Assembly of Lock-and-Key Colloids Mediated by Polymeric Depletant

详细信息    查看全文

• 作者：Hung-Yu Chang ; Chang-Wei Huang ; Yen-Fu Chen ; Shyh-Yun Chen ; Yu-Jane Sheng ; Heng-Kwong Tsao
• 刊名：Langmuir
• 出版年：2015
• 出版时间：December 8, 2015
• 年：2015
• 卷：31
• 期：48
• 页码：13085-13093
• 全文大小：513K
• ISSN：1520-5827

文摘

Polymer-mediated lock-and-key assembly via depletion attraction is purely a shape-recognition process without any molecular bonding. Since the depletion attraction relates to osmotic pressure and excluded volume, the binding tendency in a dispersion of lock-and-key colloids can be controlled by adjusting the characteristics of polymeric depletants. In this work, dissipative particle dynamics accounting for explicit solvents, polymers, and multiple lock鈥搆ey pairs are performed to investigate the influences of the polymer concentration, chain length, solvent quality, and chain stiffness. As the polymer concentration associated with osmotic pressure is increased, the binding free energy (E_b) between a lock鈥搆ey pair rises linearly and the binding fraction (胃_LK) in the dispersion grows sigmoidally. Moreover, the increases in the chain length, solvent quality, and chain stiffness lead to the expansion of the polymer size associated with excluded volume and thus both E_b and 胃_LK rise accordingly. However, E_b and 胃_LK grow to be insensitive to the chain length for long enough polymer coils but still can be enhanced if the polymer becomes rod-like. As the solvent quality is varied, 胃_LK can be dramatically altered, although the radius of gyration of polymers is slightly changed.