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Highly stretchable hydrogel shows actuation behaviour upon irradiation of infrared (IR) light. The photothermal effect induced by heat from IR absorption causes cooperative change in the network alignments in the stretched sample.
The effectiveness of energy-resolved (ER) X-ray photoelectron spectroscopy (XPS) with synchrotron radiation (SR) soft X-ray source for analysis of the outermost chemical composition of polymer materials is demonstrated. The surface molecular aggregation state of poly(ethylene glycol) (PEG)/poly(perfluorooctylethyl acrylate) (PFA-C8) was confirmed using ER-XPS. The XPS with SR soft X-ray source detect only the single bilayer structure of the PFA-C8 component, whereas the XPS with Mg Kα X-ray source detect both the PFA-C8 component at the outermost surface and PEG component at the interior.
