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. 2022 Jan 26;8(4):eabl4385. doi: 10.1126/sciadv.abl4385

Table 2. Summary of experimental and calculated data.

Weight fraction (wLigand), mole fraction (xLigand), helical pitch, p values, helical twisting power (βw), molar helical twisting power (βmol), average particle-particle distance (⟨DP−P⟩), and number of nanoshapes per full helical pitch of the chiral cholesterol-thiol–capped nanoshape additives in 5CB based on a constant weight fraction of 0.5 wt %.

Nanoshape wLigand × 10−3 xLigand × 10−4 p (μm)* βw (μm−1) βmol†‡ (μm−1) DP−P⟩ (nm) Nanoshapes
per full pitch
Free surface Lens or wedge
GNP5 (48) 1.05 4.40 12.0 13.0 −76.0 ± 3.8 − 178 ± 9.0 24.0 52
GNP10 (48) 0.77 3.30 § § || || 53.2 ||
LAR-GNR 1.10 4.68 50.0 −23.9 ± 1.2 −53.4 ± 2.7 42.8 1190
MAR-GNR (50) 2.00 8.50 1.3 1.1 −455 ± 23 −1064 ± 53 47.6 25
HAR-GNR 1.00 4.26 130.0 −7.70 ± 0.4 −18.1 ± 1.0 53.0 2452
LAR-GND 1.40 5.96 45.0 −15.6 ± 0.8 −37.3 ± 1.9 84.5 537
HAR-GND 1.35 5.75 40.0 −20.0 ± 1.0 −43.1 ± 2.2 59.4 666
GNS 1.50 6.38 15.0 14.8 −41.8 ± 2.1 −105.1 ± 5.3 106 141
GNPR 1.25 5.32 9.0 8.4 −94.6 ± 4.8 −216.0 ± 11 58.4 155
Ligand
Chol-thiol 5.0 21.2 58.0 58.0 −3.5 ± 0.2 −8.1 ± 0.4 14.6#

*The values of p obtained by the different measurement setups (Grandjean-Cano plano-convex lens, free surface, or homeotropic anchoring) are, as reported previously, in close agreement. Accuracy is ±0.3 μm.

†The negative sign indicates that the induced N*-LC phase is left handed as established by contact preparations with a known left-handed N*-LC material, cholesteryl oleyl carbonate (COC). Cooperativity among the nanoshapes leading to enhanced values for βw and βmol was again observed, supported by the anomalous trends in the plots of the inverse helical pitch (p−1) versus the nanoshape concentration (fig. S12); the standard deviations partly accounted for this.

‡βmol is the helical twisting power value when the dimensionless mole fraction (xAdditive) of the chiral additive is used. For the current dataset, xAdditive = xLigand because the nanoshapes are intrinsically achiral. To determine xLigand, the experimental TGA data (see table S7) were used.

§The helical pitch was too large to be measured and the sample appeared as an achiral N-LC phase in all experiments.

||Since p was too large to be measured, these values could not be calculated and would signify βw and βmol = 0 μm−1.

¶The curvature of available plano-convex lenses did not allow for measurement of these larger p values; only values from free surface and preparation with homeotropic anchoring conditions were used.

#DP–P here refers to the average distance between well-dispersed cholesterol disulfides used as chiral additive in 5CB.