Carbon Materials for Electronic, Environmental and Biomedical Application

Transcription

1 Carbon Materials for Electronic, Environmental and Biomedical Application Seong-Cheol Kim School of Chemical Engineering Yeungnam University

2 Nanomaterials for Electronics & Biomedical Uses 1. Organic Nanomaterials (1) Small molecules - Self-assembled monolayers (SAMs) - Organic Semiconductors (OSCs) (2) Supramolecules - Dendrimers & Hyperbranched Polymers (3) Polymers - Block copolymers - Conjugated Polymers - Photoactive Polymers 2. Carbon Nanomaterials 3. Inorganic Nanomaterials 4. Hybrid Nanomaterials

3 Future Soft Optoelectronics Touchpad electronics Touch sensor 4D electronic signature Biomedical sensor Photon sensor /imaging Nano switch Nano Materials Organic Materials Nanogenerators RAM Human-Si CMOS interfacing 2D 0D 1D + Nanorobots Smart gloves LED Active flexible electronic s Solar cell

4 Pure Carbon Nanomaterials

5 Pure Carbon Nanomaterials Richard Smally Nobel Prize in Chemistry 1996 Nobel Prize in Physics 2010 (1985) (1991) (2004) Sumio Ijjima Andre Geim Konstantin Novoselov Electrical Properties - Metallic (Conductor) - Semiconductor - Insulator

6 Fullerene The most symmetrical large molecule Discovered in Nobel prize Chemistry 1996, Curl, Kroto, and Smalley C 60, also 70, 76 and facets (12 pentagons and 20 hexagons) - prototype Richard Smally (1985) ~1 nm

7 Fullerene Symmetrical shape lubricant Large surface area catalyst Hollow caging particles Ferromagnet? - polymerized C 60 - up to 220 o C

8 Fullerene Chemically stable as graphite - most reactive at pentagons Crystal by weak van der Waals force Superconductivity - K 3 C 60 : 19.2 K - RbCs 2 C 60 : 33 K Kittel, Introduction to Solid State Physics, 7the ed

9 Organic polymer solar cells (PSCs) - light weight & good mechanical properties - low cost and easy processability Figure 1: Layer structure of the polymer solar cell with approximate film thicknesses. Electron donor (P3HT) and acceptor (PCBM) are blended together to maximize the interface where exciton dissociation into electrons and holes takes place. For an efficient photocurrent, each material must provide a continuous path for electron and hole transport to the respective contact. Isolated domains can collect charges and cause recombination.

10 Carbon Nanotubes (CNTs) History 1952 L. V. Radushkevich and V. M. Lukyanovich 50 nm MWCNT Published in Soviet Journal of Physical Chemistry Cold War hurt impact of discovery Some work done before 1991 but not a hot topic The Watershed Iijima discovers MWCNT in arc burned rods Mintmire, Dunlap, and White s predict amazing electronic and physical properties 1993 Bethune and Iijima independently discover SWCNT Add Transition metal to Arc Discharge method (same method as Bucky Balls)

11 Carbon Nanotubes (CNTs) armchair zigzag all multiwalled Zigzag (9,0) singlewalled Rope rope

12 Classification of CNTs: ropes Ropes: bundles of SWNTs triangular array of individual SWNTs ten to several hundreds tubes tubes of different diameters and chiralities in a rope (From R. Smalley s web image gallery) (From Delaney et al., Science 1998)

13 Classification of CNTs: many layers Multiwall nanotubes (Iijima 1991) russian doll structure, several inner shells typical radius of outermost shell > 10 nm (From Iijima, Nature 1991) (Copyright: A. Rochefort, Nano-CERCA, Univ. Montreal)

14 Classification of CNTs: many layers Russian roll (a) or swiss roll (b)? Equal number of walls on either side and internal caps point towards (a) optimum distance between layers of nm

15 Carbon Nanotubes (CNTs): Physical Properties Discovered 1991, Iijima To remove the dangling bonds Roll-up vector: C h na m 1 a 2

16 Carbon Nanotubes (CNTs): Physical Properties Two symmetric structures armchair zig-zag Many chiral structures chiral

17 Carbon Nanotubes (CNTs): Physical Properties Length: typical few μm High aspect ratio: length diameter 1000 quasi 1D solid Diameter: as low as 1 nm SWCNT 1.9 nm Zheng et al. Nature Materials 3 (2004) 673.

18 Carbon Nanotubes (CNTs): Electrical Properties Electrical conductance depending on helicity C h na1 ma 2 If 2n m i, then metallic Current capacity 3 else semiconductor Carbon nanotube 1 GAmps / cm 2 Copper wire 1 MAmps / cm 2 Heat transmission Comparable to pure diamond (3320 W / m. K) Thermal stability Carbon nanotube 750 o C (in air) Metal wires in microchips o C Caging May change electrical properties sensor

19 Carbon Nanotubes (CNTs): Electrical Properties Conductivity depends on nanotubes chirality (symmetry) Armchair metallic Zigzag 1/3 metallic 2/3 semiconducting Chiral semiconducting

20 Carbon Nanotubes (CNTs): Mechanical Properties Carbon nanotubes are the strongest ever known material. Young s Modulus (stiffness): Carbon nanotubes 1250 GPa Carbon fibers 425 GPa (max.) High strength steel 200 GPa Tensile strength (breaking strength) Carbon nanotubes Carbon fibers High strength steel GPa GPa ~ 2 GPa Elongation to failure : ~ % Density: Carbon nanotube (SW) gram / cm 3 Aluminium 2.7 gram / cm 3

21 Carbon Nanotubes (CNTs): Mechanical Properties SWCNT rope laid on ultra-filtration membrane AFM tip applies force to measure Shear Modulus (G) & Reduced Elastic Modulus (E r ) E r = Elastic Modulus when Searing is negligible Displacement of tube/force was measured and E r and G where calculated

22 Overview of potential applications AFM Tip Molecular electronics Transistor FED devices Displays < Energy storage: Li-intercalation Hydrogen storage Supercapacitors < Others Composites Biomedical Catalyst support Conductive materials???

