Fig. 2: SEM images, FT-IR spectra characterization and thermogravimetric analysis of hydrogels.
From: Stretchable slide-ring supramolecular hydrogel for flexible electronic devices

a Surface SEM image of Hy-α-CD/ACA-PEG20000-ACA hydrogel. b Cross-sectional SEM image of Hy-α-CD/ACA-PEG20000-ACA hydrogel. c Surface SEM image of hydrogel doped with CaCl2. d Cross-sectional SEM image of hydrogel doped with CaCl2. e The FT-IR spectra of hydrogel (olive, hydrogel doped with CaCl2; red, hydrogel doped without CaCl2). f TG curves of hydrogel (olive, hydrogel doped with CaCl2; red, hydrogel doped without CaCl2).