Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Preparation and characterization of hydrogen-bonded layer-by-layer polymer films containing magnetic nanoparticles
Download
index.pdf
Date
2014
Author
Khan, Muhammad Alyaan Ahmed
Metadata
Show full item record
Item Usage Stats
207
views
103
downloads
Cite This
Stimuli responsive layer-by-layer (LbL) polymer films are promising materials as platforms for controlled release of functional biological molecules such as drugs, proteins, growth hormones, etc. from surfaces. Recently, there has been a growing interest for preparation of LbL polymer platforms containing superparamagnetic iron oxide nanoparticles for dual functionality, i.e. bioimaging and controlled delivery of biological molecules. Moreover, if superparamagnetic iron oxide nanoparticles are embedded into temperature-responsive polymer films, an external trigger mechanism, i.e. magnetothermal trigger can also be used to release functional biological molecules on demand from the surfaces. The study presented in this thesis presents a strategy to incorporate charged iron oxide nanoparticles into neutral hydrogen-bonded polymer LbL films. First, iron oxide nanoparticles with size smaller than 20 nm were synthesized by co-precipitation technique using ultrasonication during synthesis. Iron oxide nanoparticles were characterized using dynamic light scattering, zeta-potential measurements, Fourier Transform Infrared Microscopy (FTIR) Spectroscopy, X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) imaging. For multilayer assembly, polyvinyl caprolactam (PVCL) and tannic acid (TA) were used as polymer building blocks. PVCL is a hydrogen accepting neutral polymer whereas TA has hydrogen donating hydroxyl groups with a pKa of ~ 8.5. At moderately acidic conditions, TA carries both protonated and ionized hydroxyl groups, thus can interact with PVCL through hydrogen bonding interactions, whereas it associates with positively charged iron oxide nanoparticles through electrostatic interactions. LbL films were constructed at pH 4 by immersing the substrate into solutions of TA, PVCL, TA and iron oxide nanoparticles. This process is repeated in the same order of solutions until desired number of layers is deposited at the surface. Stability of multilayers against pH was examined in detail. Multilayer growth and pH-stability were followed by UV-Visible Spectroscopy. Morphology of the multilayers were characterized using Atomic Force Microscopy (AFM). Information about magnetic properties of multilayers was obtained using Magnetic force Microscopy (MFM). Multilayers of TA/PVCL/TA/iron oxide nanoparticles were highly stable at acidic and slightly basic conditions. Moreover, these multilayers were capable of releasing ciprofloxacin, an antibiotic used for treatment of different bacterial infections in the body, at neutral and slightly basic conditions at body temperature. Release of ciprofloxacin from the multilayers was followed using UV-Visible Spectroscopy. The work in this thesis presents the first example of preparation of temperature responsive hydrogen-bonded multilayers containing magnetic iron oxide nanoparticles. In addition to temperature response, multilayers were capable of releasing ciprofloxacin by a pH trigger. Results obtained in this study form a basis for the development of more advanced responsive multilayer films for theranostic (therapeutic and diagnostic) applications.
Subject Keywords
Nanoparticles.
,
Magnetic materials.
,
Iron oxides.
,
Nanostructured materials.
URI
http://etd.lib.metu.edu.tr/upload/12617720/index.pdf
https://hdl.handle.net/11511/23894
Collections
Graduate School of Natural and Applied Sciences, Thesis
Suggestions
OpenMETU
Core
Ferritin nanocage as a magnetic carrier /
Aslan, Tuğba Nur; Volkan, Mürvet; Department of Chemistry (2015)
There is a large focus on ferritin protein cages due to its biological importance, its behaviour as a useful platform for material synthesis and also providing chemical modification of the exterior surface to create functionality. In this study, iron oxide nanoparticles were synthesized within the cavity of the ferritin (magnetoferritin). Non-radioactive rhenium was incorporated on the protein exterior via conjugation of histidine molecules by using glutaraldehyde crosslinker. 185Re was also bound to magnet...
Characterization and fatigue behavior of Ti-6Al-4V foams
Aşık, Emin Erkan; Bor, Şakir; Department of Metallurgical and Materials Engineering (2012)
Porous Ti-6Al-4V alloys are widely used in the biomedical applications for hard tissue implantation due to its biocompatibility and elastic modulus being close to that of bone. In this study, porous Ti-6Al-4V alloys were produced with a powder metallurgical process, space holder technique, where magnesium powders were utilized in order to generate porosities in the range of 50 to 70 vol. %. In the productions of Ti-6Al-4V foams, first, the spherical Ti-6Al-4V powders with an average size of 55 μm were mixed...
Synthesis, spectroscopic and computational analysis of nickel integrated germanium clusters
Öğün, Sinem Esra; Nalbant Esentürk, Emren; Department of Chemistry (2014)
Nanomaterials are attracting great deal of attention due to their wide range of applications such as in medicine, catalysis and electronics. The use of clusters either as seeds to synthesize larger molecular clusters or in assembled cluster materials is a promising way to prepare new nanomaterials. In particular, the possibility of clusters serving molecular control to design and tuning their properties to fit a particular application makes them more attractive in the search of new advanced materials. There...
Synthesis, functionalization and characterization of gold nanoparticles
Sholanbayeva, Zhanar; Nalbant Esentürk, Emren; Durucan, Caner; Department of Micro and Nanotechnology (2012)
Metallic nanoparticles (NPs) with various elemental composition, size, shape and physical or chemical properties has become active field of research. Among all the metal NPs noble metal ones are receiving much attention due to their special optical properties which make them useful for different applications. Noble metal NPs have bright colors resulting from strong surface plasmon resonance absorption usually in the visible region. The colors are size and shape dependent and provide the tuning of optical pr...
Preparation and surface modification of noble metal nanoparticles with tunable optical properties for SERS applications
Kaya, Murat; Volkan, Mürvet; Department of Chemistry (2011)
Metal nanostructures exhibit a wide variety of interesting physical and chemical properties, which can be tailored by altering their size, morphology, composition, and environment. Gold and silver nanostructures have received considerable attention for many decades because of their widespread use in applications such as catalysis, photonics, electronics, optoelectronics, information storage, chemical and biological sensing, surface plasmon resonance and surface-enhanced Raman scattering (SERS) detection. Th...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
M. A. A. Khan, “Preparation and characterization of hydrogen-bonded layer-by-layer polymer films containing magnetic nanoparticles,” M.S. - Master of Science, Middle East Technical University, 2014.