Table 2. Physicochemical data produced to characterise SSA self-association events in a H2O 5% EtOH or D2O 5% EtOH (1H NMR spectroscopy only) solution. Where the SSAs are supplied as an enantiomeric mixture, they are present in a 1 : 1 ratio. Aggregate stability and dH were obtained via zeta potential and DLS measurements respectively, at a concentration of 5.56 mM and a temperature of 298 K, following an annealing process. The dH of the aggregates listed were obtained from intensity distribution peak maxima. CAC was derived at approximately 291 K from surface tension measurements. All Q 1H NMR spectroscopy experiments were conducted with a delay time (d1) of 60 s at 298 K and a concentration of 5.56 mM, EtOH was used as the internal standard. The values given in % represent the observed proportion of compound to become 1H NMR spectroscopy silent. The slight difference in anion: cation ratio is due to increased experimental error due to decreased SSA concentration.
| SSA | Q NMR (%) | d H (nm) | Error | PDI | Error | Zeta potential (mV) | CAC (mM) | Surface tension (mN m−1) | |
|---|---|---|---|---|---|---|---|---|---|
| SSA anion | SSA cation | ||||||||
| 1 | 68 (ref. 30) | a 30 | 220 (ref. 30) | a 30 | a 30 | a 30 | −37 (ref. 30) | 11.2 (ref. 30) | 39.33 (ref. 30) |
| 3 | 50 | 44 | 266 | 19 | 0.038 | 0.0028 | −55 (±3.64) | b | 40.92c |
| 5 | 52 | 48 | 174 | 13 | 0.033 | 0.0042 | −58 (±1.50) | b | 40.92c |
| 7 | 51 | 48 | 167 | 19 | 0.029 | 0.0150 | −58 (±1.64) | b | 39.83c |
| 9 | 58 | 53 | 181 | 53 | 0.026 | 0.0120 | −66 (±0.78) | b | 39.64c |
| 3 + 5 | 31 | 33 | 238 | 3 | 0.047 | 0.0034 | −57 (±0.65) | b | 38.67c |
| 7 + 9 | 56 | 51 | 146 | 14 | 0.019 | 0.0025 | −65 (±0.31) | b | 39.25c |
a
Data not available.
b
Solubility prevented data acquisition.
c
Data collected at limit of SSA solubility = 5.56 mM.