Colloid
A colloid is a mixture of one substance spread out evenly inside another substance. They can be in two different phases or states of matter.
One substance is the dispersion medium, such as water or gas. The other is the dispersed medium, sometimes called the 'internal phase'. This is usually tiny solid particles. Otherwise, if the dispersion medium is a gas, then the internal phase can be either tiny particles or tiny droplets of a liquid.
Definition: A colloid is a substance microscopically dispersed evenly throughout another substance.[1] The dispersed-phase particles have a diameter between about 5 and 200 nanometers.[2]
Examples:
- Milk is an emulsion, which is a colloid in which both parties are liquids.
- Shaving cream and whipped cream are colloids of gas inside a liquid.
- Gels, such as agar, jelly or even opals, are colloids of liquids inside solids.
- Styrofoam and pumice are gases inside solids.
- The red colour of cranberry glass is caused by the reflection of light off gold particles in the glass. The glass is a colloid of solid particles inside the solid glass.
- Mud is usually considered a suspension because the dirt will settle, but it may be a partial colloid, particularly with very fine-grained clay.[3]
- Fog is a complex mixture in which air has both water droplets and solid particles. It may be colloidal in parts.
Colloid Media
Scanning Electron Microscope image of colloidal particles. Synthesis performed by Dr. Iotzin Rios de Anda and image taken by Dr. Jean-Charles Eloi at The Electron and Scanning Probe Microscopy Unit at the University of Bristol
Brownian motion of 350 nm polymer nanoparticles
Examples of a stable and of an unstable colloidal dispersion.
Diagram of steric stabilization and gel network stabilization in colloids.
Measurement principle of multiple light scattering coupled with vertical scanning
Aerogel: Though with a ghostly appearance like an hologram, aerogel is very solid. It feels like hard styrofoam to the touch.
I bought Jello cubes at Family Fare and ate them in Rosa Parks Circle during my lunch hour
Colloidal silica gel with light opalescence
Dessert with whipped cream
An amount of hair gel on a flat surface.
