Which material is an aluminosilicate clay that swells in water and has powerful adsorption properties, used for medical or industrial purposes?

Which material is an aluminosilicate clay that swells in water and has powerful adsorption properties, used for medical or industrial purposes?

• A. Bentonite
• B. Kaolin
• C. Montmorillonite
• D. Illite

Answer: (A)

Bentonite is the swelling aluminosilicate clay described. Its main mineral, montmorillonite, has a layered structure that hydrates as water enters between the layers. This interlayer expansion causes significant swelling, and the resulting increase in surface area and charge sites gives it strong adsorption capabilities. That combination—water-driven swelling plus high adsorption—drives its medical use as an adsorbent and its wide industrial applications in purification, decolorization, drilling fluids, cosmetics, and environmental cleanup. Kaolin does not swell appreciably and is used mainly as a filler and in ceramics. Illite also swells only a little and has lower adsorption compared to bentonite. Montmorillonite is the swelling mineral itself, but bentonite is the common material named for these swelling, highly adsorptive clays used in medical and industrial contexts.

Bentonite is the swelling aluminosilicate clay described. Its main mineral, montmorillonite, has a layered structure that hydrates as water enters between the layers. This interlayer expansion causes significant swelling, and the resulting increase in surface area and charge sites gives it strong adsorption capabilities. That combination—water-driven swelling plus high adsorption—drives its medical use as an adsorbent and its wide industrial applications in purification, decolorization, drilling fluids, cosmetics, and environmental cleanup.

Kaolin does not swell appreciably and is used mainly as a filler and in ceramics. Illite also swells only a little and has lower adsorption compared to bentonite. Montmorillonite is the swelling mineral itself, but bentonite is the common material named for these swelling, highly adsorptive clays used in medical and industrial contexts.