How does hydrogel interact with water?

How does hydrogel interact with water?

• A. has pores in cross-linked polymers, allowing water to enter
• B. repels water completely
• C. dissolves in water
• D. forms a waterproof coating

Answer: (A)

Hydrogels interact with water by absorbing it into a porous, cross-linked polymer network. The network contains hydrophilic groups that attract water, so water molecules diffuse in through the pores and the gel swells as it takes up moisture. The cross-links hold the polymer chains together, preventing dissolution, so the material stays intact while it becomes water-rich. This is why the description of water entering through pores in cross-linked polymers best captures how a hydrogel behaves. Water isn’t repelled, it isn’t simply dissolved away because of the cross-links, and it doesn’t form a waterproof coating—the gel remains swollen and hydrated.

Hydrogels interact with water by absorbing it into a porous, cross-linked polymer network. The network contains hydrophilic groups that attract water, so water molecules diffuse in through the pores and the gel swells as it takes up moisture. The cross-links hold the polymer chains together, preventing dissolution, so the material stays intact while it becomes water-rich. This is why the description of water entering through pores in cross-linked polymers best captures how a hydrogel behaves. Water isn’t repelled, it isn’t simply dissolved away because of the cross-links, and it doesn’t form a waterproof coating—the gel remains swollen and hydrated.