Tampons and pads could be replaced by new super-absorbent material

By Mark Waghorn via SWNS

A superabsorbent dressing that soaks up three times more liquid could replace kitchen towels and sanitary pads.

The newly developed material may also stop bleeding from wounds - and help clean up during surgery.

It is made from a gelatin-like material containing a polymer - a web of large molecules can draw in more than 100 times their weight in water.

Corresponding author Professor Srinivasa Raghavan, of Maryland University, said: "We reimagined what a hydrogel can look like.

"What we've done is combine the desired properties of a paper towel and a hydrogel."

He envisions the sheets being used in period proof undies - as well as picking up spills in kitchens and laboratories.

The technique described in Matter opens the door to foldable and cuttable sheets of the future that will replace towels in kitchens.

There are generally two types of materials that absorb liquids. Porous cloths and paper are flexible and easy to use - but not very absorbent.

On the other hand, hydrogels are more effective - but become brittle solids that crumble when dried.

The US team first mixed in a chemical cocktail - including acid - in a zip-top bag. Like vinegar meeting baking soda, carbon dioxide bubbles developed within the gel.

A foam-like material formed. It was sandwiched between glass slabs to form a sheet and then exposed to UV light. The liquid set around the bubbles - leaving pores behind.

Lastly, the team dipped the set sheet in alcohol and glycerol and air-dried it. This enabled the dried gel sheet to remain soft and flexible - similar to fabric.

Raghavan said: "To our knowledge, this is the first hydrogel that has been reported to have such tactile and mechanical properties."

The gel sheets also stayed soft and flexible in ambient conditions for a year - indicating stability.

Raghavan said: "We are trying to achieve some unique properties with simple starting materials."

Compared to a commercial cloth pad and a paper towel, a gel sheet the same size can absorb more than three times the amount of liquid.

When researchers placed it over 25 mL (0.8 oz) of spilled water, the sheet swelled and soaked it up within 20 seconds, holding the water without dripping. The cloth pad only absorbed about 60 percent - leaving drips behind.

The gel sheet also performed well with syrup, blood and even fluids that are a million times thicker than water.

It could absorb nearly 40 mL (1.4 oz) of blood within 60 seconds - while gauze dressing soaked up only 55 percent.

The gel sheet also holds its liquid well, whereas the blood-soaked gauze trickles. It absorbed over two times more blood than sanitary pads, sponges and gauze.

Raghavan and colleagues now plan to optimize the product by increasing absorbency.

They will strengthen the material, lowering the cost, and making the sheets reusable. The researchers are also looking to develop gel sheets for absorbing oil.

Raghavan said: "In principle, the gel sheets could be a superior form of paper towels."

Because of their flexible and absorbent nature, gel sheets also have the potential to stop bleeding from severe wounds as dressing.

Raghavan said: "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."