PDF Publication Title:
Text from PDF Page: 006
2332 SATTERFIELD ET AL. Swelling pressure measurement device. The entire cell was placed inside an insulated box (not shown) to maintain a uniform temperature. 1-kO resistor and the membrane and resistor in series were measured to determine the membrane resistance. In principle, the capacitance of the cir- cuit could also be measured, but we found that the capacitance was negligible for the nonporous, stainless steel electrodes, so there was negligible phase lag for frequencies greater than 1 Hz. The dynamics of water sorption were measured by the resistance of a membrane as it absorbed water. In a typical transient experiment, the water channels were dried thoroughly, and a dry mem- brane was positioned in the cell and clamped with a specified force. A peristaltic pump was used to flow water through the flow channels. The water flow rate was typically $10 mL/min, but the results were not dependent on the water flow as long as the flow channels stayed filled with liquid. The resistance of the membrane was measured as a function of time. Swelling Pressure The swelling pressure was measured in the envi- ronmental compression cell shown in Figure 3. Samples (1.4-cm discs) were cut from sheets of Nafion 115 and Nafion/TiO2 115 composite mem- branes that were equilibrated at the ambient tem- perature and RH. After drying at 130 8C for 1 h, the samples were $1.2 cm in diameter and were positioned between porous, stainless steel frits and compressed by a threaded screw. This apparatus had a fixed strain, as opposed to the fixed stress system used in the conductivity measurements. After vacuum evacuation of the chamber, the water vapor pressure was increased by the injec- tion of known aliquots of water. The polymer absorbed water and swelled. A load cell measured the force generated by the membrane as it swelled with water sorption. We simultaneously measured the temperature, RH, total gas pressure, and force generated by the membrane. RESULTS Fuel Cell Response and Water Sorption Figure 4 shows the iv curves for fuel cells contain- ing a Nafion 115 extruded membrane and a Nafion 115/3 wt % TiO2 membrane. Both membranes had a nominal thickness of $127 lm. The voltages obtained at the same current density were greater with the composite membrane than those obtained with Nafion. The in situ resistivity of the mem- brane was estimated from the slope of the iv curve in the ohmic region. The composite membrane had a resistivity of 20 6 2 O cm, whereas the Nafion membrane had an estimated resistivity of 30 6 4 O cm. Fuel cell tests for temperatures from 60 to 120 8C with fully humidified feeds did not show any measurable difference in the membrane resistivity for either of the membranes. Physical/Chemical Characterization Table 1 compares the density, dimensional change with water sorption, IEC, and proton conductivity for the Nafion and Nafion/TiO2 composite mem- branes. The fractional mass gain for both sets of membranes was the same to within 3%; contrary to many reports in the literature,11,39,40 we found no difference in water sorption between liquid and vapor after 24 h in a sealed container. Membranes placed in water at 100 8C for 1 h absorbed almost twice the amount of water as membranes placed in waterat258Cfor24h. Figure 3. Current–voltage sweep of fuel cells at 80 8C with fully humidified feeds for Nafion 115 and Nafion 115/3 wt % 21-nm TiO2 particle composite membranes. Journal of Polymer Science: Part B: Polymer Physics Figure 4. DOI 10.1002/polbPDF Image | Properties of Nafion and Titania Nafion Composite Membranes
PDF Search Title:
Properties of Nafion and Titania Nafion Composite MembranesOriginal File Name Searched:
MechPropNafion_2006.pdfDIY PDF Search: Google It | Yahoo | Bing
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
IT XR Project Redstone NFT Available for Sale: NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Be part of the future with this NFT. Can be bought and sold but only one design NFT exists. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Turbine IT XR Project Redstone Design: NFT for sale... NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Includes all rights to this turbine design, including license for Fluid Handling Block I and II for the turbine assembly and housing. The NFT includes the blueprints (cad/cam), revenue streams, and all future development of the IT XR Project Redstone... More Info
Infinity Turbine ROT Radial Outflow Turbine 24 Design and Worldwide Rights: NFT for sale... NFT for the ROT 24 energy turbine. Be part of the future with this NFT. This design can be bought and sold but only one design NFT exists. You may manufacture the unit, or get the revenues from its sale from Infinity Turbine. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Supercritical CO2 10 Liter Extractor Design and Worldwide Rights: The Infinity Supercritical 10L CO2 extractor is for botanical oil extraction, which is rich in terpenes and can produce shelf ready full spectrum oil. With over 5 years of development, this industry leader mature extractor machine has been sold since 2015 and is part of many profitable businesses. The process can also be used for electrowinning, e-waste recycling, and lithium battery recycling, gold mining electronic wastes, precious metals. CO2 can also be used in a reverse fuel cell with nafion to make a gas-to-liquids fuel, such as methanol, ethanol and butanol or ethylene. Supercritical CO2 has also been used for treating nafion to make it more effective catalyst. This NFT is for the purchase of worldwide rights which includes the design. More Info
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
Infinity Turbine Products: Special for this month, any plans are $10,000 for complete Cad/Cam blueprints. License is for one build. Try before you buy a production license. May pay by Bitcoin or other Crypto. Products Page... More Info
| CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com | RSS | AMP |