Question: is nafion soluble in water?
Answer: Nafion density in acetonitrile was ∼15% less than that in water. Acid pretreatment reduced Nafion film density by ∼15%. Unheated recast films were 22−100% soluble in a sonicated ethanol/water mixture. Commercial membranes and recast films heated for as little as 10 min were insoluble under the same conditions.