of the dilution to a highly ordered pyrolytic graphite substrate mounted to stainless steel SEM stub by carbon tape, and drying (≥3 h). SEM imaging was conducted using a LEO 1550 SEM with a Schottky field emitter source at 5 kV accelerating voltage, using a 30 μm aperture, at a working distance of 3–6 mm, with an InLens detector (acting as a 20 kV beambooster). Images obtained with LEO's proprietary software were analyzed by ImageJ (NIH) software's “threshold” and “analyze particles” tools to determine surface area, in conjunctionwithMicrosoft Excel and GraphPad Prism software for statistical analysis.