Tunable Liquid Crystallinity of Graphene Oxide by Polymer Crystallization

Graphene oxide (GO) can form liquid crystals (LC) in aqueous solution, which can be an advantage for many applications using GO. One of the attractive applications is GO based polymer nanocomposites where GO can act as an effective nanofiller in semicrystalline polymer matrix. Previous studies have shown that polymer can be crystallized on GO surface and thus adding GO controls the polymer crystallinity and changes the macroscopic property of GO. However, less attention has been paid to how crystallizable polymers can conversely alter the liquid crystallinity of GO. Herein, we show that GO LC can be correlated with polymer crystallization. We found that the stability and directionality of GO LC can be affected by the rate of polymer crystallization. The microstructure and rheological property of GO LC are extensively investigated with small-angle X-ray scattering and rheometry experiments at a given temperature profile for polymer crystallization.