Hydrophobic polypyrroles synthesized by aqueous chemical oxidative polymerization and their use as light-responsive liquid marble stabilizers

Abstract

Hydrophobic polypyrroles doped with perfluoroalkyl dopants can function as a liquid marble stabilizer with photothermal properties.

Synthesis of dioctyl sulfosuccinate‐doped polypyrrole grains by aqueous chemical oxidative polymerization and their use as light‐responsive liquid marble stabilizer

“…The electrical conductivities increased from 5.1 to 13.9 S cm −1 with an increase of BEHSS concentration in Py/BEHSS molar ratio range between 3/0 and 3/0.5. This result is consistent with the earlier finding that the conductivity of PPy increased by introduction of (perfluoro)alkyl dopants carrying sulfonate groups 31 . Above the Py/BEHSS molar ratio of 3/1, the conductivity decreased to 11.1 S cm −1 .…”

“…These results suggested that a surface tension gradient of 0.15 mN/m (72.27–72.12 mN/m 70 ) was generated around the LM. This surface tension gradient was smaller than those measured for the NIR laser‐induced motions of LMs stabilized by fluorinated dopant‐doped PPy, PANI and PEDOT grains (1.6–3.4 mN/m), 31–33,35 but definitely contributed to the generation of the Marangoni flow, which can work as the driving force of the LM motion. The motions of LM were videotaped and numerically analyzed (Figure 10a).…”

“…The volume‐average diameters of PPy‐BEH grains synthesized at Py/BEHSS molar ratios of 3/2, 3/1, 3/0.5, 3/0.25, 3/0.1, 3/0.05, and 3/0 were 19 ± 13 μm, 37 ± 19 μm, 58 ± 33 μm, 97 ± 66 μm, 180 ± 166 μm, 233 ± 132 μm, and 174 ± 152 μm, as determined by laser diffraction grain size distribution analysis (Figure S2). The reduction in grain size with increasing BEHSS concentration could be attributed to the function of BEHSS as a colloidal stabilizer, and bilayer of BEHSS could be formed on the grain surface, leading to exposure of negatively charged sulfonate group to aqueous phase 31 . The sulfonate group could add electrostatic stabilization effect to the grains, and thus attenuated their aggregation and coalescence.…”

“…Recently, we successfully synthesized hydrophobic conjugated polymer grains, such as polypyrrole (PPy), 31,32 polyaniline (PANI) 33,34 and poly(3,4‐ethylenedioxythiophene) (PEDOT), 35 by one‐step aqueous chemical oxidation polymerization in the presence of heptadecafluorooctanesulfonic acid, a perfluoroalkyl dopant. Furthermore, we confirmed that these conjugated polymer grains could adsorb to air‐water surface to stabilize LMs.…”

Self-Propulsion of Water-Supported Liquid Marbles Filled with Sulfuric Acid

“…Liquid marbles placed on a liquid support may be effectively propelled by soluto-capillary 38−40 and thermo-capillary Marangoni flows. 41,42 In our present work, we demonstrate that liquid marbles containing sulfuric acid may be effectively displaced by thermo-capillary Marangoni flow. 43−49 Self-propulsion took place under breaking of cylindrical symmetry of the water surface tension distribution in the vicinity of the marble contact area.…”