Porous microbeads of low cross-linked polystyrene (PS) grafted with poly(ethylene glycol) chains (PEG) are labeled at the free chain ends with 3-(1,6-diphenyl-1,3,5-hexatrienyl)propionic acid (DPH-PA) and 1-(dimethylamino)naphthalene-5-sulfonic acid (DANS), which probe the polarizability, polarity, and viscosity of their environments. The beads are investigated in a series of pure liquid phases and in acetonitrile/water mixtures by electronic absorption and steady state as well as time-resolved fluorescence spectroscopy. The extent of solvation in the polymer/liquid interphase is characterized from spectral shifts by introducing a solvation fraction which quantifies the relative amount of polymer and liquid in the solvation shell. The rotational mobility of DPH-PA is derived from time-resolved fluorescence anisotropy measurements. Depending on the liquid phase, the rotational correlation times vary strongly between tau(R)=500 ps and 100 ns. The shortest tau(R)-values are found in liquids which are able to solvate both the fluorophore and the polymer, e.g. toluene and acetonitrile. Long correlation times are observed in the presence of aliphatic hydrocarbons, which do not solvate the bead and therefore cannot penetrate into the polymeric frame, and in presence of water, which solvates PEG but not PS and DPH. In contrast, water is able to weakly solvate DANS chemically bound to the polymeric frame.