  We present results of temperature dependent measurements of dynamics of
micellar nanoparticle - polymer composites of fixed volume fraction and
variable polymer chain grafting density. For nanoparticles with lower grafting
density we observe dynamically arrested state at low temperatures corresponding
to an attractive glass while at high temperature the same system shows
relaxation typical of a repulsive glass. For higher grafting density, the low
temperature dynamics resembles more of a gel which crosses over to a repulsive
glass at high temperature. Possible reasons for such fascinating dynamical
transitions is delineated.
