A better picker-upper: Superabsorbent “gel sheets” with fabric-like flexibility

Abstract

<h2>Summary</h2> Materials to absorb aqueous liquids are either foldable cloth/paper towels (convenient to use but poorly absorbent), or superabsorbent polymer hydrogels (highly absorbent, but fragile when dried). Here, we create "gel sheets" that combine the best attributes from the above. Macrosized sheets (10 × 10 cm) are prepared by foam templating, followed by plasticization and ambient drying. The dried sheets are macroporous, flexible, soft, and robust; they can be folded, rolled up, and cut with scissors, much like fabrics. At the same time, like hydrogels, they substantially absorb water and <i>expand as they absorb</i>, which is unlike any sponges or towels. The sheets also absorb viscous liquids like blood and viscoelastic liquids like polymer solutions. Absorbed liquid is retained within the sheet when lifted, whereas excess liquid drips from towels. Such gel sheets could be used to clean up spills in homes, labs, and hospitals, and for absorbing biological fluids during surgeries.