Two nematic shells brought in contact coalesce in order to reduce their interfacial tension. We study the defect textures as the combined shell shape evolves. Using large scale computer simulations, we resolve the director field and the defect valence on the doublet, how annihilating defect pairs are selected, and the stage of coalescence at which annihilation occurs os shells of varying sizes (Figure 1 below).
The coupling of orientational order to curvature plays a key role in shaping the structure of a number of important two-dimensional systems, including superfluid films and nematic-coated colloids. Understanding this coupling can help control the morphology of particle-stabilized interfaces for applications ranging from drug delivery systems to structuring in food and cosmetic products.