Tribology of soft colloidal microgels: An oral perspective*

Oral tribology is emerging as a new paradigm in the tribology field to quantify friction in soft sliding contact surfaces¹. Using a combination of experimental techniques and theoretical considerations, this talk will cover three case studies^2-4 on tribology of soft elastomeric surfaces (with different wetting properties) in the presence of biopolymeric microgels with well-defined deformability, designed using variable cross-linking densities and particle sizes. Some of these microgels show aqueous ‘ball-bearing’ abilities depending upon their volume fraction². A case study⁴ will be presented on how these microgels can act as viscosity modifiers of the continuum, where the lubrication performance can be quantitatively described using the Newtonian plateau value (η_∞). Finally, ongoing research on development of novel soft tribo-surfaces to emulate the highly sophisticated oral mucosal surfaces engineered by the nature will be highlighted ¹.

References
1. Sarkar, et al., Curr. Opin. Colloid Interface Sci 39, 61-75 (2019).
2. Sarkar, et al., Langmuir 33, 14699-14708 (2017).
3. Torres, et al.,.Sarkar, ACS Appl. Mater. Interfaces 10, 26893-26905 (2018).
4. Sarkar, et al., Soft Matter Accepted (2019).