Water-soluble nanospheres with poly(acrylic acid) (PAA) coronas were prepared from poly(2-cinnamoylethyl methacrylate)-block-PAA (PCEMA-b-PAA) and P(CEMA-ran-OEMA)-b-PAA, where "ran" denotes the random incorporation of 2-octanoylethyl methacrylate (OEMA) into the PCEMA block. These nanospheres and polystyrene-bloch-PAA micelles uptake :perylene, a polycyclic aromatic hydrocarbon (PAH), from water. The nanospheres or micelles, with the sorbed perylene, are precipitated by CaCl2. These nanospheres may be useful in concentrating PAHs present in trace amounts in water for chemical analysis or in the reclamation of water contaminated by PAHs. Investigated in this article are factors that govern the capacities of the nanospheres and micelles, and the critical calcium concentration for inducing nanosphere or micelle precipitation.