title: On the origins of morphological complexity in block copolymer surfactants.
abstract: Amphiphilic compounds such as lipids and surfactants are fundamental building blocks of soft matter. We describe experiments with poly(1,2-butadiene-b-ethylene oxide) (PB-PEO) diblock copolymers, which form Y-junctions and three-dimensional networks in water at weight fractions of PEOintermediate to those associated with vesicle and wormlike micelle morphologies. Fragmentation of the network produces a nonergodic array of complex reticulated particles that have been imaged by cryogenic transmission electron microscopy. Data obtained with two sets of PB-PEOcompounds indicate that this type of self-assembly appears above a critical molecular weight. These block copolymers represent versatile amphiphiles, mimicking certain low molecular weight three-component (surfactant/water/oil) microemulsions, without addition of a separate hydrophobe.
authors.affiliation: Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA.
authors.forename: Sumeet
authors.initials: S
authors.lastname: Jain
authors.forename: Frank S
authors.initials: FS
authors.lastname: Bates
mesh_terms: D002070:Butadienes / Q000737:chemistry*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D020285:Cryoelectron Microscopy; D046911:Macromolecular Substances; D008823:Micelles; D015394:Molecular Structure; D008970:Molecular Weight; D020959:Polyethylene / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D012995:Solubility; D013501:Surface-Active Agents / Q000737:chemistry*; D013696:Temperature; D013816:Thermodynamics; D014783:Viscosity; D014867:Water
chemical_list: D002070:Butadienes; D046911:Macromolecular Substances; D008823:Micelles; D011108:Polymers; D013501:Surface-Active Agents; C473741:poly(1,2-butadiene-b-ethylene oxide); D014867:Water; D020959:Polyethylene