Two nematic shells brought in contact coalesce in order to reduce their combined interfacial tension, and, following this topological transition, relax to an equilibrium state. In this work, we study the defect textures as the combined shell shape evolves. By varying the sizes of the shells, we perform a quasistatic investigation of the director field and the defect valence on the doublet. Regimes are found where positive and negative defects exist due to the large negative Gaussian curvature at the neck. Using large-scale computer simulations, we determine how annihilating defect pairs on coalescing shells are selected and the stage of coalescence at which annihilation occurs.

• Received 6 January 2014

DOI:https://doi.org/10.1103/PhysRevE.89.052504