Slide 1

Lab Information 1 Prepare photoresist groups of 3 to 4 people 1 mg oil red (solvent red 27) 3.5 g isobornyl acrylate (IBA) 2.0 g 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]propane (bis-GMA) 0.18 g 2,2-dimethoxy-2-phenyl-acetophenone (DMPA) Wear gloves! Expose photoresist with UV lamp (goggles will absorb UV) Slide 2 Special Nanomaterials & Carbon Nanotechnology (Section 4.4.6) NANO 101 Introduction to Nanotechnology 2 Slide 3 3 What are special nanomaterials? Materials that are made using unique processes Materials that have unique structures and/or properties Examples: Slide 4 4 Special Nanomaterials: Outline Micro and Mesoporous Materials Ex. Zeolites, Metal-Organic Framework (MOF) Core-Shell Structures Carbon Nanotechnology Nanotubes Fullerenes Other organic molecules Slide 5 5 Micro and Mesoporous Materials http://greman.univ-tours.fr/axis- 3/porous-silicon-for-dummies-page-1- 276071.kjsp Slide 6 6 Variety of methods of synthesis Oxidation of metal foils using acids Radiation-track etching Sol-gel processing Sol-gel processing Random Mesoporous Structures aerogel: 75-90% porosity xerogel: ~ 50 % porosity Slide 7 Sol Gel Processing 7 http://www-cmls.llnl.gov/?url=science_and_technology-chemistry-solgel_chemistry Slide 8 8 Crystalline Mesoporous Structures: Zeolites Crystalline aluminosilicates First discovered in 1756 34 are naturally-occurring 3-D framework with uniformly-sized pores Pores: ~ 0.3 1.0 nm in diameter Pore volumes: ~ 0.1 0.35 ml/g Applications: Catalysts Adsorbents/molecular sieves Slide 9 9 Crystalline Mesoporous Structures: Zeolites Various arrangements Rings Cages Channels Chains http://omnibus.uni-freiburg.de/~weisenbt/7Zeolites/ZeoliteDefinition.html N&N Fig. 6.12 N&N Fig. 6.13 Slide 10 MOFs Similar to zeolites, more syntheic flexibility 10 Slide 11 11 Core-Shell Structures Core and shell made of two different materials Differences: Crystal structure (lattices, arrangements of atoms) Physical properties Example: one metallic, one insulating Method of synthesis Slide 12 12 Core-Shell Structure Example: Metal-Polymer Membrane-Based Synthesis Metal particles trapped inside pores Add polymer solution into pores and react Use as ligand and polyimerize Fratoddi et al. Nanoscale Research Letters 2011, 6:98 Slide 13 Membrane Based Core-Shell Au shell, polyaniline core 13 Nano Lett. Sep 2006; 6(9): 2166 2171. Slide 14 Other Core-Shell Semiconductor Passivation More Tunability 14 Chemistry of Materials 2011, 23, 45874598. Slide 15 Insulating Polymer (hydrocarbon chains) 15 Carbon Nanostructures Variety of properties Variety of structures 0-D Metallic conductor (graphite) Semiconductor (diamond) 1-D 2-D 3-D Slide 16 16 Carbon Fullerenes 0-dimensional carbon structure Usually C 60, but also refers to C 70, C 76, C n (n > 60) Every carbon site on C 60 is equivalent Bonded to three other carbons average bond is 1.44 (C-C is 1.46 ; C=C is 1.40 ) 20 hexagonal faces; 12 pentagonal faces Diameter: 7.10 Slide 17 17 Buckminster Fuller (1895-1983): Architect, engineer, inventor; Developed the geodesic dome Slide 18 18 Synthesis of Fullerenes Laser ablation (vaporizing graphite with a laser) Plasma arcing of graphite or coal Fullerenes found in the soot Combustion synthesis Burn hydrocarbon at low pressure http://cnx.org/contents/4a177b0e-1228-41d4-9d62- d4f0a9a3f335@1/Buckyballs:_Their_history_and_ Slide 19 19 Carbon Nanotubes Single-Walled Carbon Nanotubes (SWCNT; SWNT) Multi-Walled Carbon Nanotubes (MWCNT; MWNT) Preparation: Arc evaporation (plasma arcing) Laser ablation PECVD Electrochemical methods Addition of transition metal powder encourages SWNT growth Slide 20 20 Carbon Nanotubes (a)Armchair (b) Zigzag (c) Chiral Slide 21 Flavors of nanotubes Armchair is metallic Zigzag/Chiral are semiconducting (small bandgap) Most methods produce mixture Catalysts, sorting techniques to separate 21 Nature 512, 6164 (07 August 2014) Slide 22 22 Properties of Carbon Nanotubes Mechanical Stiff and robust structures C-C bonds in graphite (and nanotubes) is the one of the strongest bonds in nature Flexible; do not break when bent Conductivity Extremely high thermal conductivity Extremely high electrical conductivity Potential Applications: -catalysis- hydrogen storage- biological cell electrodes -resistors- flow sensors- electron field emission tips -electronic/mechanical devices - scanning probe tips http://www.rps.psu.edu/hydrogen/form.html Slide 23 23 Carbon Nanotube Applications (NEMS) Nantero is a nanotechnology company using carbon nanotubes for the development of next-generation semiconductor devices... In the field of memory, Nantero is developing NRAM, a high- density nonvolatile Random Access Memory. http://www.nantero.com/ Cedric computer made with SWNT -align nanotubes -obtain only semiconducting morphologies - 8 micron features http://www.bbc.com/news/science-environment-24232896 Slide 24 Carbon Nanotube Applications 24 Gold plate ~ (100 nm) 2 attached to outer shell of suspended MWCNT (on Si wafer) electrostatically rotate the outer shell relative to the inner core http://en.wikipedia.org/wiki/Nanomotor Slide 25 Carbon Nanotube Applications Aligned sheet of MWNT, Thermally activated 25 Nanotechnology 22 (2011) 435704 Slide 26 Other Organic Molecules Small molecules solvents metabolites reactants or monomers Large molecules; macromolecules biomolecules e.g. DNA, proteins, lipids carbon nanotubes polymers 26 acetone Slide 27 Organic Nanotechnology 27 http://www.nanowerk.com/spotlight/spotid=4343.php http://www.kurzweilai.net/butterfly-molecule- could-lead-to-new-sensors-photoenergy- conversion-devices