Stability of perpendicular and parallel lamellae within lamellae of multiblock terpolymers.
Stability of perpendicular and parallel lamellae within lamellae of multiblock terpolymers.
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DOI：
10.1021/jp1068335
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发表时间：
2010-10
期刊：
影响因子：
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通讯作者：
Yuci Xu;Weihua Li;F. Qiu;Yuliang Yang;A. Shi
中科院分区：
文献类型：
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作者：
Yuci Xu;Weihua Li;F. Qiu;Yuliang Yang;A. Shi
利用自洽平均场理论的伪谱方法研究了具有等体积分数A和组成对称（BC）(n)B（或（BC）(n)）的多嵌段三元共聚物A(BC)(n)B(或A（BC)(n)）的相行为。这些三聚体可以自组装成层叠的层状相，层状相中有垂直或平行的层状相，并且在平行相中B/C薄层的数量可以变化。这些层状相之间的相对稳定性可以通过χ(AB)N、χ(AC)N和χ(BC)N三个相互作用参数来调节。二维相图，即三维相图的截面，是在我们的计算中确定的。我们的结论是，垂直相只有在χ(AC)N≪χ(AB)N < χ(BC)N的情况下才是稳定的，这与贝茨小组的实验观察结果是一致的。此外，我们的研究结果表明，垂直相的存在在A(BC)(n)B和A(BC)(n)这两种类型的三元共聚物中是通用的，具有不同的n值，即使对于A(BC)(n)的特殊情况，即ABC线性三元共聚物也是如此。
The phase behaviors of multiblock terpolymer A(BC)(n)B (or A(BC)(n)) with equal volume fractions of A and compositional symmetric (BC)(n)B (or (BC)(n)) are investigated by using the pseudospectral method of the self-consistent mean field theory. These terpolymers can self-assemble into hierarchical lamellar phases of perpendicular or parallel lamellae within lamellae, and the number of B/C thin layers in the parallel phase can be varied. The relative stability among these hierarchical lamellar phases can be tuned by the three interaction parameters of χ(AB)N, χ(AC)N, and χ(BC)N. Two-dimensional phase diagrams, the cross sections of the three-dimensional phase diagram, are determined in our calculations. Our conclusion that the perpendicular phase is stable only in the case of χ(AC)N ≪ χ(AB)N < χ(BC)N is consistent with experimental observations by Bates's group. In addition, our results suggest that the existence of the perpendicular phase is generic in both types of terpolymers: A(BC)(n)B and A(BC)(n), with different values of n, even for the special case of A(BC)(n), that is, an ABC linear terpolymer.