Sandglass-shaped self-assembly of coil-rod-coil triblock copolymer containing rigid aniline-pentamer

The amphiphilic PEG1 500-b-EM AP-b-PEG1 500 (EM PAP) triblock copolymer of poly(ethylene glycol) (PEG) and emeraldine aniline-pentamer (EM AP) in its concentrated solution can self-assemble into a special shape like sandglass, as observed by transmission electron microscopy (TEM), field emission scanning electron microscopy (ESEM) and atomic force microscopy (AFM). This sandglass- shaped assembly is composed of several rods aggregated in the middle, with every rod being about 8 VLrn in length and 300 nm in diameter. We conclude that the special sandglass-shaped assembly may come into being because of the inducement effect of the crystallization of EM AP ts, by studying electron diffraction (ED) segmen results and wide-angle X-ray diffusion (WAXD) characterization of the EM PAP triblock copolymer.