Polyvinyl alcohol (PVOH) has been chemically modified by polymerizing hydroxyethylmethacrylate (HEMA) in aqueous solution of PVOH and finally crosslinking PVOH with glutaraldehyde to produce a semi-interpenetrating network (SIPN) membrane. Accordingly, three such SIPNs i.e., SIPNI, SIPNII, and SIPNIII were synthesized with different weight ratio of PVOH: HEMA i.e., 1:0.25 (SIPNI), 1:0.50 (SIPNII) and 1:0.75 (SIPNIII). These SIPN membranes were used for pervaporative dehydration of dioxane. PVOH without any chemical modification but crosslinked with the same amount of glutaraldehyde has also been used for this study for comparison. All the SIPN membranes were also characterized with various conventional methods like mechanical properties, DSC and TGA. Water permeability and water selectivity of the IPN membranes were found to be much higher than those of the crosslinked PVOH membrane which was not chemically modified. The permeability of the membranes were also found to increase with increase in the HEMA content in PVOH matrix.

SAMIT RAY

Polymer Science and Technology

N R SINGHA

S KAR

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Synthesis of Chemically Modified Polyvinyl Alcohol Membranes for Dehydration of Dioxane by Pervaporation

Separation Science and Technology

Herein, guar gum (GG)-g-(acrylic acid (AA)-co-3-acrylamido propanoic acid (AMPA)-co-acrylamide (AM))-g-cow buffing dust (CBD)/(GGTPCBD), a smart carbohydrate and protein-based doubly-grafted interpenetrating terpolymer hydrogel showing excellent physicochemical properties and recyclability was synthesized by in situ strategic allocation of AMPA during solution polymerization of AA and AM through systematic optimization of the amounts of components and reaction temperature for superadsorption of Hg(II), Pb(II), methyl violet (MV), methylene blue (MB), p-nitrophenol (PNP), and vitamin-C (vit.C). The in situ strategic protrusion of AMPA, grafting of both GG and CBD into AA-co-AMPA-co-AM, and ligand-selective superadsorption was inferred by advanced microstructural analyses of unadsorbed- and/or adsorbed-GGTPCBD using FTIR, 1H/13C NMR, O1s-/N1s-/C1s-/Pb4f7/2,5/2-/Hg4f7/2,5/2-XPS, UV–vis, TGA, DSC, XRD, DLS, SEM, EDX, % gel content, % −COOH, and pHPZC. The prevalence of covalent, ionic, and variegated interactions was rationalized by FTIR, fitting of kinetics data to the pseudosecond order model, and activation energies of adsorption. The BET and Langmuir isotherms fitted the best to MB and Hg(II)/Pb(II)/MV, respectively. Thermodynamically spontaneous chemisorption processes showed the maximum adsorption capacities (ACs) of 976.64, 859.23, 116.80, and 58.52 mg g−1 for Pb(II), Hg(II), MV, and MB, respectively, at 303 K, adsorbent dose = 0.01 g, and initial concentration of metal ions/dyes = 800/30 ppm. © 2018

Journal of Hazardous Materials

Carbohydrate and collagen-based doubly-grafted interpenetrating terpolymer hydrogel via Nâ€“H activated in situ allocation of monomer for superadsorption of Pb(II), Hg(II), dyes, vitamin-C, and p-nitrophenol

Polyvinyl alcohol (PVOH) has been chemically modified by polymerizing hydroxyethylmethacrylate (HEMA) in aqueous solution of PVOH and finally crosslinking PVOH with glutaraldehyde to produce a semi-interpenetrating network (SIPN) membrane. Accordingly, three such SIPN membranes, namely SIPNI, SIPNII, and SIPNIII were synthesized with different weight ratio of PVOH: HEMA i.e., 1:0.25 (SIPNI), 1:0.50 (SIPNII), and 1:0.75 (SIPNIII). These SIPN membranes were used for pervaporative separation of methanol from its mixtures with toluene. The flux and methanol selectivity of these SIPN membranes were found to be much higher than conventional PVOH membrane crosslinked with glutaraldehyde. Among the three membranes, SIPNIII with 75 wt% HEMA incorporation shows optimum performance in terms of flux and methanol selectivity. The permeability of the membranes was also found to increase with increase in HEMA content in PVOH matrix. The novelty of the work lies in synthesis and characterization of a new kind of membrane and its potential for selective removal of methanol from its mixtures with toluene. © Taylor & Francis Group, LLC.

