Why can you pee without getting wet

Infants and young children need to use diapers to prevent soiling their bodies, clothes and trousers because they can't control their own urination and defecation. Traditional diapers are made of cotton cloth with good water absorption. Why can cotton absorb water? This is because the main component of cotton cloth is cellulose. There are many small voids between cellulose molecules, and water molecules can penetrate into these voids. There are also many groups called hydroxyl (- OH) on cellulose, and hydroxyl groups are also found in water molecules. After the hydroxyl groups of water molecules are "captured" by the hydroxyl groups of cellulose, the two are "combined" together through hydrogen atoms to form hydrogen bonds, and water molecules can no longer run around. This is why cotton can absorb water.

Although the diaper made of cotton can absorb water, its water absorption capacity is not strong. The cotton cloth that has sucked a little water is wet, and it can squeeze out water with one hand. Therefore, traditional diapers need to be changed frequently in order to keep infants dry. Can you improve the water absorption of the diaper and let the diaper absorb more water?

Diapers are products with stronger water absorption function developed to meet this demand. Scientists use natural fibers such as cotton cloth as basic raw materials, add some chemicals with stronger water absorption capacity, such as ethylene oxide, and "connect" them to cellulose through "grafting" (a chemical reaction), so as to make diapers with super water absorption capacity - diapers. Diaper can absorb nearly a hundred times its own mass of water, and firmly "lock" these water in the molecules, so even if it absorbs a lot of water, it is still very dry.

It can be used to make water retaining materials for diapers. It can also be used to make absorbent paper and napkins, as well as in many fields such as soil moisturizing and medicine.