title: Fatty acid chemistry at the oil-water interface: self-propelled oil droplets.
abstract: Fatty acids have been investigated as boundary structures to construct artificial cells due to their dynamic properties and phase transitions. Here we have explored the possibility that fatty acid systems also demonstrate movement. An oil phase was loaded with a fatty acid anhydride precursor and introduced to an aqueous fatty acid micelle solution. The oil droplets showed autonomous, sustained movement through the aqueous media. Internal convection created a positive feedback loop, and the movement of the oil droplet was sustained as convection drove fresh precursor to the surface to become hydrolyzed. As the system progressed, more surfactant was produced and some of the oil droplets transformed into supramolecular aggregates resembling multilamellar vesicles. The oil droplets also moved directionally within chemical gradients and exhibited a type of chemotaxis.
authors.affiliation: ProtoLife Srl, Parco Vega, Via della Liberta 12, Marghera, Venice, Italy.
authors.forename: Martin M
authors.initials: MM
authors.lastname: Hanczyc
authors.forename: Taro
authors.initials: T
authors.lastname: Toyota
authors.forename: Takashi
authors.initials: T
authors.lastname: Ikegami
authors.forename: Norman
authors.initials: N
authors.lastname: Packard
authors.forename: Tadashi
authors.initials: T
authors.lastname: Sugawara
mesh_terms: D002633:Chemotaxis / Q000502:physiology; D005227:Fatty Acids / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry; D008823:Micelles; D008853:Microscopy; D009821:Oils / Q000737:chemistry*; D019301:Oleic Acid / Q000737:chemistry; D044367:Phase Transition; D012996:Solutions / Q000737:chemistry*; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry*; D014867:Water / Q000737:chemistry*; D017155:Wettability
chemical_list: D005227:Fatty Acids; D008081:Liposomes; D008823:Micelles; D009821:Oils; D012996:Solutions; D013501:Surface-Active Agents; D014867:Water; D019301:Oleic Acid