Crystallization technique based on diffusion mechanism of CO2 induced crystallization to fabricate nanoporous lamellar structures of PLA (Poly Lactic acid) has been discussed. The technique is known to generate 2D porous spherulites with different spherulite morphologies. Compression molded PLA samples were saturated with high pressure CO2 at 50 bar for 24 hrs and foamed at three different temperatures. Effect of foaming temperatures on the in-situ fibrillation/foaming of lamellar morphology is studied by examining the lateral cross-section of samples in SEM and POM. SEM image of lateral section shows the porous 2D spherulites with the cell size in the range of 200-500 nm. Foamed samples under polarizer exhibits the red-green birefringences illustrating the criss-cross lamellar pattern. Captured POM images showing intrinsic red-green birefringences were analyzed as binary image by using Image J software to evaluate degrees and distribution of orientation in lamellae. It is found that the nanoporous lamellar structure exhibits superoleophilic and superhydrophobic properties. Contact angle measurements were carried out for the porous crystalline PLA obtained at different temperatures. Effect of foaming temperature on the enhancement of foamability and hydrophobicity were investigated by SEM and Contact angle measurement experiments. Keywords: Scanning electron microscopy, Polarized optical microscopy, CO2 induced crystallization, Polarized optical microscopy, Birefringences, foamed PLA. Contact angle.