A series of new cationic polymeric surfactants, comprising a short hydrophobic n-alkyl (C-12 or C-16) end-group and a long hydrophilic sequence of 17-68 2-(dimethylamino)ethyl methacrylate (DMA) units, were successfully synthesized by oxyanion-initiated polymerization. A previously titrated solution of DMSO-K+ was used for quantitative formation of the potassium alcoholate initiators from the corresponding CI? or C16 alcohols. Optimum polymerization conditions were found to be at or above room temperature, using THF as solvent. Under these conditions the polymers had relatively narrow polydispersities (M-w/M-n approximate to 1.25) and both GPC and NMR spectroscopy showed no residual monomer. NMR studies of the surfactants in CDCl3 also confirmed that good control over the degree of polymerization was achieved, indicating very high initiator efficiency. Cloud points of aqueous solutions of selected polymeric surfactants were determined by turbidimetry and decreased with increasing DMA chain length, as expected. NMR spectra of the surfactants were also recorded in D2O. The C-12 surfactants each had roughly the same degree of polymerization of DMA in D2O as that obtained in CDCl3, suggesting molecular dissolution. In contrast, the apparent degrees of polymerization for the DMA blocks in the C16 surfactants were markedly higher in D2O than in CDCl3. This indicates reduced solvation for the C-16 moiety, which is consistent with micelle formation. Surface tensiometry studies indicated higher surface activities for the C-12-based surfactants compared to the C-16-based surfactants. Again, this is consistent with the hypothesis that the latter surfactants form intermolecular micelles in aqueous solution, whereas the C-12-based surfactants are molecularly dissolved. Dynamic light scattering and transmission electron microscopy studies confirmed the existence of micelles in C-16 surfactant solutions but no micelles were observed for the CI? surfactants. Finally, a selectively deuterated C-12-based polymeric surfactant was also prepared for planned neutron reflectivity studies at the air-water interface.