csd – low cost, easy setup, and irregular surface-coating

24th Modern Engineering & Technology Seminar (METS 2012), Taipei, Taiwan, Nov. 11 - 14, 2012

CSD – Low Cost, Easy Setup, and Irregular Surface-Coating

Spin-coatingDip-coatingPrintingPainting


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

AdvantagesPolymers 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).


Schematic Illustration of Metals as Simple Salts or Complexes Bound to Polymers

Ti bound to PEI as a catecholate complex

N

NTi

O

O

N

O

O

O

O

NH

Ti bound to PEIC directly

N

N

Sr

O

O

O

O

2-O

O

O

O

Sr bound to PEI as an EDTA complex

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

Adjust viscosity

Thermaltreatment

Polymer filtration &removal of all non-bound

cations & anions

Mix with polymer(adjust pH)

Apply coating

Mix different metal -polymer solutions

Selectmetal precursor

De-polymerizing the polymer in controlled environment


A Wide Range of Materials Grown by PAD: Metal-Oxides


A Wide Range of Materials Grown by PAD: Metals, Metal-Nitrides, and Metal-Carbides

366 nm UV excitation

Hg lamp (excitation 300 nm)

Adv. Mater. 20, 4704 (2008).

J. Am. Chem. Soc.133, 20735 (2011).

J. Am. Chem. Soc. 132, 2516 (2010).

0 50 100 150 200 250 3000.0

0.2

0.4

0.6

0.8

1.0

0 20 40 60 800.00

0.01

0.02

0.03

0.04

T

Re

sist

ivity

(10-

4

cm)

Temperature (K)

T

Res

istiv

ity (

10-4

cm

)

Temperature (K)

T

Angew. Chemie. Int. Ed. 121, 1518 (2009).

Angew. Chem. Int. Ed. 49, 1782 (2010).


Annealing

CVD growthSolution

permeation

Schematic Processing Steps for the Synthesis of CNT/NbC Composites

Nat. Commun. 2, 248 (2011).


25 30 35 40 45

CN

T (

100)

Nb

C (

200)

Nb

C (

111)

Inte

nsi

ty (

a. u

.)

2 (degree)

b

a

25 30 35 40 45

CN

T (

002)

Nb

C (

200)

Nb

C (

111)

Inte

nsi

ty (

a. u

.)

2 (degree)

X-Ray Diffraction Patterns of As-Synthesized CNT/NbC Composites


Morphology and Microstructure of CNT/NbC Composites


4 6 8 10 120

2

4

6

H (

T)

Temperature (K)

H // CNTs

Hc2

Hirr

3 6 9 12 15 18

0

30

60

90

120

150

Temperature (K)

Re

sis

tiv

ity

(

.cm

)

H // CNTs

5 T 4 T 3 T 2 T 1 T 0.5 T 0 T

Superconducting Properties of CNT/NbC Composites


2 4 6 8 100

2

4

6

0 45 90

6.5

7.0

7.5

8.0

Hc2 // CNTs (0°)

Hc2 CNTs (90°)

0H (

T)

Temperature(K)

Tc2

[K

]

Angle (°)

Anisotropic Properties of the Upper Critical Magnetic Field of CNT/NbC Composites


Schematic Illustration of the Processing Steps to Synthesize NbC/CNT Composites

Nanoscale 4, 2268 (2012).


X-Ray Diffraction Patterns of NbC/CNT Composites on c-Cut Al2O3 Substrates

30 40 50 60 70 80

Inte

nsi

ty (

a.u

.)

2 (degree)

(a)

0 50 100 150 200 250 300

Inte

nsi

ty (

a.u

.)

(degree)

(b) NbC (200)

Al2O3 (113)

Al2O3 (006)

NbC (222)

NbC (111)

14 16 18 20

Inte

nsi

ty (

a.u

.)

(degree)

FWHM=0.85


100 µmaa 100 nm

10 nm

bb

100 µmcc

SEM Image (top view) of NbC/CNT Composite Films


3 4 5 6 7 8 9 10 11

0

1

2

3

4

5

2 4 6 8 10 12 14 16

0.0

0.2

0.4

0.6

(T

)/(

273

K)

)

T (K)

0 T 1 T 2 T 3 T 4 T 5 T 6 T 7 T

H

c2 (

T)

T (K)

NbC/CNT NbC

Temperature Dependence of the Upper Critical Field of NbC/CNT Composites & Pure NbC Films


0 50 100 150 200 250 300

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

R

esit

ivit

y (m

.cm

)

T (K)

Current

⊥CNTs

Current ∥ CNTs

Temperature Dependence of Resistivity of NbC/CNT Films measured along Different Directions


SEM Image of NbC/CNT Composite Filmsafter Nanoindentation


Outline

Introduction

Experimental details and resultsCNT/PDMS stretchable conductorsCNT/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.

csd – low cost, easy setup, and irregular surface-coating

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