Nicolet is50 nicolet continuum

FTIR tests of the samples were acquired using a Nicolet IS50-Nicolet Continuum produced by Thermo Fisher Scientific, Ltd., where attenuated total reflection (ATR) mode was employed for sample detection. XPS analysis was performed on a Kratos Axis Ultra-DLD X-ray photoelectron spectrometer. The XRD test was performed on the PANalytical (X’Pert PRO) instrument with an X-ray of λ = 0.154 nm, operated at 40 kV and 40 mA, and the XRD profiles were collected in the 2θ range of 5°–60°. The SAXS measurements were carried out at Xeuss 3.0 SAXS system (Xenocs, France) with an X-ray of λ = 0.154 nm. The sample-to-detector distance was 1500 mm, and the exposure time was set as 600 s. The anti-freezing properties of hydrogel fibers were measured on DSC (NETZSCH 3500 Sirius) with a heating/cooling rate of 10 °C/min under nitrogen flow. All hydrogel samples were soaked in deionized water for 2 h for removing as much Gly as possible to complete freeze-drying. The freeze-dried hydrogels were brittlely exposed to cross sections with liquid nitrogen and sputtered with gold, followed by SEM (HITACHI SU8220) test.

The surface chemistry of the CNF sample was implemented by Fourier transform infrared spectrophotometer (Nicolet IS50-Nicolet Continuum, Thermo Fisher Scientific) using prepared CNF films. The spectral data was collected at wavenumber ranging from 3700 to 560 cm⁻¹.

Each freeze-dried IDF sample was mixed with KBr powder in a 1:100 ratio into an agate mortar and ground thoroughly under infrared irradiation. Thereafter, the mixture was pressed to form a uniform transparent tablet of 1–2 mm thickness and analyzed using an FTIR spectrometer (Nicolet IS50-Nicolet Continuum, Thermo Fisher Scientific, Waltham, MA, USA). During analysis, the instrument scanned over a range extending from 4000 to 400 cm⁻¹ with a resolution of 4 cm⁻¹, and executed 32 consecutive scans.