氧化銥奈米粒子披覆聚苯乙烯@聚吡咯三層核殼微球之合成與材料特性分析

Abstract

此研究分為兩部分，第一部分在水/乙醇溶液系統下合成聚苯乙烯@聚吡咯微球，並探討添加乙醇對於合成結果的影響。研究結果顯示，反應溶液中含 7%體積百分比的乙醇，明顯改善微球團聚的現象，並且大幅降低聚苯乙烯@聚吡咯微球的變形數量。然而，當乙醇含量超過15%體積百分比時，無法有效降低聚苯乙烯@聚吡咯微球的變形數量。研究第二部分使用最佳比例乙醇/水溶液製備表面官能基化聚苯乙烯@聚吡咯微球(PS@PPyNH2)，所得官能基化微球做進一步做性質的量測，包括掃描式電子顯微鏡(SEM)、表面電位(Zeta potential)、傅立葉轉換紅外光譜(FTIR)與四點探針(4-point probe)。在特定pH值下，PS@PPyNH2微球與氧化釔(IrOx)奈米顆粒具有相反的表面電荷，藉此以靜電作用力吸附氧化銥奈米粒子至PS@PPyNH2微球表面。實驗同時也發現使用不同種類的酸(鹽酸、硝酸)對於氧化銥奈米子吸附有很大的影響。從熱重分析(TGA) 測量結果顯示，在鹽酸作用下，PS@PPyNH2微球表現出較高的氧化銥奈米粒子吸附量。PS@PPyNH2披覆氧化銥奈米粒子微球(IrOx-decorated PS@PPyNH2)更進一步以穿透式電子顯微鏡(TEM)和循環伏安法(CV)分析表面形貌與電化學性質。

In this work, polystyrene microspheres coated with polypyrrole were synthesized using FeCl3 in water/ethanol cosolvent system. The effect of adding different volume percentages of ethanol for synthesis of PS@PPy microspheres was investigated. The results indicated that synthesis of PS@PPy microspheres with 7 vol% of ethanol shows a significant improvement on reducing aggregation and particle deformation ratio. However, the deformation ratio increased again when synthesis of PS@PPy microspheres with more than 15 vol% of ethanol. Amino-functionalized poloyrrole-coated PS microspheres (PS@PPyNH2) were prepared by copolymerization of pyrrole and aminated-pyrrole (PyNH2) in presence of 490 nm and 7 vol% of ethanol. The resulting particles were characterized in terms of their particle size and zeta potential. The PS@PPyNH2 microspheres were further coated with iridium oxide nanoparticles (IrOx NP) via electrostatic interactions at certain pH. Immobilization of IrOx nanoparticles by addition of different acids (HCl and HNO3) was conducted, and the weight loading of IrOx nanoparticles on PS@PPyNH2 microspheres surface was obtained by TGA. Moreover, the electrochemical properties of IrOx-decorated PS@PPyNH2 and PS@PPyNH2 microspheres were further investigated and compared by cyclic voltammetry (CV).