Relaxations of Light Scattering in Mixture of PEG-PDMS-PEG Triblock Polymer with Water in Oil Nano-Droplets

Abstract

The effect of a triblock oil soluble polymer (PEG-PDMS-PEG) on the properties of water-in-oil (W/O) droplet microemulsion (R~7.5nm) has been studied as a function of the amount of added polymer. Macroscopically one observes a substantial increase of viscosity with increase of polymer concentration that it is surpassed and effective cross-linking of the droplets takes place. SAXS measurements show that the size of the droplets is not changed by the polymer addition but it induces repulsive interactions ones at high polymer content. One fast (alpha relaxation) and two slow relaxations (beta and gama relaxations) were observed in mixture system by Quasielastic light scattering (QLS). At high polymer content the network formation leads to slowdown of beta and gama relaxations in QLS and increase in the motion of alpha. Moreover, the increasing of midblock length of polymer in mixture systems can increasing the different between slow and fast relaxation.