TY - JOUR A1 - Casse, O. A1 - Shkilnyy, A. A1 - Linders, J. A1 - Mayer, C. A1 - Häussinger, D. A1 - Völkel, A. A1 - Thünemann, Andreas A1 - Dimova, R. A1 - Cölfen, H. A1 - Meier, W. A1 - Schlaad, H. A1 - Taubert, A. T1 - Solution behavior of double-hydrophilic block copolymers in dilute aqueous solution JF - Macromolecules N2 - The self-assembly of double-hydrophilic poly(ethylene oxide)–poly(2-methyl-2-oxazoline) diblock copolymers in water has been studied. Isothermal titration calorimetry, small-angle X-ray scattering, and analytical ultracentrifugation suggest that only single polymer chains are present in solution. In contrast, light scattering and transmission electron microscopy detect aggregates with radii of ca. 100 nm. Pulsed field gradient NMR spectroscopy confirms the presence of aggregates, although only 2% of the polymer chains undergo aggregation. Water uptake experiments indicate differences in the hydrophilicity of the two blocks, which is believed to be the origin of the unexpected aggregation behavior (in accordance with an earlier study by Ke et al. [Macromolecules2009, 42, 5339–5344]). The data therefore suggest that even in double-hydrophilic block copolymers, differences in hydrophilicity are sufficient to drive polymer aggregation, a phenomenon that has largely been overlooked or ignored so far. KW - Nanotechnology KW - Small-angle X-ray scatering KW - SAXS PY - 2012 DO - https://doi.org/10.1021/ma300621g SN - 0024-9297 SN - 1520-5835 VL - 45 IS - 11 SP - 4772 EP - 4777 PB - American Chemical Society CY - Washington, DC AN - OPUS4-26072 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -