This lecture covers the phase separations of polymers in solution, discussing concepts such as C-C bond length, micelles, block-copolymer domain size, and emulsions. It delves into the miscibility of polymers, changes in entropy and enthalpy, and the Flory Huggins theory. The instructor explains the driving forces behind phase separation and the conditions under which it occurs, presenting phase diagrams and discussing the behavior of polymer solutions. The lecture concludes with a comparison between phase diagrams for two fluids and polymer solutions, highlighting the key differences.