Paper towels and rags can help with kitchen spills. But using hydrogels (a gelatin-like material in the form of dried sheets), researchers created a better picker upper that absorbs and holds about three times as much water-based liquids.Method published December 21 in the journal matter, manufactures absorbent, foldable and cuttable “gel sheets”. It may one day be used in kitchens and operating rooms to absorb fluids.
In general, there are two types of materials that absorb liquids: porous materials and hydrogels. Porous materials such as cloth and paper are flexible, foldable and easy to use, but they are not very absorbent. On the other hand, superabsorbent hydrogels made of polymers, webs of large molecules, can absorb more than 100 times their weight in water. However, when dried, these hydrogels become brittle solids and crumble.
“We reimagined what a hydrogel looks like,” said lead author Srinivasa Raghavan of the University of Maryland. “What we’ve done is combine the desirable properties of paper towels and hydrogels.”
To create the gel sheets, the research team first placed the hydrogel’s acid, base, and other ingredients in a ziplock bag. Like vinegar and baking soda, the mixture released carbon dioxide bubbles within the gel, creating a porous, foamy material. , then exposed to UV light. This caused the liquid to congeal around the air bubble, leaving a void. Finally, the team soaked the set sheets in alcohol and glycerol and let them air dry. This allowed the dried gel sheets to retain their cloth-like texture and flexibility.
“To our knowledge, this is the first hydrogel reported to have such tactile and mechanical properties,” says Raghavan. Also, gel his sheets remained soft and pliable for 1 year in ambient conditions, demonstrating stability. “We are trying to achieve some unique properties with simple starting materials.”
Compared to cloth napkins and paper towels on the market, the same size gel sheet can absorb more than 3 times more moisture. When the researcher placed the gel sheet on top of 25 mL (0.8 ounces) of spilled water, the sheet swelled, absorbed it within 20 seconds, and held the water without dripping. However, cloth pads only absorb about 60% of the water and leave a drip.
The gel sheets worked well with thicker liquids such as syrup, blood, and even liquids a million times more water. Researchers found that the gel sheets could absorb about 40 mL (1.4 ounces) of blood within 60 seconds, while the gauze dressing only absorbed 55% of the blood. The gel sheet absorbs more than twice as much blood as sanitary napkins, sponges, and gauze.
Next, the team plans to optimize the gel sheets by increasing absorbency, strengthening materials, lowering costs, and making the sheets reusable. Researchers are also looking into developing gel sheets to absorb oil.
“In principle, gel sheets can be a great form of paper towel,” says Raghavan. Flexible and absorbent, the gel sheets could also serve as a bandage to stop bleeding from serious wounds. I’m always interested in developing it further, and it would be great if it could be put to practical use.”
Original: “Better Picker Upper” absorbs 3 times more water than a paper towel
Than: University of Maryland
