Theory of Y‐ and Comb‐Shaped Polymer Brushes: The Parabolic Potential Framework,Macromolecular Theory and Simulations

当前位置： X-MOL 学术 › Macromol. Theor. Simul. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Theory of Y‐ and Comb‐Shaped Polymer Brushes: The Parabolic Potential Framework
Macromolecular Theory and Simulations ( IF 1.8 ) Pub Date : 2021-09-12 , DOI: 10.1002/mats.202100037
Inna O. Lebedeva ₁ , Ekaterina B. Zhulina ₂ , Frans A.M. Leermakers ₃ , Sergei S. Sheiko ₄ , Oleg V. Borisov _{1,

2}

Affiliation

The parabolic approximation for self-consistent molecular potential is widely used for theoretical analysis of conformational and thermodynamic properties of polymer brushes formed by linear or branched macromolecules. The architecture-dependent parameter of the potential (topological coefficient) can be calculated for arbitrary branched polymer architecture from the condition of elastic stress balance in all the branching points. However, the calculation routine for the topological coefficient does not allow unambiguously identifying the range of applicability and the accuracy of the parabolic approximation. Here the limits of applicability of parabolic approximation are explored by means of numerical self-consistent field method for brushes formed by Y-shaped and comb-like polymers. It is demonstrated that violation of the potential parabolic shape can be evidenced by appearance of multimodal distribution of the end monomer unit in the longest elastic path of the macromolecule. The asymmetry of branching of Y-shaped polymers does not disturb the parabolic shape of the potential as long as the degree of polymerization of the root segment remains sufficiently large. The same applies to comb-shape polymers with sufficiently long main chain and large number of branching points. For short comb-like polymers multiple modes in the distribution of the end monomer unit of the main chain are observed and related to deviation from the parabolic shape of the potential.

中文翻译：

Y 形和梳形聚合物刷的理论：抛物线势框架

自洽分子势的抛物线近似被广泛用于由线性或支化大分子形成的聚合物刷的构象和热力学性质的理论分析。可以从所有分支点的弹性应力平衡条件计算任意分支聚合物结构的电位的结构相关参数（拓扑系数）。然而，拓扑系数的计算例程不允许明确识别抛物线近似的适用范围和准确性。在这里，通过数值自洽场方法对由 Y 形和梳状聚合物形成的刷子探索抛物线近似的适用范围。证明了潜在抛物线形状的违反可以通过在大分子的最长弹性路径中出现末端单体单元的多峰分布来证明。只要根段的聚合度保持足够大，Y 型聚合物的支化不对称就不会干扰电位的抛物线形状。这同样适用于具有足够长的主链和大量支化点的梳状聚合物。对于短梳状聚合物，观察到主链末端单体单元分布中的多种模式，并与电位抛物线形状的偏差有关。只要根段的聚合度保持足够大，Y 型聚合物的支化不对称就不会干扰电位的抛物线形状。这同样适用于具有足够长的主链和大量支化点的梳状聚合物。对于短梳状聚合物，观察到主链末端单体单元分布中的多种模式，并与电位抛物线形状的偏差有关。只要根段的聚合度保持足够大，Y 型聚合物的支化不对称就不会干扰电位的抛物线形状。这同样适用于具有足够长的主链和大量支化点的梳状聚合物。对于短梳状聚合物，观察到主链末端单体单元分布中的多种模式，并与电位抛物线形状的偏差有关。

更新日期：2021-09-12

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11