Phase separation of a binary liquid mixture in porous media studied by nuclear magnetic resonance cryoporometry

H 1 nuclear magnetic resonance cryoporometry has been applied to study the low-temperature phase separation of the two components in a binary liquid imbibed in porous glass. The mixture of hexane and nitrobenzene was quenched below both its upper critical temperature and the freezing point of the nitrobenzene. The size distribution of phase-separated liquid domains was observed through their melting point suppression that reveals small droplets of nitrobenzene surrounded by hexane within the pores. If the bottlenecks of the porous network allow, some of these droplets coalesce and thereby completely fill parts of the network.