K575x sputter coater

Scanning electron microscopy (SEM) was performed with an FEI Quanta 600. Infrared spectra were obtained using a JASCO FT/IR-680 Plus Fourier transform infrared (FTIR) spectrometer. Raman scattering was performed on a Renishaw’s inVia Raman spectrometer using 514 nm laser source. The interferometric reflectance spectra were recorded using an AvaSpec-ULS3648 fiber optic spectrometer. EMITech K575X sputter coater was used to deposit 10 nm thick gold layer under vacuum at 30 mA for 1 min.

The monolithic aerogel samples were cut and metalized through an iridium sputter coater (EMITECH K575X Sputter Coater). Scanning electron micrographs were obtained by using an ESEM Scanning Electron Microscope (QUANTA 200 FEG, Hillsboro, OR, USA).
Composite samples were cut and metalized through a golden sputter coater and micrographs were obtained using a scanning electron microscope (FlexSEM 1000, Hitachi, Tokyo, Japan) and using a BackScattered Electron Detector (BSE).

Before and after the tests, scanning electron microscope (SEM) analysis was performed with a FEI-XL30 SEM at 20 kV. Prior to the examination, the samples had been coated with iridium under argon atmosphere for 6 seconds at 85 mA using a K575X sputter coater (Emitech, Houston, TX).

To prepare samples for SEM, we have used a protocol similar to31 with modifications. Briefly, the cells were collected by centrifugation (10 min, 500 rcf, Eppendorf centrifuge 5424R) from a 1.5 ml culture in microtubes and the supernatant was discarded. The cell pellet was re-suspended and fixed with 5% glutaraldehyde in 0.2 M cacodylate buffer for at least 3 h or overnight at 7 ^°C. Cells were collected on a polycarbonate filter (Millipore, 25 mm diameter, 1 μm pore size, Whatman Nuclepore, WHA110610). The filters were washed twice in 0.1 M cacodylate, twice in 0.05 M cacodylate and eight times in MilliQ deionized water. Subsequently, the filters were dehydrated in a series of ethanol (30%, 50%, 70%, 80%, 95%, 100%) and then in hexamethyldisilazane (HMDS), ethanol mixture (1:1 v/v) and twice in 100% HMDS. The filters were stored in a desiccator. Before imaging with SEM, samples were coated with Chromium to 15 nm thickness using K575X Sputter Coater [Emitech] to minimize charging effects while imaging.

Samples of lyophilized microparticles were prepared as follows: lyophilized microparticles stored at −20 °C were mechanically agitated until the product was freely moving powder. A small amount of power was placed on carbon tape affixed to an SEM stub, and excess powder was removed by blowing compressed air over the surface. Prepared stubs were sputter coated in an Emitech K575X Sputter Coater under argon at 4 × 10⁻³ mbar using iridium deposited using 85 mA of current for 8 s. Coated samples were then loaded into the scanning electron microscope (FEI Quanta FEG 250) and imaged using a 3 kV beam in high vacuum. Images were taken after repeated rounds of focusing and direct adjustments were performed to ensure image quality.

Mock-infected VLC inserts were fixed for scanning electron microscopy technique as previously described (Escaffre et al., 2016 (link)). Briefly, inserts were fixed for 72 h in 2.5% formaldehyde and 0.1% glutaraldehyde in 0.05 M cacodylate buffer (0.01% trinitrophenol, 0.03% CaCl₂, pH 7.2). Samples were then washed, dehydrated in ethanol, and processed through hexamethyldisilazane. After being air-dried filters were detached, mounted onto the specimen stubs and sputter-coated with iridium in Emitech K575x sputter coater (Ashford, Kent, England) at 20 mA for 20 s. Other inserts were also similarly processed until the washing step for transmission electron microscopy purpose. Samples were then incubated in 2% aqueous uranylacetate, dehydrated, infiltrated with Poly/Bed 812 prior embedding into polyethylene capsules for polymerization and sample sectioning.

Scanning electron microscopy (SEM) was used to observe the surface and cross-section microstructure of the xylan–alginate films. The films were cut into 0.5 cm × 0.5 cm strips, before being placed onto a stub holder using carbon tape, and were sputter-coated with gold using an Emitech K575x sputter coater. The cross-section of the films was taken by fracturing the films, which were dried overnight in an oven at 105 °C. The images were taken using a JOEL JSM-7001F at an acceleration voltage of 5 kV.