Pure Anisotropic Hydrogel with an Inherent Chiral Internal Structure Based on the Chiral Nematic Liquid Crystal Phase of Rodlike Viruses

Imparting ordered structures into otherwise amorphous hydrogels is expected to endow these popular materials with novel multiple-stimuli responsiveness that promises many applications. The current contribution reports a method to fabricate pure polymeric hydrogels with an inherent chiral internal structure by templating on the chiral nematic liquid crystal phase of a rodlike virus. A method was developed to form macroscopically homogeneous chiral templates by confinement induced self-assembly in the presence of monomers, cross-linkers and initiators. Polymerization induced gelation was performed without perturbing the elegant 3D chiral organization of the rodlike virus bearing double bonds. Furthermore, a suitable method was found to remove the organic virus template while keeping the desired polymeric replica intact, resulting in a pure polymeric hydrogel with a unique internal chiral feature that originates from the 3D chiral ordering of the cylindrical pores left by the virus. Multiple-stimuli responsiveness has been demonstrated and can be quantified by the change of the pitch of the chiral feature. The chiral structure endows the otherwise featureless hydrogel with a unique material property that might be used as a readout signal for sensing and acts as the basis for responsive, biomimetic nanostructured materials.