Fig. 2: Characterization and modeling of glycine crystals deposited by gas blowing at different pressures.

a Raman spectra of the crystals deposited by gas blowing of 0.01 M aqueous solution at different pressures. b AFM image of the glycine nanosheets (deposited at 1.5 bar); scale bar: 500 nm. c Raman map of the intensity (taken as height) of the peak at 2971 cm⁻¹, taken in the dotted square shown in panel b. Pixel size: 67 nm, integration time: 401 s, scale bar: 500 nm. d representative Raman spectra of the individual crystals 1 (in red) and 2 (in blue), shown in panels b and c. e Energy frameworks highlighting the stronger intermolecular interactions for glycine crystals. α-glycine (left) 3 × 2 × 3 supercell showing three bilayer planes held by 2D contact interactions and β-glycine (right) 3 × 3 × 4 supercell showing the 3D network of strong contact interactions. Blue-colored cylinders represent binding interactions, while yellow cylinders highlight repulsive interactions, in both cases the radii of the cylinder are proportional to the strength of the interaction, only interactions larger in absolute value than 15 kJ/mol are shown. f Zingg Diagram of all the possible morphologies of α-glycine simulated using CrystalGrower (blue points, details in Supplementary Table 4). All crystals here are categorized using aspect ratio of Small:Medium (S/M) and Medium:Long (M/L) to define the shapes in the Zingg diagram. The schematic shows the four possible morphologies: plate (top left), lath (bottom left), block/sphere (top right), and needle (bottom right). The red points are showing the morphologies of the nanosheets obtained by gas blow coating at 1.5 bar (data in Supplementary Table 1). The green triangle marks the average size of the nanosheets. The yellow star corresponds to the morphology of a crystal obtained by slow evaporation of water at a supersaturation of 1.5 (Supplementary Fig. 13).