title: Electric-field alignment of chitin nanorod-siloxane oligomer reactive suspensions.
abstract: Uniaxially anisotropic chitin-silica nanocomposite solids have been obtained thanks to the electric field-induced macroscopic alignment of liquid-crystalline reactive cosuspensions. We demonstrate how chitin nanorods (260 nm long, 23 nm thick) can be aligned upon the application of an alternating current (ac) electric field, and within water-ethanol suspensions containing reactive siloxane oligomers (D(h) ∼ 3 nm). The alignment at the millimeter length scale is monitored by in situ small-angle X-ray scattering (SAXS) and polarized light optical microscopy. The composition and state (isotropic, chiral nematic) of the cosuspensions are proven to be determining factors. For nematic phases, the alignment is preserved when the electric field is switched off. Further solvent evaporation induces sol-gel transition, and uniaxially anisotropic chitin-silica nanocomposites are formed after complete drying of the aligned nematic suspensions. Here, the collective response of colloidal mesophases to external electric fields and the subsequent formation of ordered nanocomposite solids would represent a new opportunity for materials design.
authors.affiliation: Institut Charles Gerhardt Montpellier, UMR 5253 CNRS/UM2/ENSCM/UM1, ENSCM, 8 rue de l'Ecole Normale, 34296 Montpellier Cedex 5, France.
authors.forename: Maria Yu
authors.initials: MY
authors.lastname: Boltoeva
authors.forename: Ivan
authors.initials: I
authors.lastname: Dozov
authors.forename: Patrick
authors.initials: P
authors.lastname: Davidson
authors.forename: Krassa
authors.initials: K
authors.lastname: Antonova
authors.forename: Laura
authors.initials: L
authors.lastname: Cardoso
authors.forename: Bruno
authors.initials: B
authors.lastname: Alonso
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Belamie