title: One-step formation of w/o/w multiple emulsions stabilized by single amphiphilic block copolymers.
abstract: Multiple emulsions are complex polydispersed systems in which both oil-in-water (O/W) and water-in-oil (W/O) emulsion exists simultaneously. They are often prepared accroding to a two-step process and commonly stabilized using a combination of hydrophilic and hydrophobic surfactants. Recently, some reports have shown that multiple emulsions can also be produced through one-step method with simultaneous occurrence of catastrophic and transitional phase inversions. However, these reported multiple emulsions need surfactant blends and are usually described as transitory or temporary systems. Herein, we report a one-step phase inversion process to produce water-in-oil-in-water (W/O/W) multiple emulsions stabilized solely by a synthetic diblock copolymer. Unlike the use of small molecule surfactant combinations, block copolymer stabilized multiple emulsions are remarkably stable and show the ability to separately encapsulate both polar and nonpolar cargos. The importance of the conformation of the copolymer surfactant at the interfaces with regards to the stability of the multiple emulsions using the one-step method is discussed.
authors.affiliation: Faculty of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China. mslzhong@scut.edu.cn
authors.forename: Liangzhi
authors.initials: L
authors.lastname: Hong
authors.forename: Guanqing
authors.initials: G
authors.lastname: Sun
authors.forename: Jinge
authors.initials: J
authors.lastname: Cai
authors.forename: To
authors.initials: T
authors.lastname: Ngai
mesh_terms: D004655:Emulsions / Q000138:chemical synthesis / Q000737:chemistry; D009821:Oils / Q000737:chemistry*; D010316:Particle Size; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D013499:Surface Properties; D014867:Water / Q000737:chemistry*
chemical_list: D004655:Emulsions; D009821:Oils; D011108:Polymers; D014867:Water