Separation of toluene-methanol mixtures by pervaporation using semi-IPN polymer membranes

Polyvinyl alcohol (PVOH) membrane, was modified both physically and chemically by incorporation of inorganic filler, sodium aluminosilicate and chemical crosslinking with maleic acid and glutaraldehyde. The change of morphology and crystallinity of PVOH by this physical and chemical modification was studied by FTIR, DSC, TGA, SEM and XRD. These membranes were evaluated in terms of its potential for dehydration of dioxane by preferential sorption and permeation using pervaporation (PV) technique. These membranes were cast in the laboratory by solution casting from the polymer and other additives. The performance of the unfilled (containing no filler) glutaraldehyde (GA) crosslinked PVOH-1 and maleic acid (MA) crosslinked PVOH-2 membranes were compared with filled (containing aluminosilicate filler) but GA crosslinked PVOH-3 and filled but MA crosslinked PVOH-4 membranes. The filled membranes were found to show higher flux and water selectivity. Among all the four used membranes, the MA crosslinked filled PVOH-4 membrane was found to show best results in terms of both water selectivity and flux. © 2009 Elsevier B.V. All rights reserved.

Journal of Membrane Science

Dehydration of 1,4-dioxane by pervaporation using filled and crosslinked polyvinyl alcohol membrane

Polyvinyl alcohol(PVOH) has been chemically modified by crosslinking copolymerization of acrylic acid(AA) and hydroxyethylmethacrylate (HEMA) in aqueous solution of PVOH and finally crosslinking PVOH with glutaraldehyde to produce a full interpenetrating network(IPN) membrane. Accordingly, three such full crosslink IPNs i.e., PVAHI, PVAHII and PVAHIII have been synthesized with different weight ratio of PVOH:Poly (AA-co-HEMA) i.e., 1:0.25 (PVAHI), 1:0.50 (PVAHII) and 1:0.75 (PVAHIII). These IPN membranes have been used for pervaporative separation of MTBE-methanol mixtures. All the PVAH membranes were also characterized with various conventional methods like FTIR, mechanical properties, DSC and TGA. Permeability and methanol selectivity of these membranes were found to increase with increasing amount of copolymer in PVOH matrix. However, among the three membranes, PVAHIII were found to show the highest flux but lower selectivity for methanol while PVAHII membrane showed optimum performance in terms of both flux and selectivity. © Taylor & Francis Group, LLC.

Synthesis of novel polymeric membrane for separation of MTBE-methanol by pervaporation

Methyl tertiary butyl ether (MTBE) is now being extensively used as a lead-free octane enhancer for green fuel. Pervaporative separation process is used for separation of methanol-MTBE mixtures encountered during manufacturing of MTBE. Three different copolymers of acrylamide with increasing amount of 2-hydroxyethyl methacrylate (HEMA), i.e. PAMHEMA-1, -2 and -3 were synthesized and the cross-linked (gelled) copolymer membranes made from these sol copolymers were used for pervaporative separation of methanol from its mixtures with MTBE over the concentration range of 0-10 wt.% methanol in feed. These hydrophilic gel copolymer membranes were found to be highly methanol selective in both sorption and diffusion through the membranes. Methanol flux was found to decrease with increase in degree of cross-linking from PAMHEMA-1 to -3 copolymer membranes. Among the three membranes PAMHEMA-3 membrane showed highest selectivity and acceptable flux (511.7, 9.9 g/m2 h for 0.53 wt.% of methanol in feed) while maximum flux with high selectivity was shown by PAMHEMA-l membrane (18.48 g/m2 h, 243 for 0.53 wt.% of methanol in feed). MTBE was also found to have a negative coupling effect on methanol permeation. The membranes were found to show both sorption as well as diffusion selectivity for methanol. © 2005 Elsevier B.V. All rights reserved.

Synthesis of highly methanol selective membranes for separation of methyl tertiary butyl ether (MTBE)-methanol mixtures by pervaporation

Sodium montmorillonite clay loaded novel mixed matrix membranes of poly(vinyl alcohol) for pervaporation dehydration of aqueous mixtures of isopropanol and 1,4-dioxane

Journal	Separation Science and Technology
Publisher	TAYLOR & FRANCIS INC
ISSN	0149-6395
Open Access	No