylene glycol)], that can often linked to nanoparticle cores via silanes [20,21]. Carlos Rinaldi and co-workers [22] synthesized stable colloidal dispersions of monodisperse magnetic nanoparticles in water by the thermal decomposition method, and exchanging the oleic acid molecules on the surface of the particles for PEG-silane chains. Larsen and co-workers [23] prepared silane-PEG-coated MNPs using a simple synthesis method based on the use of biocompatible silane-PEG as a coating agent.…”

Section: Introductionmentioning

confidence: 99%

A new procedure for preparation of polyethylene glycol-grafted magnetic iron oxide nanoparticles

Khoee

Kavand

2014

J Nanostruct Chem

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Magnetic iron oxide nanoparticles (MNPs) have been widely explored for use in biomedical applications. In the present study, iron oxide nanoparticles were connected to methoxy poly(ethylene glycol) (mPEG) via a new method. The mPEG was acrylated at first and Michael reaction was carried out between acrylated mPEG and 3-aminopropyl triethoxysilane as a coupling agent. The chemical structures of modified mPEG were characterized by Fourier transform-infrared spectroscopy (FT-IR) and nuclear magnetic resonance. In the next step, iron oxide nanoparticle was coupled with the above-mentioned adduct. Preparation of magnetic nanoparticles with average particle size of 20-30 nm was proved by scanning electron microscopy. The structure of mPEG grafted on the surface of MNPs was confirmed by FT-IR spectroscopy and thermal gravimetric analysis. The synthesized nanoparticles have the potential to be used in different biomedical applications.

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Section: Introductionmentioning

confidence: 99%

A new procedure for preparation of polyethylene glycol-grafted magnetic iron oxide nanoparticles

Khoee

Kavand

2014

J Nanostruct Chem

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“…Of synthetic polymers, PVP is water-soluble, non-charged, non-toxic, and is used in various medical applications [24]. While there is a potential concern about covalent interaction between hydrophilic polymers and magnetic nanoparticles in order to increase their stability in physiological medium [25][26][27][28][29], PVP coating on Fe 3 O 4 nanoparticles in all previous works has been achieved through noncovalent interaction. Now, polymers grafting of magnetic nanoparticles is one of the most attractive methods of surface modification [30,31].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of PVP-functionalized superparamagnetic Fe3O4 nanoparticles as an MRI contrast agent

Arsalani¹,

Fattahi²,

Nazarpoor³

2010

Express Polym. Lett.

236

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Abstract. The magnetite (Fe3O4) nanoparticles (MNPs) coated with poly(N-vinyl pyrrolidone) (PVP) via covalent bonds were prepared as T2 contrast agent for magnetic resonance imaging (MRI). The surface of MNPs was first coated with 3-(trimethoxysilyl) propyl methacrylate (silan A) by a silanization reaction to introduce reactive vinyl groups onto the surface, then poly(N-vinyl pyrrolidone) was grafted onto the surface of modified-MNPs via surface-initiated radical polymerization. The obtained nanoparticles were characterized by FT-IR (Fourier transform infrared spectroscopy), XRD (X-ray diffraction), TEM (transmission electron microscopy), VSM (vibrating sample magnetometer), and TGA (thermogravimetric analysis). The MNPs had an average size of 14 nm and exhibited superparamagnetism and high saturation magnetization at room temperature. T2-weighted MRI images of PVP-grafted MNPs showed that the magnetic resonance signal is enhanced significantly with increasing nanoparticle concentration in water. The r1 and r2 values per millimole Fe, and r2/r1 value of the PVP-grafted MNPs were calculated to be 2.6 , 72.1, and 28.1(mmol/l) -1 ·s -1 , respectively. These results indicate that the PVP-grafted MNPs have great potential for application in MRI as a T2 contrast agent. Vol.4, No.6 (2010) 329-338 Available online at www.expresspolymlett.com DOI: 10.3144/expresspolymlett.2010.42 region that they are accumulated, and hence cause negative contrast and provide a dark state in the image where the compounds are accumulated [15]. However, the direct use of magnetic nanoparticles as in vivo MRI contrast agent results in biofouling of the particles in blood plasma and formation of aggregates that are quickly sequestered by cells of the reticular endothelial system (RES) such as macrophages [16,17]. Furthermore, aggregated nanoparticles change their superparamagnetic response [7]. Therefore, in order to minimize biofouling and aggregation of particles and escape from the RES for longer circulation times, the nanoparticles are usually coated with a layer of hydrophilic and biocompatible polymer such as dextran [18], dendrimers [19], poly(ethylene glycol) (PEG) [20], and poly(vinyl pyrrolidone) (PVP) [21][22][23]. Of synthetic polymers, PVP is water-soluble, non-charged, non-toxic, and is used in various medical applications [24]. While there is a potential concern about covalent interaction between hydrophilic polymers and magnetic nanoparticles in order to increase their stability in physiological medium [25][26][27][28][29], PVP coating on Fe 3 O 4 nanoparticles in all previous works has been achieved through noncovalent interaction. Now, polymers grafting of magnetic nanoparticles is one of the most attractive methods of surface modification [30,31]. In the present study, we carried out chemical synthesis and characterization of PVP-functionalized magnetite (Fe 3 O 4 ) nanoparticles. Since the PVP was bonded to the surface of magnetite nanoparticles through covalent bonds, the prepared magnetic fluid (ferrofluid) was ve...

