Nematic-wetted colloids in the isotropic phase: Pairwise interaction, biaxiality, and defects

We calculate the interaction between two spherical colloidal particles embe dded in the isotropic phase of a nematogenic liquid. The surface of the par ticles induces wetting nematic coronas that mediate an elastic interaction. In the weak wetting regime, wt: obtain exact results for the interaction e nergy and the texture, showing that defects and biaxiality arise, although they are not topologically required. We evidence rich behaviors, including the possibility of reversible, colloidal aggregation and dispersion. Comple x anisotropic self-assembled phases might be formed in dense suspensions.