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NANOMATERIALS COURSE. HONOURS LECTURES 2008 LECTURER: DR. M. J. MOLOTO OFFICE: C204 Consultation Hours: 2 – 3, Mon – Fri OR by appointment Suggested Reading Materials: Nanochemistry: A chemical approach to nanomaterials by Geoffrey A. Ozin & Andre C. Arsenault - PowerPoint PPT Presentation
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NANOMATERIALS COURSE NANOMATERIALS COURSE HONOURS LECTURES 2008 HONOURS LECTURES 2008 LECTURER: DR. M. J. MOLOTO LECTURER: DR. M. J. MOLOTO OFFICE: C204 OFFICE: C204 Consultation Hours: 2 – 3, Mon – Fri OR by Consultation Hours: 2 – 3, Mon – Fri OR by appointment appointment Suggested Reading Materials: Suggested Reading Materials: Nanochemistry: A chemical approach to Nanochemistry: A chemical approach to nanomaterials by Geoffrey A. Ozin & nanomaterials by Geoffrey A. Ozin & Andre C. Arsenault Andre C. Arsenault Nanostructures and nanomaterials – Nanostructures and nanomaterials – synthesis, properties & applications by synthesis, properties & applications by Guozhong Cao Guozhong Cao Principles of nanotechnology: Principles of nanotechnology: molucular-based study of condensed molucular-based study of condensed matter in small systems by G. Ali matter in small systems by G. Ali Mansoori Mansoori
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NANOMATERIALS COURSENANOMATERIALS COURSEHONOURS LECTURES 2008HONOURS LECTURES 2008

LECTURER: DR. M. J. MOLOTOLECTURER: DR. M. J. MOLOTOOFFICE: C204OFFICE: C204

Consultation Hours: 2 – 3, Mon – Fri OR by appointmentConsultation Hours: 2 – 3, Mon – Fri OR by appointment

Suggested Reading Materials:Suggested Reading Materials:Nanochemistry: A chemical approach to nanomaterials Nanochemistry: A chemical approach to nanomaterials by Geoffrey A. Ozin & Andre C. Arsenaultby Geoffrey A. Ozin & Andre C. ArsenaultNanostructures and nanomaterials – synthesis, Nanostructures and nanomaterials – synthesis, properties & applications by Guozhong Caoproperties & applications by Guozhong CaoPrinciples of nanotechnology: molucular-based study Principles of nanotechnology: molucular-based study of condensed matter in small systems by G. Ali of condensed matter in small systems by G. Ali MansooriMansoori

Further publications suggested in classFurther publications suggested in class

Assignment 1Assignment 1

Choose one materials like CdS or Ag Choose one materials like CdS or Ag nanoparticles and use it to calculate the radius nanoparticles and use it to calculate the radius of the nanomaterial from the band edges. Find of the nanomaterial from the band edges. Find the equation in the texts or online.the equation in the texts or online.

Identify the material that you are not doing Identify the material that you are not doing research and discuss the nature, chemistry and research and discuss the nature, chemistry and properties in nanoscale. properties in nanoscale.

Submission date: Submission date: Duration: 1 Week.Duration: 1 Week.

ASSIGNMENT 2008ASSIGNMENT 2008

Choose from the four topics given and write at least three pages about the principle, properties and variation of size of particles of materials chosen. In relation to the size show a calculation that depicts the properties and size of particles. The four topics: (a) Carbon nanotubes (CNT), (b) Semiconductor nanoparticles (Quantum dots), (c) Thin Films and (d) Polymer Nanocomposites (PNC).

Each student must choose a topic that is not current an area of their project title.

Submission Date : Last week of lectures Week of 15 September 2008

Nanotechnology deals with small structures or Nanotechnology deals with small structures or small-sized materials with dimensions from small-sized materials with dimensions from subnanometer to several hundred nanometerssubnanometer to several hundred nanometers

1 nm = 101 nm = 10-9-9 m or 1 nm = a billionth of a metre m or 1 nm = a billionth of a metre

1 nm = 101 nm = 10-3-3 micrometer = 10 micrometer = 10 ÅÅ

1 m = 101 m = 1033 cm = 10 cm = 1066 mm = 10 mm = 1099 nm = 10 nm = 101010 Å Å

1 nm is equivalent to 10 H atoms or 5 Si atoms 1 nm is equivalent to 10 H atoms or 5 Si atoms

aligned in a linealigned in a line

HOW SMALL IS NANOHOW SMALL IS NANO

Defining Nanoscale Science

Nanoscale science can be defined as the chemistry and physics of structures that are on the length scale of 1-100 nm (1nm = 10-9 m or 10 Å), or require tolerances below 100 nm.

