User Contributed Dictionary
Adjective
- Describing any of several phenomena in which electric charge causes movement
- Describing the heating effect of an electric current
Related terms
Extensive Definition
Electrokinetic phenomena is a family of several
different effects that occur in heterogeneous fluids or in porous bodies filled
with fluid. The term heterogeneous here means a
fluid containing particles. Particles can be solid, liquid or gas bubbles with sizes on the scale
of a micrometer or
nanometer.
There is a common source of all these effects -
Double
Layer (interfacial). Influence of an external force on the diffuse
layer generates tangential motion of a fluid with respect to an
adjacent charged surface. This force might be electric, pressure
gradient, concentration
gradient, gravity.
In addition, the moving phase might be either continuous fluid or dispersed
phase.
Various combinations of the driving force and
moving phase determine various electrokinetic effects. Following
"Fundamentals of Interface and Colloid Science" by Lyklema, the
complete family of electrokinetic phenomena includes:
- electrophoresis, as
motion of particles under influence of electric field;
- electro-osmosis, as motion of liquid in porous body under influence of electric field;
- diffusiphoresis, as motion of particles under influence of a chemical potential gradient;
- capillary osmosis, as motion of liquid in porous body under influence of the chemical potential gradient;
- sedimentation potential, as electric field generated by sedimenting colloid particles;
- streaming potential/current, as either electric potential or current generated by fluid moving through porous body, or relative to flat surface;
- Colloid Vibration Current, as electric current generated by particles moving in fluid under influence of ultrasound;
- Electric Sonic Amplitude, as ultrasound generated by colloidal particles in osccilating electric field.
- electro-osmosis, as motion of liquid in porous body under influence of electric field;
There are detailed descriptions of Electrokinetic
phenomena in many books on Colloid and Interface Science, , ,,,
.