ABSTRACT Sulfonated poly(ether ether ketone) (SPEEK) can be a potential replacement of Nafion owi... more ABSTRACT Sulfonated poly(ether ether ketone) (SPEEK) can be a potential replacement of Nafion owing to its cost effectiveness and tunable sulfonation sites. The proton conductivity of SPEEK can be improved by increasing the degree of sulfonation (DS) but at the cost of sacrificing its mechanical properties. The presence of the inherited structural water in layered double hydroxide (LDH) can be highly beneficial in improving the proton conductivity of the nanocomposite membranes. SPEEK–LDH composite membranes were prepared using two varieties of LDH and characterized by FT-IR, TGA and proton conductivity measurements. The thermal stabilities of the SPEEK–LDH composite membranes increase with increasing LDH content. The proton conductivity and peak power density of the SPEEK–LDH composite containing 3 wt.% LDH have been found to be 229.6 mS cm−1 and 560 mW cm−2, respectively, compared to 147.6 mS cm−1 and 470.4 mW cm−2, respectively for SPEEK at 80 °C and 100% relative humidity.
Phosphoric acid-doped poly (2,5-benzimidazole) (DABPBI) was prepared by condensation polymerizati... more Phosphoric acid-doped poly (2,5-benzimidazole) (DABPBI) was prepared by condensation polymerization of 3,4-diaminobenzoic acid for high temperature proton electrolyte membrane fuel cells. The membranes were casted directly using a hot-press unit and characterized by fourier transform infrared spectroscopy, thermogravimetric analysis, conductivity measurement, scanning electron microscopy and tensile test. The proton conductivities of DABPBI are observed to be 0.062 and 0.018 under 30 and 1% relative humidity, respectively at a temperature of which is appreciably higher than that of Nafion 115 under similar conditions. The DABPBI membrane has demonstrated excellent thermo- mechanical properties and proton conductivity suggesting its suitability as a high temperature membrane.
ABSTRACT Nafion-clay nanocomposite membrane has been prepared by dispersing unmodified and acid a... more ABSTRACT Nafion-clay nanocomposite membrane has been prepared by dispersing unmodified and acid activated Laponite XLS in Nafion 20% dispersion. The resulting membranes possess better proton conductivity and mechanical strength as compared to the virgin membrane. Acid activation of the nanoclay leads to the in-situ generation of H3PO4 by the hydrolysis of the peptizer present on the surface of the nanoclay. The in-situ generated H3PO4 helps in improving all the technical properties of the nanocomposite including the water uptake and proton conductivity of the nanocomposite, containing acid activated clay compared to the nanocomposite, containing unmodified clay. The maximum proton conductivity of 270.2 mS/cm is achieved at 110 °C for the nanocomposite membrane containing 3% acid-activated Laponite compared to 136.2 mS/cm for the virgin Nafion. Keywords: Nafion, clay, nanocomposite, peptizer, polymer electrolyte membrane fuel cell (FEMFC), proton conductivity, membrane
Journal of Polymer Science Part B: Polymer Physics, 2008
In the present scenario, polymer clay nanocomposite is one of the frontier areas of research. Dep... more In the present scenario, polymer clay nanocomposite is one of the frontier areas of research. Depending on the dispersion of clay in the polymer matrix, it can be classified into three categories, intercalated, exfoliated, and agglomerated. However, successful thermal and ...
ABSTRACT Sulfonated poly(ether ether ketone) (SPEEK) can be a potential replacement of Nafion owi... more ABSTRACT Sulfonated poly(ether ether ketone) (SPEEK) can be a potential replacement of Nafion owing to its cost effectiveness and tunable sulfonation sites. The proton conductivity of SPEEK can be improved by increasing the degree of sulfonation (DS) but at the cost of sacrificing its mechanical properties. The presence of the inherited structural water in layered double hydroxide (LDH) can be highly beneficial in improving the proton conductivity of the nanocomposite membranes. SPEEK–LDH composite membranes were prepared using two varieties of LDH and characterized by FT-IR, TGA and proton conductivity measurements. The thermal stabilities of the SPEEK–LDH composite membranes increase with increasing LDH content. The proton conductivity and peak power density of the SPEEK–LDH composite containing 3 wt.% LDH have been found to be 229.6 mS cm−1 and 560 mW cm−2, respectively, compared to 147.6 mS cm−1 and 470.4 mW cm−2, respectively for SPEEK at 80 °C and 100% relative humidity.
Phosphoric acid-doped poly (2,5-benzimidazole) (DABPBI) was prepared by condensation polymerizati... more Phosphoric acid-doped poly (2,5-benzimidazole) (DABPBI) was prepared by condensation polymerization of 3,4-diaminobenzoic acid for high temperature proton electrolyte membrane fuel cells. The membranes were casted directly using a hot-press unit and characterized by fourier transform infrared spectroscopy, thermogravimetric analysis, conductivity measurement, scanning electron microscopy and tensile test. The proton conductivities of DABPBI are observed to be 0.062 and 0.018 under 30 and 1% relative humidity, respectively at a temperature of which is appreciably higher than that of Nafion 115 under similar conditions. The DABPBI membrane has demonstrated excellent thermo- mechanical properties and proton conductivity suggesting its suitability as a high temperature membrane.
ABSTRACT Nafion-clay nanocomposite membrane has been prepared by dispersing unmodified and acid a... more ABSTRACT Nafion-clay nanocomposite membrane has been prepared by dispersing unmodified and acid activated Laponite XLS in Nafion 20% dispersion. The resulting membranes possess better proton conductivity and mechanical strength as compared to the virgin membrane. Acid activation of the nanoclay leads to the in-situ generation of H3PO4 by the hydrolysis of the peptizer present on the surface of the nanoclay. The in-situ generated H3PO4 helps in improving all the technical properties of the nanocomposite including the water uptake and proton conductivity of the nanocomposite, containing acid activated clay compared to the nanocomposite, containing unmodified clay. The maximum proton conductivity of 270.2 mS/cm is achieved at 110 °C for the nanocomposite membrane containing 3% acid-activated Laponite compared to 136.2 mS/cm for the virgin Nafion. Keywords: Nafion, clay, nanocomposite, peptizer, polymer electrolyte membrane fuel cell (FEMFC), proton conductivity, membrane
Journal of Polymer Science Part B: Polymer Physics, 2008
In the present scenario, polymer clay nanocomposite is one of the frontier areas of research. Dep... more In the present scenario, polymer clay nanocomposite is one of the frontier areas of research. Depending on the dispersion of clay in the polymer matrix, it can be classified into three categories, intercalated, exfoliated, and agglomerated. However, successful thermal and ...
Uploads
Papers by ananta mishra