Control of molecular and microdomain orientation in a semicrystalline block copolymer thin film by epitaxy
Control of molecular and microdomain orientation in a semicrystalline block copolymer thin film by epitaxy
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DOI：
10.1021/ma992132m
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发表时间：
2000-06-27
期刊：
影响因子：
5.5
通讯作者：
Thomas, EL
中科院分区：
文献类型：
--
作者：
De Rosa, C;Park, C;Thomas, EL
外延结晶用于控制半结晶三嵌段共聚物薄膜中的分子链取向和微区结构，该共聚物由可结晶聚乙烯（PE）末端嵌段和无定形乙烯-丙丙烯（PEP）中间嵌段组成，其中微相分离是由均匀熔体结晶驱动的，其特征是小角度 和广角X射线衍射。由于结晶 PE 块和苯甲酸 (BB) 基材之间晶胞的晶体学匹配而产生的表面相互作用诱导结晶 PE 块的高取向，从而产生有序的平行层状微相分离结构。嵌段共聚物薄膜的选区电子衍射（SAD）图案以及明场（相衬）和暗场（衍射衬度）透射电子显微镜（TEM）图像证明了表面相互作用引起的优异取向。数据清楚地表明，PE 的链轴（(c) 盖上）平行于微相分离层状表面的法线（(n) 盖上）。
Epitaxial crystallization is utilized to control both molecular chain orientation and microdomain structure in a thin film of a semicrystalline triblock copolymer, composed of crystallizable polyethylene (PE) end blocks and an amorphous ethylene-alt-propylene (PEP) midblock where the microphase separation is driven by crystallization from a homogeneous melt, characterized by small-angle and wide-angle X-ray diffraction. Surface interaction due to a crystallographic matching of unit cells between the crystalline PE block and benzoic acid (BB) substrate induces high orientation of the crystalline PE block, resulting in a well-ordered parallel lamellar microphase-separated structure. The excellent orientation induced by the surface interaction is evidenced by the selected area electron diffraction (SAD) pattern and bright-field (phase contrast) and dark-field (diffraction contrast) transmission electron microscope (TEM) images of the block copolymer thin film. The data clearly show that the chain axis ((c) over cap) of PE is parallel to the normal ((n) over cap) of the microphase-separated lamellar surfaces.