Performance enhancement of the poly (vinyl alcohol) (PVA) by activated natural clay clinoptilolite for pervaporation separation of aqueous–organic mixtures

Abstract

The pervaporation (PV) performance of poly (vinyl alcohol) (PVA) is enhanced by the addition of natural clay clinoptilolite into it. Nanocomposites of glutaraldehyde cross-linked (in situ) PVA/clinoptilolite membranes were prepared by solution casting technique to investigate the water flux, selectivity, perm selectivity and enrichment factor. PV experiments using clay incorporated membrane matrix (CIMM) have been performed at 30, 40 and 50°C to separate water–isopropanol/ethanol feed mixtures containing 10–40 wt. % of water. These membranes were characterized by universal testing machine to understand the mechanical strength. The morphological analysis has been studied using scanning electron microscopy. The high content (5 and 10%) of clay in the CIMM extracts water efficiently on the permeate side with high selectivity. The hydrophilic nature of clay and the formation of CIMM are responsible to offer such increased separation of water over the organic components of the feed mixtures.

Keywords:

• Mixed matrix membranes
• Pervaporation
• Azeotropic mixtures
• Clay

Acknowledgements

Authors immensely thank Department of metallurgy, University of Johannesburg, South Africa for making available some of the experimental facilities. Karnataka University, Dharwad, India is acknowledged for the facilities and hospitality provided. Also, NRF South Africa is acknowledged for partial financial support in the form of rated researcher’s incentive fund.