Stretching of Free Chains Confined in Concave Brush-Coated Nanocylinders

详细信息    查看全文

• 作者：Rong Wang ; Sergei A. Egorov ; Andrey Milchev ; Kurt Binder
• 刊名：Macromolecules
• 出版年：2012
• 出版时间：March 13, 2012
• 年：2012
• 卷：45
• 期：5
• 页码：2580-2587
• 全文大小：491K
• 年卷期：v.45,no.5(March 13, 2012)
• ISSN：1520-5835

文摘

The structure of a free flexible macromolecule confined in a cylindrical nanopore whose wall is coated by a polymer brush is studied by Monte Carlo simulation, varying the grafting density as well as the radius of the cylindrical pore. Because of this confinement, the free chain is stretched in axial direction; while for small grafting densities of the brush the end-to-end distance increases monotonously with decreasing pore radius, a nonmonotonic variation occurs for larger grafting densities. We show that this effect is due to strong interpenetration of the free chain and the brush chains; for very narrow pores a strong layering of cylindrical shells is found, and comparison with self-consistent field calculations (SCF) shows that the latter can predict the nonmonotonic variation in qualitative accord with the simulation. The robustness of the SCF approach is then used to demonstrate the occurrence of the observed 鈥?i>penetration transition鈥?in a broader range of chain lengths and grafting densities.