Development of sulfonated graphite oxide incorporated poly(styrene sulfonic acid‐co‐malic acid) crosslinked sodium alginate membranes for pervaporation dehydration of isopropanol

Abstract

Pervaporation (PV) is a promising membrane‐based technology for dehydrating alcohols and separation of close‐boiling liquids. Poly(styrene sulfonic acid‐co‐maleic acid) (PSSAMA) crosslinked sodium alginate (NaAlg) membrane was developed, and was then modified by varying the mass% of sulfonated graphite oxide (SGO). Physicochemical properties of the resulting membranes were assessed using FTIR, WXRD, TGA, DSC, and SEM. The pervaporation study was carried out to assess membrane performance in dehydrating isopropanol. The membrane with 16 mass% of SGO exhibited the highest separation factor of 6025 and flux of 14.66 × 10−2 kg m−2 h−1 at 30°C for 10 mass% of water in the feed and were able to break the water–isopropanol azeotropic point. The activation energy for water permeation (Epw) was lower than that of isopropanol permeation (EIPA), indicating the high separation ability. Activation energies for total permeation (EP) and total diffusion (ED) ranged from 12.42 to 49.13 and 12.99 to 54.42 kJ mol−1, respectively. Negative enthalpy values (ΔHs) suggested Langmuir's sorption predominance for all membranes.Highlights The SGO incorporated crosslinked NaAlg composite membranes were prepared. The membrane containing 16 mass% of SGO showed the highest water uptake. Membrane with 16 mass% of SGO showed the highest flux and separation factor. All composite membranes showed excellent thermal and mechanical stability. Membrane with 16 mass% of SGO demonstrated excellent PV performance.