208hr sputter coater

After preparing 23% (w/w) MBPI, CTL, MTM4, and MTM8 solution with buffer in a glass vial, the mixture was heated at 90 °C for 30 min with the glass vial lid closed. After heating, the mixture was cooled at RT for 1 h and stored at 4 °C overnight. The gels were then lyophilized and crushed. The dried samples were then sputter-coated with platinum (Cressington sputter coater 208HR, Cressington Scientific Instruments Ltd., Watford, UK) and the microstructure was observed using FE-SEM (JSM-7900F, JEOL Ltd., Akishima, Tokyo, Japan) at ×300 magnification.

Samples
were prepared
for image acquisition by selecting leaves and stalk pieces for analysis
and cutting them to fit onto SEM stubs (15–30 mm squares).
The leaf and stalk fractions were further divided and oriented as
either leaf top, leaf bottom, stalk exterior, or stalk interior so
that there were 10 samples of each for the mildly, moderately, and
severely degraded group as well as the control. The samples were mounted
onto aluminum stubs using double sided adhesive. The samples were
sputter coated with 12 nm iridium using a Cressington sputter coater
208 HR (Cressington Scientific Instruments, Ltd., Watford, UK). The
sputter coating was to prevent charging during SEM imaging and was
used to normalize the differences in color among the three groups
as the mild group was light tan while the moderate and severe groups
were darker brown. This was to minimize the possibility that textural
differences found would be influenced by color differences.

Morphological analysis of cellulose and DAC was performed by FE-SEM analysis using a Hitachi S-4800 (Spectral Solutions, Solna, Sweden), equipped with an EDX (energy dispersive X-ray) detector for chemical analysis, and an EBSD (electron backscattered diffraction) detector for grain orientation and texture analysis. The samples were coated with a thin layer of gold (4 nm) using a Cressington sputter coater 208HR (Cressington Scientific Instruments Ltd., Watford, U.K.) and analysis was performed with SE In-Lens, under a high vacuum and with an operating voltage of 0.1–30 kV and a probe current of 10 nA.

SEM images were obtained by using a FEI Quanta FEG 250 ESEM (FEI Company, Hillsboro, OR, USA) operating at 15 kV. Either 3 µL of HbNPs or bare PLGA-NPs were deposited on a glass slide, mounted on a metal stub, followed by drying of the NPs and subsequent gold sputtering under vacuum (Sputter Coater 208 HR, Cressington Scientific, Ted Pella, Redding , CA, USA).

A Nova NanoSEM 450 scanning electron microscope was employed to detect any changes in the filaments’ surface. The samples were sputtered with a 10 µm coat of gold by means of a Cressington Sputter Coater 208 HR to increase their conductivity.