Figure 2.

Assessment of the morphological transition of self-assembled Janus dendrimers via 37 °C annealing in the presence of ethanol. (a–c) Cryo-TEM images of self-assemblies prepared by direct injection (a) and assemblies annealed from 37 °C after being equilibrated for 1 (b) and 3 h (c). Vesicles with two stacked bilayers are highlighted by arrows in (b). The insets display frequency histograms illustrating the distribution of the bilayer thickness. Each histogram was fitted with the Gaussian distribution, as depicted by the solid lines. (d) Typical morphologies of self-assemblies at different energy states, as indicated by different color codes [as used in the bar graphs in (e)]: eccentric MVVs (gray), OLVs (blue), and ULVs (yellow). 3D surface plots were generated by ImageJ, and details can be found in Experimental Section. Scale bars are 100 nm. (e) Quantitative measurement of assemblies obtained from direct injection (a) and post-treatment at 37 °C (b,c). For each condition, images from different areas and different batches of samples were taken and counted to minimize the error (n > 500 particles). See Supporting Information for a detailed description (Figure S5). (f,g) Relative change of hydrodynamic diameter D_h (%), derived count rates (%), PDI (%) as measured by DLS (f) and D_h (%), and particle concentration (%) as measured by NTA (g) as a function of annealing time at 37 °C. Characterization was performed on three different batches of samples (n = 3).