Synthesis and characterization of carbon nanotubes/poly vinyl alcohol nanocomposite membranes for dehydration of isopropanol

Carbon nanotubes (CNTs) were synthesized by CVD method using cyclohexanol and ferrocene as carbon precursor and catalyst, respectively. Nitric acid was used for purification and functionalization of CNTs. TEM image of CNTs before and after purification revealed that acid treatment could remove encapsulated catalyst particles. Afterward, highly pure and functionalized CNTs were incorporated in poly (vinyl alcohol) (PVA) to synthesize PVA–CNTs nanocomposite membranes. FESEM characterization was carried out to investigate dispersion of different CNTs loading in PVA matrix. The results showed that 2 wt.% CNTs loading is better dispersed in the polymer and increasing CNTs loading more than 2 wt.% agglomerates CNTs. Degree of swelling results for nanocomposite membranes showed that present of CNTs in the PVA membranes reduce the degree of swelling. Furthermore, pervaporation (PV) results revealed that incorporating of CNTs in PVA matrix increases significantly water selectivity due to rigidification of the polymer chains. The water selectivities for the pristine PVA and 2 wt.% CNTs loading nanocomposite membranes were evaluated as 119 and 1794, respectively.

Effect of CNTs loading on PV performance of PVA-X nanocomposite membranes in 10 wt.% water in IPA mixture at 30 °C.Figure optionsDownload high-quality image (131 K)Download as PowerPoint slideHighlights
► PVA–CNTs nanocomposite membranes were synthesized.
► 2 wt.% CNTs loading into PVA showed the best dispersion.
► CNTs agglomeration decreases water selectivity significantly.
► Degree of swelling decreases significantly by adding CNTs into the PVA membranes.
► PVA–CNTs nanocomposite membranes exhibit higher water selectivity than PVA membranes.