Novel Poly(vinyl alcohol)/Multiwalled Carbon Nanotube Nanocomposite Membranes for Pervaporation Dehydration of Isopropanol: Poly(sodium 4-styrenesulfonate) as a Functionalization Agent

Poly(sodium 4-styrenesulfonate)- (PSS-) wrapped multiwalled carbon nanotubes (MWNTs) were incorporated into poly(vinyl alcohol) (PVA) solution for the preparation of PVA/MWNTs-PSS nanocomposite membranes. According to field-emission scanning electron microscopy (FESEM) observations, wrapping MWNTs with PSS leads to better dispersion of the MWNTs in the polymer matrix. The membrane performances were tested in the pervaporation (PV) process for the dehydration of isopropanol (IPA). Upon addition of 0–3 wt % MWNTs-PSS to the PVA matrix, the permeance decreased, whereas the selectivity increased. For example, the water permeance decreased from 4200.8 to 3243.9 GPU, and the selectivity increased from 39.8 to 249.4 when the MWNTs-PSS content was increased from 0 to 3 wt %. The estimated permeation and diffusion parameters show that the prepared membranes provide high separation performance for water–IPA mixtures.