Disclosed is an absorbent structure comprising an acidic or basic water-swellable, water-insoluble polymer, a basic or acidic second material, and, optionally, a buffering agent, wherein the absorbent structure exhibits desirable absorbent properties. Specifically, the present invention relates to an absorbent structure having the ability to absorb a large quantity of liquid while maintaining a substantially desired and balanced pH profile on or along the upper surface of the absorbent structure. The absorbent structure is useful in disposable absorbent products, such as those disposable absorbent products that are used to absorb body liquids.