posted on 2021-05-03, 05:43authored byJeehee Lee, Eunsook Park, Aki Fujisawa, Haeshin Lee
The addition of particles during
the sol-to-gel conversion process
generally enhances the mechanical properties of the resulting hydrogels.
However, the impact of the addition of porous particles during such
a process remains an open question. Herein, we report hydrogel-to-elastomer
conversions by natural porous particles called diatom frustule silica,
namely, Melosira nummuloides. The surface pores provide
mechanical interlocking points for polymers that are reinforced by
gelation. The most critical aspect when choosing polymeric materials
is the presence of water-resistant adhesion moieties, such as catechol,
along a polymer chain, such as chitosan. Without catechol, no sol-to-gel
conversion is observed; thus, no elastomeric hydrogel is produced.
The resulting hybrid gel reveals reversible compressibility up to
a 60% strain and high stretchability even up to ∼400% in area.
Further, in vivo study demonstrates that the hybrid
composite gel can be used as a therapeutic for pressure-induced ulcers.
The synergy of chemical adhesion and physical chain entanglement via pores provides a way to fabricate a new class of 100%
water-based elastomeric materials.