Copolymers E96B18, E184B18, E315B17, and E398B19 (E = oxyethylene unit, B = oxybutylene unit) were synthesized and characterized by gel permeation chromatography (for distribution width) and 13C NMR spectroscopy (for absolute molar mass and composition). Dynamic and static light scattering was used to determine micellar properties in dilute aqueous solution at three temperatures (25, 40, and 50 °C): that is, hydrodynamic radius and hydrodynamic expansion factor, mass-average molar mass, and thermodynamic expansion factor. At a given temperature, the values of the radii and expansion factors increased as E-block length was increased, whereas values of the micelle association number decreased. The tube-inversion method was used to define the mobile−immobile (hard gel) phase boundary. At room temperature (20 °C), hard gels were formed in the concentration range 3.5−8 wt % copolymer depending on E-block length, the lowest value being for the copolymer with the longest E block (E398B19).

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We report the results of a small-angle neutron scattering study into the structure of the adsorbed layers formed at the interface in a dilute perfluorodecalin-in-water emulsion by five short chain diblock copolymers of oxyethylene (OE) and oxybutylene (OB) (OE 26OB13, OE29OB11, OE30OB7, OE27OB6, and OE58OB13). The results are discussed in the context of the Marques-Joanny-Leibler scaling description of block copolymer adsorption from selective solvents and provide an insight into the validity of the theory in the unusual limit of short chain lengths and small anchor blocks, close to the boundary between the buoy-dominated and the van der Waals-buoy regimes. The volume fraction profiles are best described by parabolic and, to a lesser extent, Gaussian functional forms. When the temperature was increased, the buoy blocks were found to contract toward the surface, giving rise to profiles that were more blocklike, in accordance with theoretical predictions by Wijmans and Zhulina (Macromolecules 1993, 26, 7214).