An anisotropic hydrogel with electrostatic repulsion between cofacially aligned nanosheets

摘要: Machine technology frequently puts magnetic or electrostatic repulsive forces to practical use, as in maglev trains, vehicle suspensions non-contact bearings. In contrast, materials design overwhelmingly focuses on attractive interactions, such the many advanced polymer-based composites, where inorganic fillers interact with a polymer matrix improve mechanical properties. However, articular cartilage strikingly illustrates how repulsion can be harnessed achieve unparalleled functional efficiency: it permits virtually frictionless motion within joints, even under high compression. Here we describe composite hydrogel anisotropic properties dominated by between negatively charged unilamellar titanate nanosheets embedded it. Crucial behaviour of this is serendipitous discovery cofacial nanosheet alignment aqueous colloidal dispersions subjected strong field, which maximizes and thereby induces quasi-crystalline structural ordering over macroscopic length scales uniformly large face-to-face separation. We fix transiently induced order transforming dispersion into using light-triggered situ vinyl polymerization. The resultant hydrogel, containing structures that align cofacially flux, deforms easily shear applied parallel yet resists compressive orthogonally. anticipate concept embedding electrostatics material, inspired cartilage, will open up new possibilities for developing soft unusual functions.