Flashcards in Surfactants Deck (16)
What is a surfactant?
Surface + active + agent
boundary between two phases
boundary between two phases, one of which is a gas
the capacity to do work
potential energy per unit surface area
What does intermolecular bonding do to molecules?
Intermolecular bonding stabilises molecules and lowers their energy.
energy required to expand the surface of a liquid by a unit area (N m−1 or dyn cm−1).
For liquids, surface tension and surface energy are...
quantitatively equivalent and often used interchangeably.
What do surfactants do?
reduce suface tension
Contact angle is...
Indicator of solid surface wettability
Tendency of liquid to adhere to solid surface
has both hydrophilic (water-loving) and hydrophobic (water- hating) portions in the same molecule.
Uses of surfactants (3)
Micelles form when...
When the liquid surface is saturated with surfactant molecules, excess surfactant molecules sink below the liquid surface and self-aggregate into micelles.
Critical micelle concentration (CMC)
Minimum surfactant concentration at which micelles begin to form.
Generally, the larger the surfactant molecule, the lower the molar CMC.