Kort beskrivelse af aktiviteten: Detergents are molecules that have a hydrophobic and a hydrophilic part. Detergents can dissolve in water up to a certain concentration even though the hydrophobic part and water do not “like” to interact with each other. Above this concentration, detergents will assemble into so called micelle structures, since it is energetically more favorable for them to aggregate into structures where the hydrophobic part of the molecule is shielded from water. Formation of these micelle structures will happen at different concentrations (critical micelle concertation CMC) dependent on what detergent is used and the environmental conditions such as temperature, salt concentration, additives, and pH.

Micelles play an important role in many processes. The simplest application is removal of stains (typically more hydrophobic) from fabric with soup. There soap (micelles) act as an emulsifier to make stains more soluble. But micelles also play an important role in medicine as nano-carriers for gene delivery, drug delivery and diagnostic applications. Micelle formation is also essential for the absorption of fat-soluble vitamins and fat within the human body. A detergent called Bile salts formed in the liver and secreted by the gall bladder allows micelles of fatty acids to form. This allows the absorption of lipids and lipid-soluble vitamins (A, D, E, and K) by the small intestine.

In the project you determine the CMC of different kind of detergents (such as SDS, Tween 20, ……) and investigate the influence of environmental factors such as salt concentration on the micelle formation.

Faglig relevans: Kemi, bioteknologi

Nøgleord: Micelles, CMC

Forberedelse: Materiale tilsendes

Tidspunkter for besøget: Aftales med kontaktperson

Maks. antal personer: 3-4 elever

Besøgets varighed: 2 dage, inkl. lidt rundvisning på Nano

Mødested: Skjernvej 4a, 9220 Aalborg

Kontaktperson: gymnasieportalen@adm.aau.dk Eva Maria Petersen, Institut for Materialer og Produktion

Evt. detaljeret beskrivelse / Bilag: