Super-selective polysulfone hollow fibre membranes for gas separation: Assessment of molecular orientation by Raman spectroscopy

It has been shown that the polarized Raman scattering method previously developed For quantitative analysis of molecular orientation in polyethylene can be applied to polysulfone hollow fibre membranes. The orientation parameters for the in-plane vibration of the benzene ring in the active layers of the membranes were determined for different processing conditions of the fibres. The results reported here confirm the fact, revealed previously by IR spectroscopy, that the spinning of membrane fibres at high shear rates may induce anisotropy at the molecular level in the active layer.