The self-propelled motion of micrometer-sized oil droplets in nonequilibrium
systems has attracted considerable attention as a primitive type of
inanimate chemical machinery. We investigated the dynamics of n-heptyloxybenzaldehyde droplets in a cationic
reactive surfactant solution with the objective of controlling the movement of self-propelled oil droplets.
(1) We designed a novel molecular system that lengthened the locomotion time of oil droplets by using estercontaining
cationic surfactants, (2) we evaluated the dynamics of oil droplets in a solution of a gemini cationic
surfactant with various alkyl chain lengths in the linker to induce a locomotion mode change of the droplets
and induce a conformational change in the flexible linked molecule, and (3) we examined the behavior of
oil droplets in a microchannel in a solution containing a gemini cationic surfactant that has a carbonate linkage.
These droplets exhibited two motions during the hydrolysis of the carbonate linkage, generating two surfactant
Keywords: Cationic surfactant, hydrolysis, ion-exchange reaction, nonequilibrium system, oil droplet,
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