title: Formation of a new crystalline form of anhydrous β-maltose by ethanol-mediated crystal transformation.
abstract: β-Maltose monohydrate was transformed into an anhydrous form by ethanol-mediated method under several temperatures with agitation. A new stable anhydrous form of β-maltose (Mβ(s)) was obtained, as substantiated by the X-ray diffraction patterns. Mβ(s) obtained by this method presented a fine porous structure, resulting in greater specific surface area compared to those of β-maltose monohydrate and anhydrous β-maltose obtained by vacuum drying (Mβ(h)). The crystal transformation presumably consisted of two steps: dehydration reaction from the hydrous to amorphous forms and crystal formation from the amorphous forms to the noble anhydrous form. The kinetics of these reactions were determined by thermal analysis using Jander's equation and Arrhenius plots. The overall activation energies of the dehydration reaction and the formation of anhydrous maltose were evaluated to be 100 and 90 kJ/mol, respectively.
authors.affiliation: Department of Chemistry and Biotechnology, Tottori University, Koyama Minami 4-101, Tottori 680-8552, Japan.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Verhoeven
authors.forename: Tze Loon
authors.initials: TL
authors.lastname: Neoh
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Ohashi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Furuta
authors.forename: Sayaka
authors.initials: S
authors.lastname: Kurozumi
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Yoshii
mesh_terms: D003460:Crystallization; D018360:Crystallography, X-Ray; D000431:Ethanol / Q000737:chemistry*; D007536:Isomerism; D007700:Kinetics; D008320:Maltose / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D000431:Ethanol; D008320:Maltose