Definition of semipermeable in US English:



  • (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.

    • ‘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.’
    • ‘This can be provided by a number of commercially available special dressings, including semipermeable films, foams, hydrocolloids, and calcium alginate swabs.’
    • ‘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.’
    • ‘The passive movement of fluid through a semipermeable membrane from a region of lower solute concentration to a region of higher solute concentration.’
    • ‘The vascular endothelium forms a semipermeable membrane that controls blood-tissue exchange.’
    • ‘This absorbent dressing should be covered with a semipermeable dressing to provide a barrier to the shed virus.’
    • ‘Also, because of the different concentrations of calcium salts in a slab from one spot to the next, it's possible for semipermeable membrane effects to generate high water pressure in localized areas.’
    • ‘The particles do not pass through normal filter paper nor do they dialyze through a semipermeable membrane.’
    • ‘Membranes are semipermeable, highly selective barriers containing ion channels and pumps to modulate and maintain balance as required.’
    • ‘Diffusion of water across a semipermeable membrane such as the cell's plasma membrane is known as diffusion.’
    • ‘The membrane is described as semipermeable because it allows water, but not dissolved substances, to cross it.’
    • ‘In addition, the membrane is semipermeable, allowing for fluid and gas exchange.’
    • ‘According to the release, the severe brush-burn feeling can be avoided by using semipermeable dressings, which let moisture and air reach the skin.’
    • ‘With water potential in the plant at less than zero all the time, positive turgor is possible in cells only in the presence of solutes and the delineating semipermeable membrane backed by the mechanically strong wall.’
    • ‘If a U-shaped glass tube were divided in two by a semipermeable membrane and filled with two solutions the osmotic pressure could be shown.’
    • ‘The analogy emerges that some hybrid zones act as semipermeable membranes that provide a conduit for gene flow at some loci and restrict it at others.’
    • ‘When health care workers are involved in patient care, they should cover their vaccination site with a semipermeable dressing and wear long-sleeved clothing to further reduce the risk of transmission.’
    • ‘The semipermeable membrane at the probe tip allows exchange of soluble molecules between the probe and the surrounding tissue.’
    • ‘A semipermeable membrane allows small solvent molecules to pass through, but not the larger solute molecules.’
    • ‘In the reverse osmosis process, pressure is applied to water to force it through a semipermeable membrane.’