具磁性奈米結構之氧化鐵/共軛高分子複合材料之合成、性質與應用

Nanostructured Fe3O4 magnetic/conjugated polymer Composites: Synthesis, Properties and Applications

李曉燕(Shiao-Yen Lee)

指導教授 ： 芮祥鵬 ； 王立義

國立臺北科技大學/工程學院/有機高分子研究所/博士(2010年)

https://doi.org/10.6841/NTUT.2010.00126

摘要

本研究之目的為利用氧化鐵為核心分子製備具有導電性及磁性之核-殼型奈米粒子，並探討此類材料的磁性與電性特徵。實驗中使用之製備方法包括：合成一有機介面連結分子，該分子主要含有可與iron oxide進行化學吸附的phosphonoic acid、可作為ATRP聚合反應之起始劑的alkyl bromide及連結兩類官能基的alkyl spacer等三部分；其次將前述之介面連結分子吸附及自組裝於氧化鐵之表面上，形成self-assembled monolayers（SAMs），並藉以將氧化鐵粒子分散且穩定於有機溶劑中，另外同時探討alkyl spacer長度的大小對於SAMs之排列形態與吸附密度的影響；然後利用ATRP方法進行surface-initiated polymerization，將polystyrene成長於奈米粒子表面，並以FT-IR、UV-Vis 及XRD 鑑定導電性高分子與四氧化三鐵之結構，並證明兩者間的作用力；以TGA、TEM與SEM分別鑑定其熱性質與微觀型態；以超導量子干涉磁量儀與四點探針法量測導磁與導電性；隨後以磺酸化反應將polystyrene轉化為親水性之PSSNa；最後再應用template-guided polymerization方法來合成polyaniline或poly(3,4-ethylenedioxythiophene)等導電高分子，並將其纏繞於於親水性高分子鏈段上，形成磁-電性核殼型奈米粒子。由於本方法係以經介面連結分子穩定於溶劑中之磁性粒子為中心，由內向外方式成長高分子鏈及纏繞導電性高分子，因此可確保每一核殼粒子中只含一個磁性粒子，並位於粒子之中心位置。另外，ATRP方法的採用則可讓我們合成分子量分佈狹窄之高分子鏈，並可藉由控制分子鏈之長度精確調控導電高分子殼層之厚度與含量。

關鍵字

導電性高分子 ； 四氧化三鐵 ； 電與磁複合材料 ； 核-殼型納米粒子

並列摘要

In the present study the synthesis of well-defined conducting magnetic poly (3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS)@Fe3O4 core-shell nanoparticles, we was developed via the combination of atom transfer radical polymerization method and in situ counterion-induced polymerization technique. The schematic procedure consists three major steps. Firstly step, the monodispersed Fe3O4 nanoparticles were adsorbed by a monolayer of (2-bromo-2-methylpropanoate)octylphosphonic acid (Br-MPOP) followed by the ATRP from these Br-MPOP. Effective binding between phosphonic acid and metal oxide can therefore cause a steric effect, and then to promote the dispersity of nanoparticles. Notably, the size and thickness of uniform polymer shells formed on the Br-terminated Fe3O4 nanoparticles surfaces can be changed by adjusting the reaction time of ATRP. In the next step, the PS-coated Fe3O4 was then transformed into water-soluble polymers with a PSS structure by soft sulfonation. A thin shell of PSS on the Fe3O4 core not only makes all of the nanoparticles soluble in water, but also yields an effective template for the wrapping of PEDOT chains around the surface of PSS@Fe3O4 nanoparticles. Finally, highly stable PEDOT-PSS@Fe3O4 nanoparticles were prepared via the oxidation polymerization of 3,4-ethylenedioxythiophene (EDOT) by PSS-guided polymerization, yielding core-shell nanoparticles with both conductive and magnetic properties. This approach ensures that each core-shell particle consists of only one iron oxide nanocrystal in its center and uniformly thick polymer shell, enabling the synthesis of hybrid materials with tailored magnetic and conductive features.

並列關鍵字

Conducting polymers ； core-shell nanoparticles ； Fe3O4 ； conducting magnetic hybrids

參考文獻

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