Colloid and Interface Science

Colloid and interface science represents a specific chemical branch which deals with multi-phase systems such as colloids or heterogeneous systems consisting of a mechanical mixture of particles between 1 nm and 1,000 nm. Strictly speaking it is a question of systems in which one or more phases are dispersed in a continuous medium. In applied colloid science, however, the upper size limit of a dispersed phase is often extended to 10,000 to 100,000 nm. In contrast to colloid science, interface science concerns those dispersions which do possess an extraordinary large interfacial area between two of the phases. These phases can be droplets, bubbles, or particles.

Colloid and interface science is a very important scientific displicine which has ramifications as well as applications in chemical industry, biotechnology, nanotechnology, pharmaceuticals, minerals, microfluidics, and ceramics. A number of famous and well-known authors have already published many books dedicated to this branch of science. Furthermore there also exists a glossary of terms ‘Nomenclature in Dispersion Science and Technology’ which was released by the USA National Institute of Standards and Technology (NIST).

Concerning the general term of colloidal systems which are also called colloidal suspensions or colloidal solutions it should be mentioned that colloidal systems do represent the main subject of interface and colloid science. Strictly speaking interface and colloid science is a very specific field of study which was introduced in 1861 by Thomas Graham, a very popular Scottish scientist.

Regarding a general colloid system it has to be said that a colloidal system is composed of two separate phases – strictly speaking a so-called dispersed phase and a continuous medium. Consequently a colloid which represents a specific substance being microscopically dispersed can either be solid, gaseous, or liquid. An example therefore would be milk: Milk is an emulsified colloid consisting of liquid butterfat globules which are dispersed throughout a water-based liquid. Of course there exists a wide range of different other familiar substances which do represent colloids. Exemplary colloids are such as hair sprays (dispersed phase: liquid ; continuous medium: gas), cloud (dispersed phase: solid ; continuous medium: gas), shaving cream (dispersed phase: gas ; continuous medium: liquid), mayonnaise (dispersed phase: liquid ; continuous medium: liquid), blood (dispersed phase: solid ; continuous medium: gas), and gelatin (dispersed phase: liquid ; continuous medium: solid). Tissues such as curtains, Gardinen or clothes do not represent colloids but can contain other chemical substances.

Further information about Colloid and Interface Science: http://www.ecis-web.eu