Bio-degradable Poly (l-lactic acid) (PLLA) scaffolds were prepared by using thermal liquid-liquid phase separation method. A solution of PLLA-Dioxane was prepared by dissolving PLLA in dehydrated 1, 4-Dioxane. This PLLA-Dioxane solution was then directionally frozen in vials of similar dimensions but made of different materials (borosilicate glass, aluminum and copper). The frozen solution was then placed in a freeze-dryer to allow for the frozen dioxane to sublimate or lyophilized. The porosities of the resulting PLLA scaffolds were calculated and their porous structures were studied and compared between the three different vials (and the corresponding cooling rates).