Kinetics of phase separation and pattern formation in polyelectrolyte and salt solutions
A quest of understanding complex behavior of flexible polyelectrolyte has been made in this thesis. A phase separating system, sodium polystyrene sulfonate and barium chloride, (NaPSS-BaCl2) has been studied with different quench depths around critical temperature. It was found that the complexity of polyelectrolyte system manifests itself as a non classical behavior of phase separation kinetics. One of the striking results was that even in deep temperature quenches, the induction time (lag time) has been always observed. Dynamic light scattering data revealed the formation of aggregates has an intermediate step at length scale of 50nm where the size did not increase appreciably as the population of the continuously increased. In the other part of the thesis, sodium polystyrene sulfonate and sodium chloride, NaPSS-NaCl solutions, can reveal very interesting patterns when a drop of mixture is placed on glass and evaporated. The crystallization of NaCl was mediated with the amount of NaPSS, temperature and humidity. Patterns can be modified and controlled by tuning these parameters.
0794: Materials science