New Fiber Reinforced Hydrogels are Tougher Than Metal

fiber hydrogel

There are currently major efforts being undertaken around the world to create materials that are friendly to both the environment and society. Among them are those that are made up of different materials, but still exhibit the merits of each component.

Professor Jian Ping Gong, from the Hokkaido University, has led a team of researchers that focused on using hydrogels to create a reinforced material. Although such a substance would have the potential to be used as a structural biomaterial, no material strong and reliable enough for long-term use has been manufactured up until now.

To solve the problem, the researchers combined hydrogels that contain high levels of water, with glass fiber fabric to produce tough, yet bendable materials.

The team employed the same technique that is used to produce reinforced plastics. They found that a mixture of polyampholyte (PA) gels and glass fiber fabric with a single fiber measuring around 10μm in diameter produced a strong tensile material. PA is a type of hydrogel the team had developed earlier. To make the material, they simply immerse the fabric in a PA precursor solution for polymerization.

New fiber-reinforced hydrogel consists of polyampholyte (PA) gels and glass fiber fabric. Toughness is increased by dynamic ionic bonds between the fiber and hydrogels, and within the hydrogels. (Image credit: Hokkaido University)

When used on its own, the fiber-reinforced hydrogels developed by the team are 100 times tougher than hydrogels and 25 times tougher than glass fiber fabric in terms of the energy needed to destroy them. A synergistic toughening is enabled when these materials are combined. The team hypothesizes that the increase in toughness is caused by dynamic ionic bonds between the hydrogels and fiber, and within the hydrogels. The fiber’s toughness increases in relation to that of the hydrogels. The newly developed hydrogels were found to be 5 times tougher than carbon steel.

Gong noted that the fiber-reinforced hydrogels are environmentally friendly, with a water level of 40 percent. He added that as the material is durable, reliable and flexible, it has multiple potential applications. Apart from manufacturing and fashion uses, it could also be used as artificial tendons and ligaments, as these are subjected to strong load-bearing tensions. The principles applied with the present study to create tough materials, can also be applied to other soft components, including rubber.

The full study was published in the journal Advanced Functional Materials.