超材料為一熱門研究題目,D. R. Smith於2000年發表在微波波段可以產生負折射率的人造複合材料廣為人知。而至今尚未有三維架構且在可見光波段下的負折射超材料。要形成負折射需要同時存在負的電容率(ε<0)與負的磁導率(μ<0),而先前本實驗室利用50 nm金粒子與20 nm金粒子成功合成出核心(金)-衛星(金)奈米金屬叢集結構,經過COMSOL模擬確認其模態為電偶極,表示在可見光波段下對於高頻電場有所反應,因此此論文將探討如何利用高分子電解質製作出對於高頻磁場可見光波段有所反應的核心(聚苯乙烯)-衛星(金)奈米粒子叢集,並利用COMSOL模擬驗證其共振峰值模態在可見光波段下對高頻磁場有所反應。 在研究中發現,核心粒子分散性、不同的複合方式對於奈米粒子叢集結構皆有影響,而本論文嘗試優化各個製程過程中會影響奈米粒子叢集結構之因素,並利用COMSOL模擬驗證此奈米粒子結構在可見光波段下有磁偶極與磁四極之磁反應模態。 未來希望能夠將本論文之奈米粒子叢集結構結合本實驗室先前核(金)-衛星(金)奈米金屬叢集結構,將其共振波段調變至相同頻率,藉此可以形成在可見光波段下三維負折射超材料。
Negative refractive index is a popular topic of metamaterials. In 2000, D.R. Smith published the articical material which has negative refractive index in microwave regime. Until now, there is no metamaterial which has negative refractive index with three-dimensional structure at optical regime. If we want to make the negative refractive index, our structure must simultaneously have negative permittivity(ε<0) and permeability(μ<0). In this report, we assemble a 100 nm polystyrene core particle and 20 nm gold satellite particles through the polyelectroplyte to form a polystyrene core-satellite assembly (PS-CSA) and we proved this PS-CSA has magnetic response in optical regime by using the multipole analysis method.