Su 70 electron microscope

Thermogravimetric analysis (TGA) was performed using a Shimadzu TGA-50 system, in the temperature range from 25 to 800°C at a heating rate of 10°C min^–1, under a static atmosphere of air. Polarized optical microscopy (POM) images were obtained with an Olympus BX41 microscope, using crossed polarizers. Scanning Electronic Microscopy (SEM) images were registered with a Hitachi SU-70 electron microscope. The samples were attached to aluminum stubs using double-sided carbon adhesive tape or carbon glue. Pictures were obtained from the surface and cross-section areas. All the samples were sputter-coated with carbon through an EMITECH K950X Turbo Evaporator, at a single pulse, on an outgassing time of 30 s and an evaporating time of 2 s. Transmission electron microscopy (TEM) images were obtained by a Philips CM200 microscope with an accelerating potential of 100 keV. TEM samples were prepared using a method described by Giasson et al. (1988) (link).
UV-Vis reflectance spectroscopy was carried out using a Perkin-Elmer Lambda 950 UV/Vis/NIR spectrophotometer and a Spectralon integrating sphere (Ø = 150 mm). The freestanding film surface was placed perpendicularly to the incident beam and the spectra were acquired as a function of the incident angle (15° < θ < 60°) with 5° steps, as illustrated in Supplementary Scheme 1.