title: Impact of electrolytes on double emulsion systems (W/O/W) stabilized by an amphiphilic block copolymer.
abstract: In this work, the block copolypeptide surfactant, poly(l-lysine·HBr)40-b-poly(racemic-leucine)20, was synthesized and characterized, then used to build water-in-oil-in-water (W/O/W) double emulsions. Double emulsions are usually prepared by a two-step emulsification process and commonly stabilized using a combination of hydrophilic and hydrophobic surfactants. Herein, we report a one-step phase inversion process to produce water-in-oil-in-water (W/O/W) double emulsions stabilized by a synthetic diblock copolymer and electrolyte. It was found that the O/W ratio and the type of electrolyte had a marked effect on the formation and type of the double emulsions. Moreover, double emulsions containing an NaCl isotonic solution were stable for at least two months, whereas those using glucose as a substitute for NaCl showed a clear compartmental change. The mechanism behind this was related to the electrostatic interaction between the anion of the electrolyte and the cation of the polylysine residues, which affected the HLB value and curvature. This novel finding is very interesting in terms of both scientific research and practical applications.
authors.affiliation: Department of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China; Jiangsu Kanion Pharmaceutical Co., Ltd. Lianyungang, 222047, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China.
authors.forename: Jingxin
authors.initials: J
authors.lastname: Gou
authors.affiliation: Department of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Sun
authors.affiliation: Department of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China.
authors.forename: SiCong
authors.initials: S
authors.lastname: Geng
authors.affiliation: Department of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Hu
authors.affiliation: Department of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China.
authors.forename: Keru
authors.initials: K
authors.lastname: Zhang
authors.affiliation: Department of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Lin
authors.affiliation: Jiangsu Kanion Pharmaceutical Co., Ltd. Lianyungang, 222047, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Xiao
authors.affiliation: Department of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China. Electronic address: tanglab@126.com.
authors.forename: Xing
authors.initials: X
authors.lastname: Tang
mesh_terms: D004573:Electrolytes / Q000737:chemistry*; D004655:Emulsions; D057927:Hydrophobic and Hydrophilic Interactions; D009997:Osmotic Pressure; D011108:Polymers / Q000737:chemistry*; D066244:Proton Magnetic Resonance Spectroscopy; D017550:Spectroscopy, Fourier Transform Infrared; D013501:Surface-Active Agents / Q000737:chemistry; D013816:Thermodynamics
chemical_list: D004573:Electrolytes; D004655:Emulsions; D011108:Polymers; D013501:Surface-Active Agents
keywords: Block copolymer; Double emulsions; Electrolytes; Electrostatic interaction; Stability