以PS-b-PEO與PS-b-P4VP塊式高分子操控CdS奈米粒子形成二維與三維奈米陣列並探討其對於塊式高分子型態之影響

Abstract

此論文主旨為利用有機雙塊式高分子自身組織成二維與三維週期性結構的特性作為模版，操控無機CdS奈米粒子，形成特定結構之奈米陣列，並探討CdS奈米粒子對塊式高分子結構造成之影響。 在第二章中，利用不同分子量之PS-b-PEO塊式高分子操控CdS奈米粒子形成體心立方(body-center cubic)與六方柱狀(hexagonal-packed cylinders)結構之奈米複材，並探討CdS奈米粒子表面之-OH基對於塊式高分子微結構之影響。CdS奈米粒子破壞PEO domains的結晶特性導致在amorphous-crystalline PS-b-PEO中的奈米複材之最後結構將僅取決於其體積分率。 在第三章中，以不同分子量之PS-b-PEO塊式高分子操控CdS奈米粒子製備形成二維特殊結構CdS陣列，並探討CdS奈米粒子表面之-OH基對於塊式高分子薄膜結構從柱狀結構至球狀結構之轉換。 可利用分子量來操控CdS奈米團的間隔，並可以利用patterned substrate來達到大面積的規則結構。 CdS奈米粒子的光學特性並不會因為塊式高分子操控的影響改變其原本光學特性。 第四章中則利用PS-b-P4VP塊式高分子操控CdS奈米粒子形成層狀結構之奈米複材，並探討CdS表面-COOH基對於塊式高分子結構從柱狀結構至層狀結構之轉換。此種奈米結構轉換結果與文獻中理論推導的計算結果相符合。 我們藉由本論文的研究結果可以得到以下結論，利用奈米粒子與對於塊式高分子之間所造成的分子間作用引力(結晶形成與破壞、形成氫鍵之強弱)，將會影響塊式高分子兩項間的引力參數(interaction parameter)，進而影響奈米複材最後之結構與特性。

In this thesis, 3-D nanostructure of CdS clusters by dispersing pre-synthesized CdS nanoparticles, containing hydroxyl groups on surface, in the PEO block selectively of polystyrene-b-poly(ethylene oxide) (SEO) block copolymers as template in the bulk form was prepared, and the effects of surface-modified CdS nanoparticles on the crystallinity and morphological transformation of bulk SEO block copolymers were discussed in Chapter 2. In the Amorphous-Crystalline Bulk SEO system, CdS nanoparticles hinder crystallization of PEO domains, and induce the composites form a structure decided by the volume fraction only. (BCC structure for VPEO/HSEO = 0.11, and HEX structure for VPEO/LSEO = 0.39) The effects of hydrogen bonding between surface-hydroxylated CdS clusters and PEO chains on morphological transformation of the CdS/SEO thin film were illustrated in Chapter 3. Ordered 2-D spatial arrangement of CdS clusters in monolayered SEO thin films by using solvent selectivity to sequester CdS nanoparticles in PEO domains of SEO block copolymer thin films was fabricated. Large-scale ordered structure of CdS clusters is available by a patterned substrate. Surface-modified CdS nanoparticles maintain their original optical properties. Moreover, the morphological transformation of polystyrene-b-poly(4-vinylpyridine) (S4VP) to a lamellar structure from a cylindrical structure by incorporating CdS nanoparticles were also demonstrated in Chapter 4. CdS nanoparticles, in this case, containing a chemically-active carboxylic acid groups on surface were modified by mercaptoacetic acid and connected to the pyridine groups in the poly(4-vinylpyridine) (P4VP) chains of S4VP block copolymers. This morphological transformation, induced by hydrogen bonding between CdS nanoparticles and P4VP chains, is consistent with the phase diagram predicted by a theoretical study of the copolymer/particle mixture system. We can concluded that the final structure of nanoparticles/bloc copolymers system is also affected by the interaction parameter. The interaction parameter between the two phases in nanoparticles/block copolymers system is related to the intermolecular force between nanoparticles and block copolymers, such as the formation and reduction of hydrogen bonds and crystallization.