title: Gemini-induced columnar jointing in vitreous ice. Cryo-HRSEM as a tool for discovering new colloidal morphologies.
abstract: A gemini surfactant is able to promote columnar jointing in vitreous ice where long pillars, often of hexagonal cross section, are formed. This jointing is visible by cryo-high-resolution scanning electron microscopy (cryo-HRSEM), in which colloidal suspensions in bulk water are cooled rapidly in liquid ethane, thereby avoiding the potential artifacts with other types of EM. The jointing is proposed to arise from a new type of colloidal morphology where the surfactant self-assembles into hexagonal columns. Evidence for this mechanism comes from a cryo-HRSEM photo of an ice-free hexagonal "skeleton" composed of surfactant. Cryo-HRSEM, a method that is just beginning to realize its potential, would seem to have a promising future in the discovery of additional and as yet unimagined colloidal structures.
authors.affiliation: Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA.
authors.forename: Fredric M
authors.initials: FM
authors.lastname: Menger
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.forename: Kevin L
authors.initials: KL
authors.lastname: Caran
authors.forename: Victor A
authors.initials: VA
authors.lastname: Seredyuk
authors.forename: Robert P
authors.initials: RP
authors.lastname: Apkarian