聚苯胺包覆四氧化三鐵顆粒之製備與研究

本研究之目的為合成聚苯胺包覆四氧化三鐵(PAni-encapsulated Fe3O4)顆粒。首先，以共沉法合成Fe3O4磁性流體，在反應終了後加入月桂酸(lauric acid)作為懸浮劑；經過反覆洗滌與磁場分離後，加入十二烷基磺酸鈉(SDS)作為聚苯胺合成之模板進行原位聚合反應(in-situ polymerization)。實驗中以FT-IR、UV-Vis及XRD鑑定聚苯胺與四氧化三鐵之結構，並證明兩者間的作用力；以TGA、DSC與TEM、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。以此方法所得到的聚苯胺包覆四氧化三鐵懸浮液兼具導電與導磁特性。以聚胺酯作為高分子基材，將經過離心、冷凍乾燥程序的複合粒子粉末與其摻混製成膜材，從事電/磁場屏蔽(100~1000MHz)以及電磁波吸收(2~18GHz)測試。結果發現其效果不若預期，原因包括兩者的合成條件互相抵觸，以及介面活性劑的添加量限制了其應用性等。未來若能自本研究之概念出發，從其他合成機制著手，或以其他的導電高分子取代聚苯胺，也許就能排除這些不利因素，得到具實際應用性的導電/導磁複合材料。

關鍵字

磁性流體；四氧化三鐵；聚苯胺；電磁波吸收；電/磁場遮蔽；原位聚合反應

並列摘要

The aim of this study is to synthesize polyaniline-encapsulated Fe3O4 particles. At first, Fe3O4 ferromagnetic fluid is synthesized by oxidation co-precipitation method, and lauric acid is added into the fluid as emulsifier after reaction. After repeated washing and magnetic separation, SDS is added into the reacting system as templates for in-situ polymerization of polyaniline (PAni). The structure of PAni and polyurethane and the interaction between Fe3O4 and PAni is characterized by FT-IR, UV-Vis spectroscopy and XRD. Furthermore, TGA, DSC, TEM, and SEM are used to analyze thermal properties and morphology of these products, respectively. The magnetic and conductive properties are analyzed by superconducting quantum interference device magnetometer and by the four-probe method. Electric/magnetic field shielding (100~1000MHz) and electro-magnetic wave absorbing (2~18GHz) effectiveness is evaluated by blending these composites with polyurethane resin. However, due to the adverse effect of surfactants and the limited reaction conditions, the products show unexpectedly poor effectiveness. This research leaves open the possibility that the concept of conducting polymer/ ferromagnetic particles combination can be carried out by other mechanisms. If so, its applicability to electromagnetic wave absorption may be accomplished.

並列關鍵字

polyaniline ； electromagnetic wave absorption ； Fe3O4 ； in-situ polymerization ； ferrofluid

參考文獻

1. Bitter, “On inhomogeneities in the magnetization of ferromagnetic materials”, Physical Review, 38, 19, 1930.

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9. J. Shimoiizaka, “Sink-float separator using permanent magnetic and water base magnetic fluid”, IEEE Transactions on Magnetics, 16, 2, 1980.

10. M. Aldissi, Inherent Conducting Polymers, Noyes Data Corp., New Jersey, 1989.

國際替代計量

聚苯胺包覆四氧化三鐵顆粒之製備與研究

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