Scientists age quantum dots in a test tube

Researchers from MIPT and the RAS Institute of Problems of Chemical Physics have proposed a simple and convenient way to obtain arbitrarily sized quantum dots required for physical experiments via chemical aging. The study ...

Researchers develop method to create colloidal diamonds

The colloidal diamond has been a dream of researchers since the 1990s. These structures—stable, self-assembled formations of miniscule materials—have the potential to make light waves as useful as electrons in computing, ...

Having a ball: Crystallization in a sphere

Crystallization is the assembly of atoms or molecules into highly ordered solid crystals, which occurs in natural, biological, and artificial systems. However, crystallization in confined spaces, such as the formation of ...

Controlled dynamics of colloidal rods

Colloidal particles have become increasingly important for research as vehicles of biochemical agents. In future, it will be possible to study their behavior much more efficiently than before by placing them on a magnetized ...

Polymers can fine-tune attractions between suspended nanocubes

Colloids are complex mixtures in which microscopic particles of one substance are suspended evenly throughout another. They can be prepared in many different ways, but to achieve desirable properties in the final mixture, ...

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A colloid is a substance microscopically dispersed evenly throughout another substance.

A colloidal system consists of two separate phases: a dispersed phase (or internal phase) and a continuous phase (or dispersion medium). A colloidal system may be solid, liquid, or gaseous.

Many familiar substances are colloids, as shown in the chart below. In addition to these naturally occurring colloids, modern chemical process industries utilize high shear mixing technology to create novel colloids.

The dispersed-phase particles have a diameter of between approximately 5 and 200 nanometers. Such particles are normally invisible in an optical microscope, though their presence can be confirmed with the use of an ultramicroscope or an electron microscope. Homogeneous mixtures with a dispersed phase in this size range may be called colloidal aerosols, colloidal emulsions, colloidal foams, colloidal dispersions, or hydrosols. The dispersed-phase particles or droplets are affected largely by the surface chemistry present in the colloid.

Some colloids are translucent because of the Tyndall effect, which is the scattering of light by particles in the colloid. Other colloids may be opaque or have a slight color.

Colloidal solutions (also called colloidal suspensions) are the subject of interface and colloid science. This field of study was introduced in 1861 by Scottish scientist Thomas Graham.

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