We have developed a method based on the Mie theory for determining the local polymer concentration inside spherical nanoparticles, thereby obtaining vital information about whether the particles are swelling in the solvent or if they are contracted into a more compact structure. In addition, this method can be used to calculate the number density of the particles, the molecular weight of the particles, and (if $M_n$ of the polymer is known) the aggregation number. The calculations are based on the relationship between the size of the nanoparticles and the turbidity of the sample.

• Received 26 April 2011

DOI:https://doi.org/10.1103/PhysRevE.84.022401