Lecture Notes on Nanomaterials / X-ray Diffraction / Synthesis

Graphene One atom thick layer of graphite Hexagonal pattern of carbon atoms Low resistivity Low mass Low spring constant High strength Why a Graphene Electrostatic Loudspeaker? Thinness and low mass densi...

Graphene One atom thick layer of graphite Hexagonal pattern of carbon atoms Low resistivity Low mass Low spring constant High strength Why a Graphene Electrostatic Loudspeaker? Thinness and low mass density allow for smaller sized speaker Low mass, low spring constant, and high strength produces a great overall frequency response High strength ensures better fidelity Tools to Characterize Nanomaterials  MFe2O4 Spinel Ferrite Synthesis  Nanostructured Materials Classification: Nanoparticles (including quantum dots) exhibit quantum size effects Nanorods and nanowires Thin films Bulk materials made of nanoscale building blocks or consisting of nanoscale nanostructures Nanoparticle Synthesis Strategies Liquid-phase synthesis Liquid-Phase Synthesis Coprecipitation Sol-gel Processing Hydrothermal Microwave Synthesis Sonochemical Synthesis Coprecipitation Coprecipitation reactions involve the simultaneous occurrence of nucleation, growth, coarsening, and/or agglomeration processes. Coprecipitation reactions exhibit the following characteristics: (i) The products are generally insoluble species formed under conditions of high supersaturation. (ii) Nucleation is a key step, and a large number of small particles will be formed. (iii) Secondary processes, such as Ostwald ripening and aggregation, dramatically affect the size, morphology, and properties of the products. (iv) The supersaturation conditions necessary to induce precipitation are usually the result of a chemical reaction. xAy+(aq) + yBx-(aq)  AxBy(s) Typical coprecipitation synthetic methods: (i) metals formed from aqueous solutions, by reduction from nonaqueous solutions, electrochemical reduction, and decomposition of metallorganic precursors; (ii) oxides formed from aqueous and nonaqueous solutions; (iii) metal chalconides formed by reactions of molecular precursors; (iV) microwave/sonication-assisted coprecipitation. Sol-gel processing The sol-gel process is a wet-chemical technique that uses either a chemical solution (sol short for solution) or colloidal particles (sol for nanoscale particle) to produce an integrated network (gel). Metal alkoxides and metal chlorides are typical precursors. They undergo hydrolysis and polycondensation reactions to form a colloid, a system composed of nanoparticles dispersed in a solvent. The sol evolves then towards the formation of an inorganic continuous network containing a liquid phase (gel). Formation of a metal oxide involves connecting the metal centers with oxo (M-O-M) or hydroxo (M-OH-M) bridges, therefore generating metal-oxo or metal-hydroxo polymers in solution. After a drying process, the liquid phase is removed from the gel. Then, a thermal treatment (calcination) may be performed in order to favor further polycondensation and enhance mechanical properties. Hydrothermal/Solvothermal Synthesis In a sealed vessel (bomb, autoclave, etc.), solvents can be brought to temperatures well above their boiling points by the increase in autogenous pressures resulting from heating. Performing a chemical reaction under such conditions is referred to as solvothermal processing or, in the case of water as solvent, hydrothermal processing. TiO2 ZnIn2S4 Yu, J. C. et al. J. Solid State Chem. 2005, 178, 321; Cryst. Growth Des. 2007, 7, 1444 Microwave-Assisted Synthesis Microwaves are a form of electromagnetic energy with frequencies in the range of 300 MHz to 300 GHz. The commonly used frequency is 2.45G Hz. Interactions between materials and microwaves are based on two specific mechanisms: dipole interactions and ionic conduction. Both mechanisms require effective coupling between components of the target material and the rapidly oscillating electrical field of the microwaves. Dipole interactions occur with polar molecules. The polar ends of a molecule tend to re-orientate themselves and oscillate in step with the oscillating electrical field of the microwaves. Heat is generated by molecular collision and friction. Generally, the more polar a molecule, the more effectively it will couple with the microwave field.  