Calcite

For the AFM experiments we used a modified commercial atomic force microscope [22 (link)] with custom photothermal cantilever excitation [23 (link)] and a custom three-dimensional scanning and data acquisition mode [24 (link)] in the frequency-modulation mode [25 (link)]. The quantities given in this work are labelled as introduced in [26 (link)]. After cleaving calcite (Korth Kristalle, Germany) and magnesite (SurfaceNet, Germany) in air, ethanol (Sigma Aldrich, article number 32205, purity ≥ 99.8%) was injected in the liquid cell. Since the ethanol was exposed to air during the measurement, it constantly evaporates, making it necessary to repeatedly inject ethanol during a measurement session. Cantilevers of type TAP300 GB-G were used. The acquisition time for each vertical slice (trace and retrace) of a 3D map was 10 s and the frequency of the (approach and retract) z-modulation was 10 Hz, corresponding to 50 approach and 50 retract curves per vertical slice. For typical operation parameters, we refer to our earlier work [5 (link),24 (link),26 (link)].
While we show frequency shift data in the main text, we include a detailed discussion on the static deflection in Supporting Information File 1, where we also discuss the robustness and reproducibility of the AFM results.

Table 1 ▸ shows details of the single phases used in this work: d-(+)-glucose (99%), d-(−)-fructose (99%) and α-lactose monohydrate (≥99%) from Sigma; d-(+)-xylose (>99%) and calcite (>99%) from Sigma–Aldrich; quartz (99.56%) from ABCR; zincite (99.99%) from Aldrich; micronized gypsum marketed by BELITH SPRL (Belgium). Insoluble anhydrite (i-A) was synthesized by heating the micronized gypsum at 973 K for 1 h in a furnace. All the mixtures were prepared by grinding the weighed phases by hand in an agate mortar for 20 min to ensure homogeneity.