scholarly journals Novel Silica Functionalized Monosodium Glutamate/PVA Cross-linked Membranes for Alkali Recovery by Diffusion Dialysis

2021 ◽  
Author(s):  
Muhammad Adnan Ashraf ◽  
Atif Islam ◽  
Muhammad Arif Butt
Keyword(s):  
Water Uptake ◽  
Separation Factor ◽  
Monosodium Glutamate ◽  
Sol Gel ◽  
Exchange Capacity ◽  
Effect Of Temperature ◽  
Poly Vinyl Alcohol ◽  
Sol Gel Process ◽  
Water Swelling ◽  
Diffusion Dialysis

Abstract In this work, two types of silica functionalized monosodium glutamate (GMSG and VMSG)/ poly(vinyl alcohol) (PVA) were cross-linked by sol-gel process to prepare novel hybrid cation exchange membranes (CEMs). The prepared membranes were systematically characterized by FTIR, ion exchange capacity (IEC), TGA, water uptake, water swelling, mechanical strength and diffusion dialysis (DD) performance for alkali separation using NaOH/Na2WO4 solution. The FTIR peaks around 1260-1350 cm−1 confirmed the secondary C−N linkages. The cross-linking between GMSG/VMSG and PVA was verified by the presence of stretching peaks of Si−O−C, Si−O−Si, C−O−C, and −C(=O)−O−C groups between 1080-1120 cm−1. TGA results indicated that GMSG membranes showed relatively high thermal stability as compared to VMSG membranes. Water uptake and degree of swelling decreased while IEC values increased with the increase of GMSG/VMSG content in membrane matrix. The mechanical properties of the membranes improved up to 40% GMSG/VMSG content. The NaOH dialysis coefficient (UOH) values improved while values of separation factor (S) declined with the increase of GMSG/VMSG content. Finally, the effect of temperature was studied and it was found that increase in temperature from 25 to 45 °C resulted in increase of diffusion coefficient and decrease of separation factor for both GMSG/VMSG crossed-linked with PVA membranes.

scholarly journals Synthesis of proton exchange membranes for dual-chambered microbial fuel cells

2018 ◽  
Vol 83 (5) ◽  
pp. 611-623 ◽  
Author(s):  
Sandeep Dharmadhikari ◽  
Prabir Ghosh ◽  
Manivannan Ramachandran
Keyword(s):  
Fuel Cells ◽  
Water Uptake ◽  
Microbial Fuel Cells ◽  
Oxygen Demand ◽  
Proton Exchange Membranes ◽  
Exchange Capacity ◽  
Proton Exchange ◽  
Poly Vinyl Alcohol ◽  
Precursor Material ◽  
Anodic Chamber

Proton exchange membranes (PEMs) were synthesized using three different compositions of poly(oxyethylene) (POE), poly(vinyl alcohol) (PVA), chitosan (CS) and phosphoric acid (PA) in weight ratios of 1:1:1:1, 1:2:1:1 and 1:3:1:1 by physical blending and the casting method. Water uptake of the membrane increases with increasing concentration of PVA. A higher percentage of water uptake signifies a higher ion exchange capacity (IEC) of the synthesized membrane. The synthesized membranes were evaluated in microbial fuel cells (MFCs) and the performance observed. The synthesized membranes were characterized for identification of precursor material and inter polymer interactions using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy analysis, respectively. The removal of chemical oxygen demand (COD) depends on the microbial activity in the anodic chamber. In the present study, the composition of the membrane was optimized and compared with other membranes that had been synthesized by different compositions of all materials. COD removal in the MFC-3 setup connected with an M-3 membrane was found to be 88 %.

Synthesis of Pseudoboehmite - Aging Effect

2019 ◽  
Vol 958 ◽  
pp. 5-10
Author(s):  
Antonio Hortencio Munhoz Jr. ◽  
Renato Meneghetti Peres ◽  
Leila Figueiredo Miranda ◽  
Raphael Cons Andrades ◽  
Matheus Francelino Bezerra da Silva ◽  
...  
Keyword(s):  
Surface Area ◽  
High Purity ◽  
Sol Gel ◽  
Aging Effect ◽  
High Specific Surface Area ◽  
Poly Vinyl Alcohol ◽  
Gamma Alumina ◽  
Aluminum Compound ◽  
Molecular Precursors ◽  
Sol Gel Process

The Pseudoboehmite is an aluminum compound used as an alumina precursor and it is produced by sol-gel process. The sol-gel process is a methodology to produce porous, vitreous or crystalline ceramics started by molecular precursors. Pseudoboehmite with high purity, high specific surface area and porous homogeneity was obtained by sol-gel process. The material was used to produce gamma-alumina with surface area ranging from 211.2-288.1m2/g. It was studied the effect of aging time, temperature of aging and poly (vinyl alcohol) addition in the synthesis.

