Microdomain Orientation of PS-b-PMMA by Controlled Interfacial Interactions

详细信息    查看全文

• 作者：Sujin Ham ; Changhak Shin ; Eunhye Kim ; Du Yeol Ryu ; Unyong Jeong ; Thomas P. Russell ; Craig J. Hawker
• 刊名：Macromolecules
• 出版年：2008
• 出版时间：September 9, 2008
• 年：2008
• 卷：41
• 期：17
• 页码：6431-6437
• 全文大小：594K
• 年卷期：v.41,no.17(September 9, 2008)
• ISSN：1520-5835

文摘

The microdomain orientation in thin films of cylinder- and lamella-forming diblock copolymers, polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA), was investigated as a function of the film thickness and the composition of random copolymers composed of styrene (S) and methyl methacrylate (MMA), denoted as P(S-r-MMA), that were anchored to the substrate. Using scanning force microscopy (SFM) and grazing incidence small-angle X-ray scattering (GISAXS), the dependence of the microdomain orientation on film thickness around lattice period (or d-spacing, L₀), where the microdomain orientations normal to the film surface could be achieved, showed that the optimal condition for the balanced interfacial interactions (the so-called neutrality in random copolymer) was 0.64 of PS mole fraction (X_PS) for the cylindrical microdomain having narrow compositional range of P(S-r-MMA) from 0.52 to 0.72 of X_PS, whereas for the lamella microdomain it was observed at X_PS = 0.55 ranging extensively from 0.48 to 0.78.