Fig. 4: 3D crystal from helical NP motifs.
From: Encoding hierarchical 3D architecture through inverse design of programmable bonds
a, The desired helical NP motif (left) possesses 16 voxels, but three designed mesovoxels (Mesovoxels 5–7; right) with different degrees of information compression yield the target crystal. SEM images of the corresponding assemblies are shown below. b, Experimental SAXS data for three superlattices designed from Mesovoxel 5 (black), Mesovoxel 6 (blue) or Mesovoxel 7 (green) with obtained S(q) and model S(q) (red) with the associated Bragg peak locations (see Supplementary Figs. 40–45 for details and indexing). The modelled S(q) corresponds to the space group I4122 (Supplementary Fig. 54) with lattice parameters a = b = 120 nm, c = 240 nm and α = β = γ = 90° with NP filling at the following sites: (0,0,0), (1/2,0,1/4), (1/2,1/2,1/2) and (0,1/2,3/4). c, Serial-section SEM imaging provides a volumetric reconstruction of NP positions within a 3D crystal formed by Mesovoxel 7. 3D schematics of the crystal faces (left), 2D NP schematics through different faces (middle) and serial section SEM reconstructions (right), with the associated Miller indices, are shown for the designed and measured crystal organizations of helical NP motifs, which correspond to space group I4122. Scale bars, 100 nm. An SEM image of the serially sectioned silicate structures reveals long-range NP organizations over several microns throughout the interior of the crystal.