Synthesis and characterization of poly(vinyl alcohol)/water glass (SiO2) nano-hybrids via sol-gel process

2010 ◽  
pp. n/a-n/a
Author(s):  
Sobha Rani Tenkayala ◽  
Marata Chinna Subbarao Subha ◽  
Venkata Reddy Gorla ◽  
Yong Ha Kim ◽  
Chowdoji Rao Kashayi ◽  
...  
Keyword(s):  
Vinyl Alcohol ◽  
Water Glass ◽  
Sol Gel ◽  
Synthesis And Characterization ◽  
Poly Vinyl Alcohol ◽  
Alcohol Water ◽  
Sol Gel Process

scholarly journals Quaternized Diaminobutane/Poly(vinyl alcohol) Cross-Linked Membranes for Acid Recovery via Diffusion Dialysis

Membranes ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 786
Author(s):  
Muhammad Ashraf ◽  
Atif Islam ◽  
Muhammad Arif Butt ◽  
Hafiz Abdul Mannan ◽  
Rafi Ullah Khan ◽  
...  
Keyword(s):  
Water Uptake ◽  
Vinyl Alcohol ◽  
Thermo Gravimetric Analysis ◽  
Expansion Ratio ◽  
Iron Chloride ◽  
Poly Vinyl Alcohol ◽  
Anion Exchange Membranes ◽  
Gravimetric Analysis ◽  
Acid Recovery ◽  
Diffusion Dialysis

Diffusion dialysis (DD) using anion exchange membranes (AEM) is an effective process for acid recovery and requires the preparation of suitable materials for AEMs, characterized by unique ions transport properties. In this work, novel AEMs composed of quaternized diaminobutane (QDAB) and poly(vinyl alcohol) (PVA) were cross-linked by tetraethoxysilane (TEOS) via the sol–gel process. The prepared AEMs were systematically characterized by Fourier-transform infrared (FTIR) spectroscopy, ion-exchange capacity (IEC) analysis, thermo gravimetric analysis (TGA), water uptake, linear expansion ratio (LER), and mechanical strength determination, scanning electron microscopy (SEM), and DD performance analysis for acid recovery using a hydrochloric acid/iron chloride (HCl/FeCl2) aqueous mixture and varying the QDAB content. The prepared AEMs exhibited IEC values between 0.86 and 1.46 mmol/g, water uptake values within 71.3 and 47.8%, moderate thermal stability, tensile strength values in the range of 26.1 to 41.7 MPa, and elongation from 68.2 to 204.6%. The dialysis coefficient values were between 0.0186 and 0.0295 m/h, whereas the separation factors range was 24.7–44.1 at 25 °C. The prepared membranes have great potential for acid recovery via diffusion dialysis.

scholarly journals Physical Properties of Poly(vinyl alcohol)/Silica Hybrid Prepared by Sol-Gel Process.

1996 ◽  
Vol 53 (4) ◽  
pp. 218-224 ◽  
Author(s):  
Shoichiro YANO ◽  
Takeshi FURUKAWA ◽  
Mitsuo KODOMARI ◽  
Kimio KURITA
Keyword(s):  
Physical Properties ◽  
Vinyl Alcohol ◽  
Sol Gel ◽  
Poly Vinyl Alcohol ◽  
Sol Gel Process ◽  
Silica Hybrid

scholarly journals Development of Crack-Free Alumina Sol-gel/Poly(vinyl Alcohol) Membranes for Glucose Oxidase Immobilization

2007 ◽  
Vol 7 (1 & 2) ◽  
pp. 61 ◽  
Author(s):  
Fui Ling Wong ◽  
Azila Abdul Aziz
Keyword(s):  
Glucose Oxidase ◽  
Simple Procedure ◽  
Sol Gel ◽  
Composite Membranes ◽  
Hybrid Membrane ◽  
Poly Vinyl Alcohol ◽  
Support Material ◽  
Sol Gel Process ◽  
Alumina Sol ◽  
Gel Membranes

A simple procedure to incorporate PVA into alumina sol-gel membrane was investigated as a suitable support material for glucose oxidase. The alumina sol was prepared using aluminum iso-propoxide via the sol-gel process. PVA was employed as the organic binder to enhance the mechanical strength of the fragile sol-gel membranes. The ability of the hybrid membrane to retain glucose oxidase and the apparent enzyme activities were studied. The resulting composite membranes were found to be crack-free, stable, and still very active after 60 days. However, the enzyme leakage period was observed to be quite long. The enzyme was still leaking from the membrane after more than 10 days albeit at a very low level.

scholarly journals Polysiloxane Hybrids via Sol-Gel Process: Effect of Temperature on Network Formation

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 677
Author(s):  
Maria Criado ◽  
Isabel Sobrados ◽  
Jesus Sanz
Keyword(s):  
Hybrid Materials ◽  
Room Temperature ◽  
Network Formation ◽  
Sol Gel ◽  
Effect Of Temperature ◽  
Molar Ratio ◽  
High Demand ◽  
Sol Gel Process ◽  
Anticorrosion Properties ◽  
The Ideal

The effect of temperature on the network formation of polysiloxane hybrids was evaluated since this type of material is currently in high demand. In the last decades, the deposition of these coatings on different substrates, mostly metals, has demonstrated anticorrosion properties. Sol-gel hybrids were prepared by mixing 3-methacryloxypropyltrimethoxysilane (MPTS) and tetramethyl orthosilicate (TMOS) with a molar ratio of 1. The formation, thickness and composition of these hybrid materials were evaluated by nuclear magnetic resonance (NMR) spectroscopy and scanning electron microscopy (SEM), respectively. The results showed that the temperature plays an important role in the network formation, the total condensation degree and the total dimensionality of the hybrid materials. At room temperature, the polysiloxane hybrids presented total condensation degrees lower than 75% and a total dimensionality (dtotal) = 2.5, while those obtained at 65 °C presented total condensation degrees higher than 80% and a dtotal = 2.8. The ideal conditions to prepare polysiloxane hybrids are 65 °C for 4 h, where this shows a higher atomic percentage of Si and a greater thickness.

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