scholarly journals Effect of Sulfonated Block Copolymer on the Equilibrium and Thermal Properties of Sulfonated Fluoroblock Copolymer Blend Membranes

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Edward M. A. Guerrero-Gutiérrez

Polymeric membrane technologies demand the synthesis of new polymers to enhance their equilibrium, thermal, and transport properties. Therefore, the focus of this investigation was the evaluation of the equilibrium and thermal properties of a sulfonated fluoroblock copolymer blend membrane composed of sulfonated poly(styrene-isobutylene-styrene) (SIBS SO3H) and a novel sulfonated fluoroblock copolymer composed of poly(4-fluo- rostyrene) (P4FS), poly(styrene) (PS) and poly(isobutylene) (PIB). The fluoroblock copolymer was synthesized using Atom Transfer Radical Polymerization (ATRP) and cationic polymerization. First, the molecular weight and the thermal stability of the block copolymer were determined using Gel Permeation Chromatography (GPC) and Thermogravimetric Analysis (TGA). Second, the chemical composition was monitored utilizing Fourier Transform Infrared spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy. The molecular weight of P4FS-b-PS was Mn ~ 36,100; this value increased 8% after the cationic polymerization. The equilibrium properties of the membrane were evaluated using the water uptake and Ion-Exchange Capacity. The degradation behavior and the thermal transitions were determined using TGA and Differential Scanning Calorimetry (DSC), respectively. This newly membrane exhibited water uptake higher than 608% related to the improvement of 36% in the ion-exchange capacity and the increment of 25.31% and 25.24% in the energy required to produce the thermal transitions induced by the addition of the sulfonated fluoroblock copolymer.

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 914 ◽  
Author(s):  
Lucia Mazzapioda ◽  
Stefania Panero ◽  
Maria Assunta Navarra

Nafion composite membranes, containing different amounts of mesoporous sulfated titanium oxide (TiO2-SO4) were prepared by solvent-casting and tested in proton exchange membrane fuel cells (PEMFCs), operating at very low humidification levels. The TiO2-SO4 additive was originally synthesized by a sol-gel method and characterized through x-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and ion exchange capacity (IEC). Peculiar properties of the composite membranes, such as the thermal transitions and ion exchange capacity, were investigated and here discussed. When used as an electrolyte in the fuel cell, the composite membrane guaranteed an improvement with respect to bare Nafion systems at 30% relative humidity and 110 °C, exhibiting higher power and current densities.


2006 ◽  
Vol 4 (1) ◽  
pp. 56-64 ◽  
Author(s):  
Tetsuya Yamaki ◽  
Junichi Tsukada ◽  
Masaharu Asano ◽  
Ryoichi Katakai ◽  
Masaru Yoshida

We prepared novel ion exchange membranes for possible use in polymer electrolyte fuel cells (PEFCs) by the radiation-induced graft copolymerization of styrene and new crosslinker bis(vinyl phenyl)ethane (BVPE) into crosslinked polytetrafluoroethylene (cPTFE) films and subsequent sulfonation and then investigated their water uptake, proton conductivity, and stability in an oxidizing environment. In contrast to the conventional crosslinker, divinylbenzene (DVB), the degree of grafting of styrene∕BVPE increased in spite of high crosslinker concentrations in the reacting solution (up to 70mol%). Quantitative sulfonation of the aromatic rings in the crosslinked graft chains resulted in the preparation of membranes with a high ion exchange capacity that reached 2.9meq∕g. The bulk properties of the membranes were found to exceed those of Nafion membranes except for chemical stability. The emphasis was on the fact that the BVPE-crosslinked membranes exhibited the higher stability in the H2O2 solution at 60°C compared to the noncrosslinked and DVB-crosslinked ones, as well as decreased water uptake and reasonable proton conductivity. These results are rationalized by considering the reactivity between styrene and the crosslinker, which is an important factor determining the distribution of the crosslinks in the graft component. In the case of BVPE, the crosslinks at a high density were homogeneously incorporated even into the interior of the membrane because of its compatibility with styrene while the far too reactive DVB led to a crosslink formation only near the surface. The combination of both the cPTFE main chain and BVPE-based grafts, i.e., a perfect “double” crosslinking structure, is likely to effectively improve the membrane performances for PEFC applications.


