In the present study, effect of different materials and ways to increase the hydrophobicity of PVC membrane and improving its performance in CO 2 absorption are investigated. For this purpose, methods such as utilizing additives with hydrophobic nature, including some nanoparticles like silicon carbide nanoparticles, graphene nanosheet, hydrophobic materials like estearat, teflon polymer and calcium fluoride are investigated and also electrospinning method is used to cover membranes surface with hydrophobic polyvinylidine fluoride nanofibers. At first, appropriate weight for the base membrane were selected and then the mentioned additives were added to the polymer solution in weight percentage of 1, 2 and 3. Mean pore size, LEPw, porosity and contact angle are the important parameters of the membrane in the membrane contactor. These parameters were investigated based on the results of the analysis. After examining the membranes structure, they were investigated in carbon dioxide absorption test by using membrane contactor system. At the end, between 35 synthesized membrane, M6, M14, M24, M26, M30, M33 and M35 were compared with pure M4 membrane in terms of structure, hydrophobicity improvement and carbon dioxide absorption performance. Based on the results, the M30 membrane with 2 weight percent of graphene as an additive had an acceptable result in the absorption test (short and long term) and it was selected as sample membrane. The amount of absorption flux for this membrane was 1.2 × 10 -3 mol/m 2 .s at a liquid velocity of 0.0439 m/s which is 58% higher than non-additive polyvinyl chloride membrane (M4). This increase can be attributed to an increase to the resistance toward wetting (36% increase), 29% increase in membranes hydrophobicity and membrane structures improvement. Also In long term contact with water, the membrane has the lowest drop (23.8%) in 192 hours which shows the long term performance of this membrane.