Self-Assembly of Patterned Porous Films from Cyclic Polystyrenes via the Breath Figure Method

The architecture of polymers plays a crucial role in self-assembly processes. However, the effect of end groups is still not understood thoroughly in many processes including the breath figure method, which is effective for preparing patterned porous films. Herein, we synthesized a series of well-defined cyclic polystyrenes by the combination of atom transfer radical polymerization and azide-alkyne click cyclization and investigated the self-assembly behaviors. The corresponding linear polymers were also compared. Results indicate that polar end groups dramatically improve the regularity of the self-assembled films. For cyclic polystyrenes without any end group, the ability to form patterned porous films is between two groups of linear samples. On the one hand, the results confirm the effect of polar end groups in the breath figure method. On the other hand, the impact of cyclic topology is also verified. This work reveals the nature of stabilization of templating droplets via the polymers by the measurement of the precipitation rate. It is the first time to introduce cyclic polymers to the breath figure process, and the results enlighten us on the molecular architecture design and provide insights into the self-assembly mechanism.