- 學位論文
合成核殼型奈米顆粒及其應用於剪切增稠流體之研究探討
Synthesis of Core-Shell Nanoparticles and Its Application as Shear Thickening Fluid
摘要
剪切增稠流體(shear thickening fluid)，為非牛頓流體的一種，其特徵為在低剪切速率時黏度較低，表現出液體之狀態，而於高剪切速率下，黏度則會急速上升。此種流體性質可被應用於國防液態裝甲(liquid armor)之研究，即在平日低速活動時呈現有如輕柔衣物的特性，但若突然施予高速衝擊，黏度會瞬間提高，產生固體之特性，達到防護作用。目前液態裝甲主要是以二氧化矽作為剪切增稠流體中之主要顆粒，但研究結果顯示其抗穿刺效果極為有限，僅能抵檔低速外力之撞擊。因此本研究提議將具有剪切增稠性質之二氧化矽合成在高硬度的氧化鋁上，合成核殼型(氧化鋁/二氧化矽)奈米微粒作為其分散相，結合氧化鋁及二氧化矽之優點，有效提升液態裝甲之防護作用。本研究使用溶膠-凝膠法(sol-gel method)將氧化鋁奈米微粒與四乙氧基矽烷(TEOS)進行縮合反應，在氧化鋁奈米微粒上長出二氧化矽外殼，且利用動態光散射粒徑分析儀、穿透式電子顯微鏡及介面電位分析儀量測證明成功的合成出核殼型(氧化鋁/二氧化矽)奈米微粒。再將核殼型(氧化鋁/二氧化矽)奈米微粒利用超音波震盪棒分散在聚乙二醇中並配製成不同體積分率之分散液，利用流變儀(rheometer)觀察二氧化矽披覆在氧化鋁表面上的流變性質，也就是其在高剪切速率下是否有剪切增稠效應，最後探討核殼型(氧化鋁/二氧化矽)奈米微粒之剪切增稠現象應用於液態裝甲之可行性及全面最佳性質。
並列摘要
Shear thickening fluid, a type of non-Newtonian fluid, changes viscosity based on shear rate. It has low viscosity at low shear rates, and high viscosity at high shear rates. Thus, this fluid stays mobile under normal conditions, but swiftly hardens upon high-speed impact, resulting in a material useful in liquid armor. So far, most studies have focused on silica-based material as the primary particles in shear thickening fluids, but they often show limited resistance to puncturing. Herein, an approach to synthesize core-shell (alumina/silica) nanoparticles, which can be used as the dispersed phase in the liquid armor materials. Notably, the combination of alumina and silica materials shows significant advantage for enhancing the protective properties of the liquid armor. The core-shell nanoparticles in this study were synthesized using a sol-gel process wherein the silica shell was grown on alumina nanoparticles via a condensation reaction with TEOS. Subsequently, characterization was performed through dynamic light scattering, TEM, and zeta potential measurements. Rheometer measurements were also made using the as-synthesized nanoparticles (treated via sonication) dispersed in a polyethylene glycol medium with varying volume fractions. Thus, the rheological properties of the core-shell system could be investigated and the shear thickening phenomenon observed at high shear rates. Finally, the application of alumina/silica core-shell nanoparticles in liquid armor and the optimization of their comprehensive feasibility and rheological properties are discussed.
參考文獻
延伸閱讀
- 簡士勛（2013）。氧化鋁及核殼型奈米顆粒應用於剪切增稠流體之研究探討〔碩士論文，國立臺灣大學〕。華藝線上圖書館。https://doi.org/10.6342/NTU.2013.01237
- 李曜全（2009）。可控制粒徑分布型態微、奈米氣懸微粒產生技術之研究〔博士論文，國立臺灣大學〕。華藝線上圖書館。https://doi.org/10.6342/NTU.2009.10423
- 許彩珍（2007）。製備經摻雜奈米粒子與其特性研究〔碩士論文，國立清華大學〕。華藝線上圖書館。https://www.airitilibrary.com/Article/Detail?DocID=U0016-1411200715104169
- 張鈞傑（2006）。自組裝團聯共聚物/奈米無機顆粒超結構之製備與其相轉換研究〔碩士論文，國立臺灣大學〕。華藝線上圖書館。https://doi.org/10.6342/NTU.2006.02810
- 龍順文（2010）。Synthesis of Core-Shell Cu-Sn Nanoparticles by Chemical Reduction Method〔碩士論文，中原大學〕。華藝線上圖書館。https://doi.org/10.6840/cycu201000330