TY - JOUR
T1 - Locomotion Mode of Micrometer-Sized Oil Droplets in Solutions of Cationic Surfactants Having Ester or Ether Linkages
AU - Hirono, Ayana
AU - Toyota, Taro
AU - Asakura, Kouichi
AU - Banno, Taisuke
N1 - Funding Information:
We thank Prof. Hiroyuki Kitahata and Yuki Koyano (Chiba Univ.) for the assistance of moving picture analysis. This work was supported by JSPS KAKENHI grants no. 16H04032 for T.T. and 16K17504 for T.B.
Publisher Copyright:
© 2018 American Chemical Society.
PY - 2018/7/3
Y1 - 2018/7/3
N2 - Micrometer-sized self-propelled oil droplets under a far-from-equilibrium condition have drawn much attention because of their potential as a dynamic model for the chemical machinery in living organisms. To clarify the effect of interactions between the system components (surfactant, oil, and water) on the locomotion mode of droplets, we investigated the behaviors of oil droplets composed of n-heptyloxybenzaldehyde (HBA) in solutions of cationic surfactants having or not having an ester or an ether linkage. It was observed that in solutions of cationic surfactants having an ester or an ether linkage, spherical HBA droplets self-propelled by changing their direction frequently. On the other hand, when this functional group is absent, a slow self-propelled motion of the oil droplets concurrent with the evolution of aggregates on their surface was observed. From the results of measurement of interfacial tension and assessment of self-emulsification, we determined that the attractive interactions of cationic surfactants without an ester or an ether linkage with HBA are stronger than those having the linkage. The difference in the locomotion mode of oil droplets is probably explained from the viewpoint of the interactions among the system components.
AB - Micrometer-sized self-propelled oil droplets under a far-from-equilibrium condition have drawn much attention because of their potential as a dynamic model for the chemical machinery in living organisms. To clarify the effect of interactions between the system components (surfactant, oil, and water) on the locomotion mode of droplets, we investigated the behaviors of oil droplets composed of n-heptyloxybenzaldehyde (HBA) in solutions of cationic surfactants having or not having an ester or an ether linkage. It was observed that in solutions of cationic surfactants having an ester or an ether linkage, spherical HBA droplets self-propelled by changing their direction frequently. On the other hand, when this functional group is absent, a slow self-propelled motion of the oil droplets concurrent with the evolution of aggregates on their surface was observed. From the results of measurement of interfacial tension and assessment of self-emulsification, we determined that the attractive interactions of cationic surfactants without an ester or an ether linkage with HBA are stronger than those having the linkage. The difference in the locomotion mode of oil droplets is probably explained from the viewpoint of the interactions among the system components.
UR - http://www.scopus.com/inward/record.url?scp=85048371385&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85048371385&partnerID=8YFLogxK
U2 - 10.1021/acs.langmuir.8b01352
DO - 10.1021/acs.langmuir.8b01352
M3 - Article
C2 - 29878786
AN - SCOPUS:85048371385
SN - 0743-7463
VL - 34
SP - 7821
EP - 7826
JO - Langmuir
JF - Langmuir
IS - 26
ER -