1 nm 2 nmEthane C-C Bond

1.543 Å

or

0.1543 nm

http://www.nobel.se/chemistry/laureates/1996/index.html

1 nm 2 nm

A Gold Nanoparticle:about 300 Gold Atoms

C60 – Buckminsterfullerene

Nano and LifeNano and Life

PerspectivePerspective

Atom 0.1 nmAtom 0.1 nm

DNA (width) 2 nmDNA (width) 2 nm

Protein 5 – 50 nmProtein 5 – 50 nm

Virus 75 – 100 nmVirus 75 – 100 nm

Materials internalized by cells < 100 nmMaterials internalized by cells < 100 nm

Bacteria 1,000 – 10,000 nmBacteria 1,000 – 10,000 nm

White Blood Cell 10,000 nmWhite Blood Cell 10,000 nm

BiopharmaceuticsBiopharmaceuticsDrug DeliveryDrug Delivery

Drug EncapsulationDrug Encapsulation

Functional Drug CarriersFunctional Drug Carriers

Drug DiscoveryDrug Discovery

Implantable MaterialsImplantable MaterialsTissue Repair and ReplacementTissue Repair and Replacement

Implant CoatingsImplant Coatings

Tissue Regeneration ScaffoldsTissue Regeneration Scaffolds

Structural Implant MaterialsStructural Implant Materials

Bone RepairBone Repair

Bioresorbable MaterialsBioresorbable Materials

Smart MaterialsSmart Materials

Implantable DevicesImplantable DevicesAssessment and Treatment Assessment and Treatment

DevicesDevices

Implantable SensorsImplantable Sensors

Implantible Medical DevicesImplantible Medical Devices

Sensory AidsSensory AidsRetina ImplantsRetina ImplantsCochlear ImplantsCochlear Implants

Surgical AidsSurgical AidsOperating ToolsOperating Tools

Smart InstrumentsSmart InstrumentsSurgical RobotsSurgical Robots

Diagnostic ToolsDiagnostic ToolsGenetic TestingGenetic Testing

Ultra-sensitive Labeling Ultra-sensitive Labeling andand

Detection TechnologiesDetection TechnologiesHigh Throughput Arrays High Throughput Arrays

andandMultiple AnalysesMultiple Analyses

ImagingImagingNanoparticle LabelsNanoparticle Labels

Nanotechnology :Nanotechnology : A technology of design, fabrication and A technology of design, fabrication and

applications of nanostructures and applications of nanostructures and nanomaterialsnanomaterials

Is concerned with materials and systems Is concerned with materials and systems whose structures and components whose structures and components exhibit novel and significantly improved exhibit novel and significantly improved physical, chemical and biological physical, chemical and biological properties, phenomena and processes properties, phenomena and processes due to their nanoscale sizedue to their nanoscale size

Is a multidisciplinary field: chemists, Is a multidisciplinary field: chemists, physisits, material scientists, engineers, physisits, material scientists, engineers, molecular biologists, pharmacologists molecular biologists, pharmacologists etc.etc.

Physical properties of nanomaterialsPhysical properties of nanomaterials Nanomaterials may have a significantly lower melting point or phase transition Nanomaterials may have a significantly lower melting point or phase transition

temperature and appreciably reduced lattice constants, due to a huge fraction of temperature and appreciably reduced lattice constants, due to a huge fraction of surface atoms in the total amount of atomssurface atoms in the total amount of atoms

Mechanical properties of nanomaterials may reach the theoretical strength, Mechanical properties of nanomaterials may reach the theoretical strength, which are one or two orders of magnitude higher than that of single crystals in which are one or two orders of magnitude higher than that of single crystals in the bulk form. The enhancement in mechanical strength is due to the reduced the bulk form. The enhancement in mechanical strength is due to the reduced probability of defects.probability of defects.

Optical properties of nanomaterials can be significantly different from bulk Optical properties of nanomaterials can be significantly different from bulk crystals. E.g. The optical absorption peak of a semiconductor nanoparticle shifts crystals. E.g. The optical absorption peak of a semiconductor nanoparticle shifts to short wavelength, due to an increased band gap. The colour of metallic to short wavelength, due to an increased band gap. The colour of metallic nanoparticles may change with their sizes due to surface plasmon resonance.nanoparticles may change with their sizes due to surface plasmon resonance.

Electrical conductivity decreases with a reduced dimension due to increased Electrical conductivity decreases with a reduced dimension due to increased surface scattering. However, electrical conductivity of nanomaterials could also surface scattering. However, electrical conductivity of nanomaterials could also be enhanced appreciably, due to the better ordering in microstructure, e.g. be enhanced appreciably, due to the better ordering in microstructure, e.g. polymeric fibrils.polymeric fibrils.

Magnetic properties of nanostructured materials are distinctively different from Magnetic properties of nanostructured materials are distinctively different from that of bulk materials. Ferromagnetism of bulk materials disappears and that of bulk materials. Ferromagnetism of bulk materials disappears and transfers to superparamagnetism in the nanometer scale due to the huge surface transfers to superparamagnetism in the nanometer scale due to the huge surface energy.energy.

