Scaled functions of osmotic compressibility and correlation length of polystyrene in diethyl malonate

The angular distribution of scattered light intensity for polystyrene in diethyl malonate was measured along the isochores near the critical concentration. The zero-angle scattered intensity Ic,oT [i.e., lim_k→0(IcT) and is directly proportional to the isothermal osmotic compressibility χT] and the correlation length ξ were obtained as a function of temperature and composition. The scaled functions of the Ic,oT and ξ were examined as a function of the scaling parameter. The pseudospinodal generalization was found to be valid for even a macromolecular solution. In addition, some considerations concerning the reduced quantities of Ic,oT and ξ in terms of the scaling laws are reported.