Table 1.
Helical twisting power (βW), molar helical twisting power (βmol), and particle-particle distances (DP-P) for a given concentration of chiral additives in 5CB
| Chiral additive abbreviation | βW / μm−1 wt.%−1 a | βmol / μm−1 mol−1 a | DP-P at 0.5 wt.% / nm b | |
|---|---|---|---|---|
| center-to-center | edge-to-edge | |||
| Cholesterol-capped GNRs | ||||
| GNR1 (AR: 4.3) | −382 ± 94c | −5723 ± 1506c | 54 | 39 |
| GNR2 (AR: 2.2) | −248 ± 58c | −3727 ± 568c | 93 | 66 |
| Cholesterol-capped Au NPs | ||||
| NP1 (∅ = 1.8 nm)21 | −8.7 | −42.2 | 9.7 | 3.0 |
| NP2 (∅ = 5.5 nm)21 | −29.0 | −319.8 | 35 | 24 |
| NP3 (∅ = 10.1 nm)21 | →0d | →0d | 68 | 53 |
| Cholesterol-based ligands | ||||
| Chol-silane 1 | −2.8 | −6.0 | 3.7 | 3.25 |
| Chol-disulfide 121 | −5.0 | −19.0 | 3.35 | 2.9 |
| Chol-disulfide 221 | −5.0 | −22.0 | 3.5 | 3.0 |
| Commercially available and frequently used organic chiral additives | ||||
| COC | −7.4 | −40.4 | 3.7 | 3.2 |
| CB-1555 | +8.8 | +21.3 | 2.9 | 2.5 |
| R81155 | +12.1 | +44.0 | 3.2 | 2.8 |
| ZLI-4572 | +30.3 | +157.7 | 3.6 | 3.2 |
aThe sign indicates the handedness of the induced N*-LC phase. The opposite enantiomer of a particular chiral additive molecule gives the same value but opposite sign; a negative sign indicates a left-handed N*-LC phase and a positive sign a right-handed
bThe particle-particle distance, DP–P (center-to-center and edge-to-edge), refers to the chiral correlation length, that is the distance between chiral additive particles or molecules to maintain a certain helical pitch throughout the bulk
cThe particular ranges of these values were derived from the p values measured at lower concentrations (up to 0.3 wt.%) and the p values after cooperative amplification at higher concentrations of the GNRs in 5CB (>0.3 wt.%) (see Fig. 6h)
dThe helical pitch was too large to be measured, and the sample appeared achiral nematic as indicated by the appearance of a typical Schlieren texture. Hence, no HTP value could be calculated