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Title:	Size controlled synthesis of surface modified calcium ferrite magnetic nanoparticles
Authors:	Noor Humam Sulaiman Al-Metwali (P70158)
Supervisor:	Mariyam Jameelah Ghazali, Assoc. Prof. Dr.
Keywords:	Nanostructured materials -- Magnetic properties Universiti Kebangsaan Malaysia -- Dissertations Dissertations, Academic -- Malaysia
Issue Date:	26-Nov-2018
Description:	In general, magnetic nanoparticles possess remarkable properties, such as superparamagnetism, coercivity, magnetic saturation, and shape anisotropy. Small particle size presents effective surface that govern the magnetic behaviour of each individual particle. For a superparamagnetic state, the magnetic moment of nanoparticles fluctuates around the axes of magnetisation. Thus, the magnetic nanoparticles display a large magnetic moment with a fast response to the applied magnetic fields. In a drug delivery system, magnetic nanoparticle must be protected with suitable coating materials to reduce agglomeration of nanoparticles and toxicity, which can adversely affect drug properties and prevent the blocking of blood vessels. The methods were used showed difficulty to control the size of nanoparticles due to the long reaction time for sol-gel and reaction temperature for co-precipitation method. Moreover, small particles show a large surface area-to-volume ratio. Hence, most drug deliveries are linked with small particles size below 20 nm to generate a fast drug release. Calcium ferrite (CaFe2O4) nanoparticles are considered as excellent materials in biomedical application. Recent development in synthesis method focuses on controlling the particle size of CaFe2O4 nanoparticles. Additionally, titanium dioxide (TiO2) is an efficient surface-coating material applied to isolate nanoparticles for various biomedical applications. TiO2 is also the most remarkable coating material among all tested polymers and surfactants due to its superior photocatalyst properties, good chemical stability, and biocompatibility. In this work, the development and characterization of CaFe2O4 nanoparticles with TiO2 coating layers were carried out. To achieve this, CaFe2O4 nanoparticles were initially synthesized through three different techniques, namely, sol-gel, auto-combustion, and co-precipitation. The physical properties of synthesized nanoparticles were characterized by using a field emission scanning electron microscope (FESEM), an x-ray diffraction (XRD), and a transmission electron microscopy (TEM). The magnetic property was analyzed by using a vibrating sample magnetometer (VSM). TEM and VSM analyses showed that uncoated CaFe2O4 nanoparticles synthesized using the sol-gel, co-precipitation, and auto-combustion methods presented a size range of 14-20, 10-12, and 5-12 nm, respectively. Further comparison between the three processes showed that the autocombustion was the most suitable method in synthesizing uniform and small-sized of CaFe2O4 nanoparticles. It was found that its magnetic saturation (Ms) was 31.104 emu/g, which was sufficient to enable an external magnetic field to control the movement of nanoparticles within the blood vessels. Furthermore, the coating layer of TiO2 on the CaFe2O4 nanoparticles exerted significant effect on the physical and magnetic properties of the synthesized particles. The Ms of TiO2-coated CaFe2O4 nanoparticle was reduced to 4.34 emu/g, which was almost 10 times lower than that of the uncoated ones. A decrease in Ms retained the superparamagnetic properties with reduced particle induction capability, which can affect the long response time and low particle response to the external force. The size of TiO2-coated CaFe2O4 nanoparticles was in the range of 8-20 nm with few agglomerations. In short, it can be concluded that nanoparticles that synthesized by using auto-combustion is most preferable for improved the physical properties. The presence of TiO2 coating layer also improved the degree of agglomeration, which was beneficial to the magnetic nanoparticle application for future drug delivery system, particular in targeted cancer treatment.,Ph.D.
Pages:	146
Call Number:	TA418.9.N35M495 2018 3 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Engineering and Built Environment / Fakulti Kejuruteraan dan Alam Bina

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