Polymetric Electrolytes

Solid polymeric electrolytes (SPEs) are used as polymer electrolyte membranes in PEM fuel cells.
fuel cell schematic

Schematic of a typical proton exchange membrane (PEM) fuel cell.

Cross-linkable sulfonated SPE formulations
	659401 *Poly(styrene-ran-ethylene), sulfonated, cross-linkable, 5 wt.% solution in 1-propanol* Contains <0.5% vinyl silane cross-linking agent Styrene 76 wt.% Sulfonated styrene units 32-38% Conductivity = 0.1184 S/cm The ionic conductivity can increase up to 50% when heating from RT to 67 °C. Treat with 0.5 M Sulfuric acid for 20 min to strengthen after cross-linking. Material becomes cross-linked w/800-1000 mJ/cm² UV exposure after drying at 110°C for 10-15 min; or at 140-150°C for 1 min.

	659444 *Polystyrene-block-poly(ethylene-ran-butylene)block-polystyrene, sulfonated, cross-linkable, 5 wt.% solution in 1-propanol* Contains <0.5% vinyl silane cross-linking agent Styrene 29 wt.% Sulfonated styrene units 55-65% Conductivity = 0.1078 S/cm The ionic conductivity can increase up to 50% when heating from RT to 67 °C. Treat with 0.5 M Sulfuric acid for 20 min to strengthen after cross-linking. Material becomes cross-linked w/800-1000 mJ/cm² UV exposure after drying at 110°C for 10-15 min; or at 140-150°C for 1 min.

Other sulfonated SPE formulations

	659592 *Poly(styrene-ran-ethylene), sulfonated, 5 wt.% solution in 1-propanol* Styrene 76 wt.% Sulfonated styrene units 32-38% Conductivity = 0.1494 S/cm The ionic conductivity can increase up to 50% when heating from RT to 67 °C.

	448885 Polystyrene-block-poly(ethylene/butylene)-block-polystyrene, sulfonated solution, 5 wt.% solution in propanol and dichlorethane Styrene 29 wt.% Sulfonated styrene units 55-65% Conductivity ~ 0.07 S/cm

A spin coat system is recommended for casting these polymers into films. Click here to view the tech bulletin on the spin coat system. (78.2 KB PDF)

Spin-Coating Systems
Product Name	Product #
Chemat precision spin-coater, 2-stage, 220V	Z551589
Chemat precision spin-coater, 2-stage, 115V	Z551562

Manual Film-Casting Instructions

To cast a film without using a spin coat system, the following procedure is recommended:
1.  Concentrate solution to 600 centapoise viscosity (typically 6-9 wt. % polymer).
2.  Preheat the casting surface to 35°C. A clean, flat teflon-coated glass surface is recommended.
3.  Secure a silicone release liner to the casting surface.
4.  Place a small drop of the polymer solution on the release liner.
5.  Draw the polymer solution down the release liner.
6.  Dry the film for 30 min. For controlled evaporation it is recommended to cover surface with aluminum foil that has been perforated with small pinholes.

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