Sc7620 mini sputter coater

All AFM images were acquired using ScanAsyst Fluid
+ probes (Bruker)
in peak force tapping mode with a nominal spring constant of 0.4 N·m^–1. Each probe was calibrated using the thermal tuning
module before use. The images were obtained in an air atmosphere.
For the SEM analysis, a low electron beam energy of 3 kV and a current
of 30 pA were employed. Before the examination, each sample was coated
with a thin film (1–3 nm) of Au–Pd alloy to prevent
electrical charging of the sample surface. The alloy layers were deposited
using a Polaron SC7620 Mini Sputter Coater.

Eggs found immediately after activation in water were fixed in a 4% formalin solution. The fixed samples were dehydrated in an increasing series of alcohols and then in acetone. The eggs thus prepared were dried with liquid CO₂ at the so-called critical point, after which the samples were mounted on saucers and sputtered with a thin layer of gold and palladium alloy (Polaron SC7620 Mini Sputter Coater, Laughton, UK). The slides were then observed using a scanning microscope (SU8000, Hitachi, Japan), and images of the egg cases were stored in a computer’s memory for later analysis.

The Fourier transform infrared (FTIR) spectroscopy was performed in an attenuated total reflectance mode (ATR-FTIR) on a NICOLET NEXUS model spectrometer. All spectra were recorded in a spectral range of 4000–650 cm⁻¹ with an accumulation of 32 scans at a resolution of 4 cm⁻¹.
The morphology of CNC, extruded PLA and composite filaments as well as 3D printed scaffolds were observed using HITACHI S4800 scanning electron microscopy. The samples were sputter-coated for 30 s with platinum using a Polaron SC7620 Mini Sputter Coater for SEM analysis. Image J software was employed to calculate the mean filament diameter by taking average at 20 points and the pore size by taking average of 8 pores, which is denoted as mean ± standard deviation. Topography of the scaffolds’ surfaces was analyzed using 3D optical microscopy (Keyence) and a confocal chromatic roughness tester (STIL SA) equipped with a CHR1000 sensor.
The porosity of the scaffold was obtained by a liquid displacement method as reported in the literature^{64 (link)}. Briefly, the scaffolds were immersed in tubes containing a specific amount of ethanol (W₁) for 30 min. Then, the total weight of immersed scaffolds and ethanol was noted as W₂. After removing the scaffolds, the residual ethanol in the tubes was noted as W₃. The porosity of the scaffolds was measured according to the following equation: $$Porosity\left(\%\right)=100\ast \frac{W_1-W_3}{W_2-W_3}$$