Lecture

Micelle formation: structure and shapes

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

In course

MSE-209: Transfer phenomena in materials science

Ce cours porte sur le transfert de la chaleur par conduction, convection et rayonnement, ainsi que sur la diffusion à l'état solide. D'après les règles phénoménologiques (Equations de Fourrier et Fick), des problèmes de solution 1-D et 2-D ainsi que modèle ...

Description

This lecture covers the critical micelle concentration (CMC) of hexane, the influence of salt on CMC, the structure of aggregates determined by intermolecular forces, the packing parameter of amphiphiles, and the shapes of aggregates. It also discusses the aspect ratio's impact on aggregate shape, the packing parameter of spheres, examples of aggregates like sodium dodecyl sulfate, and methods to make elliptical micelles spherical. Furthermore, it explores the theory of detergent action, vesicles as delivery vehicles for hydrophobic ingredients, and the mobility and diffusion of phospholipids in bilayers.

This video is available exclusively on Mediaspace for a restricted audience. Please log in to MediaSpace to access it if you have the necessary permissions.

Watch on Mediaspace

Official source

Related concepts (22)

Micelle

A micelle (maɪˈsɛl) or micella (maɪˈsɛlə) (plural micelles or micellae, respectively) is an aggregate (or supramolecular assembly) of surfactant amphipathic lipid molecules dispersed in a liquid, forming a colloidal suspension (also known as associated colloidal system). A typical micelle in water forms an aggregate with the hydrophilic "head" regions in contact with surrounding solvent, sequestering the hydrophobic single-tail regions in the micelle centre. This phase is caused by the packing behavior of single-tail lipids in a bilayer.

Sodium dodecyl sulfate

Sodium dodecyl sulfate (SDS) or sodium lauryl sulfate (SLS), sometimes written sodium laurilsulfate, is an organic compound with the formula and structure . It is an anionic surfactant used in many cleaning and hygiene products. This compound is the sodium salt of the 12-carbon organosulfate. Its hydrocarbon tail combined with a polar "headgroup" give the compound amphiphilic properties that make it useful as a detergent. SDS is also component of mixtures produced from inexpensive coconut and palm oils.

Critical micelle concentration

In colloidal and surface chemistry, the critical micelle concentration (CMC) is defined as the concentration of surfactants above which micelles form and all additional surfactants added to the system will form micelles. The CMC is an important characteristic of a surfactant. Before reaching the CMC, the surface tension changes strongly with the concentration of the surfactant. After reaching the CMC, the surface tension remains relatively constant or changes with a lower slope.

Phospholipid

Phospholipids are a class of lipids whose molecule has a hydrophilic "head" containing a phosphate group and two hydrophobic "tails" derived from fatty acids, joined by an alcohol residue (usually a glycerol molecule). Marine phospholipids typically have omega-3 fatty acids EPA and DHA integrated as part of the phospholipid molecule. The phosphate group can be modified with simple organic molecules such as choline, ethanolamine or serine. Phospholipids are a key component of all cell membranes.

Amphiphile

An amphiphile (from the Greek αμφις amphis, both, and φιλíα philia, love, friendship), or amphipath, is a chemical compound possessing both hydrophilic (water-loving, polar) and lipophilic (fat-loving) properties. Such a compound is called amphiphilic or amphipathic. Amphiphilic compounds include surfactants (these detergents are commonly called "soap" but are different from traditional soap in both composition and method of action for cleaning). The phospholipid amphiphiles are the major structural component of cell membranes.

Related lectures (38)

Vesicles: Structure and Properties

Explores the structure and properties of liposomes and polymersomes, discussing their stability, phases, and responsiveness.

Micelle Formation: Structure and Shape

Explores micelle formation, aggregate structure, shapes, and applications as delivery vehicles.

Micelles: Structure and Properties

Explores the formation and properties of micelles, the role of amphiphilic molecules in solubilizing fats, lyotropic liquid crystals, surface tension, and the Gibbs adsorption isotherm.

Liquid Crystals: Structure and Properties

Covers liquid crystal formation, micelle structure, amphiphilic molecules, and surface tension in fluids.

Modeling synaptic transmission: Stochastic Dynamics MOOC: Simulation Neurocience