Coil to globule transition for high molecular weight sodium sulfonated polystyrene

We have studied the effect of temperature on the conformation of 500 kDa sodium sulfonated polystyrene (NaPSS) in 4.5M salt solution using Dynamic Light Scattering. The measurements were carried out at different solution temperatures from 25Ž to 5Ž with five degree interval. The solutions were quenched to the desired temperature from 25Ž before measurements were carried out on them. The buffer solution of pH 7.0 with 4.5M of salt and at 25 Ž acts as a ƒÆ-solvent for sodium sulfonated polystyrene. A sharp decrease in chain size was observed at 10Ž indicating a transition from coil to globular state