Living Polymer Systems at a Solid Substrate: Computer Simulation of a Soft, Coarse-Grained Model and Self-Consistent Field Theory
Living Polymer Systems at a Solid Substrate: Computer Simulation of a Soft, Coarse-Grained Model and Self-Consistent Field Theory
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固体基质上的活性聚合物系统：软、粗粒度模型和自洽场论的计算机模拟
DOI：
10.1021/acs.macromol.5b01055
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发表时间：
2015
期刊：
影响因子：
5.5
通讯作者：
M. Müller
中科院分区：
文献类型：
--
作者：
D.-W. Sun;M. Müller
采用基于粒子模拟的软、粗颗粒模型和自洽场理论(SCFT)，研究了在体相和薄膜中均有环形成的致密活性聚合物体系的性质。总体上，我们的结果证实了环状聚合物的分子量分布呈现指数衰减和幂规律的组合。线性链的指数分布几乎不受成环的影响，只有相应的平均相对分子质量略有降低。在较低的链段密度下，环状聚合物的单体比例增加。在薄膜中，环的形成不影响窄界面的宽度，在那里段密度上升到体值。由于环状聚合物的分子伸展比直链的分子伸展小，因此宽界面的空间范围减小。在窄界面上，我们发现局部成环受到五个方面的影响：(1)固体底物对链构象的镜像和反向折叠(Silberberg论点)以及其他四个方面，即(2)降低链段密度，(3)链末端的富集化，(4)非键合单体的明显分离，(5)环聚合物的降维。在宽相界面上，局部成环主要由第一个方面促进。通过比较基于粒子的模拟结果和SCFT的结果，我们在宽界面上观察到了很好的一致性，但是局部结构的不同导致了窄界面上的差异。此外，SCFT结果表明，薄膜厚度的减小增加了薄膜内整体环的形成。
Using particle-based simulation of a soft, coarse-grained model and self-consistent field theory (SCFT), we investigate the properties of dense living polymer systems with ring formation both in the bulk and in thin films. In the bulk, our results confirm that the molecular weight distribution of ring polymers exhibits a combination of an exponential decay and a power law. The exponential molecular weight distribution of linear chains is hardly affected by ring formation, only the corresponding mean molecular weight is slightly reduced. At lower segment density, the fraction of monomers of ring polymers is increased. In thin films, ring formation does not influence the width of the narrow interface, where the segment density rises to the bulk value. Since the molecular extension of ring polymers is smaller than that of linear chains, the spatial extent of the wide interphase is, however, reduced. In the narrow interface, we find that the local ring formation is affected by five aspects: (1) the mirroring of chain conformations and back-folding by the solid substrate (Silberberg argument) and other four aspects at the solid substrate, i.e., (2) the reduced segment density, (3) the enrichment of chain ends, (4) the pronounced segregation of nonbonded monomers, and (5) the reduced dimensionality of ring polymers. In the wide interphase, the local ring formation is enhanced mainly by the first aspect. By comparing the results from the particle-based simulation and SCFT, we observe good agreement in the wide interphase, but the difference in the local structure leads to differences in the narrow interface. Additionally, the SCFT results show that a decrease of the film thickness increases the global ring formation within the thin film.
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影响因子：
5.5
作者：
Ranjan, Amit;Qin, Jian;Morse, David C.
通讯作者：
Morse, David C.
平衡聚合物的约束：场论模型和平均场解
DOI：
--
发表时间：
2006
期刊：
影响因子：
--
作者：
Edward H. Feng;G. Fredrickson
通讯作者：
G. Fredrickson
DOI：
--
发表时间：
1986
期刊：
Physical review. A, General physics
影响因子：
--
作者：
Petschek;Pfeuty;Wheeler
通讯作者：
Wheeler
DOI：
--
发表时间：
1999
期刊：
Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics
影响因子：
--
作者：
Marcus Müller;J. Wittmer;Michael E. Cates
通讯作者：
Michael E. Cates
DOI：
10.1039/c0cp02868a
发表时间：
2011-05
期刊：
Physical chemistry chemical physics : PCCP
影响因子：
--
作者：
M. Müller;B. Steinmüller;K. Daoulas;A. Ramírez-Hernández;J. D. de Pablo
通讯作者：
M. Müller;B. Steinmüller;K. Daoulas;A. Ramírez-Hernández;J. D. de Pablo