2020 ◽  
Vol MA2020-02 (38) ◽  
pp. 2442-2442
Author(s):  
Garrett Huang ◽  
Mrinmay Mandal ◽  
Alexandra Dobbs ◽  
Katelyn Groenhout ◽  
Paul A Kohl

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Abdul Hamid ◽  
Muhammad Khan ◽  
Fakhar Hussain ◽  
Amir Zada ◽  
Tiehu Li ◽  
...  

Abstract Three types (type-A, B, and C) of composite polymeric membranes (CPMs) based on poly vinyl chloride (PVC) and different fillers (sodium polyacrylate and sodium polyacrylate-graphite) soaked in water and 0.5 N HCl were prepared using solvent casting method. Different physicochemical parameters such as microscopic surface study, water uptake, perpendicular swelling, density, porosity (ε), ion exchange capacity, and conductivity of the as the prepared CPMs were evaluated. Interestingly, type-A CPM cast with filler-A has greater values of the above parameters except density and ionic conductivity than those of type-B and C CPMs. The water uptake of type-A, B and C composite membranes was respectively in the range of 220.42–534.70, 59.64–41.65, and 15.94–2.62%. Ion exchange capacity of type-A, B and C CPMs was in the range of 3.669 × 107–2.156 × 107, 5.948 × 107–1.258 × 107, and 1.454 × 107–1.201 × 107 m.eq.g−1 respectively while the conductivity order was type-A < B < C. These types of CPMs may be helpful in many applications including proton exchange membranes, fuel cell like devices, as sensors for different metals, gas purification, water treatment, and battery separators.


2014 ◽  
Vol 13 (1) ◽  
pp. 7
Author(s):  
Bambang Piluharto ◽  
Imam Syafi’i ◽  
R. Indahsari ◽  
Tanti Haryati

Sulfonated polysulfone membrane is one of the alternative membranes as replacing Nafion membrane for the fuel cell application. This membrane was prepared by introducing sulfonic group in the polysulfone structure backbone, so that provides the ionic membrane. However, more ionic groups in the SPSF membrane lead to loss mechanical stability. This study aims to prepare the hybrid membrane from SPSF and bentonite. In here, various of bentonite concentrations were used as variable to study water uptake and ion-exchange capacity properties. As the results, increasing bentonite concentrations lead to increase water uptake and ion-exchange capacity. By the functional group analysis, proved that adding bentonite in SPSF did not change structure of SPSF, means that interaction between SPSF and bentonite were physical interactions.


Author(s):  
Hyung-Hwan An ◽  
◽  
Changyun Shin ◽  

We studied a new ion exchanger for high ion exchange capacity (IEC) and rapid ion exchange. Polystyrene nanofiber ion exchangers (PSNIEs) were prepared by electrospinning from solutions of dissolved polystyrene followed by sulfonation. Coating and sulfonation were used to modify the glass fiber surface with polystyrene to produce cation exchanger fiber (CEF). We present new experimental results on the performance of PSNIE and CEF related to parameters of IEC, water uptake, and surface morpoholgy. IEC and water uptake of PSNIE depend on sulfonation time. IEC reached 3.74 mmol/g at relatively high water uptake of 0.6 to 0.77g H2O/g-dry-PNIE. IEC and water uptake of CEF reached 3.61mmol/g-CEF and 0.25g H2O/g-dry-CEF.


Membranes ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 352
Author(s):  
Paulina A. Sosa-Fernández ◽  
Jan W. Post ◽  
Harrison L. Nabaala ◽  
Harry Bruning ◽  
Huub Rijnaarts

Electrodialysis (ED) has been recently proposed to desalinate polymer-flooding produced water (PFPW), a byproduct stream from the oil and gas industry rich in charged polymers. However, process performance is limited by fouling occurring on the ion-exchange membranes, particularly on the anionic ones (AEMs). Thus, this study aimed to correlate the properties of different AEMs with their performance while desalinating PFPW, ultimately evaluating their significance when fouling is to be minimized and operation improved. Six stacks containing different homogeneous and commercially available AEMs were employed to desalinate synthetic PFPW during 8-days ED experiments operated in reversal mode. AEMs recovered from the stacks were analyzed in terms of water uptake, ion-exchange capacity, permselectivity, and area resistance, and compared with virgin AEMs. Relatively small changes were measured for most of the parameters evaluated. For most AEMs, the water uptake and resistance increased, while the ion-exchange capacity (IEC) and permselectivity decreased during operation. Ultimately, AEMs with high area resistance were linked to the fast development of limiting current conditions in the stack, so this property turned out to be the most relevant when desalinating PFPW.


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