Evo25

Surface
morphologies were imaged using a scanning electron microscopy
(SEM) (EVO25, Carl Zeiss, Germany), following a thin gold film sputtering,
at 5 kV voltage and 5 pA current. FTIR spectra was recorded with a
spectrophotometer (Spectrum Two, PerkinElmer, ATR mode). A digital
microscope (Keyence, VHX-7000) and a GXML3200B compound microscope
were used to observe the self-healing process and examine the damage
to coatings following liquid impact tests. The powder X-ray diffraction
(PXRD) of the MOF powder was recorded on a Stoe STADI-P spectrometer
with tube voltage of 40 kV, tube current of 40 mA in a stepwise scan
mode (5° min^–1). The transparency was assessed
using an Orion AquaMate UV–vis spectrophotometer. The contact
angles and the contact angle hysteresis were measured on a custom
designed goniometer setup with at least three samples tested for statistics.^{32 (link)}

SEM images were taken using scanning electron microscopy (ZEISS EVO MA 25, Zeiss Evo 25, Germany). Images were prepared with a voltage of 5–10 kV. Samples were dehydrated before imaging. The specimens were connected to a 5 mm diameter stub pin using a 350 mm diameter pin. The samples were coated with gold using a sputtering method for 2 min at 15 Ma (JEOL Ltd., Tokyo, Japan) under an argon atmosphere, and images were taken at different resolutions. To evaluate the surface topography of scaffolds, 3D surface reconstruction (3DSM, Carl Zeiss scanning electron microscopy) and MountainsSEM® were used.

The morphology of the strand surfaces at different time points of degradation was analyzed by scanning electron microscopy (SEM). Scaffolds were dried, gold sputtered using a Sputter Coater (JFC-1200 Fine Coater; Jeol, Peabody, MA, USA), and imaged by SEM (EVO 25; Zeiss, Oberkochen, Germany).

Scanning electron microscopy (SEM) using a Zeiss EVO 25 instrument coupled with energy-dispersive X-ray spectroscopy (EDS) (Oxford X-act) was employed to analyze the coprolite samples. Tiny pieces of the coprolite samples were broken off for analysis, with one sample taken from the surface and another from the inner portion of each coprolite. Three coprolites (IVPP V 27941/3, IVPP V 27941/45, and IVPP 27941/49) were selected for these studies. Additionally, a sediment sample from the Na Duong coal mine was used as a comparison. Prior to analysis, all samples were attached to a stub and coated with a thin layer of gold.

The rheological properties of the liquid resins used for printing were measured using a Discovery Hybrid rotational rheometer (DHR3, TA instrument). The viscosities of the liquid resins before printing were measured at different shear rates (from 0.1 to 1000 s⁻¹) under ambient conditions (23 °C). Differential scanning calorimetry (DSC) measurements were carried out on a Mettler Toledo DSC 3 STARe system instrument. The samples were heated from − 20–200 °C at a rate of 5 °C/min. Each measurement applied two heating-cooling cycles, and the data were acquired from the second heating process. Fourier transform infrared (FTIR) spectra of cured objects with various formulations were obtained using a spectrophotometer (Spectrum Two™, Perkin Elmer, ATR mode) in the region of 4000–600 cm⁻¹, with a resolution of 4 cm⁻¹. The fracture surface morphologies of dog-bone specimens were imaged using scanning electron microscopy (SEM) (EVO25, Carl Zeiss, Germany). For SEM observation, the specimens with suitable dimensions were fixed on the metal stake using double-sided adhesive carbon tapes and coated with a thin gold film, and then observed under an accelerating voltage of 5 kV. Thermal gravimetric analysis (TGA) was performed on a TA Instruments SDT 650 system from 40° to 500°C in a nitrogen environment at a heating rate of 10 °C/min.