Atomic Force Microscopy (AFM) images were acquired using a Dimension FastScan-Bio (Bruker) on a Nanoscope V controller. Peak Force tapping in air was performed using ScanAsyst Fluid probes (Bruker) with a spring constant of approximately 0.60 N/m (probes were calibrated individually using the thermal noise method), a peak force amplitude 150 nm, a setpoint 1.2nN, a peak force tapping frequency of 1 kHz and scan rate of approximately 0.5-2 Hz, depending upon image size and resolution. Deflection sensitivity was calibrated on a sapphire sample prior to measuring the sample. Data were acquired in Quantitative Nanomechanical Mode, including the adhesion channel. Although tip radius was not calibrated (a nominal value of 5 nm was input) this does not affect any measurements presented. All data was processed and analyzed using Nanoscope Analysis 3.0. In order to preserve an accurate representation of the 3D terrace structure and subsequent line sections, the images were initially levelled with a 0-order line fit (i.e., a DC offset) to eliminate z-drift between scan lines, and then flattened with a 1D plane-fit using a manually defined reference plane encompassing a single flat terrace region, made possible due to the inherent linearity of the FastScan scanner.