Journal article
Detachment of colloids from a solid surface by a moving air–water interface
Journal of colloid and interface science, Vol.326(1), pp.143-150
2008
Handle:
https://hdl.handle.net/2376/104605
PMID: 18684467
Abstract
Colloid attachment to liquid–gas interfaces is an important process used in industrial applications to separate suspended colloids from the fluid phase. Moving gas bubbles can also be used to remove colloidal dust from surfaces. Similarly, moving liquid–gas interfaces lead to colloid mobilization in the natural subsurface environment, such as in soils and sediments. The objective of this study was to quantify the effect of moving air–water interfaces on the detachment of colloids deposited on an air-dried glass surface, as a function of colloidal properties and interface velocity. We selected four types of polystyrene colloids (positive and negative surface charge, hydrophilic and hydrophobic). The colloids were deposited on clean microscope glass slides using a flow-through deposition chamber. Air–water interfaces were passed over the colloid-deposited glass slides, and we varied the number of passages and the interface velocity. The amounts of colloids deposited on the glass slides were visualized using confocal laser scanning microscopy and quantified by image analysis. Our results showed that colloids attached under unfavorable conditions were removed in significantly greater amounts than those attached under favorable conditions. Hydrophobic colloids were detached more than hydrophilic colloids. The effect of the air–water interface on colloid removal was most pronounced for the first two passages of the air–water interface. Subsequent passages of air–water interfaces over the colloid-deposited glass slides did not cause significant additional colloid removal. Increasing interface velocity led to decreased colloid removal. The force balances, calculated from theory, supported the experimental findings, and highlight the dominance of detachment forces (surface tension forces) over the attachment forces (DLVO forces).
Metrics
11 Record Views
Details
- Title
- Detachment of colloids from a solid surface by a moving air–water interface
- Creators
- Prabhakar Sharma - Section for Environmental Engineering, Aalborg University, Aalborg 9000, DenmarkMarkus Flury - Department of Crop and Soil Sciences, Center for Multiphase Environmental Research, Washington State University, Pullman, WA 99164-6420, USAJun Zhou - Department of Crop and Soil Sciences, Center for Multiphase Environmental Research, Washington State University, Pullman, WA 99164-6420, USA
- Publication Details
- Journal of colloid and interface science, Vol.326(1), pp.143-150
- Academic Unit
- Crop and Soil Sciences, Department of
- Publisher
- Elsevier Inc
- Identifiers
- 99900547098001842
- Language
- English
- Resource Type
- Journal article