nn9b04708_si_003.avi (257.36 kB)
Surface Wettability-Directed Propulsion of Glucose-Powered Nanoflask Motors
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posted on 2019-10-18, 13:36 authored by Changyong Gao, Chang Zhou, Zhihua Lin, Mingcheng Yang, Qiang HeChemically
driven colloidal motors capable of implementing different
movements under a common environment are of great importance for various
complex tasks. However, the key parameters underlying different motion
behaviors are incompletely understood. Here, we demonstrate that carbonaceous
nanoflask (CNF) motors move spontaneously in glucose powered by the
cascade reaction of glucose oxidase and catalase, and their directional
propulsion can be premeditated by controlling the surface wettability
of nanomotors. The hydrophilic CNF motors move from the round-bottom
to the opening neck (backward), whereas the hydrophobic CNF motors
swim from the opening neck to the round-bottom (forward). We demonstrate
that the backward motion of the hydrophilic CNF motors is driven by
the local glucose gradient due to self-diffusiophoresis, and the forward
movement of the hydrophobic CNF motors is caused by the locally produced
glucose acid gradient. The fluid simulation reveals that the hydrophilic
and hydrophobic CNF motors correspond to the puller and pusher models,
respectively. Our study offers a minimal strategy to manipulate the
direction of motion of motors for specific applications and to change
the hydrodynamic behaviors of glucose-powered motors.