Surfactant

Summary

Surfactants are chemical compounds that decrease the surface tension or interfacial tension between two liquids, a liquid and a gas, or a liquid and a solid. Surfactants may function as emulsifiers, wetting agents, detergents, foaming agents, or dispersants. The word "surfactant" is a blend of surface-active agent, coined 1950. Composition and structure Surfactants are usually organic compounds that are akin to amphiphilic, which means that this molecule, being as double-agent, each contains a hydrophilic "water-seeking" group (the head), and a hydrophobic "water-avoiding" group (the tail). As a result, a surfactant contains both a water-soluble component and a water-insoluble component. Surfactants diffuse in water and get adsorbed at interfaces between air and water, or at the interface between oil and water in the case where water is mixed with oil. The water-insoluble hydrophobic group may extend out of the bulk water phase into a non-water phase such as air or o

Official source

https://en.wikipedia.org/wiki/Surfactant

About this result

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

Related publications (100)

Related publications

Related people (13)

Related people

Related units (11)

Related units

Related concepts (84)

An emulsion is a mixture of two or more liquids that are normally immiscible (unmixable or unblendable) owing to liquid-liquid phase separation. Emulsions are part of a more general class of two-pha

A detergent is a surfactant or a mixture of surfactants with cleansing properties when in dilute solutions. There are a large variety of detergents, a common family being the alkylbenzene sulfonates,

Soap is a salt of a fatty acid used in a variety of cleansing and lubricating products. In a domestic setting, soaps are surfactants usually used for washing, bathing, and other types of housekee

Related concepts

Related courses (44)

Related courses

Related lectures (73)

Related lectures

A process for increasing the fastness to light, the fluorescence polarisation and fluorescence quantum yield of cyanine dyes, which process comprises stabilising cyanine dyes with the aid of micellar structures of a) surfactants and/or b) surfactant crown ether complexes of monovalent of divalent transition metal cations, or c) mixtures of surfactants, in each case in combination with non-surfactant, nitrogen-containing or nitrogen- and oxygen-containing 16- to 18-membered crown ether complexes of monovalent or divalent transition metal cations.

(Ciba-Geigy A.-G., Switz.).1980

Selective Adsorption of Proteins on Single-Wall Carbon Nanotubes by Using a Protective Surfactant

Anton Knyazev

The dispersion of highly hydrophobic carbon materials such as carbon nanotubes in biological media is a challenging issue. Indeed, the nonspecific adsorption of proteins occurs readily when the nanotubes are introduced in biological media; therefore, a methodology to control adsorption is in high demand. To address this issue, we developed a bifunctional linker derived from pyrene that selectively ena-bles or prevents the adsorption of proteins on single-wall carbon nanotubes (SWNTs). We demonstrated that it is possible to decrease or completely suppress the adsorption of proteins on the nanotube sidewall by using proper functionalization (either covalent or noncovalent). By subsequently activating the functional groups on the nanotube derivatives, protein adsorption can be recovered and, therefore, controlled. Our approach is simple, straightforward, and potentially suitable for other biomolecules that contain thio or amino groups available for coupling.

2011

Self-cleaning and wear-resistant polymer nanocomposite surfaces

Feyza Karasu Kiliç, Yves Leterrier, Luca Alois Egon Müller

Superhydrophobic self-cleaning and wear-resistant nanocomposite surfaces were produced by mimicking the hierarchical structure of the lotus leaf using a combination of rapid self-assembly and a UV nano-imprint lithography (UVNIL) process with a silicone master. Two different acrylate formulations containing acrylated silica nanoparticles and an acrylated silicone surfactant were used. The presence of the silicone master did not suppress the spontaneous migration of the surfactant to the polymer surface, which increased its hydrophobic character. Adding acrylated silica particles considerably increased the viscosity of the acrylate suspensions and led to a shear-thinning behavior. However the particles did not prevent the fast migration process of the surfactant and further increased the hydrophobicity of the material, due to increased nanoscale roughness of the nanocomposite surface. The largest increase of hydrophobicity was achieved for the UVNIL printed lotus surfaces using the acrylate formulation with lowest viscosity. These surfaces became superhydrophobic for the highest investigated concentration of silica. These nanocomposite lotus surfaces were, in addition, very hard with a microhardness above 400 MPa and particularly wear-resistant, and were self-cleaning with respect to hydrophobic contamination.

2018