Coordination Chemistry Reviews 253 (2009) 2835–2851 Contents lists available at ScienceDirect Coordination Chemistry Reviews journal homepage: www.elsevier.com/locate/ccr Review Polymer/clay and polymer/carbon nanotube hybrid organic–inorganic multilayered composites made by sequential layering of nanometer scale films Paul Podsiadlo a,1,2 , Bong Sup Shim a,1,3 , Nicholas A. Kotov a,b,c,∗ a Department of Chemical Engineering, University of Michigan, Ann Arbor, MI 48109, USA b Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI 48109, USA c Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA Contents 1. Introduction .......................................................................................................................................... 2835 2. LBL assemblies of clays ............................................................................................................................... 2836 2.1. Structure and properties of clay particles .................................................................................................... 2836 2.2. Structural organization in clay multilayers .................................................................................................. 2836 2.3. Clay multilayers as high-performance nanocomposites ..................................................................................... 2838 2.4. Applications of clay multilayers in biotechnology ........................................................................................... 2841 2.5. Anisotropic transport in clay multilayers .................................................................................................... 2842 2.6. Clay multilayers for optical and electronic applications ..................................................................................... 2843 2.7. 3D conformal coatings ....................................................................................................................... 2844 3. LBL assemblies of carbon nanotubes ................................................................................................................. 2844 3.1. Structure and properties of CNTs ............................................................................................................ 2844 3.2. Structural organization in multilayers of carbon nanotubes ................................................................................ 2846 3.3. Electrical conductor applications ............................................................................................................ 2846 3.4. Sensor applications ........................................................................................................................... 2847 3.5. Fuel cell applications ......................................................................................................................... 2848 3.6. Nano-/micro-shell LBL coatings and biomedical applications ............................................................................... 2848 4. Conclusions .......................................................................................................................................... 2849 Acknowledgments ................................................................................................................................... 2850 References ........................................................................................................................................... 2850 article info Article history: Received 12 February 2009 Accepted 6 September 2009 Available online 12 September 2009 Keywords: Layer-by-layer Clay nanoparticles Carbon nanotubes Multilayered assemblies abstract This review article focuses on the preparation and applications of layer-by-layer (LBL) assembled organic/inorganic films. As model systems we use incorporation of two multi-functional nanomaterials in the LBL: the clay nanosheets and carbon nanotubes. All the aspects of the composite design start- ing with the structure of the individual nano-scale building blocks and their interactions with polymer matrix, orientation of the inorganic components in the multilayer, origin of record properties, and most likely applications of the resulting materials are given. Special attention is placed on the understanding of the control parameters for key functional properties such as mechanical strength/stiffness/toughness, electrical transport, transparency, and some properties relevant for biological applications. © 2009 Published by Elsevier B.V. ∗ Corresponding author at: Department of Chemical Engineering, University of Michigan, 2300 Hayward St., Ann Arbor, MI 48109, USA. Tel.: +1 734 763 8768; fax: +1 734 764 7453. E-mail address: kotov@umich.edu (N.A. Kotov). 1 These authors contributed equally to this review. 2 Current address: Argonne National Laboratory, Center for Nanoscale Materials, 9700 S. Cass Ave., Bldg. 440 A132C, Argonne, IL 60439, USA. 3 Current address: Department of Materials Science and Engineering, University of Delaware, Newark, DE 19716, USA. 1. Introduction Nanotechnology has grown to be an area of research with tremendous scientific and economic potential. Just as the previ- ous century has seen an explosion in the microprocessor and later biotechnology industries, this century is clearly becoming domi- nated by nanoscience. Nanomaterials can nowadays be synthesized with great control in respect to their composition, e.g. inorganic, organic, polymeric, biological, as well as structure and function. 0010-8545/$ – see front matter © 2009 Published by Elsevier B.V. doi:10.1016/j.ccr.2009.09.004