α | fraction of collisions leading to surface oxidation | [-] |
β | collision frequency | [m3 s−1] |
δ | total coating thickness | [m] |
δs | smooth coating thickness | [m] |
ε | coating efficiency | [%] |
ρSiO2 | density of SiO2 | [kg m−3] |
ρTiO2 | density of TiO2 | [kg m−3] |
τ | characteristic sintering time | [s] |