Summary of the characteristics of silica nanoparticles functionalised with varying concentrations of HEC. Data show the means ± standard deviation.
| Sample | % mass of HEC (w/v) | Yield (%) | Hydrodynamic radius, nm (DLS) | PDI (DLS) | Hydrodynamic radius, nm (NTA) | Particle radius, nm (TEM)a | Graftingb density (μg nm−2) | Surface thiol content (μmol g−1) |
|---|---|---|---|---|---|---|---|---|
| Y1 | 0 | 58 ± 2 | 25 ± 1 | 0.102 | 37 ± 1 | 15 | — | 552 ± 185 |
| Y2 | 0.1 | 61 ± 3 | 27 ± 2 | 0.143 | 50 ± 5 | 19 | 0.058 | 348 ± 41 |
| Y3 | 0.5 | 60 ± 1 | 54 ± 2 | 0.210 | 59 ± 3 | 19 | 0.064 | 267 ± 83 |
| Y4 | 1 | 62 ± 3 | 97 ± 11 | 0.236 | 78 ± 3 | 17 | 0.202 | 189 ± 24 |
| Y5 | 2 | 65 ± 4 | 190 ± 30 | 0.241 | 99 ± 4 | 20 | 0.144 | 207 ± 20 |
a
Exemplary TEM images are shown in Fig. SI1.
b
It should be noted that grafting density calculations used the surface area of an individual nanoparticle obtained by TEM analysis, as this was most accurate to the raw particle size. It should also be noted, that given the likely presence of free HEC in the dispersion, there may be some error in these calculations.