Extended Data Fig. 1: Characterization of the building blocks of nematic colloids.
From: Thermally reconfigurable monoclinic nematic colloidal fluids
a, Three-photon excitation fluorescence spectra of 5CB obtained for polarizations (P) of excitation light parallel and perpendicular to nm. The inset shows the chemical structure and length of a 5CB molecule. b, Scanning electron micrographs of silica-coated disks. c, Transmission electron micrograph image of a single disk on a copper grid. d, A zoomed-in view of the region in the red square in c, showing the silica layer. e, Schematic of a disk with the NaYF4 core, silica layer and polyethylene glycol functionalization. f, Photon-upconverting luminescence spectrum of disks used in confocal imaging. g–i, Simplified schematics of an effective building block of a molecular–colloidal LC formed by a disk (blue) in a fluid host of molecular rods (grey), illustrating its orthorhombic (g), monoclinic (h) and uniaxial (i) symmetries at different orientations. j, Orientational probability versus θ at different T values marked next to the distributions. The peaks of the curves correspond to θe, as depicted with a black dashed line at θe = 32° ± 1° for T = 33.0 ± 0.1 °C. The error in measuring θ is ±1°. k, Schematics of the main notations. l, Asymmetry of the colloidal surface anchoring potential Ue(θ) ≈ ε2(θ − θe)2 + ε3(θ − θe)3 + ε4(θ − θe)4, plotted for ε2 = 88, ε3 = −550 and ε4 = 1,608. m, Time-lapse bright-field micrographs of a disk in 5CB, showing its field-induced motion when subjected to an electric field EDC (black arrow) generated by a d.c. voltage of 5 V applied to in-plane electrodes 1 mm apart. The elapsed time and nm orientations are marked on the micrographs. n, Displacement versus time for disks with different charges in 5CB when subjected to 5 V between electrodes 1 mm apart. o, Histograms of the disk Brownian displacement probed along and perpendicular to nm using video microscopy, with the inset showing a bright-field micrograph of a disk in 5CB. Solid curves are Gaussian fits to experimental data. Errors in measuring the displacements in n, o are ±10 nm. a.u., arbitrary units.
