Pluronic P123 is a symmetric triblock copolymer comprising poly(
ethylene oxide
Ethylene oxide is an organic compound with the chemical formula, formula . It is a cyclic ether and the simplest epoxide: a three-membered ring (chemistry), ring consisting of one oxygen atom and two carbon atoms. Ethylene oxide is a colorless ...
) (PEO) and poly(
propylene oxide
Propylene oxide is an epoxide with the molecular formula C3H6O. This colourless volatile liquid with an odour similar to ether, is produced on a large scale industrially. Its major application is its use for the production of polyether polyols f ...
) (PPO) in an alternating linear fashion, PEO-PPO-PEO. The unique characteristic of PPO block, which is
hydrophobic
In chemistry, hydrophobicity is the chemical property of a molecule (called a hydrophobe) that is seemingly repelled from a mass of water. In contrast, hydrophiles are attracted to water.
Hydrophobic molecules tend to be nonpolar and, thu ...
at temperatures above 288 K and is soluble in water at temperatures below 288 K, leads to the formation of
micelle
A micelle () or micella () ( 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). ...
consisting of PEO-PPO-PEO triblock copolymers. Some studies report that the hydrophobic core contains PPO block, and a hydrophilic corona consists of PEO block. In 30wt% aqueous solution Pluronic P123 forms a cubic gel phase.
The nominal chemical formula of P123 is HO(CH
2CH
2O)
20(CH
2CH(CH
3)O)
70(CH
2CH
2O)
20H, which corresponds to a molecular weight of around 5800 g/mol. Triblock copolymers based on PEO-PPO-PEO chains are known generically as
poloxamer
Poloxamers are nonionic triblock copolymers composed of a central hydrophobic chain of polyoxypropylene (poly(propylene oxide)) flanked by two hydrophilic chains of polyoxyethylene (poly(ethylene oxide)). The word was coined by BASF inventor, ...
.
Poloxamers have behaviors similar to those of hydrocarbon
surfactants
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. The word ''surfactant'' is a blend of "surface-active agent",
coined in 1950. As t ...
, and will form
micelles
A micelle () or micella () ( 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). ...
when placed in a selective solvent such as water. They can form both spherical and cylindrical micelles
Uses
P123 has been used in the synthesis of mesoporous materials including
FDU-14.
Dissolved P-123 forms micelles that are used as the backbone to make structured mesoporous materials such as
SBA-15.
References
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Copolymers