Preparation, characterization, and testing of a composite membrane with pH sensitivity

In this article, a novel poly‐(acrylic acid‐acrylonitrile) (PAA‐AN)/filter paper composite membrane with pH‐sensitivity was developed. The membrane was composed of three layers. The top and bottom layers were made of PAA‐AN copolymer, while the middle layer was filter paper. The filter paper was used to enhance the strength of the membrane. The PAA‐AN/filter paper membrane showed evident pH sensitivity and pH reversibility as the pH value changed between 2.0 and 9.5. With the increase of the PAA‐AN copolymer amount in the composite membrane, the pH sensitivity increased. The Cu (II) ion‐exchange experiment indicated that the membrane could bind metal ions and could be used as ion‐exchange membrane to purify water. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011