  Emulsions comprising isotropic fluid drops within a nematic host are of
interest for applications ranging from biodetection to smart windows, which
rely on changes of molecular alignment structures around the drops in response
to chemical, thermal, electric and other stimuli. We show that absorption or
desorption of trace amounts of common surfactants can drive continuous
transformations of elastic multipoles induced by the droplets within the
uniformly aligned nematic host. Out-of-equilibrium dynamics of director
structures emerge from a controlled self-assembly or desorption of different
surfactants at the drop-nematic interfaces, with ensuing forward and reverse
transformations between elastic dipoles, quadrupoles, octupoles and
hexadecapoles. We characterize inter-transformations of droplet-induced surface
and bulk defects, probe elastic pair interactions and discuss emergent
prospects for fundamental science and applications of the reconfigurable
nematic emulsions.
