Summary: | 碩士 === 國立中興大學 === 化學系 === 91 === To extend the utility of nanoparticles in different analytical fields, methods to generate magnetic nanoparticles have been proposed in recent years. The purpose in development of methods to produce magnetic nanoparticles is simply that magnetic nonoparticles exhibit the unique properties such as easily to be concentrated and manipulated through external magnetic fields. To broaden the application of this type of materials, surface modifications of the magnetic nonaparticles have also been proposed through chemical bonding methods. The tedious modification process limits the usage of the modification methods in the literature.
To improve the method in production of magnetic nanoparticles and to simplify the surface modification procedures, a new method in production of magnetic nanoparticles was proposed in this work. In this method, silver ion was used as oxidation agent to oxidize ions of Fe(II) to form a solution that containing both Fe(II) and Fe(III) ions. After precipitated with ammonia hydroxide, magnetic nanoparticles containing silver metals can be produced. By this way, the modifications of the magnetic nanoparticles were much easier than literature methods and the procedure to produce magnetic nanoparticles was also simplified. To study the morphology of the produced nanoparticles by different formula, scanning electron microscope was used. Results indicated that nanoparticles in diameter of few nm to around 200 nm could be produced using proper formula. To examine the amount of silver in the magnetic nanoparticles, energy dispersive X-ray spectrometry (EDS) was used. The results indicated that formula influenced the amount of silvers in the nanoparticles strongly but the distribution of the silver in any of the formula was highly homogenous. To further provide that the active amount of silver on the surface of the nanoparticles, thio containing compounds was used to react with the produced nanoparticles. The IR signals of the thio compounds were used as an indication of the amount of silver on the surface of the magnetic nanopartilces. Results indicated that the surface of magnetic nanoparticles contained large amount of silver and can be easily chemical modified by the silvers.
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