Friction of thin hydrogels layers: poroelasticity and interfacial dissipation

We investigate the contribution of poroelastic drainage to indentation and frictional response of thin hydrogel layers. Model hydrogel networks are elaborated using a click-chemistry route. By playing with the chemical nature of the constituents and their structure (crosslink density), hydrogels films with varied elastic and swelling properties are synthesized.

Synthesis of model hydrogel networks using a click-chemistry route

Frictional properties are investigated using dedicated contact experiments where the water content within the gel layer confined between glass substrates is continuously monitored during the course of poroelastic drainage. Experimental results are discussed in the light of poroelastic contact models derived within the framework of a thin film approximation.

Frictional sliding: changes in the contact shape as a function of the Pe Number defined as the ratio of the characteristic poroelastic time to the contact time. When Pe<1, the contact is at the poroelastic equilibrium which would be achieved under a purely normal loading; when Pe>>1 the decrease in the contact size is due to the developement of a pore pressure imbalance within the out-of-equilibrium contact.

References

L. Ciapa, J. Delavoipiere, Y.Tran, E. Verneuil and A. Chateauminois
Transient sliding of thin hydrogel films: the role of poroelasticity
Soft Matter 16 (2020) 6539-6548

J. Delavoipière, B. Hertefeu, J. Teisseire, A. Chateauminois, Y. Tran, M. Fermigier and E. Verneuil, Swelling dynamics of surface-attached hydrogel thin films in vapor flows Langmuir 34 (2018) 15238-15244
 

J. Delavoipière, Y. Tran, E. Verneuil, B. Herteufeu, C.-Y. Hui and A. Chateauminois
Friction of poroelastic contact with thin hydrogel layers
Langmuir 34 (2018) 9617-9626
 

Poroelastic indentation of mechanically confined hydrogel layers
J. Delavoipière, Y. Tran, E. Verneuil and A. Chateauminois
Soft Matter 12 (2016) 8049