S 4800 fe sem system

PVA/DL-alanine polycrystal samples of 2 × 2 cm² size were frozen in liquid nitrogen for approximately 5 s and then cut to a suitable size to obtain clean cross-sectional SEM images of the PVA/DL-alanine polycrystals. The cut samples were fixed to the SEM sample holder so that their cross-sections were exposed for photography on the SEM holder, then the cut samples were coated with platinum (Pt) thin film through DC sputtering in an Ar gas ambient at a power of about 20 mA × 500 V for about 4–5 min by employing a sputter coater (SMC 12R-plus, Semian, South Korea) in vacuum of 5 × 10⁻² mbar to obtain better cross-sectional SEM images by improving the electrical conductivity of the cross sections in which the SEM images are taken. The cross-sectional SEM images of PVA/DL-alanine polycrystals were taken by S-4800 FE-SEM system (Hitachi, Japan), and the voltage and current were set to 10 kV and 10 μA, respectively, and the measurement was carried out in vacuum at room temperature without intentional cooling. See also Figures S1 and S10 in the supplemental information section, and in Figure S10, the change of the thickness of the upper and the lower parts of the PVA/DL-alanine polycrystals according to the r is presented.

Scanning electron microscopy (SEM) images of the samples were obtained by using a Hitachi S4800 FE-SEM system with 10 kV accelerating voltage and 10 mA of beam current. Transmission electron microscopy (TEM) analysis was carried out on a JEM-2100 electron microscope operating at 200 kV. UV-vis spectra of samples were collected on a UV scanning spectrophotometer (Cary 50) equipped with an integrating sphere from 200 to 800 nm. Static contact angles were measured using the sessile drop method with a 3 μL certain liquid droplet and a telescopic goniometer (Rame-Hart, Inc., Mountain Lake, NJ).

FE-SEM images were obtained using the S-4800 FE-SEM system (Hitachi, Tokyo, Japan). All samples were coated with OsO₄ using a Vacuum Device (Ibaraki, Japan). The crystalline phases of Si₃N₄ determined by powder XRD (LabX XRD-6000, SHIMADZU Corporation. Kyoto, Japan), and the chemical structures were characterized by ATR-FTIR spectroscopy (IRAffinity-1S; Shimadzu Corporation, Kyoto, Japan). Chemical composition and chemical bonding were determined by XPS (PHI X-tool; ΦULVAC-PHI, Inc., Kanagawa, Japan) and Raman Spectroscopy (RAMAN touch, Nanophoton, Osaka, Japan).