Table 1.
Comparison of the adsorbed mass calculated from the Sauerbrey and the Voigt models after 8 ha.
| Solute | Δf/n experiment (Hz) | Δf/n from Voigt fit (Hz) | ΔMSauerbrey (ng/cm2) | ΔMVoigt (ng/cm2) | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| n = 3 | n = 5 | n = 7 | n = 3 | n = 5 | n = 7 | n = 3 | n = 5 | n = 7 | ||
| Agarose | 17.1 ± 0.5 | 16.2 ± 0.6 | 16.1 ± 0.6 | 16.9 ±0.5 | 16.1 ± 0.6 | 16.0 ± 0.5 | 303 ± 9 | 287 ± 10 | 285 ± 10 | 554 ± 12 |
| PEG (Thiol tagged) | 53.5 ± 1.2 | 43.4 ± 1.2 | 37.5 ± 1.3 | 53.1 ± 1.2 | 43.5 ± 1.1 | 37.3 ± 1.3 | 947 ± 21 | 768 ± 21 | 664 ± 22 | 1778 ± 27 |
a
The density and viscosity of the bulk solution were assumed to be 1000 kg/m3 and 0.001 Pa-s, respectively. The assumed value of 1200 kg/m3 for density of the adsorbed layer gave the best fit for the Voigt viscoelastic model. The listed data are the averages of four experimental runs. The value of error function (χ2) for the agaorse gel varied from 3.4–4.0×107 whereas that for PEG brush (thiol tagged) varied from 7.9–8.7×107 as per Eq. (9).