以耗散粒子動力學研究溫度對於PS-b-PI 分相形態影響

Study of Temperature Effect on Morphology in PS-b-PI System via Dissipative Particle Dynamics

楊巡(Yang, Hsun)

指導教授 ： 張榮語

國立清華大學/工學院/化學工程學系/碩士(2010年)

摘要

本研究以耗散粒子動力學模擬方法討論固定單體數目之分子鏈段聚苯乙烯-聚異戊二烯雙團聯式共聚合體(PS-b-PI)分相情形。改變鏈段PS/PI組成比例以及平衡溫度下，我們可以觀察到自組裝的現象以及最終平衡形態。初步階段，建立耗散粒子動力學模型之程式，以及將程式模擬結果與文獻比對，PS-b-PI系統，將模擬情形之比對。第二階段，將系統的平衡溫度(T=300K、350K、400K、450K、500K、550K)進行電腦模擬，結果繪製成相圖、將相圖與文獻比對。在同組成分率下設定的溫度由低到高的時候，分相的結果會循著一定的規則變化。由層板分相變為穿孔性層板，由穿孔性層板改為六角柱狀堆積，由六角柱狀堆積改為體心立方堆積，由體心立方堆積變為無序排列。

關鍵字

耗散粒子動力學 ； 雙團聯式共聚合體 ； 形態 ； 溫度

並列摘要

In this research we carried out studies upon phase separation of the polystyrene-polyisoprene diblock copolymers (PS-b-PI) with a fixed number of monomers via dissipative particle dynamics (DPD) simulation. When altering the fractional composition (PS/PI) of the copolymer we observed self-assembly phenomenon and equilibrium morphology of PS-b-PI. The first part of our study is the establishment of the DPD model followed by comparison of simulation results with literature. The second part is altering the simulation equilibrium temperature of system (T= 300K, 350K, 400K, 450K, 500K, 550K), deriving the resulting phase diagram and mapping the results with effective Flory-Huggins parameter chart. Our results show that when the equilibrium temperature is increased while the fractional composition remains constant, the change of equilibrium morphology follows this rule: varying from lamellar layer to perforated lamellar layer, from perforated lamellar layer to hexagonal cylinders, from hexagonal cylinders to body-centered cubic, from body-centered cubic to disorder phase.

並列關鍵字

Dissipative Particle Dynamics ； DPD ； PS-b-PI ； Diblock copolymer ； Morphology ； Temperature

參考文獻

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