Fabrication and Physicochemical Study of B2SA-Grafted Poly(vinyl Alcohol)–Graphene Hybrid Membranes for Dehydration of Bioethanol by Pervaporation

Abstract

Tetraethylorthosilicate (TEOS)-crosslinked poly(vinyl alcohol) (PVA) solution was prepared and treated with benzaldehyde 2 sulphonic sodium salt acid (B2SA) for sulfonation. Different contents of graphene were incorporated into B2SA-grafted PVA–TEOS hybrid membrane to improve the membrane stability, mechanical strength, and overall pervaporation performance of the membranes. Membranes were fabricated using the casting technique. Developed membranes were then analyzed for their physicochemical changes by means of Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscope (SEM), wide-angle X-ray diffraction (WAXD), thermogravimetric analysis (TGA), contact angle analysis (CA), and mechanical strength. The lower d-spacing value observed in WAXD was evidence for the decreased inter-chain distance between the polymer chains. DSC exhibited the enhanced thermal stability of the developed membranes compared to the plane PVA membrane with enhancement in Tg value (106 °C), which was well above the pervaporation experimental temperature. Incorporation of graphene induced higher mechanical strength to the fabricated membranes. Further, the membranes were tested for the pervaporation separation of bioethanol. All the membranes were stable throughout the pervaporation studies, with M-2 G showing the total permeation flux of 11.66 × 10−2 kg/(m2 h) at 30 °C.

Pervaporation performance of poly(vinyl alcohol)‐graft‐poly(N‐hydroxymethyl acrylamide) membranes for dehydration of isopropyl alcohol‐water mixture

“…The enhancement of the transport features of the PVA membrane owing to the grafting of PNHMA moieties was related to the PNHMA structure, increased hydrophilic properties, decreased membrane crystallinity, causing to an alteration in the free volume and increase of the swelling degree of copolymeric membranes. Similar findings were also stated in the literature 3,18,43,44 . The PVA‐g‐PNHMA membrane with a grafting percentage of 34% (the highest grafting percentage found under optimum conditions) is selected for further studies of the impact of membrane thickness on pervaporation separation performance because it possesses the best pervaporation separation efficiency with the highest separation factor and reasonable flux.…”

Nanobacterial Cellulose Production and Its Antibacterial Activity in Biodegradable Poly(vinyl alcohol) Membranes for Food Packaging Applications

“…Further, the peaks at 1541 and 1399 cm –1 were due to C–C stretching and ring vibrations. The peak at 1064 cm –1 could be associated with an ether C–O–C stretching vibration. ,− …”

“…The crystalline nature of the developed non-cross-linked membranes was estimated based on an X-ray diffractogram. Figure B illustrates that WAXD of pristine PVA (M) had a strong crystalline diffraction peak at 2θ = 19.6°, which indicates that the pristine M contains both amorphous and crystalline natures in the membrane matrix. − In membranes M-5 mass % NBC and M-10 mass % NBC, the intensity found of the diffraction peak was enhanced at 2θ = 20°. This was due to the interaction between PVA and NBC, which results in the crystalline nature of the membrane.…”

Fabrication and Characterization of Poly(vinyl alcohol)-chitosan-capped Silver Nanoparticle Hybrid Membranes for Pervaporation Dehydration of Ethanol

“…Xia et al [ 34 ] developed PVA nanohybrid membranes by incorporating organosilica, and used this membrane for ethanol dehydration by PV and achieved selectivity of 1026 and flux of 0.145 kg.m −2 h −1 . Our previous work [ 35 ] fabricated B 2 SA-grafted Poly(vinyl alcohol)–graphene hybrid membranes for ethanol dehydration by PV. Among these, the membrane containing 2 wt.% of graphene exhibited selectivity of 4187 with a flux of 0.1166 kg.m −2 h −1 .…”