Search results
Results from the WOW.Com Content Network
In chemistry, a suspension is a heterogeneous mixture of a fluid that contains solid particles sufficiently large for sedimentation. The particles may be visible to the naked eye , usually must be larger than one micrometer , and will eventually settle , although the mixture is only classified as a suspension when and while the particles have ...
A colloid is a heterogeneous mixture where the dispersed particles have at least in one direction a dimension roughly between 1 nm and 1 μm or that in a system discontinuities are found at distances of that order. [8] A suspension is a heterogeneous dispersion of larger particles in a medium. Unlike solutions and colloids, if left undisturbed ...
The Tyndall effect is light scattering by particles in a colloid such as a very fine suspension (a sol). Also known as Tyndall scattering, it is similar to Rayleigh scattering, in that the intensity of the scattered light is inversely proportional to the fourth power of the wavelength, so blue light is scattered much more strongly than red light.
In solutions, solutes will not settle out after any period of time and they cannot be removed by physical methods, such as a filter or centrifuge. [12] As a homogeneous mixture, a solution has one phase (solid, liquid, or gas), although the phase of the solute and solvent may initially have been different (e.g., salt water).
A colloid has a dispersed phase (the suspended particles) and a continuous phase (the medium of suspension). The dispersed phase particles have a diameter of approximately 1 nanometre to 1 micrometre. [2] [3] Some colloids are translucent because of the Tyndall effect, which is the scattering of light by particles in
Colloids are formed by phase separation, though not all phase separations forms colloids - for example oil and water can form separated layers under gravity rather than remaining as microscopic droplets in suspension. A common form of spontaneous phase separation is termed spinodal decomposition; it is described by the Cahn–Hilliard equation.
The depletion force is an effect of increased osmotic pressure in the surrounding solution. When colloids get sufficiently close, that is when their excluded volumes overlap, depletants are expelled from the interparticle region. This region between colloids then becomes a phase of pure solvent. When this occurs, there is a higher depletant ...
A sol is a colloidal suspension made out of tiny solid particles [1] in a continuous liquid medium. Sols are stable, so that they do not settle down when left undisturbed, and exhibit the Tyndall effect, which is the scattering of light by the particles in the colloid. The size of the particles can vary from 1 nm - 100 nm.