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 $\frac{I_{c,o}}{T}$ [i.e., ${\lim }_{k\to 0}\left(\frac{I_c}{T}\right)$ and is directly proportional to the isothermal osmotic compressibility ${\chi }_T$] and the correlation length $\xi$ were obtained as a function of temperature and composition. The scaled functions of the $\frac{I_{c,o}}{T}$ and $\xi$ 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 $\frac{I_{c,o}}{T}$ and $\xi$ in terms of the scaling laws are reported.