la6b00525_si_001.pdf (426.94 kB)
Dopamine Polymerization in Liquid Marbles: A General Route to Janus Particle Synthesis
journal contribution
posted on 2016-03-10, 00:00 authored by Yifeng Sheng, Guanqing Sun, To NgaiCoating
a liquid with a particle shell not only renders a droplet
superhydrophobic but also isolates a well-confined microenvironment
for miniaturized chemical processes. Previously, we have demonstrated
that particles at the liquid marble interface provide an ideal platform
for the site-selective modification of superhydrophobic particles.
However, the need for a special chemical reaction limits their potential
use for the fabrication of Janus particles with various properties.
Herein, we combine the employment of liquid marbles as microreactors
with the remarkable adhesive ability of polydopamine to develop a
general route for the synthesis of Janus particles from micrometer-sized
superhydrophobic particles. We demonstrate that dopamine polymerization
and deposition inside liquid marbles could be used for the selective
surface modification of microsized silica particles, resulting in
the formation of Janus particles. Moreover, it is possible to manipulate
the Janus balance of the particles via the addition of surfactants
and/or organic solvents to tune the interfacial energy. More importantly,
owing to the many functional groups in polydopamine, we show that
versatile strategies could be introduced to use these partially polydopamine-coated
silica particles as platforms for further modification, including
nanoparticle immobilization, metal ion chelation and reduction, as
well as for chemical reactions. Given the flexibility in the choice
of cores and the modification strategies, this developed method is
distinctive in its high universality, good controllability, and great
practicability.