title: Anhydrous octyl-glucoside phase transition from lamellar to isotropic induced by electric and magnetic fields.
abstract: A static deuterium nuclear magnetic resonance (2HNMR) technique (magnetic field, B = 7.05 T) was employed to monitor the thermotropic lamellar phase of the anhydrous 1:1 mixture sample of octyl-b-D-glucoside (βOG) and that of partially deuterium labelled at the alpha position on the chain, i.e.,βOG-d2In the absence of an electric field, the2H NMR spectrum of the mixture gives a typical quadrupolar doublet representing the aligned lamellar phase. Upon heating to beyond the clearing temperature at 112 °C, this splitting converts to a single line expected for an isotropic phase. Simultaneous application of magnetic and electric fields (E = 0.4 MV/m) at 85 °C in the lamellar phase, whose direction was set to be parallel or perpendicular to the magnetic field, resulted in the change of the doublet into a single line and this recovers to the initial doublet with time for both experimental geometries. This implies E- and B-field-induced phase transitions from the lamellar to an isotropic phase and a recovery to the lamellar phase again with time. Moreover, these phase transformations are accompanied by a transient current. A similar observation was made in a computational study when an electric field was applied to a water cluster system. Increasing the field strength distorts the water cluster and weakens its hydrogen bonds leading to a structural breakdown beyond a threshold field-strength. Therefore, we suggest the observed field-induced transition is likely due to a structure change of the βOG lamellar assembly caused by the field effect and not due to Joule heating.
authors.affiliation: Centre of Fundamental and Frontier Science of Self-Assembly, Department of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Rauzah
authors.identifier: 0000000240749783
authors.initials: R
authors.lastname: Hashim
authors.affiliation: School of Information Systems Engineering, Osaka Sangyo University, 3-1-1 Nakagaito, Daito-Shi, Osaka 574-8530, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Sugimura
authors.affiliation: Centre of Fundamental and Frontier Science of Self-Assembly, Department of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Hock-Seng
authors.initials: HS
authors.lastname: Nguan
authors.affiliation: Centre of Fundamental and Frontier Science of Self-Assembly, Department of Chemistry, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Matiur
authors.initials: M
authors.lastname: Rahman
authors.affiliation: Department of Biophysics, Max-Planck-Institut für Medizinische Forschung, Jahnstrasse 29, D-69120 Heidelberg, Germany.
authors.forename: Herbert
authors.initials: H
authors.lastname: Zimmermann