Well-defined block copolymers of poly(ethylene glycol)-block-polystyrene (PEG-b-PS) were synthesized by atom transfer radical polymerization with predetermined molecular weights and narrow molecular weight distributions (1.06-1.08). The single crystals of PEG-b-PS copolymers were grown in chlorobenzene/octane mixed theta solvent using self-seeding technique. The effect of self-seeding temperature (T (s)) on single crystal lateral size was evaluated. The atomic force microscopy (AFM) height images were indicative of increasing the single crystal lateral sizes, which were of several microns, via elevating T (s). The non-ideal structures were increasing by moving away from the optimized T (s) (41.5 A degrees C). Here, we studied the transition point between non-interaction and interaction regimes in a mixed theta solvent for PS as well. The impact of the PS block hindrance and the influence of crystallization temperature on thickness, tethering density and reduced tethering density of PS brushes were also investigated. Although these factors did not have the same effect on thickness and tethering density, the trend of their influence on reduced tethering density was the same. The results were recognized by AFM, transmission electron microscopy and small angle X-ray scattering.