Which term describes a material that swells when absorbing water?

Which term describes a material that swells when absorbing water?

• A. Imbibition
• B. Syneresis
• C. Tempering
• D. Viscosity

Answer: (A)

Imbibition is the process where a material absorbs water and swells. When a hydrophilic or porous substance takes in water, water molecules enter the material and push the structure to expand, which is exactly what happens when something swells in water. That makes imbibition the best fit for describing swelling due to water absorption. Syneresis is the opposite—it’s the expulsion of liquid from a gel as it contracts or dries. Tempering is a heat-treatment or conditioning process, and viscosity is about a fluid’s thickness or resistance to flow, not swelling.

Imbibition is the process where a material absorbs water and swells. When a hydrophilic or porous substance takes in water, water molecules enter the material and push the structure to expand, which is exactly what happens when something swells in water. That makes imbibition the best fit for describing swelling due to water absorption. Syneresis is the opposite—it’s the expulsion of liquid from a gel as it contracts or dries. Tempering is a heat-treatment or conditioning process, and viscosity is about a fluid’s thickness or resistance to flow, not swelling.