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CSD – Low Cost, Easy Setup, and Irregular Surface-Coating. Spin-coating Dip-coating Printing Painting. Polymer-Assisted Deposition (PAD): A Chemical Solution Route for A Wide Range of Materials.
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CSD – Low Cost, Easy Setup, and Irregular Surface-Coating • Spin-coating • Dip-coating • Printing • Painting
Polymer-Assisted Deposition (PAD): A Chemical Solution Route for A Wide Range of Materials • A chemical solution technique to deposit films – by mixing metal precursors with water-soluble polymers • Advantages • Polymers effectively bind metal precursors. • Stabilize metal ions from hydrolysis in water • Control solution stability, reactivity, and processibility • Thin films can be deposited in a more homogeneous manner when metals bind with polymers that have regular ligand sites. Nat. Mater. 3, 529 (2004).
Ti bound to PEIC directly Ti bound to PEI as a catecholate complex Sr bound to PEI as an EDTA complex Schematic Illustration of Metals as Simple Salts or Complexes Bound to Polymers PEI (polyethylenimine) PEIC (carboxylated-polyethylenimine) EDTA (ethylenediaminetetra-aceticacid)
Elements Coordinated with Polymers to Form Stable Precursor Solutions Chem. Soc. Rev., in press.
Schematic Illustration of Main Processing Steps Used to Grow Films by PAD Select metal precursor Mix with polymer (adjust pH) Polymer filtration & removal of all non-bound cations & anions Mix different metal - polymer solutions Adjust viscosity De-polymerizing the polymer in controlled environment Apply coating Thermal treatment
Hg lamp (excitation 300 nm) 366 nm UV excitation A Wide Range of Materials Grown by PAD: Metals, Metal-Nitrides, and Metal-Carbides Adv. Mater. 20, 4704 (2008). J. Am. Chem. Soc. 132, 2516 (2010). J. Am. Chem. Soc. 133, 20735 (2011). Angew. Chem. Int. Ed. 49, 1782 (2010). Angew. Chemie. Int. Ed. 121, 1518 (2009).
CVD growth Solution permeation Annealing Schematic Processing Steps for the Synthesis of CNT/NbC Composites Nat. Commun. 2, 248 (2011).
X-Ray Diffraction Patterns of As-Synthesized CNT/NbC Composites a b
Morphology and Microstructure of CNT/NbC Composites
Superconducting Properties of CNT/NbC Composites
Anisotropic Properties of the Upper Critical Magnetic Field of CNT/NbC Composites
Schematic Illustration of the Processing Steps to Synthesize NbC/CNT Composites Nanoscale4, 2268 (2012).
X-Ray Diffraction Patterns of NbC/CNT Composites on c-Cut Al2O3 Substrates
SEM Image (top view) of NbC/CNT Composite Films a 100 µm 100 µm 10 nm b 100 nm c
Temperature Dependence of the Upper Critical Field of NbC/CNT Composites & Pure NbC Films
Temperature Dependence of Resistivity of NbC/CNT Films measured along Different Directions Current ⊥CNTs Current ∥ CNTs
SEM Image of NbC/CNT Composite Films after Nanoindentation
Outline • Introduction • Experimental details and results • CNT/PDMS stretchable conductors • CNT/NbC composites • Summary
Summary • Carbon nanomaterials are emerging as the materials of choice for both electronic and energy applications. • Polymer-assisted deposition is a powerful technique to deposit a wide range of materials with desired structural and physical properties. • Nanocomposites composed of carbon nanomaterials and other functional/structural materials provide new opportunities for improved and/or enhanced functionalities.