title: Friction and adhesion forces of Bacillus thuringiensis spores on planar surfaces in atmospheric systems.
abstract: The kinetic friction force and the adhesion force of Bacillus thuringiensis spores on planar surfaces in atmospheric systems were studied using atomic force microscopy. The influence of relative humidity (RH) on these forces varied for different surface properties including hydrophobicity, roughness, and surface charge. The friction force of the spore was greater on a rougher surface than on mica, which is atomically flat. As RH increases, the friction force of the spores decreases on mica whereas it increases on rough surfaces. The influence of RH on the interaction forces between hydrophobic surfaces is not as strong as for hydrophilic surfaces. The friction force of the spore is linear to the sum of the adhesion force and normal load on the hydrophobic surface. The poorly defined surface structure of the spore and the adsorption of contaminants from the surrounding atmosphere are believed to cause a discrepancy between the calculated and measured adhesion forces.
authors: Georgia Institute of Technology, Atlanta, Georgia 30332-0373, USA.
authors: Hyojin
authors: H
authors: Kweon
authors: Sotira
authors: S
authors: Yiacoumi
authors: Costas
authors: C
authors: Tsouris
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry / Q000378:metabolism; D001272:Atmosphere; D001413:Bacillus thuringiensis / Q000378:metabolism*; D001422:Bacterial Adhesion; D018441:Biofilms; D017276:Friction; D005898:Glass / Q000737:chemistry; D006046:Gold / Q000737:chemistry / Q000378:metabolism; D006813:Humidity; D057927:Hydrophobic and Hydrophilic Interactions; D018625:Microscopy, Atomic Force; D019736:Prostheses and Implants / Q000382:microbiology*; D013171:Spores, Bacterial / Q000378:metabolism*; D055672:Static Electricity; D013499:Surface Properties
chemical_list: D000538:Aluminum Silicates; D006046:Gold; C011934:mica