Silica coating of monodisperse hydrophobic magnetite nanoparticles through reverse microemulsion techniques

Download

index.pdf

Date

2012

Author

Ergül, Zeynep

Metadata

Show full item record

Item Usage Stats

312
views

152
downloads

Magnetic nanoparticles find broad applications in biomedical field such as drug delivery, hyperthermia and magnetic resonance imaging (MRI). For these applications magnetic nanoparticles need to be coated with suitable materials which are soluble, biocompatible and nontoxic. Among these materials, silica is the most often used coating material. This thesis is focused on preparation of silica coated iron oxide magnetic nanoparticles. Magnetic iron oxide nanoparticles are synthesized by thermal decomposition method. In the presence of iron acetylacetonate Fe(acac)3, a high boiling point organic solvent and a reducing agent, particle sizes ranging from about 5 nm to 7 nm were obtained. Nanoparticles were characterized by transmission electron microscopy (TEM). The obtained nanoparticles were coated with ultra thin silica shell via reverse microemulsion method. The influence of the amount of Igepal CO-520, NH4OH and TEOS was studied systematically and their amounts were optimized to yield monodisperse and well defined particles. The size of the silica coated magnetic nanoparticles and their agglomerates were determined by TEM images and particle size analyzer (zeta sizer). X-Ray photoelectron spectroscopy (XPS) was used to confirm the presence of silica whenever the coating could not be seen by TEM measurements. Magnetic nanoparticles having 4-6 nm thickness of silica shell were obtained. The results showed that the amount of surfactant Igepal CO-520 played an important role in the reaction system.

Subject Keywords

Nanoparticles., Decomposition method.

URI

http://etd.lib.metu.edu.tr/upload/12614019/index.pdf
https://hdl.handle.net/11511/21275

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

RF Coil Design for MRI Applications in Inhomogeneous Main Magnetic Fields Yılmaz, Ayşen; Eyueboglu, B. M. (2006-09-01) Conventional Magnetic Resonance Imaging (MRI) techniques require homogeneous main magnetic fields. However, MRI applications that are executed in inhomogenous main magnetic fields have been developed in recent years. In this study, RF coil geometries are designed for MRI applications in inhomogeneous magnetic fields. Method of moments is used to obtain the current density distribution on a predefined surface that can produce a desired magnetic field, which is perpendicular to the given inhomogenous main mag...
SNR and total acquisition time analysis of multi-echo FLASH pulse sequence for current density imaging Sadighi, Mehdi; Şişman, Mert; Eyüboğlu, Behçet Murat (2021-12-01) Magnetic Resonance Current Density Imaging (MRCDI) is an imaging modality providing cross-sectionalcurrent densityðJ Þinformation inside the body. The clinical applicability of MRCDI is highly dependenton the sensitivity of the acquired noisy current-induced magnetic flux densityðB zÞdistributions.Here, a novel analysis is developed to investigate the combined effect of relevant parameters of the RFspoiled gradient echo (FLASH) pulse sequence on the SNR level and the total acquisition time (TAT) of theacqui...
Quantum chemical calculations of warfarin sodium, warfarin and its metabolites Tekin, Emine Deniz (Calisir); ERKOÇ, Figen; YILDIZ, İLKAY; Erkoç, Şakir (2008-07-01) The structural, vibrational and electronic properties of warfarin sodium, warfarin and its metabolites have been investigated theoretically by performing the molecular mechanics (MM+ force field), the semi-empirical self-consistent-field molecular-orbital (AM1), and density functional theory calculations. The geometry of the molecules have been optimized, the vibrational dynamics and the electronic properties of the molecules have been calculated in their ground state in gas phase.
Electrical impedance tomography using the magnetic field generated by injected currents Birgul, O; Ider, YZ (1996-11-03) In 2D EIT imaging, the internal distribution of the injected currents generate a magnetic field in the imaging region which can be measured by magnetic resonance imaging techniques. This magnetic field is perpendicular to the imaging region on the imaging region and it can be used in reconstructing the conductivity distribution inside the imaging region. For this purpose, internal current distribution is found using the finite element method. The magnetic fields due to this current is found using Biot-Savar...
Applications of the multifunctional magnetic nanoparticles for development of molecular therapies for breast cancer Aşık, Elif; Güray, Tülin; Volkan, Mürvet; Department of Biotechnology (2015) The understanding of how magnetic nanoparticles (MNPs) interact with living system is one of the prerequisite pieces of information needed to be obtained before any further development for desired biomedical applications. In this study, Cobalt Ferrite magnetic nanoparticles (CoFe-MNPs) in their naked and silica-coated forms were characterized. In vitro cell culture for their likely cytotoxicity and genotoxicity potential were examined. The apoptosis, lipid peroxidation, ROS formation and oxidative stress re...

Citation Formats

Z. Ergül, “Silica coating of monodisperse hydrophobic magnetite nanoparticles through reverse microemulsion techniques,” M.S. - Master of Science, Middle East Technical University, 2012.