Self-assembled structures with crystalline order in aqueous block polymer systems
Block polymers dispersed into a solvent that prefers one block strongly over the other blocks can spontaneously arrange into nanoscale structures, such as spherical or cylindrical micelles. These nanoscale structures can pack into three dimensional crystalline grains. The final properties of a material with crystalline nanostructure are dependent on many factors including the thermal and shear history of the sample. Any additional components to the system may change the nanoscale structure which will consequently change the final mechanical properties. In this work a practical understanding of block polymer phases is established, along with useful processing techniques. Widely accessible rheological techniques are used to demonstrate a unique fingerprint between FCC and BCC crystalline phases. We then demonstrate the importance of shear processing by using large amplitude oscillatory shear to accelerate a crystalline order transition to occur within minutes rather than months. The mobility of proteins through the aqueous channels in block polymer crystals is quantified with a semiautonomous Fluorescence Recovery After Photobleaching microscope built for this work. The outcome of this work is a set of guiding principles to allow for systematic design of a material with a crystalline block polymer structure.
- Doctor of Philosophy (PhD)