結合共溶劑退火法及微接觸式壓印術製備具有微奈米層級結構之團鏈共聚物薄膜

Fabrication of block copolymer thin films with hierarchical ordering upon solvent annealing combined with micro-contact printing

林眉熏(Mei-syun Lin)

指導教授 ： 孫亞賢

國立中央大學/工學院/化學工程與材料工程學系/碩士(2011年)

摘要

本研究以兩種不同分子量的聚苯乙烯聚氧化乙烯(polystyrene-block-poly(ethylene oxide), PS-b-PEO)團鏈共聚合物，藉由混合溶劑退火方法，觀察其微觀相分離結構。藉由控制共溶劑組成成份，誘導PS-b-PEO薄膜內部形成有序微觀相分離結構與排向。然而，由於薄膜易受溶劑膨潤影響而產生非潤濕現象，使得PS-b-PEO薄膜無法維持均一的厚度而產生薄膜破裂，也造成微觀相分離結構無法形成大範圍有序陣列。因此，進一步將薄膜的非潤濕特性結合奈米模板，利用微接觸式壓印與溶劑退火製備具有層級結構之PS-b-PEO薄膜。首先，探討薄膜經由兩種不同極性的混合溶劑退火後，以原子力顯微鏡(AFM)與小角度X光散射儀(GISAXS)觀察及鑑定表面與內部之微相分離結構，其結果顯示，藉由不同混合溶劑的組成比例，可得到多樣性微相奈米結構之薄膜，如六角堆積柱狀結構、層板結構、雙連續相結構；值得一提的是，具有高分子量的PS-b-PEO薄膜在甲苯與丙醇溶劑退火後可形成多樣的微胞結構。經由微米接觸壓印將尾端接有氫氧基之聚苯乙烯均聚物預先以微米陣列方式接枝於基材上，接著將PS-b-PEO旋鍍於聚有微米陣列模板的基材上，可形成具有微米陣列的PS-b-PEO水滴形薄膜。經由溶劑退火後，水滴形薄膜內部的奈米結構受到膜厚與薄膜圓形弧面之影響，使得微相結構由柱狀轉變成非柱狀的結構。

關鍵字

團鏈共聚物 ； 溶劑退火 ； 微接觸式壓印術 ； 薄膜

並列摘要

In the study, I investigated microphase?separated structures of solvent annealed PS-b-PEO thin films of two types of molecular weight in mixed vapors of binary nonpolar/polar solvents. Ordered microphase-separated nanostructures were achieved by controlling solvent annealing conditions, in which one of the key parameters is the compositions of co-solvent vapors. However, the main drawback for solvent annealing is that block copolymer thin films often dewet on top of substrates during solvent annealing in solvent vapors. Thus, large scale microphase?seperated nanostructures with an ordered array could not generate since the thin films became inhomogenous in film thickness due to solvent-indueced dewetting. Moreover, I fabricated micro-patterned droplets that have ordered nanostructures at a nanometer scale by a combinationtorial approach of solvent annealing and micro-contact imprinting. First, I discussed that various morphologies were formed in thin films exposed to vapors of binary nonpolar/polar solvents of different compositions. By an tomic force microscopy (AFM) and grazing-incident small-angle X-ray scattering (GISAXS), I identified that the nanostructures were comprised of vertically-oriented cylinders with hexagonal packing, vertical lamellae and bicontinuous complex domains. Specially, various kinds of micelles were formed, after high-molecular-weight PS-b-PEO thin films were solvent annealed in co-solvent vapors of toluene and propanol. Finally, micro-patterned thin films were prepared by spin coating on substrates that were grafted by a pre-patternned layer of PS brushes by micro-contact imprinting. After solvent annealing, the thin films formed an array of spherical droplets at a microscopic scale. The nanostructures were generated within the spherical droplets. Due to the effect of thickness and radius curvature, the nanostructures transferred from cylinders to non-cylinders.

並列關鍵字

solvent annealing ； micro-contact printing

參考文獻

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