A new super-absorbent pad that can absorb three times more liquid is set to transform traditional tampons and pads.
The sheet is made of a gelatinous material containing a polymer that can absorb more than an ounce of blood in 60 seconds — current gauze dressings only absorb 55 percent of that amount.
The gel sheet also performed well with syrup, blood, and even liquids a million times thicker than water.
Scientists are now trying to strengthen the material and develop reusable sheets for the market.
Professor Srinivasa Raghavan of Maryland University and co-author of the study said: ‘In principle, the gel sheets could be a superior form of paper towels.’
Scientists created a super absorbent sheet made of hydrogel. The group claims it can hold three times more blood than current dressings
There are generally two materials that absorb liquids: porous materials and hydrogels.
Cloth and paper are porous materials and while they are flexible, they are not very absorbent.
On the other hand, superabsorbent hydrogels made of polymer, a web of large molecules, can absorb more than 100 times their own weight in water.
However, when dried, these hydrogels become brittle solids that crumble.
“We’ve reimagined what a hydrogel can look like,” Raghavan told SWS.
“What we’ve done is combine the desirable properties of a paper towel and a hydrogel.”
The road to the superabsorbent began when the team mixed a chemical cocktail — including acid — in a zip-top bag.
“Like vinegar and baking soda, carbon dioxide bubbles developed in the gel,” the researchers said.
Once a foam-like material formed from the brew, the team placed it between glass plates until it developed into a plate, which was then exposed to UV light. The liquid settled around the bubbles, leaving pores.
Finally, the sheet was dipped in alcohol and glycerol and air dried, leaving it soft and flexible.
“To our knowledge, this is the first hydrogel to have such tactile and mechanical properties,” Raghavan said.
The gel sheets also remained soft and flexible under ambient conditions for a year, indicating stability.
“We’re trying to achieve some unique properties with simple starting materials,” Raghavan said.
Compared to a commercially available cloth pad and paper towel, a gel sheet of the same size can absorb more than three times as much liquid.
The sheet is made of a gelatinous material containing a polymer that can absorb more than an ounce of blood in 60 seconds. On the left is the new sheet and on the right is a traditional dressing
The new gel sheet (left) also collected all the fluid during testing, while the gauze dressing (right) barely absorbed the fluid
When researchers placed it over 0.8 ounces of spilled water, the sheet swelled and absorbed within 20 seconds, holding the water without dripping.
The cloth pad only absorbed about 60 percent and left drips.
The gel sheet also holds its fluid well as the blood-soaked gauze drips. It absorbed more than twice as much blood as sanitary napkins, sponges and gauze pads.
Raghavan and colleagues now plan to optimize the product by increasing its absorbency.
Due to their flexible and absorbent nature, gel sheets may also be able to stop the bleeding of serious wounds as a dressing.