Conventional Heating by Conduction conductive heat heating by convection currents slow and energy inefficient process The temperature on the outside surface is in excess of the boiling point of liquid  Heating by Microwave Irradiation Solvent/reagent absorbs MW energy Vessel wall transparent to MW Direct in-core heating Instant on-off inverted temperature gradients ! Sonochemical Synthesis Ultrasound irradiation causes acoustic cavitation -- the formation, growth and implosive collapse of the bubbles in a liquid The implosive collapse of the bubbles generates a localized hot spots of extremely high temperature (~5000K) and pressure (~20MPa). The sonochemical method is advantageous as it is nonhazardous, rapid in reaction rate, and produces very small metal particles. Examples: sonochemical synthesis of mesoporous TiO2 particles Mesoporous TiO2 20 kHz sonochemical processor Topics  What is nano?  How do properties change at the nanoscale?  Are nano products safe?  What are some careers related to nanotechnology? Intro to Nano http://www.nisenet.org/catalog/media/intro_nano_video How Small is Nano? http://www.nisenet.org/catalog/media/how_small_nano_video  The Scale of Things – Nanometers and More Things Natural Things Manmade 10-2 m 1 cm 10 mm Head of a pin 1-2 mm The Challenge Ant 1,000,000 nanometers = ~ 5 mm 10-3 m 1 millimeter (mm) Microwave MicroElectroMechanical Dust mite (MEMS) devices 10 -100 m wide 200 m 10-4 m 0.1 mm 100 m Microworld Fly ash Human hair ~ 10-20 m ~ 50-120 m wide O P O O -5 10 m 0.01 mm O O O O 10 m O O O O O O O O Pollen grain Red blood cells O O O O O O O O Infrared Red blood cells S S S S S S S S with white cell ~ 2-5 m 1,000 nanometers = Zone plate x-ray “lens” 10-6 m 1 micrometer (m) Outer ring spacing ~35 nm Visible Fabricate and combine nanoscale building blocks to make useful devices, 0.1 m 10-7 m e.g., a photosynthetic 100 nm reaction center with integral semiconductor Ultraviolet storage. Nanoworld Self-assembled, 0.01 m Nature-inspired structure ~10 nm diameter 10-8 m Many 10s of nm 10 nm ATP synthase Nanotube electrode 10-9 m 1 nanometer (nm) Carbon buckyball Soft x-ray ~1 nm diameter Carbon nanotube ~1.3 nm diameter DNA 10-10 m Quantum corral of 48 iron atoms on copper surface Atoms of silicon 0.1 nm ~2-1/2 nm diameter positioned one at a time with an STM tip Office of Basic Energy Sciences spacing ~tenths of nm Office of Science, U.S. DOE Corral diameter 14 nm What is Nanotechnology? Nanotechnology involves manipulating matter at unprecedentedly small scales to create new or improved products that can be used in a wide variety of ways. http://www.nsf.gov/statistics/seind12/pdf/c07.pdf Nanotechnology: Small, Different, New Key ideas: 1. The nanometer is extremely small. 2. At the nanometer scale, materials may behave differently. 3. We can harness this new behavior to make new technologies. Why Nano Education? Drawbacks Advantages  Not inherently interesting  Fun! (compared to dinosaurs!)  