2019-06-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/672252摘要：高分子薄膜具有廣泛的應用範圍，例如可應用於微電子及光學塗層領域。 儘管高分子薄膜可以藉由簡單的溶液加工技術，例如浸塗或旋塗來製造，但是 如何避免薄膜發生後續的除潤現象，而保有長期的穩定性，仍是尚未解決的重 要問題。塗佈形成之高分子薄膜的穩定性與此高分子液體在基材上的自發潤濕 行為，有重要的關聯性。高分子液體在基材上，會呈現不同的潤濕行為，例如 除潤、部分除潤及完全潤濕型態。若此高分子液體不能自發地完全潤濕基材， 則在此基材上所形成之薄膜不易維持長期穩定性。因為高分子膜的除潤會損害 膜功能，所以不論就基礎層面或從塗層應用領域而言，充分了解高分子液體在 基材上的潤濕狀態，是極其重要的。影響高分子在基材上潤濕現象的可能因子 包含 : 高分子化學性質、高分子分子量(長度)、組成結構比、溫度、基材粗糙 度、及基材表面能等。近年來，學者嘗試許多不同的方法，例如在基材表面改 質或藉由在高分子液體中加入極小量的奈米粒子填料，即可改變高分子液體的 潤濕行為，進而抑制由此高分子液體塗佈形成之薄膜的除潤現象。然而，前者 需透過高分子接枝，接枝長度及密度仍待研究；而後者的成效，則依賴於控制 高分子薄膜中奈米粒子的分佈狀況。 在本三年期計畫中，首先我們將使用耗散粒子動力學來研究高分子液體在 基材上的自發潤濕行為。我們預計系統性地研究高分子化學性質、高分子長度、 嵌段高分子組成、溫度、基材粗糙度和基材表面能，對高分子液體在基材上之 潤濕行為的影響，並且特別關注自發形成高分子薄膜(完全潤濕)的條件。接著， 我們將研究基材表面改質對高分子液體在基材上潤濕行為的影響。改質方式為 在基材上接枝一些相容的高分子，藉由改變接枝高分子的長度、密度或混合的 比例，改變基材的表面能，以達到促進熱力學穩定膜的形成。此外，我們也計 劃在高分子液體中加入奈米粒子，研究該液體之潤濕行為的變化；討論奈米粒 子之大小，形狀和濃度，如何影響奈米粒子在高分子薄膜中之分佈，特別是奈 米粒子在薄膜中的表面偏析和內體聚集現象間的轉變。最後，我們將研究奈米 粒子在薄膜中的分佈情形，對薄膜長期穩定性的影響。這些研究成果，可以成 為未來塗層抑制除潤設計的重要資訊。<br> Abstract: Thin polymeric films have been exploited in extensive technological applications, such as microelectronics to optical coatings. Though such films are easy to produce by simple solution processing techniques such as dip or spin coating, their long-term stability against dewetting is a crucial concern that is yet to be completely resolved. The stability of the dip- or spin-coated polymer films depends significantly on the spontaneous wetting behaviors of the polymer liquid on the substrate. Different behaviors, such as dewetting, partially wetting, and completely wetting, can emerge. The polymer films tend to be unstable if the polymer liquid cannot spontaneously and completely wet the substrate. Since dewetting often compromises film functions, a full understanding of the polymer liquid/substrate wetting behaviors is essential both fundamentally and from the standpoint of coating applications. Many factors, such as polymer length, polymer composition, substrate roughness, and surface energy can affect the polymer liquid/substrate wetting behavior. Recently, two general approaches have been proposed for inhibiting dewetting and they involve substrate surface modification by grafting polymers or addition of nanoparticles to the polymer films in extremely small quantities. However, the success of these methods relies significantly on the proper choices of the length and density of the grafting polymers or the control of nanoparticle distribution in the polymer films. In this three-year project, we intend first to use Dissipative Particle Dynamics to study the spontaneous wetting behaviors of polymer liquids on substrates. The effects of polymer species, polymeric length, polymeric composition of block copolymers, temperature, substrate surface roughness and surface energy on the wetting behaviors of various polymer liquids will be systematically investigated, with special attention to acquiring conditions leading to the formation of thermodynamically stable polymer thin films, i.e. complete wetting. Next, we will study the influence of surface modification on the wetting behavior of the polymer liquid. The substrate is modified by grafting compatible polymers onto the surface, and the surface energy of the substrate can be varied by changing the length, grafting density or mixing proportion of the grafted polymer so as to promote the formation of thermodynamically stable film. Then, we plan to investigate the effects of the addition of nanoparticles on the wetting behaviors of the polymer liquids on substrates. Subsequently, the influences of nanoparticle size, shape, and concentration on the phase behavior of a thin film of polymer/nanoparticle blend, especially the crossover between surface segregation and bulk aggregation of the nanoparticles, are explored. Finally, the impact of nanoparticle distribution to the long-term stability of the polymer/nanoparticle thin film will be demonstrated. These results can guide potential design criteria of dewetting suppression for coating applications.高分子薄膜除潤自發潤濕耗散粒子動力學polymer thin filmdewettingspontaneous wettingdissipative particle dynamics