When heated above the LCST (45 °C), the copolymers are expected to transition from hydrated and flexible coils to collapsed globules. SANS data for copolymers 5a4 and 5c1 above the LCST were successfully fitted with a Sphere model. This indicates formation of dense spherical polymer nanogels rather than vesicles (polymersomes), which confirms the conclusions from the cryo-TEM images (Figure ). The insertion of 20% cyclopropyl repeating units (5c1) did not affect the final morphology and the scattering data could again be fitted with the simple Sphere model. The best-fit diameters were 47.6 ± 1.0 nm (5a4) and 78.0 ± 0.5 nm (5c1), respectively. Data for size obtained by SANS, cryo-TEM and DLS are similar and the trend of forming larger structures with 5c1 compared to 5a4 was consistent across all the measurements. SANS typically shows the smallest diameter of all the three methods, because it does not account for the hydration shell in the measurement.