SEGMENT DENSITY DISTRIBUTION OF SYMMETRICAL DIBLOCK COPOLYMERS AT THE INTERFACE BETWEEN 2 HOMOPOLYMERS AS REVEALED BY NEUTRON REFLECTIVITY
SEGMENT DENSITY DISTRIBUTION OF SYMMETRICAL DIBLOCK COPOLYMERS AT THE INTERFACE BETWEEN 2 HOMOPOLYMERS AS REVEALED BY NEUTRON REFLECTIVITY
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DOI：
10.1021/ma00007a020
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发表时间：
1991-04-01
期刊：
影响因子：
5.5
通讯作者：
SATIJA, SK
中科院分区：
文献类型：
--
作者：
RUSSELL, TP;ANASTASIADIS, SH;SATIJA, SK
用中子反射率法研究了对称的聚苯乙烯（PS）和聚甲基丙烯酸甲酯（PMMA）的嵌段共聚物P（S-b-MMA）的链段密度分布。选择性标记的P（S-b-MMA）或PS或PMMA与氘块提供了必要的对比度，以隔离在界面处的组件的段的分布。从一系列的实验结果被用来解决一组同时的线性方程组，产生的PS和PMMA段的均聚物和共聚物在界面处的段密度分布。结果发现，PS和PMMA段之间形成的界面可以用双曲正切函数描述，有效宽度为75埃。该宽度比在不存在二嵌段共聚物的情况下在PS和PMMA均聚物之间以及在本体中纯P（S-b-MMA）的PS和PMMA层状微区之间发现的宽度宽50%。PS和PMMA均聚物在界面区域有明显的渗透，共聚物在均聚物界面处所占的面积比共聚物在本体层状结构中所占的面积大30%。
The segment density distribution of symmetric, diblock copolymers of poly(styrene), PS, and poly(methyl methacrylate), PMMA, denoted P(S-b-MMA), were investigated by neutron reflectivity. Selective labeling of either block of the P(S-b-MMA) or of the PS or PMMA with deuterium provided the contrast necessary to isolate the distribution of the segments of the components at the interface. Results from a series of experiments were used to solve a simultaneous set of linear equations that yielded the segment density profiles of the PS and PMMA segments of the homopolymers and copolymers at the interface. It was found that the interface formed between the PS and PMMA segments could be described by a hyperbolic tangent function with an effective width of 75 angstrom. This width is 50% broader than that found between the PS and PMMA homopolymers in the absence of the diblock copolymer and between the PS and PMMA lamellar microdomains of the pure P(S-b-MMA) in the bulk. A significant penetration of the PS and PMMA homopolymers into the interfacial region was also found. The area occupied by the copolymer at the interface between the homopolymers is 30% larger than that of the copolymers in the bulk, lamellar microstructure.