本研究中,首先我們用熱裂解法,以用改變反應溫度並保持反應恆溫溫度與穩定劑的濃度的方式,藉此合成三種不同粒徑的Fe3O4奈米顆粒與3種不同粒徑的CoFe2O4奈米顆粒。將其中一種Fe3O4奈米顆粒藉由吸附有機界面連結分子的方式進行表面改質,並利用界面連結分子末端所帶有的鹵素官能基當作起始劑,來進行活性自由基聚合反應,在Fe3O4奈米顆粒表面包覆polystyrene,形成核殼型奈米顆粒。以此方式製備出來的核殼型奈米顆粒則利用TEM,GPC,FT-IR等儀器測量其性質。 將所合成之7種不同的磁性奈米粒子,分散於矽油之中,配製成7種磁性流體。藉由雙平板的黏度測試儀來測量這7種磁性流體的磁流變性質,藉此了解磁性奈米粒子對於磁性流體的磁流變性質的影響,並掌握控制磁性流體的磁控性質的方法。
In this study, both of Fe3O4 and CoFe2O4 nanopartilces with 3 different sizes were synthesized by varying the reaction temperature and concentration of surfactant during the thermal decomposition reaction of metal complex and high boiling point solvent.One kind of the synthesized Fe3O4 nanopartilces was surface modified by adsorbing a molecular linker which had a alkyl bromide group to act as an initiator for growing polystyrene via atom transfer radical polymerization (ATRP). To form PS@Fe3O4 core-shell like nanoparicles.The thus-prepared magnetite nanparicles were characterized by TEM,GPC,FT-IR. Mix the magnetite nanoparticles with silicone oil to synthesize 7 kinds of ferrofluids and find their magneto rheology characteristics. In this way ,we understanded how magnetite nanoparticles effect the magneto rheology characteristics of ferrofluids.