Anti-wetting polyvinylidene fluoride membrane incorporated with hydrophobic polyethylene-functionalized-silica to improve CO2 removal in membrane gas absorption

Membrane gas absorption (MGA), an attractive technology for carbon dioxide (CO2) separation was used in conjunction with polyvinylidene fluoride (PVDF) membranes. In order to improve the membrane's CO2 absorption flux and gas selectivity, silica nanoparticles functionalized with low-density polyethylene (LDPE) were incorporated into PVDF matrix to produce an anti-wetting protection layer to overcome membrane wetting; a critical issue in regards to the MGA process. FESEM micrograph and EDX line-scan profile clearly show that f-silica were dispersed evenly in the composite membrane due to the better interactions with PVDF polymer chains in the presence of LDPE. LEPw, a measure of membrane wettability, was improved from 4.75 bar (pristine PVDF membrane) up to 13.55 bar for silica/PVDF composite membrane. More importantly, embedding silica nanoparticles into PVDF matrix improved both the CO2 absorption flux from 0.66 x 10(-4) mol/m(2) s to 2.32 x 10(-4) mol/m(2) s (3.5 times higher) and selectivity from 3.48 up to 29.4 (8.5 times higher) in comparison to the pristine PVDF membrane. In short, the results indicated that f-silica was effective in producing anti-wetting protection in PVDF membrane to improve CO2 removal in membrane gas absorption.