導電高分子╱中空金屬奈米粒子複合薄膜之合成及其可調變電致色變╱表面電漿整合光學特性

Abstract

利用團聯共聚高分子（block copolymer）軟模板所合成之各式實心金屬奈米粒子，由於粒子表 面具有各種功能性之官能基，再加上粒子本身具有表面電漿共振效應（SPR），深具應用潛力，故廣 泛地受到重視。但對於實心奈米粒子而言，結構因子（包括尺寸、維度、成分、排列）對其SPR 特 性（波峰及波寬）之影響並不顯著。反觀中空金屬奈米粒子，少許之殼層厚度變化便足以使其SPR 產生數百nm 之偏移。因此本研究主要以導電高分子PEDOT:PSS 之電致色變（electrochromism）性 質為主體，搭配中空Ag、Au 與Pt 及其合金（Ag-Au，Ag-Pt）奈米粒子對結構及組裝敏感之SPR 特性，來達到吸光波段調變以及吸光強化之目的。此研究之概念有別於過去利用EC 材料與實心奈 米粒子混摻之研究。 在中空奈米粒子之合成上，基於團隊過去研究的基礎，更進一步利用團聯共聚高分子方法，以 及二階段伽凡尼取代反應（Galvanic Replacement Reaction），來合成特殊多維度、多形貌之高分子表 面修飾中空奈米粒子。並藉由高分子自組裝技術，在玻璃基板上製備二維或三維實心/中空奈米粒子 週期性陣列結構。本計畫擬利用臨場UV-NIR 吸收光譜分析來了解中空奈米粒子合成過程、團聯共 聚高分子自組裝過程、以及其複合薄膜之EC 與SPR 整合光學特性。因此，本計畫充滿了學術、技 術、與應用之挑戰與重要性。

Using block copolymers as soft-templates for solid metallic nanoparticle synthesis in potential applications have attracted much attention due to the features of surface functional groups and surface plasmonic resonance (SPR). However, for ‘solid’ metallic nanoparticles, their SPR properties (including peak shift and broadening) are not so sensitive to the structural factors such as the size, dimension, composition and arrangement. In contrast with sold nanoparticles, ‘hollow’ nanoparticles have demonstrated a much higher SPR sensitivity to their structures, for instance, shell thickness. In this plan, we will combine the electrochromism (EC) of conducting polymers of PEDOT:PSS with the structural sensitive SPR of Ag, Au, Pt, and their alloyed (Ag-Au and Ag-Pt) nanoparticles to have tunable EC/SPR optical responses and an enhancement of optical absorption. Based on our previous studies, we will use block copolymer techniques and the two-step galvanic replacement reaction to synthesize various hollow metallic nanoparticles with different dimensions and morphologies. With the assistance of block copolymers, the prepared hollow nanoparticles will then be dispersed onto the glass substrates periodically under various conditions for the optical characterizations. In addition, the formation mechanism of hollow nanoparticles, the self-assembling process of nanoparticles and polymers as well as the EC/SPR combined properties will be characterized by an in-situ UV-NIR spectroscopy.