Breaks down disciplinary  Below visible threshold, boundaries younger kids have  Cutting-edge problems visualizing  Relevant to future jobs  Unexpected properties and careers Nano Not Widely Understood National Science Board's Science and Engineering Indicators 2012 Americans remain largely “24% of Americans report unfamiliar with nano- having heard ‘a lot’ or ‘some’ technology, despite about nanotechnology, up four increased funding and a percentage points from 2008 growing numbers of and 2006” products on the market “44% of Americans report that use nanotechnology. having heard ‘nothing at all’ about nanotechnology” http://www.nsf.gov/statistics/seind12/pdf/c07.pdf An Interdisciplinary Endeavor Chemistry Biology Physics Engineering Nanoscience & Nanotechnology Medicine Materials Science Biotechnology Information Technology What is Nano?  How Big is a Nanometer? http://www.nisenet.org/catalog  How Big is a Nanometer? http://www.nisenet.org/catalog  How Big is a Nanometer? http://www.nisenet.org/catalog  How Big is a Nanometer? http://www.nisenet.org/catalog  How Big is a Nanometer? http://www.nisenet.org/catalog  How Big is a Nanometer? http://www.nisenet.org/catalog  How Big is a Nanometer? http://www.nisenet.org/catalog  How Big is a Nanometer? http://www.nisenet.org/catalog  How Big is a Nanometer? http://www.nisenet.org/catalog How Big is a Nanometer? http://www.nisenet.org/catalog How Big is a Nanometer? http://www.nisenet.org/catalog How Big is a Nanometer?  In the time it takes to read this sentence, your fingernails will have grown approximately one nanometer (1 nm). www.starling-fitness.com How Big is a Nanometer?  If you could paint a teaspoon of paint one nanometer thick, how much area would it cover? ? Joon Han and Justin Smith / Wikimedia Commons How Big is a Nanometer?  If you could paint a teaspoon of paint one nanometer thick, how much area would it cover? Joon Han, Justin Smith, Kbh3rd, The Anomebot, Pete Markham / Wikimedia Commons How Big is a Nanometer?  To cover a football field with a 1nm thick layer of paint, you would need just 1 teaspoon of paint! Joon Han and Justin Smith / Wikimedia Commons How Big is a Nanometer? Sugar cubes  How many sugar molecules in a sugar cube?  What do we need to know (estimate)?  Sugar cube = (1 cm)3  1 sugar molecule = (1 nm)3   1021 sugar molecules in a sugar cube Biswarup Ganguly / Wikimedia Commons Activity: Measure Yourself http://www.nisenet.org/catalog  Did Scientists “Create” Nano?  No, it was already in nature! centimeters to micrometers micrometers http://www.nisenet.org/catalog nanometers  Did Scientists “Create” Nano?  No, it was already in nature! centimeters to micrometers micrometers http://www.nisenet.org/catalog nanometers Smallness Leads to New Properties Sometimes gravity loses! http://www.nisenet.org/catalog Smallness Leads to New Properties Surface area is really important! http://www.nisenet.org/catalog Surface Areas at the Nanoscale 1 cm cubes 1 mm cubes 1 nm cubes http://www.nano.gov/nanotech-101/special How Surface Area Scales (Changes) For a fixed total volume, decreasing the radius by a factor of two doubles the surface Crushing a 1cm particle into nano particles increases the surface area thousands of times! 36 How Surface Area Scales (Changes) 1 nm particles → 1010 m2 1 micron particles → 107 m2 1 cm particles → 103 m2 nano 37 Smallness Leads to New Properties Reactivity Melting point Bulk Gold Bulk Aluminum Strength Conductivity Color Nano Aluminum Nano Gold http://www.carterrecycling.com/myimages/aluminum_cans.jpg http://healthewoman.org/2008/11/11/how-healthy-is-your-workplace/ http://mrsec.wisc.edu/Edetc/nanolab/gold/images/goldp6.jpg http://texasenterprise.org/article/warren-buffet-and-new-calculus-gold Nano and Me - Aluminum http://www.nisenet.org/catalog Stained Glass: Size Matters Gold particles http://www.cas.muohio.edu/nanotech/education/k_12.html http://www.horiba.com/scientific/ Stained Glass: Size and Shape Matter Controlling the Quantum World: The Science of Atoms, Molecules, and Photons, 2007 Stained Glass: Size and Shape Matter Controlling the Quantum World: The Science