CH250 Intermediate Analysis – Part 1 Materials & Nanotechnology Dr Raymond Whitby C407

Overview Defining nano Formation of nanocarbon Viewing the nanoscale; direct analysis Indirect analysis of the nanoscale Adsorption experiment

1. Defining nano © iPod Nano © Tata Nano

Nanoscale 50nm 2nm Ommatidia Lens © Google images

The Royal Society “We define (the nanoscale) to be from 100nm down to the size of atoms (approximately 0.2nm) because it is at this scale that the properties of materials can be very different from those at a larger scale”

Geometry Nanomaterials are materials that have a structural component smaller than 100 nanometers (nm) in at least one dimension x y z 100nm

Componentry At present there is no clear differentiation between nanomaterials and molecules, therefore, traditional chemistry can be viewed as a form of nanoscience. Deciding factors? Stability, chemical reactivity or inertness, solubility, inorganic materials? Single polymer strand atom cluster / particle benzene

Importance of nano (1) Two main reasons cause nanomaterial properties to significantly change from their bulk scale equivalents, those being an increase in the relative surface area and quantum effects. These can led to dramatic changes or enhancement of their fundamental properties such as material strength, electrical or thermal characteristics and heightened (bio)chemical reactivity. 30nm = 5% of atoms on surface 10nm = 20% of atoms on surface 3nm = 50% of atoms on surface N.B. not to scale!

Effects of gold on the nanoscale A model relating gold nanoparticle size and melting temperature for VLS grown silicon nanowire © Yanfeng, et al., Journal of Semiconductors, Vol. 31, No. 1 January 2010

Importance of nano (2) As matter is reduced in size, quantum effects can become the dominant factor of a material’s properties. This is particularly evident when approaching the smaller end of the nanoscale. “The harmonic oscillator and the systems it models have a single degree of freedom. More complicated systems have more degrees of freedom, for example two masses and three springs (each mass being attached to fixed points and to each other). In such cases, the behavior of each variable influences that of the others. This leads to a coupling of the oscillations of the individual degrees of freedom. For example, two pendulum clocks (of identical frequency) mounted on a common wall will tend to synchronise. This phenomenon was first observed by Christaan Huygens in 1665.” Wikipedia

Quantum confinements in dots CdSe quantum dots “quantum dots are semiconductors whose conducting characteristics are closely related to the size and shape of the individual crystal. Generally, the smaller the size of the crystal, the larger the band gap, the greater the difference in energy between the highest valence band and the lowest conduction band becomes, therefore more energy is needed to excite the dot, and concurrently, more energy is released when the crystal returns to its resting state” © Benoit Dubertret 2004 & Wikipedia on Quantum dots

Allotropes of carbon Coal Diamond Graphite © Google images

Nanocarbons 1985 to 1992 1nm C60 – Buckminster fullerene Single-walled carbon nanotube Multi-walled carbon nanotube © Google images

A reflection on size

Nanocarbon gallery © Google images

Bio-molecule immobilisation Delocalised attraction of modified pyrene © H. Dai , JACS, 2001, 123 (16), pp 3838–3839

Bio-molecule cross-linking Ferritin covalently coupled to MWCNTs © Huang, et al., Nano Letters, 2002, 2 (4), pp 311–314

Cancer treatment Carbon nanotube-enhanced thermal destruction of cancer cells in a noninvasive radiofrequency field © Gannon, et al., Cancer. 2007 Dec 15;110(12):2654-65.

Enzymatic activity enhancement Candida rugosa Lipases (CRL) in hydrolysis of p-nitrophenylpalmitate Enhancement of lipase activity in non-aqueous media upon immobilization on multi-walled carbon nanotubes © Shah, et al., Chem Cent J. 2007; 1: 30

DNA sensor © M. Meyyappan @ http://www.ipt.arc.nasa.gov

Magnetic manipulation © Prof. Toru Maekawa, Toyo University, Japan

Nanocontact Manipulation © www.nanotechnik.com

Carbon nanotube circuitry Carbon nanotube advantages: Small diameter High aspect ratio Highly conductive along axis High mechanical strength High thermal conductivity © M. Meyyappan @ http://www.ipt.arc.nasa.gov

Carbon nanotube reinforcement © Easton-Bell Sports and www.zyvex.com

Commercial products “the addition of Zyvex’s NanoSolve™ Materials to (Easton’s Stealth CNT) baseball bats strengthens composite structures to provide improved handle designs with optimized flex, responsiveness, and more ‘kick’...” © Easton-Bell Sports

© Easton-Bell Sports

Bone replacement material Multiwall carbon nanotubes enhance the fatigue performance of physiologically maintained methyl methacrylate–styrene copolymer © Marrs, et al., Carbon, 2007, vol. 45, no10, pp. 2098-2104

Advanced uses Carbon nanofibres

Advanced uses Carbon nanofibres

Strengthening the future © www.acceleratingfuture.com

Questions on nano What is the definition of the nanoscale? What about nanomaterials? Describe the differences between atoms and nanomaterials? What is the difference between nanoscience and nanotechnology? Which area of science is the best to invest in for nanotechnology enhancement?

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