Segregation of chain ends to the surface of a polymer melt
Segregation of chain ends to the surface of a polymer melt
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链端偏析到聚合物熔体表面
DOI：
10.1140/epje/i2014-14078-1
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
P. Mahmoudi
中科院分区：
文献类型：
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作者：
M. Matsen;P. Mahmoudi
自一致场论（SCFT）用于研究不可压缩聚合物熔体表面的自由连接链，每个链由N个离散单体组成，由任意电位的键连接。由于熵的考虑，末端单体倾向于积聚在靠近表面的狭窄区域（在单体尺度上），这导致末端进一步进入熔体（在分子尺度上）的轻微损耗。由于减少了构型熵可用聚合物表面附近,我们发现一个熵的贡献的表面张力随着聚合度的增加而增加,N .尽管许多数量依赖于精确的债券潜在连接单体,止于表面的多余的极限无限N,远程损耗的函数形式的结束,和N依赖的表面张力是普遍的。
Self-consistent field theory (SCFT) is used to examine the surface of an incompressible polymer melt of freely jointed chains, each consisting of N discrete monomers connected by bonds of an arbitrary potential. As a result of entropic considerations, the end monomers tend to accumulate in a narrow region next to the surface (on the monomer scale), which causes a slight depletion of ends further into the melt (on the molecular scale). Due to the reduced configurational entropy available to polymers in the vicinity of a surface, we find an entropic contribution to the surface tension that increases with the degree of polymerization, N. While many quantities are dependent on the precise bond potential connecting the monomers, the excess of ends at the surface in the limit of infinite N, the functional form of the long-range depletion of ends, and the N dependence of the surface tension turn out to be universal.