Table 1.
Physical parameters of solvents at 20 °C, calculated thermophoretic mobility and drift velocity at a constant τ of 2, and relative τ derived from the observed drift velocity.
| Solvent | εb | η [cP] | κ [W m−1 K−1] | ζ [mV] | DT [µm2 K−1 s−1] | ∇Ta [K µm−1] | u [µm s−1] | uobs [µm s−1] (95% CI)b | τ (relative)c |
|---|---|---|---|---|---|---|---|---|---|
| water | 80.1 | 1.00 | 0.598 | −48.6 | 8.21 | −1.99 | −16.3 | −7.6 (−9.4, −5.9) | 1 |
| 50% EtOH | 50.3 | 2.41 | 0.317 | −13.9 | 1.69 | −3.74 | −0.6 | −20.9 (−23.1, −18.7) | 106 |
| 50% DMSO | 75.5 | 3.46 | 0.327 | −74.3 | 5.08 | −3.61 | −18.3 | −3.7 (−4.5, −2.9) | 0.15 |
aThe maximum temperature gradient from Fig. 2c is used for ∇T and κp is 0.05 W m−1 K−1.
bConfidence intervals (CI) at 95% for the observed velocity.
cRelative τ was calculated from experimentally observed drift velocities and other physical parameters and was normalized to the value for water.