Modeling of the van der Waals forces during the adhesion of capsule-shaped bacteria to flat surfaces

• Main Authors: Mohamed Zuki, Fathiah, Edyvean, Robert G.J., Pourzolfaghar, Hamed, Kasim, Norherdawati
• Format: Article
• Language: English
• Published: MDPI 2021
• Subjects: TP Chemical technology
• Online Access: http://eprints.um.edu.my/25876/1/25876.pdf; http://eprints.um.edu.my/25876/; https://doi.org/10.3390/biomimetics6010005

A novel model is developed to evaluate the van der Waals (vdW) interactions between a capsule shaped bacterium (P. putida) and flat minerals plates in different approach profiles: Vertically and horizontally. A comparison of the approaches to the well-developed spherical particle to mineral surface (semi-infinite wall and spherical) approach has been made in this investigation. The van der Waals (vdW) interaction potentials for a capsule-shaped bacterium are found using Hamaker’s microscopic approach of sphere to plate and cylinder to plate either vertically or horizontally to the flat surface. The numerical results show that a horizontal orientated capsule shaped bacterium to mineral surface interaction was more attractive compared to a capsule shaped bacterium approaching vertically. The orientation of the bacterial approaching a surface as well as the type and topology of the mineral influence the adhesion of a bacteria to that surface. Furthermore, the density difference among each type of bacteria shape (capsule, cylinder, and sphere) require different amounts of energy to adhere to hematite and quartz surfaces. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.