title: Anisotropic structure and transport in self-assembled layered polymer-clay nanocomposites.
abstract: Using the layer-by-layer (LbL) assembly technique, we create a polymer-clay structure from a unique combination of LbL materials: poly(ethylene imine), Laponite clay, and poly(ethylene oxide). This trilayer LbL structure is assembled using a combination of hydrogen bonding and electrostatic interactions. The films were characterized using ellipsometry, profilometry, X-ray photon spectroscopy, atomic force microscopy, scanning electron microscopy, wide-angle X-ray diffraction, grazing-incidence small-angle X-ray scattering, and electrochemical impedance spectroscopy (EIS). We observe a layered, anisotropic structure, which resulted in in-plane ion transport 100 times faster than cross-plane at 0% relative humidity. This study represents a first application of EIS in determining anisotropic ion transport in LbL assemblies and its correlation to structural anisotropy.
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
authors.forename: Jodie L
authors.initials: JL
authors.lastname: Lutkenhaus
authors.forename: Elsa A
authors.initials: EA
authors.lastname: Olivetti
authors.forename: Eric A
authors.initials: EA
authors.lastname: Verploegen
authors.forename: Bryan M
authors.initials: BM
authors.lastname: Cord
authors.forename: Donald R
authors.initials: DR
authors.lastname: Sadoway
authors.forename: Paula T
authors.initials: PT
authors.lastname: Hammond
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry*; D016880:Anisotropy; D000077215:Clay; D004563:Electrochemistry; D007097:Imines / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011095:Polyethylenes / Q000737:chemistry*; D055672:Static Electricity
chemical_list: D000538:Aluminum Silicates; D007097:Imines; D011095:Polyethylenes; C505405:poly(ethylene imine); D011092:Polyethylene Glycols; D000077215:Clay