Review of the proton exchange membranes for fuel cell applications

Recent development of polymer electrolyte membranes for fuel cells.

Organic―inorganic nanocomposite polymer electrolyte membranes for fuel cell applications

This critical review presents a discussion on the major advances in the field of organic–inorganic hybrid membranes for fuel cells application. The hybrid organic–inorganic approach, when the organic part is not conductive, reproduces to some extent the behavior of Nafion where discrete hydrophilic and hydrophilic domains are homogeneously distributed. A large variety of proton conducting or non conducting polymers can be combined with various functionalized, inorganic mesostructured particles or an inorganic network in order to achieve high proton conductivity, and good mechanical and chemical properties. The tuning of the interface between these two components and the control over chemical and processing conditions are the key parameters in fabricating these hybrid organic–inorganic membranes with a high degree of reproducibility. This dynamic coupling between chemistry and processing requires the extensive use and development of complementary ex situ measurements with in situ characterization techniques, following in real time the molecular precursor solutions to the formation of the final hybrid organic–inorganic membranes. These membranes combine the intrinsic physical and chemical properties of both the inorganic and organic components. The development of the sol–gel chemistry allows a fine tuning of the inorganic network, which exhibits acid-based functionalized pores (–SO3H, –PO3H2, –COOH), tunable pore size and connectivity, high surface area and accessibility. As such, these hybrid membranes containing inorganic materials are a promising family for controlling conductivity, mechanical and chemical properties (349 references).

Design and properties of functional hybrid organic–inorganic membranes for fuel cells

Predictive models for mixed-matrix membrane performance: a review.

Nafion-functionalized multiwalled carbon nanotubes (MWCNT-Nafion) are prepared through an ozone-mediated process. The chemical structure of MWCNT-Nafion is characterized by Raman spectroscopy, Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy. Nafion chains covering on the outer surfaces of MWCNTs in MWCNT-Nafion is observed in high-resolution transmission electron micrographs. The Nafion fraction of MWCNT-Nafion is about 12 wt%. MWCNT-Nafion is effective to prepare Nafion/MWCNT-Nafion composite membranes for proton exchange membrane fuel cells. Compared to the pristine Nafion membrane, the composite membrane with a MWCNT-Nafion loading of 0.05 wt% (N/MN-0.05) exhibits an 1.5-fold increase of mechanical strength and a five-fold increase of proton conductivity. In single cell tests, the current density at 0.6 V and the maximum power density measured with the N/MN-0.05 composite membrane are 1556 mA cm−2 and 650 mW cm−2, respectively. Both of the values are 1.5-times the values measured with a pristine Nafion membrane.

Preparation and applications of Nafion-functionalized multiwalled carbon nanotubes for proton exchange membrane fuel cells

Preparation and properties of nanocomposite membranes of polybenzimidazole/sulfonated silica nanoparticles for proton exchange membranes

Polybenzimidazole (PBI)-functionalized silica nanoparticles modified PBI nanocomposite membranes for proton exchange membranes fuel cells

Nafion- and polybenzimidazole (PBI)-functionalized multiwalled carbon nanotubes (MWCNT–Nafion and MWCNT–PBI) have been prepared through an ozone mediated process and used as additives in the preparation of PBI/MWCNT nanocomposite membranes. Scanning electron microscopy images of the nanocomposite membranes show a high compatibility between functionalized-MWCNTs and the PBI matrix. Addition of the functionalized MWCNTs enhances the thermal and mechanical properties of the composite membranes. Moreover, compared to the proton conductivity of 0.03 S cm−1 of the phosphoric acid (PA)-doped PBI membrane, the PA-doped nanocomposite membranes containing 0.2 wt% of MWCNT–Nafion (N-0.2) and MWCNT–PBI (P-0.2) have proton conductivities of 0.05 and 0.08 S cm−1 at 160 °C under anhydrous conditions, respectively. In single cell tests at 150 °C, N-0.2 and P-0.2 demonstrated maximum power densities of 700 and 600 mW cm−2, respectively. The values are much higher than that found with pristine PBI membrane (530 mW cm−2).

Polybenzimidazole membranes modified with polyelectrolyte-functionalized multiwalled carbon nanotubes for proton exchange membrane fuel cells

The Phyllanthus acidus (L.) Skeels has been used as traditional medicine. It has been proved to have hepatoprotective, anti-inflammatory, antidiabetic, and antioxidant properties. Toxicology data in pregnant women are still unknown. The purpose of this study is to assess the safety of an ethanol extract of Phyllanthus acidus (L.) Skeels leaves (EEPA) on pregnant women and fetuses. The pregnant Wistar rats were divided into five groups: a negative control (vehicle), a positive control (5-fluorouracil 10 mg/kg), and three experiment groups (22.5, 90, and 1000 mg/kg). The extract was given orally between the 6th and 15th days of pregnancy, during the organogenesis phase of fetal growth. The EEPA found light maternal toxicity. It was demonstrated by the lower weight of fetuses from rats given EEPA and the lower number of fetuses than the vehicle. EEPA did not cause abnormalities in the skeleton or organs of the fetus, but the pale color and smaller size of the fetal's kidneys, heart, and lungs were observed after a dose of 1000 mg/kg. Although the EEPA affected fetal weight during pregnancy and the genetic disorders require further research.

Suryani

Papers

Preparation and applications of Nafion-functionalized multiwalled carbon nanotubes for proton exchange membrane fuel cells

Preparation and properties of nanocomposite membranes of polybenzimidazole/sulfonated silica nanoparticles for proton exchange membranes

Polybenzimidazole (PBI)-functionalized silica nanoparticles modified PBI nanocomposite membranes for proton exchange membranes fuel cells

Polybenzimidazole membranes modified with polyelectrolyte-functionalized multiwalled carbon nanotubes for proton exchange membrane fuel cells

Evaluation Teratogenicity of Phyllanthus Acidus (L.) Skeel Leaf Ethanol Extract in Pregnant Wistar Rats