uniform thickness subsequently solvent annealing process was conducted to acquire the equilibrium morphology as gyroid nanostructure with large scale orientation to alleviate the effect of substrate chemically modified substrate was prepared by using polystyrene with hydroxyl chain end a substrate with a neutral or non preferential wetting of the substrate for ps plla could be prepared from this modification as shown in fig2 the thin film morphologies are different to the morphology of bulk sample when the thickness of the ps plla thin films is approximately smaller than 4 times of the d spacing of the 211 g planes as a result the equilibrium morphology as gyroid nanostructure can be obtained for samples with thickness larger than 130 nm see fig3 although it is possible to cause surface roughing due to the solvent annealing treatment the variation in thickness can be reasonably controlled by dedicated solvent removal for thick enough samples as the case examined here for practical applications different coating processes such as slot coating and gravure coating should be available to provide cost effective approaches for the formation of large area coatings in fact a tentative test has been done by using blade coating method for the purpose it is noted that the formation of the thin film sample with gyroid nanostructure is thermodynamically driven process via solvent annealing treatment in this work as a result similar results for.