23 Application of Carbon Nanotubes (CNTs): CNT / polymer composite -Transparent electrical conductor -Thickness: nm -High flexibility Wu et al. Science 305 (2004) 1273.

24 Field-effect Nano-transistors Bachtold, Dekker et al. Science 294 (2001) 1317.

25 Chemical Sensors (a) Increase in a single SWNT conductance when 20 ppm of NO 3 are added to an Ar gas flow. (b) Same with 1% NH 3 added to the Ar gas flow Demonstration of the ability of SWNTs in detecting molecule traces in inert gases.

26 Application of Carbon Nanotubes (CNTs): Scanning Probe Microscope `New` microscopes CNT on tip of an AFM finer tip = higher resolution Small diameters of SWNTs were supposed to bring higher resolution than MWNTs due to the extremely short radius of curvature of the tube end. But commercial nanotube based tips use MWNTs for processing convenience.

27 Application of Carbon Nanotubes (CNTs): Field-emission display Field Emitters phosphore Advantage of FED - High contrast level - Fast response time - Lower power consumption

28 Application of Carbon Nanotubes (CNTs): Yarn - CVD-grown MWCNT forest - Operation: -196 o C < T < 450 o C - Electrically conducting - Toughness comparable to Kevlar - No rupture in knot Single yarn : MPa 2-ply yarn : Mpa - High creep resistance and δ Zhang, Atkinson and Baughman, Science 306 (2004) 1358.

29 Application of Carbon Nanotubes (CNTs): Fuel Cell: Hydrogen Storage Aim: 5-7 wt% H 2 SWCNT - Dillon et al. (1997) : 8 wt% (questionable) - Tarasov et al. (2003): 2.4 wt% reversible, 25 bar H 2, -150 o C. Carbon Cones - Mealand & Skjeltorp, (2001) US Patent 6,290,753 Eldrid Svåsand, IFE Kjeller

30 Application of Carbon Nanotubes (CNTs): Fuel Cell: Hydrogen Storage CNTs as catalyst carrier for DMFC - Electrodes larger surface area, higher conductivity and excellent mechanical properties MWNTs researched for both cathode and anode: more efficient than conventional Pt-VulcanXC72R system Karl-Winnacker-Institute of Dechema e.v. in cooperation with the MPI for Solid State Research and the ICVT Institute of the University of Stuttgart are working on a SWNT-DMFC-Anode

31 Charge Storage Battery & Capacitor Anode (Oxidation) : Li x C 6 (s) xli + + xe + C 6 (s) Cathode (Reduction) : Li 1-x Mn 2 O 4 (s) + xli + + xe LiMn 2 O 4 (s) Net Rxn: Li x C 6 (s) + Li 1-x Mn 2 O 4 (s) LiMn 2 O 4 (s) + C 6 (s) E 전지 = 3.7 V J. Fischer, Matt Ray/EHP MIT/Riccardo Signorelli Lithium Ion Batteries Ultra Capacitors

32 Application of Carbon Nanotubes (CNTs): Nanomaterials in Water Filtration

33 Modification of CNT for medical application Materials today 2011, 14,

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35 Graphene (The First Nanocarbon) - Graphene is a one-atom-thick planar sheet of sp 2 -bonded carbon atoms that are densely packed in a honeycomb crystal lattice - The name graphene comes from graphite + -ene = graphene Nobel Prize in Physics 2010 (2004) Andre Geim Konstantin Novoselov High resolution transmission electron microscope images (TEM) of graphene

36 Graphene: Electrical Properties

37 Graphene: Mechanical & Optical Properties - High Young s modulus (~1,100 Gpa) - High fracture strength (125 Gpa) - Graphene is as the strongest material ever measured, some 200 times stronger than structural steel A representation of a diamond tip with a two nanometer radius indenting into a single atomic sheet of graphene (Science, 321 (5887): 385) - Monolayer graphene absorbs πα 2.3% of white light (97.7 % transmittance), where α is the fine-structure constant.

38 Graphene (How to get?) Preparation methods Top-down approach (From graphite) - Micromechanical exfoliation of graphite (Scotch tape or peel-off method) - Creation of colloidal suspensions from graphite oxide or graphite intercalation compounds (GICs) Bottom up approach (from carbon precursors) - By chemical vapor deposition (CVD) of hydrocarbon (Cu or Ni) - By epitaxial growth on electrically insulating surfaces such as SiC - By epitaxial growth on metal surfaces

39 Graphene : Top-down approach Mechanically Chemically Peel-off method Graphene

40 Graphene : Bottom-up approach Chemical Vapor Deposition Graphene

41 Chemical Modification of Graphenes Chem. Soc. Rev., 2015, 44,

42 Graphene: Application Integrated circuit Transparent electrode Transistor & Memory Solar Cell OLED B.H. Hong, Nat. Nanotechnol. 2010, 5, 574.

43 Application of Carbon Nanomaterials in Water Filtration Biofouling of membranes

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45 Water desalination using nanoporous single-layer graphene Nature Nanotechnology 2015, 10, Porous silicone Water flow: 10 6 g/m 2 s at 40 o C ~ 3 H 2 O/pore pico-sec

46 Drug Delivery & Photo-thermal Therapy Using Graphene Oxide Materials today 2011, 14,

47 Thank you everyone You can see it as much as you know it!