[Unidirectionally-oriented Membrane Formation of Supra-polysaccharides Sacran and Application to Drug Delivery...

The geometric structures of soft materials can be controlled on the macro-scale using interfacial or mechanical instability, e.g., fingering patterns of viscous liquid and buckling patterns of gels during swelling/deswelling. These patterns can be used as smart materials for capturing/releasing and mass-transportation applications. Here we introduce the emergence of a uniaxially oriented membrane by drying an aqueous liquid-crystalline solution, composed of megamolecular supra-polysaccharides "sacran", from a limited space. By controlling the geometries of the evaporation front, multiple nuclei emerge that grow into upright membranes with uniaxial orientation. Notably, the uniaxially orientated membrane composed of rod-like microdomains is rationally formed along the dynamic three-phase contact line. Besides, the membrane macroscopically partitions the three-dimensional cuboid cell for evaporating the aqueous solution. We envision that such a uniaxially oriented membrane can be used as soft biomaterials such as dialysis membranes with directional controllability in medical and pharmaceutical fields.