Technical Abstract: Wheat gluten films of varying thicknesses formed at 30C to 70C were treated with cold sulfuric acid to produce sulfated gluten films. Chemical, thermal, thermal stability, and water uptake properties were characterized for neat and sulfated films. The sulfated gluten films were able to absorb up to thirty times their weight in deionized water. However, this value dropped to 3.5 when the film was soaked in a 0.9% (w/w) NaCl solution. The films were also soaked four times in deionized water and each soaking resulted in reduced water uptake capacity. The temperature of film formation had no effect on final water uptake properties. Also, thinner films had higher concentrations of sulfate groups than thicker films, resulting in higher water uptake values. In addition, sulfated gluten films had comparable glass transition temperatures, but lower thermal stability than neat gluten films.