Interaction Between Polymer Brush-Coated Spherical Nanoparticles: Effect of Solvent Quality
详细信息 查看全文
- 作者：Federica LoVerso ; Sergei A. Egorov ; Kurt Binder
- 刊名：Macromolecules
- 出版年：2012
- 出版时间：November 13, 2012
- 年：2012
- 卷：45
- 期：21
- 页码：8892-8902
- 全文大小：824K
- 年卷期：v.45,no.21(November 13, 2012)
- ISSN：1520-5835
文摘
The interaction between two spherical polymer brushes in solvents of variable quality is studied by molecular dynamics simulation and by self-consistent field theory, varying both the radius of the spherical particles and their distance, as well as the grafting density and the chain length of the end-grafted flexible polymer chains. Both the potential of mean force between the particles as a function of their distance is computed, for various choices of the parameters mentioned above, and the structural characteristics are discussed (density profiles, average end-to-end distance of grafted chains, etc.) It is found that for rather short chain lengths and not too large grafting densities, isolated spherical brushes in the poor solvent regime exhibit incomplete coverage of the nanoparticle, rather than a complete coverage, i.e., a core鈥搒hell structure where the nanoparticle is covered homogeneously by a dense polymeric film. This latter case occurs for long chains and/or high grafting densities. When two such incompletely covered spherical brushes are close by, they form a dense liquid bridge from the collapsed grafted chains, creating an elongated spherocylindrical structure. Then the potential of mean force exhibits a deep minimum, of order 100kBT. However, these structures where two spherical brushes are tightly bound together are out-of-equilibrium structures. Near the 螛 point, a weak binding of spherical nanoparticles which stay essentially undeformed occurs.