Synthesis and Characterization of Polyvinyldene Fluoride/ Low Density Polyethylene/ Montmorillonite Mixed Matrix Membrane for CO2 Removal

Membrane gas separation technology has taken in a new form in its application through the growing branches of mixed matrix membrane (MMM). The existing usage of polymeric membranes is fairly insufficient to meet the demand of the industry due to its lack in stability and separation capabilities, even though they are competitively advantageous over the conventional separation methods. The MMM developed by introducing inorganic fillers into the polymeric matrices, is significantly improvised in its separation properties with trivial loss in membrane stability. The properties attained by the MMM combines the advantageous characteristics of high permeability and flexibility of the polymer; and high selectivity, thermal and chemical stability of the inorganic particles. With a wide range of polymeric and inorganic material being implemented into the MMM concept, this project is aimed to synthesize asymmetric nanoclay-polyvinyldene fluoride (PVDF)-low density polyethylene (LDPE) MMM by incorporating various amount of montmorillonite (MMT) nanoclay mineral into the polymer matrix. The development of this PVDF/LDPE/MMT MMM is intended specifically for separation of CO2 from natural gas (CH4). The MMMs were fabricated via dry-wet phase inversion technique with N,N-dimethylacetamide (DMAc) used as solvent and distilled water as the coagulant. The fabricated MMMs were characterized using field emission scanning electron microscopy (FESEM) and thermal gravimetric analysis (TGA) to study the thermal properties and surface morphology of the membrane. Permeability and selectivity of the resultant membrane towards CO2/CH4 separation is investigated through gas permeation tests. The morphology of the membranes highly depends on the clay mineral loading as validated by FESEM. PVDF/LDPE/3wt% MMT MMM exhibits the highest CO2 permeance and CO2/CH4 selectivity relative to the pristine PVDF/LDPE membrane.