PNIPAAM/銀金屬系統的合成與型態

Abstract

本論文根據PNIPAAM在水溶液中的相轉換特性，設計一系列的實驗，來研究PNIPAAM/銀離子系統中，銀離子與PNIPAAM高分子的作用力，以及還原出來的銀金屬之型態。 藉由FTIR的結果分析，確認了PNIPAAM高分子上的醯胺官能基和銀金屬奈米顆粒以及銀離子之間存在著作用力；並藉由分別在高於和低於LCST兩種狀況下，混合PNIPAAM水溶液及銀離子的方式，確認了PNIPAAM的相轉換過程可以將銀離子困在高分子中，且在處於相分離狀態的PNIPAAM表面仍然存有可以吸附銀離子的醯胺官能基。 之後藉由上面分析的結果，設計不同步驟的原位合成法，來研究不同狀態之下還原的銀金屬形態的不同。在室溫下的反應中，可以生成橢圓到棒狀之間的奈米銀。而在反應溫度高於LCST時，藉由調整在系統中加入銀離子的溫度，可以觀察到不同的銀金屬和PNIPAAM高分子的形態。

In this thesis, in order to study the interaction between PNIPAAM/silver ion in the system, and the morphology of formed silver nanoparticles, a series of experiments were designed based on PNIPAAM’s phase transition feature in aqueous solution. By the results of FTIR analysis confirmed the interaction between the amide functional groups locate on PNIPAAM chain and silver metal nanoparticles or silver ions; and by mixing PNIPAAM solution and silver ions in different temperature, below or above the LCST, the FTIR results shows that the PNIPAAM phase transition process can trap silver ions, and in the globule state of PNIPAAM the a portion of amide functional groups that located at the surface still can interact with silver ion in the water phase. By these analyses, we designed a several different method in- situ synthesis, to study the different morphologies of silver metal, reduction under different condition. In the room temperature reaction, nano-silver shapes between the oval to rod-like. When the reaction temperature is higher than the LCST, by mixing PNIPAAM solution and silver ions in different temperature(which means PNIPAAM in different states), the different morphology of formed nano-silver/PNIPAAM can be observed.