Fig. 2: Phase behavior of the amphiphilic random copolymer in water.

a Synthetic route to P(DA-r-PEGA) by RAFT copolymerization. b SAXS data of P(DA₉₆-r-PEGA₇₅) as a function of polymer weight fraction (w_p). The data obtained at room temperature are plotted. Peak positions marked with orange and blue triangles are assigned to the structure factors from the bilayer-folded lamellae and the unfolded lamellae. c SAXS data of P(DA-r-PEGA)s with i_DA = 55% and different N. Concentration is fixed at 64 wt%. The SAXS pattern of C12E9 is also shown as a reference at N = 1. Peak positions marked with gray triangles are assigned to the structure factors from the hexagonal geometry. d Photo of 64 wt% aqueous solution of P(DA₇₃-r-PEGA₅₉) at room temperature showing the gel state. Yellow color comes from the trithiocarbonate moiety included at the chain end. e Polarized optical micrograph of spherulites obtained upon slow cooling (0.5 °C/min) of the 64 wt% solution of P(DA₇₃-r-PEGA₅₉) from the isotropic state at 55 °C. f Cross-sectional TEM image of the vitrified solution of P(DA₇₃-r-PEGA₅₉) at 60 wt% concentration. The solution contained 5 wt% of sodium silicate and 0.2 M HCl. The microtomed film was further stained with RuO₄. g–i Phase diagrams for the polymers with i_DA = 55% (g), 60% (h), and 50% (i) as a function of w_p, N, and temperature (T). The following phases were identified by SAXS analysis: L_α (fluidic multilamellar, gray); H_I (hexagonal, violet); L_α + H_I (red); L_f (bilayer-folded lamellar) + L_{α or} H_I (blue); I (isotropic, green). Blue shade indicates the phase boundary for the L_f + L_{α or} H_I phase.