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“…For this purpose, energetic interaction forces that govern the system, such as attraction forces (van der Waals interaction) and repulsive forces (osmotic and elastic) were estimated. The contribution of these forces was determined regarding potential energy experienced by two identical spherical particles as a function of their separation distance by Barrera, C., Herrera, A., & Rinaldi, C., (2009), (Park, Huang, Corti, & Franses, 2010).…”

Section: Colloidal Stability Modelmentioning

confidence: 99%

“…For this analysis, the Van der Waals' attraction energy is expressed as a function that depends on the radius of the nanoparticles, the chain length of the surfactant molecule (Oleic Acid, 1.5 nm; Yang, Peng, Wen, & Li, 2010), and the Hamaker constants (Barrera et al, 2009) (Bergström, 1997).…”

Section: Colloidal Stability Modelmentioning

confidence: 99%

Evaluation of colloidal stability, kinematic viscosity and flash point of B10 Diesel/Biodiesel blends using nanostructured additives based on Al2O3 and oleic acid

Herrera

Ojeda

Peñaloza

et al. 2017

CT&F Cienc. Tecnol. Futuro

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A lumina nanoparticles were synthesized by sol-gel method and submitted to thermal treatment at 750 and 1000 °C. X-ray diffraction was used to determine crystal formation with sizes up to 280 nm. To achieve stable suspensions, a nano-additive was mixed with the diesel/biodiesel blends along with oleic acid surfactant to obtain concentrations of nano-additives at 10 and 20 ppm. For this, alumina nanoparticles were firstly mixed with 20 mL of oleic acid by using an ultrasonicator. Then, this mixture was heated at 80°C under constant agitation for 1 hour, and it was subsequently submitted to ultrasound for 30 minutes. Colloidal stability was evaluated according to Deryaguin-Landau-Verwey-Oberbeek (DLVO) theory by analyzing the total interaction energy of the system. Effects on the kinematic viscosity and flash point of the B10 blend were determined according to ASTM D-445 and ASTM D-93 regulations. The application of nano-additives in biodiesel blends showed an increase of the kinematic viscosity from 2.75 cSt to 3.33 cSt at 40°C with 20 ppm of nanoparticles in the B10 blend, while flash point increased from 65 °C to 66 °C. These results could represent a beneficial effect for engines performance due to their better lubricant capacity. On the other hand, fuels with high enough flash point are easy to handle for transportation and storage. Then, the implementation of nano-additives represents a good opportunity for the biofuels industry. ABSTRACTHow to cite: Herrera, Adriana., Ojeda, K.A., Peñaloza, A.D. Rincón, A. Evaluation of Colloidal Stability, Kinematic Viscosity and Flash Point of B10 Diesel/Biodiesel Blends using Nano-structured Additives based on Al2O3 and Oleic Acid (2017 72L as nanopartículas de Alúmina fueron sintetizadas por el método de sol-gel y sometidas a un tratamiento térmico a 750 y 1000 °C. Se utilizó la técnica de difracción de rayos-X para determinar la formación de cristales con tamaños de hasta 280 nm. Con el propósito de producir suspensiones estables, el nano-aditivo fue mezclado con una solución de diesel/biodiesel usando ácido oleico como un surfactante, obteniendo concentraciones de nano-aditivos de 10 y 20 ppm. Para esto, las nanopartículas de Alúmina se mezclaron primero con 20 mL de ácido oleico usando un baño de ultrasonido. Luego, la mezcla se calentó a 80°C bajo agitación constante por 1 hora, y subsecuentemente se llevó al ultrasonido por 30 minutos. La estabilidad coloidal se evaluó de acuerdo a la teoría de Deryaguin-Landau-Verwey-Oberbeek (DLVO) analizando la energía total de interacción del sistema. Los efectos sobre la viscosidad cinemática y el punto de inflamación de las mezclas B10 fueron determinados de acuerdo a las normas ASTM D-445 y ASTM D-93. La aplicación de los nano-aditivos a las mezclas de biodiesel mostraron un incremento en la viscosidad cinemática desde 2.75 cSt hasta 3.33 cSt a 40°C con una concentración de 20 ppm de nanopartículas en la mezcla B10, mientras que el punto de inflamación incrementó desde 65 °C hasta 66 °C. Estos resultados pueden representar ...

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Colloidal dispersions of monodisperse magnetite nanoparticles modified with poly(ethylene glycol)

Cited by 128 publications

References 51 publications

A new procedure for preparation of polyethylene glycol-grafted magnetic iron oxide nanoparticles

A new procedure for preparation of polyethylene glycol-grafted magnetic iron oxide nanoparticles

Synthesis and characterization of PVP-functionalized superparamagnetic Fe3O4 nanoparticles as an MRI contrast agent

Evaluation of colloidal stability, kinematic viscosity and flash point of B10 Diesel/Biodiesel blends using nanostructured additives based on Al2O3 and oleic acid

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