Crosslinked chitosan/poly (vinyl alcohol) blends with proton conductivity characteristic

Witt, Maria Alice; Barra, Guilherme Mariz de Oliveira; Bertolino, José Roberto; Pires, Alfredo T. N.

doi:10.1590/s0103-50532010000900014

Cited by 28 publications

(24 citation statements)

References 8 publications

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“…However, the excessive swelling of PVA-PWA composite membranes limits their mechanical strength. For PEM applications, PVA is commonly incorporated into the PEM as a crosslinked partner via aldol condensation [60][61][62][63][64][65][66][67][68][69][70] or esterification [49,[71][72][73][74][75][76] to form a 3D network structure. Moreover, the degree of crosslinking of the PVA-based membranes has been shown to be easy to control via successive chemical treatments (aldol condensation or esterification).…”

Section: Poly (Vinyl Alcohol) (Pva)mentioning

confidence: 99%

Water Soluble Polymers as Proton Exchange Membranes for Fuel Cells

2012

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Abstract:The relentless increase in the demand for useable power from energy-hungry economies continues to drive energy-material related research. Fuel cells, as a future potential power source that provide clean-at-the-point-of-use power offer many advantages such as high efficiency, high energy density, quiet operation, and environmental friendliness. Critical to the operation of the fuel cell is the proton exchange membrane (polymer electrolyte membrane) responsible for internal proton transport from the anode to the cathode. PEMs have the following requirements: high protonic conductivity, low electronic conductivity, impermeability to fuel gas or liquid, good mechanical toughness in both the dry and hydrated states, and high oxidative and hydrolytic stability in the actual fuel cell environment. Water soluble polymers represent an immensely diverse class of polymers. In this comprehensive review the initial focus is on those members of this group that have attracted publication interest, principally: chitosan, poly (ethylene glycol), poly (vinyl alcohol), poly (vinylpyrrolidone), poly (2-acrylamido-2-methyl-1-propanesulfonic acid) and poly (styrene sulfonic acid). The paper then considers in detail the relationship of structure to functionality in the context of polymer blends and polymer based networks together with the effects of membrane crosslinking on IPN and semi IPN architectures. This is followed by a review of pore-filling and other impregnation approaches. Throughout the paper detailed numerical results are given for comparison to today's state-of-the-art Nafion ® based materials.

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Section: Poly (Vinyl Alcohol) (Pva)mentioning

confidence: 99%

Water Soluble Polymers as Proton Exchange Membranes for Fuel Cells

2012

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“…The addition of GO to the membranes reduced the σprot. Although the analyses were carried out after 24 h of immersion in water to guarantee proper hydration, the low thickness of the membranes (30 µm) may have resulted in lower hydration degree and high desorption rate of swelled humidity, which is crucial for proton transport through the membrane [23,24]. As well, the addition of GO nanoparticles seemed to have promoted a highly compact structure that reduced the hydration ability and hindered the proton transport pathways.…”

Section: Proton Conductivitymentioning

confidence: 99%

Functionalised Poly(Vinyl Alcohol)/Graphene Oxide as Polymer Composite Electrolyte Membranes

Cháfer¹,

Teruel-Juanes²,

Badía³

et al. 2019

Journal of Renewable Materials

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Crosslinked poly(vinyl alcohol) (PVA) based composite films were prepared as polyelectrolyte membranes for low temperature direct ethanol fuel cells (DEFC). The membranes were functionalised by means of the addition of graphene oxide (GO) and sulfonated graphene oxide (SGO) and crosslinked with sulfosuccinic acid (SSA). The chemical structure was corroborated and suitable thermal properties were found. Although the addition of GO and SGO slightly decreased the proton conductivity of the membranes, a significant reduction of the ethanol solution swelling and crossover was encountered, more relevant for those functionalised with SGO. In general, the composite membranes were stable under simulated service conditions. The addition of GO and SGO particles permitted to buffer the loss and almost retain similar proton conductivity than prior to immersion. These membranes are alternative polyelectrolytes, which overcome current concerns of actual commercial membranes such as the high cost or the crossover phenomenon.

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“…The main degradation stages occur due to dehydration, degradation and decomposition of polymeric backbone and blend. 4,6,24 Thermal degradation starts at 140 °C for lower CS content membranes (Figure 3 (A)). DTG (Figure 3 (A)) shows that SSA crosslink interferes directly with membrane degradation process.…”

Section: Thermal Propertiesmentioning

confidence: 99%

Preparation and Characterization of an Eco-Friendly Polymer Electrolyte Membrane (PEM) Based in a Blend of Sulphonated Poly(Vinyl Alcohol)/ Chitosan Mechanically Stabilised by Nylon 6,6

Oliveira

Mendes

2016

Mat. Res.

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Membranes for fuel cell applications were prepared using two polymer blends: poly(vinyl alcohol) (PVAL) and chitosan (CS), 80/20 (w/w) and 60/40 (w/w) with and without nylon. Sulfosuccinic acid (SSA) was used both as a crosslinking and a sulfonating agent. An increasing in the SSA content raised ionic exchange capacity and consequently proton conductivity in the membranes. The addition of nylon has improved membrane mechanical properties by decreasing stiffness. Membranes presented good proton conductivity (around 10 -2 S cm -1 ) and lower H 2 and methanol permeability rather than the standard membrane Nafion ® 115. Membranes which showed to be stable under fuel cell operation were tested using hydrogen and methanol fuels. Membrane PVAL:CS, 80/20 (w/w), containing SSA crosslinker, (PVAL+CS)/SSA, of 4/1 (mol/mol), has shown the best performance under fuel cell environment. However, results have shown that an improvement is required in the adhesion between the membrane and the electrodes.

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Crosslinked chitosan/poly (vinyl alcohol) blends with proton conductivity characteristic

Cited by 28 publications

References 8 publications

Water Soluble Polymers as Proton Exchange Membranes for Fuel Cells

Water Soluble Polymers as Proton Exchange Membranes for Fuel Cells

Functionalised Poly(Vinyl Alcohol)/Graphene Oxide as Polymer Composite Electrolyte Membranes

Preparation and Characterization of an Eco-Friendly Polymer Electrolyte Membrane (PEM) Based in a Blend of Sulphonated Poly(Vinyl Alcohol)/ Chitosan Mechanically Stabilised by Nylon 6,6

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