Fig. 3: Overtone photothermal (OPT) spectroscopy and imaging of phase-separation patterns of PS & PMMA blends and stripe-structured PMMA.
From: Overtone photothermal microscopy for high-resolution and high-sensitivity vibrational imaging
a Schematics of spin-coating procedures used for the preparation of microphase separation patterns of PS and PMMA blends. b OPT spectra of pure PMMA and PS as a guide for wavelength selection for PS and PMMA imaging. c, d OPT single-frame images at 1140 nm and 1170 nm, corresponding to the absorption of PS and PMMA, respectively. These images present complementary patterns of the distribution of PS and PMMA domains. e Overlaid channel of c, d, showing the combined distribution of PS and PMMA domains. f Plot of cross-section profiles along the dashed line marked in e. g OPT image of the striped PMMA nanostructures at 1170 nm. h Corresponding AFM topography image of the same field-of-view, providing additional structural information. i Co-plot of the OPT signal cross-section and the height information of PMMA stripe nanostructures. a was created with BioRender.com released under a Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International license.
