The Role of the Electrostatic Force in Spore Adhesion
- Georgia Institute of Technology
- University of Tennessee, Knoxville (UTK)
- ORNL
Electrostatic force is investigated as one of the components of the adhesion force between Bacillus thuringiensis (Bt) spores and planar surfaces. The surface potentials of a Bt spore and a mica surface are experimentally obtained using a combined atomic force microscopy (AFM)-scanning surface potential microscopy technique. On the basis of experimental information, the surface charge density of the spores is estimated at 0.03 {micro}C/cm{sup 2} at 20% relative humidity and decreases with increasing humidity. The Coulombic force is introduced for the spore-mica system (both charged, nonconductive surfaces), and an electrostatic image force is introduced to the spore-gold system because gold is electrically conductive. The Coulombic force for spore-mica is repulsive because the components are similarly charged, while the image force for the spore-gold system is attractive. The magnitude of both forces decreases with increasing humidity. The electrostatic forces are added to other force components, e.g., van der Waals and capillary forces, to obtain the adhesion force for each system. The adhesion forces measured by AFM are compared to the estimated values. It is shown that the electrostatic (Coulombic and image) forces play a significant role in the adhesion force between spores and planar surfaces.
- Research Organization:
- Oak Ridge National Laboratory (ORNL)
- Sponsoring Organization:
- ME USDOE - Office of Management, Budget, and Evaluation; ORNL work for others
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 989705
- Journal Information:
- Environmental Science & Technology, Journal Name: Environmental Science & Technology Journal Issue: 16 Vol. 44; ISSN 1520-5851; ISSN 0013-936X
- Country of Publication:
- United States
- Language:
- English
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