We present the fabrication of chitosan hydrogels exhibiting a bilayered structure. This bilayered structure, as shown by SEM and confocal microscopy, is composed of a thin dense superficial zone (SZ), covering a deeper zone (DZ) containing microchannels orientated perpendicularly to the SZ. We show that such structure favors diffusion of macromolecules within the hydrogel matrix up to a critical pressure, σc, above which channels start to collapse. Moreover, we found that the SZ provided a higher wear resistance than the DZ which was severely damaged at a pressure equal to the elastic modulus of the gel. The coefficient of friction (CoF) of the SZ remained independent of the applied load with µSZ = 0.38 ± 0.02, while CoF measured at DZ exhibited two regimes: an initial CoF close to the value found on the SZ, and a CoF that decreased to µDZ = 0.18 ± 0.01 at pressures higher than the critical pressure σc. Overall, our results show that hierarchical structuring is a promising avenue in controlling and improving the wear resistance of soft materials such as hydrogels.

Interfacial structuring of chitosan hydrogel provide enhanced wear protection

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.