1 research outputs found
Catalytically Initiated Gel-in-Gel Printing of Composite Hydrogels
Herein, we describe a method to 3D
print robust hydrogels and hydrogel composites via gel-in-gel 3D printing
with catalytically activated polymerization to induce cross-linking.
A polymerizable shear-thinning hydrogel ink with tetramethylethylenediamine
as catalyst was directly extruded into a shear-thinning hydrogel support
bath with ammonium persulfate as initiator in a pattern-wise manner.
When the two gels came into contact, the free radicals generated by
the catalyst initiated the free-radical polymerization of the hydrogel
ink. Unlike photocuring, a catalyst-initiated polymerization is suitable
for printing hydrogel composites of varying opacity, since it does
not depend upon light penetration through the sample. The hydrogel
support bath also exhibited a temperature-responsive behavior in which
the gel “melted” upon cooling below 16 °C. Therefore,
the printed object was easily removed by cooling the gel to a liquid
state. Hydrogel composites with graphene oxide and multiwalled carbon
nanotubes (MWCNTs) were successfully printed. The printed composites
with MWCNTs afforded photothermally active objects, which have utility
as stimuli-responsive actuators