Em ace200 sputter

Scanning electron microscopy (SEM) studies were performed using a Verios G4 UC (Thermo Scientific, Brno, Czech Republic) device equipped with energy dispersive X-ray (EDX) analyzer (Octane Elect Super SDD detector, Mahwah, NJ, USA). The CS-CPL and CS_EDTA-CPL microbeads were coated with a 10 nm platinum layer using a Leica EM ACE200 Sputter to provide electrical conductivity and to prevent charge build-up during exposure to the electron beam. SEM analysis was carried out in high vacuum mode using a secondary electron detector (Everhart-Thornley Detector, Thermo Scientific, Brno, Czech Republic) at an accelerating voltage of 5 kV.

Scanning Electron Microscopy (SEM) images of the hydrogels were recorded with a Verios G4 UC (Thermo Scientific, Brno, Czech Republic) device equipped with an energy dispersive X-ray (EDX) analyzer (Octane Elect Super SDD detector, Mahwah, NJ, USA). Prior to analysis, the sponges were coated with a 10 nm platinum layer using a Leica EM ACE200 Sputter. The SEM analysis was performed in high vacuum mode, using a concentric backscattered or an Everhart-Thornley detector, and at an accelerating voltage of 10 kV. The pore sizes of CS/CMC or CS/DA-CMC hydrogels were evaluated from SEM micrographs using Image J 1.53 v software by averaging at least 15 measured pores per sample. The porosity (P, %) of the hydrogels was determined using Equation (4) [54 (link),55 (link),56 (link)]: $$P=\left(1-\raisebox{1ex}{${\rho }_{app}$}\!\left/ \!\raisebox{-1ex}{${\rho }_s$}\right.\right)\times 100$$
where ρ_app and ρ_s are the apparent density of prepared hydrogels and the specific density of polymeric skeleton (ρ_s = 1.4063 g/cm³), respectively. ρ_app (g/cm³) was calculated using Equation (5) [54 (link),55 (link)]: $${\rho }_{app}=\frac{m}{V}$$
where m and V are the weight and volume, respectively, of rectangular shaped samples.