Self-assembled amphiphiles scattering

Finally, we have designed and synthesized a series of block copolymer surfactants for C02 applications. It was anticipated that these materials would self-assemble in a C02 continuous phase to form micelles with a C02-phobic core and a C02-philic corona. For example, fluorocarbon-hydrocarbon block copolymers of PFOA and PS were synthesized utilizing controlled free radical methods [104]. Small angle neutron scattering studies have demonstrated that block copolymers of this type do indeed self-assemble in solution to form multimolecular micelles [117]. Figure 5 depicts a schematic representation of the micelles formed by these amphiphilic diblock copolymers in C02. Another block copolymer which has proven useful in the stabilization of colloidal particles is the siloxane based stabilizer PS-fr-PDMS [118,119]. Chemical... 

Mortensen K (2000) Small angle scattering studies of block copolymer micelles, micellar mesophases and networks. In Alexandridis P, Lindman B (eds) Amphiphilic block copolymers self assembly and applications. Elsevier, Amsterdam... 

Although the influence of water on the PEG conformational stmcture is widely accepted, it is less clear to what extent the water stmcture is modified by the presence of PEG. The density depression illustrated in Fig. 3 would suggest that a modified water stmcture potentially exists several nanometers beyond the nominal bmsh length. This is comparable to recent neutron-scattering observations (Schwendel et al., 2002) on ethylene-oxide self-assembled monolayers. The general idea is that this effect be linked to the hydrophobic effect in the vicinity of the amphiphilic PEG layer. 

Key words Self-assembly - phase transition - slow dynamics -amphiphiles - neutron scattering... 

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