title: The role of crystal polarity in alpha-amino acid crystals for induced nucleation of ice.
abstract: The hydrophobic faces of single crystals of a series of pairs of racemic and chiral-resolved hydrophobic alpha-amino acids were used as a substrate, onto which water vapor has been cooled to freezing. The morphologies and molecular packing arrangements within each crystal pair are similar but only one of each pair exhibits a polar axis, parallel to the hydrophobic face exposed to water. Those crystals that have a polar axis induce a freezing point higher by 4 degrees to 5 degrees C than the corresponding crystals that do not have a polar axis. The results are interpreted in terms of an electric field mechanism that helps align the water molecules into ice-like clusters en route to crystallization.
authors.affiliation: Department of Materials and Inferfaces, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: M
authors.initials: M
authors.lastname: Gavish
authors.forename: J L
authors.initials: JL
authors.lastname: Wang
authors.forename: M
authors.initials: M
authors.lastname: Eisenstein
authors.forename: M
authors.initials: M
authors.lastname: Lahav
authors.forename: L
authors.initials: L
authors.lastname: Leiserowitz
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D000818:Animals; D003460:Crystallization; D007053:Ice; D007536:Isomerism; D008958:Models, Molecular
chemical_list: D000596:Amino Acids; D007053:Ice