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Download fileFast-Moving Self-Propelled Droplets of a Nanocatalyzed Belousov–Zhabotinsky Reaction
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posted on 2021-10-20, 22:14 authored by D. Jaya
Prasanna Kumar, Chaitra Borkar, Pratyush DayalSelf-sustained locomotion by virtue
of an internalized chemical
reaction is a characteristic feature of living systems and has inspired
researchers to develop such self-moving biomimetic systems. Here,
we harness a self-oscillating Belousov–Zhabotinsky (BZ) reaction,
a well-known chemical oscillator, with enhanced kinetics by virtue
of our graphene-based catalytic mats, to elucidate the spontaneous
locomotion of BZ reaction droplets. Specifically, our nanocatalysts
comprise ruthenium nanoparticle decorations on graphene oxide, reduced
graphene oxide, and graphene nanosheets, thereby creating 0D–2D
heterostructures. We demonstrate that when these nanocatalyzed droplets
of the BZ reaction are placed in an oil-surfactant medium, they exhibit
a macroscopic translatory motion at the velocities of few millimeters
per second. This motion is brought about by the combination of enhanced
kinetics of the BZ reaction and the Marangoni effect. Our investigations
reveal that the velocity of locomotion increases with the electrical
conductivity of our nanocomposites. Moreover, we also show that the
positive feedback generated by the reaction–diffusion phenomena
results in an asymmetric distribution of surface tension that, in
turn, facilitates the self-propelled motion of the BZ droplets. Finally,
we explore a system of multiple nanocatalyzed BZ droplets and reveal
a variety of motions caused by their mutual interactions. Our findings
suggest that through the use of 0D–2D hybrid nanomaterials,
it is possible to design fast-moving self-propelled synthetic objects
for a variety of biomimetic applications.
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positive feedback generatedmillimeters per secondknown chemical oscillatorbased catalytic matspropelled synthetic objectsinternalized chemical reactionmacroscopic translatory motionreduced graphene oxidemoving biomimetic systemsbz reaction dropletspropelled dropletsliving systemsgraphene oxidebiomimetic applicationspropelled motionnanocatalyzed dropletsbz reactionbz dropletssustained locomotionsurfactant mediumsurface tensionspontaneous locomotionmutual interactionsmoving selfmotions causedmarangoni effectlocomotion increasesinspired researchersgraphene nanosheetsfindings suggestenhanced kineticselectrical conductivitycharacteristic featureasymmetric distributionalso show