Search results
Results from the WOW.Com Content Network
The difficulty in filling the volume of the interior of a bilayer, while accommodating the area per head group forced on the molecule by the hydration of the lipid head group, leads to the formation of the micelle. This type of micelle is known as a normal-phase micelle (or oil-in-water micelle).
Having the characteristics of soaps, sodium stearate has both hydrophilic and hydrophobic parts, a carboxylate and a long hydrocarbon chain. These two chemically different components induce the formation of micelles, which present the hydrophilic heads outwards and their hydrophobic (hydrocarbon) tails inwards, providing a lipophilic environment for hydrophobic compounds.
The shape of a micelle is directly dependent on the packing parameter of the surfactant. Surfactants with a packing parameter of N S {\displaystyle N_{\text{S}}} ≤ 1/3 appear to have a cone-like shape which will pack together to form spherical micelles when in an aqueous environment (top in figure).
Micellar solutions form when the concentration of amphiphile exceeds the critical micelle concentration (CMC) or critical aggregation concentration (CAC), which is when there are enough amphiphiles in the solution to clump together to form micells.
A mixture of soap and water is an everyday example of a lyotropic liquid crystal. Biological structures such as fibrous proteins showings relatively long and well-defined hydrophobic and hydrophilic ‘‘blocks’’ of aminoacids can also show lyotropic liquid crystalline behaviour. [6]
For example, a reactive group A on a 20-mer (a polymer with 20 monomer units) has the same reactivity as another group A on a 2000-mer. Using the above assumptions, let us examine a homopolymerization reaction starting from a single monomer with z-functional groups with a fraction p of all possible bonds already having been formed.
A handmade soap bar Two equivalent images of the chemical structure of sodium stearate, a typical ingredient found in bar soaps Emulsifying action of soap on oil. Soap is a salt of a fatty acid (sometimes other carboxylic acids) used for cleaning and lubricating products as well as other applications. [1]
A micellar cubic phase is a lyotropic liquid crystal phase formed when the concentration of micelles dispersed in a solvent (usually water) is sufficiently high that they are forced to pack into a structure having a long-ranged positional (translational) order. For example, spherical micelles a cubic packing of a body-centered cubic lattice.