Fig. 4: Mechanism of stretchable polymers with ultralong phosphorescence.
From: Stretchable phosphorescent polymers by multiphase engineering
a SAXS profile plots of copolymers PABEs and homopolymer HPAA, supporting the microphase-separated morphology in the designed block copolymers, while HPAA shows no scattering peak. b Related 2D SAXS images of PABEs films. c TEM images of PABE (left), PABE-b (middle), and PABE-d (right) provide clear evidence of the microphase-separated structure with PAA phase (dark spheres with diameters of 10–30 nm) dispersed in continuous PBMA phase (gray areas). The PAA segment was selectively stained with uranyl acetate. Scale bar: 300 nm. d 2D-WAXS pattern of PABE film. e Confocal fluorescence images of PABE, PABE-b, and PABE-d. λex = 405 nm. Scale bar: 20 μm. Yellow channel (570–600 nm): phosphorescence of DBI in PAA matrix. f Snapshots of the simulated structures for PABE, PABE-b, and PABE-d in the bulk. These amphiphilic copolymers spontaneously assemble into microphase-separated structures. g Proposed mechanism of ultralong phosphorescence from amphiphilic block copolymers. Fluo., Phos., and Exc. refer to fluorescence, phosphorescence, and excitation, respectively.
