Journal
ACS APPLIED MATERIALS & INTERFACES
Volume 1, Issue 11, Pages 2573-2579Publisher
AMER CHEMICAL SOC
DOI: 10.1021/am900498u
Keywords
composite materials; polymeric materials; fuel cells; proton conductivity; selectivity
Funding
- National Science Foundation [CBET-0932740]
- Petroleum Research Fund [48373-AC7]
- Div Of Chem, Bioeng, Env, & Transp Sys
- Directorate For Engineering [0932740] Funding Source: National Science Foundation
Ask authors/readers for more resources
A series of new Nafion-based composite membranes have been prepared via an in situ sol-gel reaction of 3-(trihydroxyIsilyl)propane-I-sulfonic acid and solution casting method. The morphological structure; ion-exchange capacity, water uptake, proton conductivity, and methanol permeability of the resulting composite membranes have been extensively investigated as functions of the content of sulfopropylated polysilsesquioxane filler, temperature, and relative humidity. Unlike the conventional Nafion/silica composites, the prepared membranes exhibit an increased water uptake and associated enhancement in proton conductivity compared to unmodified Nafion. In particular, considerably high proton conductivities at 80 and 120 C under 30% relative humidity have been demonstrated in the composite membranes, which are over 2 times greater than that of Nafion. In addition to a remarkable improvement in proton conductivity, the composite membranes display lower methanol permeability and superior electrochemical selectivities in comparison to the pure Nafion membrane. These unique properties could be exclusively credited to the presence of pendant sulfonic acid groups in the filler, which provides fairly continuous proton-conducting pathways between filler and matrix in the composite membranes and thus facilitates the proton transport without the anticipated trade-off between conductivity and selectivity. This work opens new opportunities of tailoring the properties of Nafion-the benchmark fuel cell membrane-to obviate its limitations and enhance the conductive properties at high temperature/low humidity and in direct methanol fuel cells.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available