title: Highly stable phase change material emulsions fabricated by interfacial assembly of amphiphilic block copolymers during phase inversion.
abstract: This study introduced a robust and promising approach to fabricate highly stable phase change material (PCM) emulsions consisting of n-tetradecane as a dispersed phase and a mixture of meso-2,3-butanediol (m-BDO) and water as a continuous phase. We showed that amphiphilic poly(ethylene oxide)-b-poly(ε-caprolactone) block copolymers assembled to form a flexible but tough polymer membrane at the interface during phase inversion from water-in-oil emulsion to oil-in-water emulsion, thus remarkably improving the emulsion stability. Although the incorporation of m-BDO into the emulsion lowered the phase changing enthalpy, it provided a useful means to elevate the melting temperature of the emulsions near to 15 °C. Interestingly, supercooling was commonly observed in our PCM emulsions. We attributed this to the fact that the PCM molecules confined in submicron-scale droplets could not effectively nucleate to grow molecular crystals. Moreover, the presence of m-BDO in the continuous phase rather dominated the heat emission of the emulsion system during freezing, which made the supercooling more favorable.
authors: Department of Applied Chemistry and ‡Department of Bionano Technology, Hanyang University , Ansan 426-791, Republic of Korea.
authors: Hanhee
authors: H
authors: Park
authors: Dong Wan
authors: DW
authors: Han
authors: Jin Woong
authors: JW
authors: Kim
mesh_terms: D002072:Butylene Glycols / Q000737:chemistry; D004655:Emulsions; D057927:Hydrophobic and Hydrophilic Interactions; D007783:Lactones / Q000737:chemistry*; D008567:Membranes, Artificial; D008958:Models, Molecular; D008968:Molecular Conformation; D044367:Phase Transition; D011092:Polyethylene Glycols / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D002072:Butylene Glycols; D004655:Emulsions; D007783:Lactones; D008567:Membranes, Artificial; C473831:poly(ethylene oxide)-b-poly(caprolactone); D014867:Water; D011092:Polyethylene Glycols; C026978:2,3-butylene glycol