1.3.5 Scanning Electron Microscopy and Energy-Dispersive X-ray Spectroscopy Analysis (P may be added subsequently)
To observe the microstructure of the hydrogels, this experiment employed a field emission scanning electron microscope (SEM) for morphological characterization of the samples. Hydrogel samples with crosslinking degrees of 1.32 × 10^-4, 3.95 × 10^-4, 6.59 × 10^-4, 1.05 × 10^-3, and 2.63 × 10^-3 were selected. These samples were first subjected to vacuum treatment, then coated with gold for 120 seconds, and finally attached to a conductive adhesive for testing. Additionally, to evaluate the uniformity of C, N, O, and Y element distribution, energy-dispersive X-ray spectroscopy (EDS) mapping was performed on sample Y-HG-1.