Abstract
Nafion, a perfluorosulfonate ionomer, was modified to increase its thermal stability and reduce its methanol permeability. Hybrid membranes of TiO 2-SiO2/Nafion and TiO2·SiO 2·P2O5/Nafion were prepared using an infiltration sol-gel method. Si(OC2H5)4 and Ti(OC4H9)4 were infiltrated into dry Nafion™ membranes, followed by hydrolysis and condensation reactions in first HCl and then NH4OH solutions. The level of inorganic content was controlled by the infiltration time, incorporating up to 50 wt%. Solvent uptake, swelling, water content and proton conductivity were measured at room temperature. Hybrid membranes of TiO2·SiO2/Nafion with ∼30 wt% of infiltrated oxides showed a significantly lower methanol uptake of ∼20wt% and a swelling ratio of 1.15, as compared to those of unmodified Nafion™ membrane, ∼60wt% for methanol uptake and 1.8 for swelling ratio. Proton conductivities for TiO2-SiO2/Nafion hybrid membranes decreased with increasing infiltrated oxides. However, infiltrated membranes treated in phosphoric acid solutions to increase the number of P-OH groups showed a six-fold increase in proton conductivity.
| Original language | English (US) |
|---|---|
| Article number | S8.4 |
| Pages (from-to) | 153-158 |
| Number of pages | 6 |
| Journal | Materials Research Society Symposium Proceedings |
| Volume | 822 |
| State | Published - 2004 |
| Event | Nanostructured Materials in Alternative Energy Devices - San Francisco, CA, United States Duration: Apr 13 2004 → Apr 15 2004 |
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering