We
describe the role of functional polymer surfactants in the construction
and triggered collapse of droplet-based fibers and the use of these
macroscopic supracolloidal structures for reagent compartmentalization.
Copolymer surfactants containing both zwitterionic and tertiary amine
pendent groups were synthesized for stabilization of oil-in-water
droplets, in which the self-adherent properties of the selected zwitterions
impart interdroplet adherence, while the amine groups provide access
to pH-triggered coalescence. Macroscopic fibers, obtained by droplet
extrusion, were prepared with reagents embedded in spatially distinct
components of the fibers. Upon acidification of the continuous aqueous
phase, protonation of the polymer surfactants increases their hydrophilicity
and causes rapid fiber disruption and collapse. Cross-linked versions
of these supracolloidal fibers were stable upon acidification and
appeared to direct interdroplet passage of encapsulants along the
fiber length. Overall, these functional, responsive emulsions provide
a strategy to impart on-demand chemical reactivity to soft materials
structures that benefits from the interfacial chemistry of the system.