Effect of polydispersity on the tensile modulus of diblock copolymers in a lamellar phase.
Effect of polydispersity on the tensile modulus of diblock copolymers in a lamellar phase.
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DOI：
10.1063/1.2035082
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发表时间：
2005-09
期刊：
影响因子：
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通讯作者：
Ying Jiang;Rui Huang;Haojun Liang
中科院分区：
文献类型：
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作者：
Ying Jiang;Rui Huang;Haojun Liang
我们计算了由多分散两嵌段共聚物自组装而成的具有层状微结构的纳米材料的拉伸模数。我们观察到拉伸模数K33对拉伸模数的主要贡献，K33的大小主要取决于K33(U)的贡献(内能对K33的贡献)。我们发现，对于我们的多分散模型，较大的多分散性指数(PDI)会削弱材料；我们将这一现象归因于当嵌段的多分散性增加时平衡时较大的片层结构域尺寸以及短链和长链之间的竞争。我们发现，在这个体系中，较长的链加强了材料，但较短的链由于PDI的影响而削弱了材料。剪切模数对拉伸模数的贡献很小。
We have calculated the tensile moduli of nanomaterials having lamellar microstructures prepared through the self-assembly of a polydisperse diblock copolymer. We observed that the extensional moduli K33 provided the major contribution to the tensile modulus and that the value of K33 depended mainly on the contribution of K33(U) (the internal energy contribution to K33). We found that a larger polydispersity index (PDI) weakens the material for our polydisperse model; we attribute this phenomenon to the larger lamellar domain size at equilibrium when the polydispersity of the block increases and to the competition between short and long chains. We found that longer chains in this system strengthen the material, but shorter chains weaken it as a result of the influence of the PDI. The shear modulus contributed negligibly to the extensional moduli.