(Of a material or membrane) allowing certain substances to pass through it but not others, especially allowing the passage of a solvent but not of certain solutes.
More example sentences
- In dialysis a solution is passed over a semipermeable membrane, allowing solutes up to a certain size (but not larger molecules) to diffuse across the membrane to a second solution.
- A semipermeable membrane allows small solvent molecules to pass through, but not the larger solute molecules.
- Graham found that the rate at which some substances, such as inorganic salts, pass through a semipermeable membrane is up to 50 times as great as the rate at which other substances, such as proteins, do so.