 |
| Titel |
Particle based superhydrophobicity - Lab model to field behaviour |
| VerfasserIn |
Christopher A. E. Hamlett, Neil J. Shirtcliffe, Michael I. Newton, Glen McHale, Sujung Ahn, Robert Bryant, Stefan H. Doerr |
| Konferenz |
EGU General Assembly 2011
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250046423
|
|
|
|
|
|
| Zusammenfassung |
| Soil water repellency can be caused by such factors as volatile organic compounds released
during wildfires, microbial action within the soil or organic contaminants. The chemical
hydrophobicity imparted by such factors can be amplified by the topography of the soil
causing water repellency which, in turn, can lead to enhanced erosion. We present a
mathematical model to predict the water repellency of soil systems in relation to the particle
size and configuration of such particles. Our model relates the size of the particles in the top
layer (radius = r) to the size of the particles in the next layer down (radius = R) and
relates them to a critical contact angle (θc) of the impinging liquid which results in
spontaneous imbibition into the particle bed. The model is tested by performing
molarity of ethanol (MED) drop testing on simplified model representing a sandy
surface soil layer to allow the critical contact angle to be measured. Such models
consist of three layers of hydrophobic bead packs with the base layer fixed, the
second layer being the same size as the fixed base layer. Beads in the top layer are
smaller than those in the underlying layers to give packs with r/R values -¤ 1. The
critical contact angle can then be extrapolated by measuring advancing contact angles
of microscope slides modified in the same way as the beads. Results show good
correlation between the measured critical contact angle and those predicted by the model. |
|
|
|
|
|
|