of Atoms, Molecules, and Photons, 2007 Stained Glass: Size and Shape Matter Controlling the Quantum World: The Science of Atoms, Molecules, and Photons, 2007 Stained Glass: Size and Shape Matter Particle shape also affects the color! http://commons.wikimedia.org/wiki/File:Native_gold_nuggets.jpg http://www.cat.gov.in/technology/laser/lpas/pps.html Activity: Nano Fabric and Magic Sand http://www.nisenet.org/catalog http://www.stevespanglerscience.com/product/magic-sand Activity: Nano Fabric water air nano-roughened surface http://www.nisenet.org/catalog Zoom into a Lotus Leaf http://www.nisenet.org/catalog  Activity: Nano Sunblock  Some sunscreen use chemicals  Other sunscreens use zinc oxide http://www.nisenet.org/catalog vitaderminstitute.com/  Sunscreens vs Sunblocks, Continued How could sunscreen and sunblock work? Sunscreen/Sunblock Sunscreen/Sunblock Sunscreen/Sunblock Skin Skin Skin Absorption Reflection Transmission 49  Sunscreens vs Sunblocks, Continued How could sunscreen and sunblock work? Sunscreen/Sunblock Sunscreen/Sunblock Sunscreen/Sunblock Skin Skin Skin Absorption Reflection Transmission Sunscreens and sunblocks both usually work through absorption of UV rays 50 Sunblocks are better because they absorb more of the UV rays Inorganic Sunblocks Absorb UV Better ideal UVB UVA visible 51  Nano Sunblock Traditional zinc oxide sun Modern zinc oxide sun blocks are blocks are very visible fairly invisible after application vitaderminstitute.com/ http://www.tackletour.com/reviewbluelizard.html  Nano Sunblock Same black:white ratio Can see larger white circles much better http://www.nisenet.org/catalog Nano Sunblock Particles need to be really small to be less noticeable! Nano ZnO and TiO2 Reflect Less Light UVB UVA visible ideal 55 Similar to Halftone Printing http://desktoppub.about.com/od/scanninggraphics/ss/color_to_bw_6.htm  Activity: Gummy Capsules When the liquid droplets come into contact with the salt water, a chemical reaction takes place and creates a polymer. http://www.nisenet.org/catalog What’s a Polymer? Polymers are made up of many many molecules all strung together to form really long chains (and sometimes more complicated structures, too). Examples of polymers Where do you find polymers? http://pslc.ws/macrog/kidsmac/index.htm  Activity: Graphene http://www.nisenet.org/catalog  Forms of Carbon Diamond Graphite Graphene Nanotube Buckyball Diamond Graphite Phase can be really important! Structure/bonding really affect properties Diamond is one of the hardest materials Graphite is soft and slippery; it’s a good lubricant http://commons.wikimedia.org/wiki/File:Diamond_and_graphite2.jpg http://www.intechopen.com/source/html/16991/media/image2.png Activity: Mitten Challenge http://www.nisenet.org/catalog Why We Need “Special” Microscopes  Can you see nanoscale objects with a regular optical microscope?  Let’s say that the smallest object you can resolve with your eyes is about 0.1 – 0.2 mm which is 100,000 – 200,000 nm  With a 100x objective, you should be able to resolve objects that are 1000 – 2000 nm  So, with a 1000x objective, we should be able to resolve objects that are 100 – 200nm, right? Why We Need “Special” Microscopes  Can you see nanoscale objects with a regular optical microscope? 