semipermeable

As adjectives the difference between impermeable and semipermeable

is that impermeable is waterproof while semipermeable is permeable to some things and not to others, as a cell membrane which allows some molecules through but blocks others substances.

As a noun impermeable

is raincoat.

As an adjective semipermeable

is permeable to some things and not to others, as a cell membrane which allows some molecules through but blocks others substances.

As a noun permeator is

a device, containing a semipermeable membrane, used to desalinate water by reverse osmosis.

As an adjective semipermeable

is permeable to some things and not to others, as a cell membrane which allows some molecules through but blocks others substances.

As a noun aquitard is

a semipermeable layer along an aquifer.

As adjectives the difference between semipermeable and impermeant

is that semipermeable is permeable to some things and not to others, as a cell membrane which allows some molecules through but blocks others substances while impermeant is that cannot permeate through a specified semipermeable membrane.

As adjectives the difference between semipermeable and permeant

is that semipermeable is permeable to some things and not to others, as a cell membrane which allows some molecules through but blocks others substances while permeant is (biochemistry) able to pass through or into a given semipermeable membrane or polymer.

As a noun permeant is

(biochemistry) a substance which is able to pass through or into a membrane or polymer.