Gel sheets soak up three times as much liquid as paper towel

^- ⁺ A^- A⁺ 21/12/2022

Scientists at the University of Maryland have developed a novel material with excellent absorption abilities, which they imagine finding use everywhere from kitchens to operating theaters. The team’s gel sheet can soak up and hold around three times more liquid than your regular paper towel, and can also be used to absorb thicker fluids like blood and syrup.

In creating their gel sheets, the scientists set out to walk the line between the two types of materials generally used to soak up liquids, namely hydrogels and porous materials like cloth and paper. Hydrogels can boast excellent absorption abilities and soak up more than 100 times their weight in water, but become brittle and crumbly when they dry.

“We reimagined what a hydrogel can look like,” says corresponding author Srinivasa Raghavan of the University of Maryland. “What we’ve done is combine the desired properties of a paper towel and a hydrogel.”

The team achieved this by mixing acetic acid, sodium bicarbonate and other ingredients together in a zip-lock bag. These ingredients interact to release carbon dioxide bubbles and form a porous foam-like material. Glass slabs were used to press that material flat inside the bag, and the resulting sheet was then exposed to UV light to set the bubbles and pores in place. The material is then dipped in alcohol and glycerol and dried, making it soft, flexible, and able to be cut like fabric.

Placing the sheet over a pool of spilled water saw it swell and soak up more than three times as much liquid as cloth pads and paper towel, and do so without dripping. It also offered superior performance when soaking up thicker liquids like syrup and blood. The gel sheet proved capable of soaking up nearly 40 ml (1.4 oz) of blood within 60 seconds, compared to a gauze dressing that soaked up only 55% of that amount.

“To our knowledge, this is the first hydrogel that has been reported to have such tactile and mechanical properties,” says Raghavan. “We are trying to achieve some unique properties with simple starting materials.”

The team is now working to increase the absorbency further, make the material stronger and reusable, and develop versions to soak up oil. Raghavan imagines these one day being deployed in kitchens, science labs and surgeries, and being used in wound dressings.

“In principle, the gel sheets could be a superior form of paper towels,” says Raghavan. “I’m always interested in taking our inventions further than just publishing a paper. It would be wonderful to take it to actual practical use.”

The research was published in the journal Matter.

Source: Cell Press via EurekAlert

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