Chitosan/silica coated carbon nanotubes composite proton exchange membranes for fuel cell applications

In this study, we incorporated commercially available p‐toluene sulfonic acid coated boehmite nanofillers (commercially known as OS1) into the chitosan (CS) matrix to fabricate CS–OS1 nanocomposite membranes with a high proton conductivity for fuel‐cell applications. These nanocomposite membranes were characterized by Fourier transform infrared spectroscopy, energy‐dispersive X‐ray spectroscopy, X‐ray diffraction analysis, scanning electron microscopy, and thermogravimetric analysis. Their mechanical properties, water uptake, ion‐exchange capacity, and proton conductivity were also determined. The results show that the incorporation of OS1 to CS chains can inhibit the mobility of CS chains and, hence, enhance the thermal stability and mechanical properties of CS–OS1 nanocomposite membranes. The composite membrane with 5 wt % OS1 showed a proton conductivity of 0.032 S/cm; this was almost equal to that of commercially available Nafion 117. We concluded that CS–OS1 nanocomposite membranes have potential for fuel‐cell applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 46904.

Section: Resultssupporting

confidence: 89%

Preparation and performance of nanoparticle‐reinforced chitosan proton‐exchange membranes for fuel‐cell applications

Ahmed

Cai

Ali

et al. 2018

“…The incorporation of sulfonated MWCNTs into the CS matrix results in the occurrence of electrostatic and hydrogen bonding interaction between SO 3 H groups of MWCNTs and NH 2 groups of CS. This reduces the water absorption capacity of CS, resulting in a decrease in water uptake. Moreover, the hydrophobic nature of MWCNTs also results in a decrease in water uptake .…”

Section: Resultsmentioning

confidence: 99%

“…The increase in proton conductivity of both types of composite membranes can be attributed to (1) the homogenous dispersion of MWCNTs in the CS matrix at a low MWCNTs loading and (2) the electrostatic interaction and formation of sulfonic acid‐amine acid–base pairs (SO 3 − …. 3 + HN) that can simulate the formation of uninterrupted transport channels in CS/MWCNTs membrane . The proton concentration and mobility are key parameters for the proton conductivity of PEM.…”

Section: Resultsmentioning

confidence: 99%

“…However, it is very difficult to disperse carbon nanotube (CNT) homogeneously in the polymer matrix due to the strong Van der waals force; and an ionic channel can be formed in PEM due to the high electronic conductivity of CNT, which may lead to short‐circuiting in PEMFCs . To overcome these problems, Si, Ti, Zr, and phosphonate functionalized CNT are commonly used for modification of PEM . Recently, carbon nanomaterials (MWCNTs and fullerene) with sulfonic acid groups have been widely used in the fabrication of composite membranes .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Novel sulfonated multi‐walled carbon nanotubes filled chitosan composite membrane for fuel‐cell applications

Ahmed

Ali

Cai

et al. 2019

In the present study, multi‐walled carbon nanotubes (MWCNTs) were sulfonated by 1,3‐propane sultone and distillation–precipitation polymerization, respectively, and then incorporated into chitosan (CS) to prepare CS/MWCNTs composite membranes for fuel cell applications. CS/MWCNTs membranes show better thermal and mechanical stability than pure CS membrane due to the strong electrostatic interaction between the SO3H groups of MWCNTs and the NH2 groups of CS, which can restrict the mobility of CS chain. The sulfonated MWCNTs provide efficient proton hopping sites (SO3H, SO3− …. 3+HN), thereby resulting in the formation of continuous proton conducting channels. The composite membranes with 5 wt % of MWCNTs modified by two different ways show a proton conductivity of 0.026 and 0.025 S·cm−1, respectively. In conclusion, CS/MWCNTs membrane is a promising proton exchange membrane for fuel‐cell applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47603.

“…Chitosan (CS) is the product generated from the deacetylation of chitin, and has been extensively studied in the field of polymer electrolyte membranes because of the following benefits: (1) CS has many functional groups (e.g., NH 2 and OH) that easily allow chemical modification to tailor its properties for fuel cell application; (2) the hydrophilicity of CS is a desirable property for the ion transport under the condition of low humidity; (3) CS possesses high alcohol fuel barrier ability, which can decrease the fuel consumption and thus increase the fuel cell efficiency; and (4) CS is low cost, eco‐friendly, and abundant in environment. Moreover, when a CS membrane is swollen in water, the conduction of hydroxyl ions in it becomes possible because the amino groups of CS can be protonated and simultaneously leave OH − free.…”

Section: Introductionmentioning

confidence: 99%

Quaternized chitosan/functionalized carbon nanotubes composite anion exchange membranes

Jang

Chuang

Tsen

et al. 2019

Natural alkaline polyelectrolyte chitosan has been considered to be a promising anion exchange membrane (AEM) material due to its low cost and easy quaternization. To further improve the ionic conductivity and mechanical property of quaternized chitosan (QCS), QCS functionalized carbon nanotubes (QCS@CNTs) were prepared and used as a novel nanofiller to modify the membrane matrix. The QCS coating layer on the surface of CNTs can not only improve the dispersion of CNTs and thus promote the load transfer from the QCS matrix to stiff CNTs, but also endow CNTs with a certain hydroxide ions exchange ability. The results show that the addition of QCS@CNTs slightly decreased the ionic conductivity of the composite membranes while the tensile strength and alkaline stability of these membranes were significantly improved, indicating the potential application of these composite membranes in AEM fuel cells. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47778.