Polyethylene surfactant assemblies

Recently, a new class of inhibitors (nonionic polymer surfactants) was identified as promising agents for drug formulations. These compounds are two- or three-block copolymers arranged in a linear ABA or AB structure. The A block is a hydrophilic polyethylene oxide) chain. The B block can be a hydrophobic lipid (in copolymers BRIJs, MYRJs, Tritons, Tweens, and Chremophor) or a poly(propylene oxide) chain (in copolymers Pluronics [BASF Corp., N.J., USA] and CRL-1606). Pluronic block copolymers with various numbers of hydrophilic EO (,n) and hydrophobic PO (in) units are characterized by distinct hydrophilic-lipophilic balance (HLB). Due to their amphiphilic character these copolymers display surfactant properties including ability to interact with hydrophobic surfaces and biological membranes. In aqueous solutions with concentrations above the CMC, these copolymers self-assemble into micelles. 

Nonionic surfactants are known to produce all kinds of self-assembly structure, particularly microemulsions, with and without the presence of a cosurfactant. This is probably due to several reasons. One is that the interaction between neighboring nonionic polar groups such as polyethylene oxide chains or polyhydroxyl head groups is much weaker than the interaction befiveen neighboring ionic groups. In commercial nonionic surfactants systems, an additional reason is the polydispersity of the surfactant oligomers in terms of... 

A triblock copolymer, Pluronic F-68, (polyethylene oxide-polypropylene oxide- polyethylene oxide triblock copolymer), a synthetic surfactant [74] was adsorbed to hydrophobic substrata such as PDMS to form low-density polymer brush-coatings [86]. The PEO-PPO-PEO triblock copolymers in many ways exhibit a similar behavior as low molecular weight non-ionic surfactants. The tendency of these amphiphilic polymers to self-assemble in aqueous systems and at interfaces has led to widespread applications for the stabilization of macromolecular colloidal suspensions and for the manipulation of surface properties [92]. Anti-fouling properties of Pluronic copolymers result from the fact that the Pluronic copolymers PPO domain, which... 

---