【作者】 阎长江；

【导师】 王铀；

【作者基本信息】 哈尔滨工业大学 ， 材料物理与化学， 2010， 硕士

【摘要】 对于工程学中应用范围较广的介观和纳米结构,聚合物薄膜去润湿的自发形态是一种有应用价值前景的方法。去润湿在基底的过程是以一定范围的尺寸孔洞形成并生长,最终,产生的各向同性孔洞合并为液滴的聚集态。这种去润湿结构的平均尺寸以及主导波长均取决于初始膜的厚度和界面张力的大小。然而,最终去润湿结构的随意性和缺少长程有序性,阻碍着去润湿作为一种可行性的表面图案技术应用于工程学微结构。因而,在器件制造的潜在应用价值上,将如何使长程有序和调控去润湿结构图案是一大挑战。本论文主要研究了嵌段聚合物薄膜在由无水乙醇、蒸馏水和二甲苯组成的混合溶剂熏蒸作用下的去润湿行为,并且发现苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)在该混合溶剂的熏蒸作用下,发生去润湿形成了稳定的分层结构——“蛋糕”结构,该结构在微纳米电子器件结构中有重要的应用前景。借助光学显微镜和原子力显微镜等实验手段来研究高分子溶液膜的去润湿行为:分析并探讨了薄膜厚度、温度和湿度对SBS薄膜去润湿形成“蛋糕”结构的影响,当厚度小于15nm,温度在20～40℃之间,湿度在30-60%范围内为最佳条件,并发现混合溶剂是一种新的机理诱导薄膜去润湿。这种混合溶剂诱导去润湿过程由渗透、取代、合并和聚集来完成,不同于以往的热诱导去润湿和良溶剂诱导去润湿。总之,通过对这种混合溶剂诱导聚合物去润湿图案“蛋糕”结构形成的影响因素和机理的简单讨论,为制备可调控有序纳米微结构模板的新工艺提供了依据。更多还原

【Abstract】 Morphological self-organization in dewetting of a thin polymer film is a promising method for engineering meso- and nanoscale structures over large areas. Dewetting on a substrate progresses with the formation and growth of randomly placed holes with a certain mean length-scale.Eventually, coalescence of holes produces an isotropic collection of droplets. The average diameters of the dewetted structures as well as their dominant wavelength depend on the initial film thickness (h0) and interfacial tension of the polymer film. However, randomness of the final dewetted structures and lack of long range order hinders the utility of dewetting as a viable surface patterning technique for engineering of small structures. Thus, the challenge is to bring long-range order and alignment to the dewetted structures with potential applications in fabrication of devices.In this present paper, we had studied the thin polymer film dewetting behavior under the fumigation of three-phase evenly mixed solvent, which is composed if ethanol, distilled water and xylene. We found that only styrene-butadiene-styrene block copolymer(SBS) of mixed xylene solvent film under the fumigation of that mixed solvent had taken place dewetting and assembled a stable hierarchical structure---the cake-like structure. Such structures are of importance in view of their potential applications in micro-and nano-electronic devices.In this work, we use optical microscopy and atomic force microscopy to investigate the dewetting behavior of the thin polymer solution film。We work on the effect of the thickness of SBS, temperature and humidity on the dewtting. The results manifested that the SBS xylene thin film can fabricate ordered cake-like structure only when the thickness of the film is less than 15nm, and temperature is between 20℃and 40℃.We use water and ethanol and xylene as mixed solvent to study the mixed solvent induced dewetting process. It is found that mixed solvent induced the dewetting of the thin polymer by a new mechanism. The process of the mixed solvent induced dewetting may first undergo penetration, followed by replacement, coalescent, and finally aggregation. It can be seen that the mechanism of the mixed solvent induced dewetting is different from that of the thermal dewetting and usual good-solvent-induced dewetting.In a word, through a simple discussion of this mechanism, we can provide a theoretical basis for a new method to fabricate ordered micro/nanostructures pattern and templates.更多还原