Gas Permeation through Polysulfone-Polyl mide (PSF-PI) Miscible Blend Membrane

Gas permeation through polysulfone-polyimide (PSF-PI) miscible blend
membranes were studied through the permeability of Carbon Dioxide (C02) and
Methane (CH4) gas. The asymmetric polymer blend membranes were be fabricated with
varying weight percentage ratios (100:0, 95:5, 90:10, 85:15, 80:20) of polysulfone and
polyimide respectively, by a solution cast method or in other words, by wet phase
inversion method. The solvents that will be used for the study are N-methyl Pyrrolidone
(NMP) and Dichloromethane (DCM) and the membranes will be subjected to immersion
in the Ethanol bath (EtOH). Apart from studying the effects of solvents to the
membrane, cloud point determinations were also studied as gave a better view on the
point where the dope solution phase separates. Different parameters during fabrication
will produce different morphologies of the membranes, which includes the formation of
microvoids, porosity, skin layer type and structure of the membrane. These were
observed through the SEM Test, Scanning Electron Microscopy, where the photographs
of the membrane on molecular level have been obtained. SEM gave a better insight on
the membrane structure and homogeneity of the membrane casting solution. The
permeability of CO2 and CH4 across the membrane will subject to the morphologies of
the membranes produced from the research. The effects of varying parameters during
the fabrication stage will affect the permeability and selectivity of CO2 across the
membrane. The compatibility of the membranes was also studied in parallel with the
cloud point determination mentioned earlier. For polymers, polymer blends may be in
homogenous form or heterogeneous form. The homogeneity of the membranes were
studied through the FTIR tests (Fourier Transform Infrared Spectroscopy) and UTM
(Universal Testing Machine). The PSF-PI combination will show a homogeneous
miscible blend, where this compatibility is essential in a new blend polymer material,
suitable for the preparation of gas separation membranes. Such membranes will produce
combined satisfactory gas permeation properties, reduced cost and advanced resistance
(harsh to chemicals, significant temperature conditions, improved tolerance to
plasticizing gases).