100 nm particle Particles on the nanoscale interact differently with light! http://www.yorktech.com/science/craig/PHS/Graphics/EM_spectrum.jpg  Types of “Special” Microscopes Optical Scanning Transmission microscope electron electron microscope microscope http://en.wikipedia.org/wiki/Optical_microscope http://en.wikipedia.org/wiki/Scanning_electron_microscope http://itg.beckman.illinois.edu/microscopy_suite/equipment/TEM/  Types of “Special” Microscopes Scanning electron microscope Transmission electron microscope http://www.nhm.ac.uk/research-curation/science-facilities/analytical-imaging/imaging/high-resolution-sem/ultra-plus/examples/index.html http://www.princeton.edu/~cml/html/research/templated_ceramics.html Activity: Special Microscopes http://www.nisenet.org/catalog A Boy And His Atom: The World's Smallest Movie http://www.youtube.com/watch?v=oSCX78-8-q0 Scanning Probe Microscopy (SPM) http://virtual.itg.uiuc.edu/training/AFM_tutorial/ Scanning Probe Microscopy (SPM) Images of a fibroblast cell from an optical microscope (using fluorescence) and an atomic force microscope http://www.nisenet.org/catalog/programs/exploring_tools_-_special_microscopes_nanodays_08_09_10_11 http://www.asylumresearch.com/Gallery What Can You Do with SPM?  Measure surface topography (“hills”, “valleys”)  Measure roughness http://www.asylumresearch.com/Gallery  What Can You Do with SPM?  Measure surface topography (“hills”, “valleys”)  Measure roughness  Measure electrical/chemical properties Müller et al. Nature Chemical Biology 2009 Müller and Dufrêne Nature Nanotechnology 2008 What Can You Do with SPM?  Measure surface topography (“hills”, “valleys”)  Measure roughness  Measure electrical/chemical properties  Measure material properties (elasticity, strength) (i) cancer cell (ii) normal cell Cross Nature 2007 What Can You Do with SPM? all cells  Measure surface topography (“hills”, “valleys”)  Measure roughness cancer cells  Measure electrical/chemical properties  Measure material properties (elasticity, strength) normal cells Cross Nature 2007 What Can You Do with SPM?  Measure surface topography (“hills”, “valleys”)  Measure roughness  Measure electrical/chemical properties  Measure material properties (elasticity, strength)  Move atoms! http://www.thenanoage.com/visualization-manipulation.htm Silver: Great Idea!  Used to prevent spoilage throughout history  1800’s: silver used for ulcers  1920’s: used in wound management  Multiple studies found it prevents and inhibits the growth of bacteria Nano Silver Products http://www.samsung.com/, http://www.conair.com/, http://www.diabeticsocks4less.com/diabeticcare, http://mrsec.wisc.edu/ Silver: Always a Good Idea?  Overdose of macro silver causes Argyria  Inhibits “good bacteria”  Prevents photosynthesis in algae  Toxicity of nano silver still unknown http://en.wikipedia.org/wiki/Argyria Wonders and Worries of Nano http://www.nisenet.org/catalog Consumer Products with Nano Any technology has risks and benefits Who should make decisions about whether to use certain nanotechnologies? Should doctors use nanosilver catheters to prevent infections? What about using a nanosilver washing machine? http://www.nisenet.org/catalog Would you use a dangerous technology? Gasoline can be dangerous, too! To make gas safer, there are regulations for producing, transporting and using it safely How can we think ahead so we reduce the risks associate with new nanotechnologies? http://www.nisenet.org/catalog Applications of Nanotechnology Nanotechnology could change how we create, transmit, store, and use energy Examples: super-efficient batteries, low- resistance transmission lines, cheaper solar cells New flexible, thin film solar cells are easier to produce and install, use less material, and are cheaper to make http://www.nisenet.org/catalog Nanofiltration for Clean Water In many places, people do not have access to clean water Nanofiltration systems are a promising solution to this problem http://www.nisenet.org/catalog Nanofiltration for Clean Water http://www.lifesaversystems.com/press-media/videos Nanofiltration for Clean Water http://www.lifesaversystems.com An Interdisciplinary Endeavor Engineering Physics Chemistry Medicine Nanoscience & Nanotechnology Biotechnology Materials Science Biology Information Technology Do You Love Nano, Too? http://www.nisenet.org/catalog