semi-permeable

A semi-permeable membrane allows water molecules to pass through but blocks larger salt ions.

Definition

1. Adjective:
   • Partially permeable: "semi-permeable" describes a material or membrane that allows some substances (such as small molecules or ions) to pass through it, but prevents the passage of others (typically larger molecules). This term is most commonly used in biology, chemistry, and physics to describe cell membranes or synthetic filters.

Usage Examples

• (Describes a biological membrane's selective barrier function.)
• (Refers to a synthetic filter used in water treatment.)
• (Explains a medical application of the concept.)

Advanced Usage

• "semi-permeable barrier": a boundary that selectively restricts the movement of particles or substances.

  • The blood-brain barrier acts as a semi-permeable barrier, protecting the brain from harmful substances while allowing essential nutrients to cross. (Describes a physiological structure with selective permeability.)

• "semi-permeable nature": the inherent property of being partially permeable.

  • The semi-permeable nature of the plastic film made it ideal for food packaging that needs to control moisture loss. (Describes a material's functional characteristic.)

Variants and Related Words

• Permeable (adj): allowing liquids or gases to pass through completely.

  • The soil is permeable, so rainwater drains quickly. (Contrasts with semi-permeable's partial nature.)

• Permeability (n): the state or quality of being permeable.

  • The membrane's permeability to glucose was measured in the experiment. (Refers to the degree to which a substance can pass through.)

• Impermeable (adj): not allowing anything to pass through.

  • The plastic sheet is impermeable to water. (Opposite of semi-permeable.)

Synonyms

• Selectively permeable: allowing only certain substances to pass.

  • A selectively permeable membrane is crucial for cellular function. (Synonym emphasizing the selection process.)

• Partially permeable: having limited ability to allow passage.

  • The partially permeable layer controls the flow of nutrients. (A direct synonym.)

Phrasal Verbs

Related Idioms