K. Stahler et al., Multicompartment polymeric micelles based on hydrocarbon and fluorocarbon polymerizable surfactants, LANGMUIR, 15(22), 1999, pp. 7565-7576
The synthesis of multicompartment polymeric micelles (MCPMs) has been achie
ved by aqueous radical terpolymerization of a water-soluble monomer (acryla
mide) with both hydrocarbon (H) and fluorocarbon (F) surfactants (surfmers)
in the micellar state. The selected H- and F surfmers are CH2=CHCON(C2H5)C
H2CH2N(CH3)(2)CH2COOC16H33/Br/Cl (HS6) and CH2=CHCONHCH2CH2N(CH3)(2)CH2COOC
H2CH2C8F17/Br (FS3), respectively. Their mutual incompatibility in aqueous
solution has been checked by conductivity and surface tension experiments.
Two cmc values are found, in favor of the coexistence of two distinct types
of micelles at surfactant concentrations above 1 mmol/L (second cmc) over
a broad composition range. The solubilization properties of the pure and mi
xed surfactant systems have been studied for different hydrophobic probes.
Significant differences in the solubilization capacity occur due to the nat
ure of the dye, of the surfactant, and of the micelle shape and composition
. A kinetic study on the incorporation behavior of the H- and F-surfmers in
the polyacrylamide backbone during a batch polymerization shows a composit
ional drift as a function of conversion which is attributed to micellar eff
ects. A semicontinuous process has been designed which allows the correctio
n for this compositional drift. The presence of well-segregated H- and F-mi
crodomains in terpolymers could be inferred from viscosity and fluorescence
experiments. Furthermore, the solubilization of decalin is enhanced in ter
polymer solutions with respect to that of copolymer solutions. This was att
ributed to the formation of larger hydrocarbon cores in the former case due
to repulsive H/F interactions in the polymeric chains.