Self-purification is an intrinsic thermodynamic property of nanostructures and Self-purification is an intrinsic thermodynamic property of nanostructures and nanomaterials. Any heat treatment increases the diffusion of impurities, intrinsic nanomaterials. Any heat treatment increases the diffusion of impurities, intrinsic structural defects and dislocations, and one can easily push them to the nearby structural defects and dislocations, and one can easily push them to the nearby surface. Increased perfection would have appreciable impact on the chemical surface. Increased perfection would have appreciable impact on the chemical and physical properties. For example, chemical stability would be enhanced.and physical properties. For example, chemical stability would be enhanced.

Properties of nanostructured materials are size dependant. Properties can be tuned Properties of nanostructured materials are size dependant. Properties can be tuned simply by adjusting the size, shape or extent of agglomeration. simply by adjusting the size, shape or extent of agglomeration.

Properties of a material vary with the Properties of a material vary with the size of the materialsize of the material

(Bulk) Gold is a shiny yellow metal(Bulk) Gold is a shiny yellow metal Nanoscopic gold, Nanoscopic gold, i.e. i.e. clusters of gold atoms clusters of gold atoms

measuring measuring 1 nm1 nm across, appears red across, appears red Bulk gold does not exhibit catalytic propertiesBulk gold does not exhibit catalytic properties Au nanocrystal is an excellent low temperature Au nanocrystal is an excellent low temperature

catalyst.catalyst. Therefore, if we can control the processesTherefore, if we can control the processes

that make a nanoscopic material, then we can that make a nanoscopic material, then we can control the material’s properties.control the material’s properties.

Therefore, if we can control the processes that make a nanoscopic material, then we can control the material’s properties.

Nanofabrication techniques: grouped Nanofabrication techniques: grouped according to the form of productsaccording to the form of products

Nanoparticles: Nanoparticles: colloidal processing colloidal processing flame combustion flame combustion phase segregation phase segregation

Nanorods or nanowires: Nanorods or nanowires: template-based electroplating template-based electroplating solution-liquid-solid growth (SLS) solution-liquid-solid growth (SLS)

Thin films: Thin films: Chemical vapour deposition (Chemical vapour deposition (CBDCBD and MOCVD) and MOCVD) Molecular beam epitaxyMolecular beam epitaxy Atomic layer depositionAtomic layer deposition

Nanostructured bulk materials:Nanostructured bulk materials: Photonic bandgap crystals by self-assembly of nanosized Photonic bandgap crystals by self-assembly of nanosized

particlesparticles

INTRODUCTIONINTRODUCTION Nanoscale science is concerned with the creation of structures Nanoscale science is concerned with the creation of structures

on the length scale of 1-100 nm.on the length scale of 1-100 nm.

There are two driving forces for nanoscale science:There are two driving forces for nanoscale science:

(i) The(i) The top-down top-down approach which is driven by the approach which is driven by the microelectronic industry.microelectronic industry.

(ii) The (ii) The bottom-up bottom-up approach which was initially driven by the approach which was initially driven by the curiosity of chemists to emulate natures large functioning curiosity of chemists to emulate natures large functioning biomoleculesbiomolecules, but is increasingly being driven by a convergence , but is increasingly being driven by a convergence with the top-down approach to make new nanoelectronic with the top-down approach to make new nanoelectronic devices.devices.

Thus, nanoscale science is more than creating structures on the Thus, nanoscale science is more than creating structures on the length scale of 1-100 nm; it is about making nanostructures length scale of 1-100 nm; it is about making nanostructures which also function in some way.which also function in some way.

There are two approaches to making There are two approaches to making structures on the nanoscale,structures on the nanoscale,

The bottom-up approachThe bottom-up approach:: whereby structures whereby structures are made atom-by-atom and molecule-by-are made atom-by-atom and molecule-by-molecule, harnessing covalent, ionic, metallic molecule, harnessing covalent, ionic, metallic or non-covalent bonds. This approach or non-covalent bonds. This approach represents how nature self-assembles represents how nature self-assembles functioning nanostructures, such as enzymes functioning nanostructures, such as enzymes and viruses, orand viruses, or

The top-down approachThe top-down approach:: whereby structures whereby structures are etched into bulk materials such as silicon. are etched into bulk materials such as silicon. This approach represents how silicon chips This approach represents how silicon chips are fabricated, are fabricated,

How Do We Make Things Small?How Do We Make Things Small?NanofabricationNanofabrication

How Do We Make Things Small?How Do We Make Things Small?NanofabricationNanofabrication

Nat

ure

m

nm

Å

Biological World

Structureleads to Function

Lithographic Techniques

Covalent Chemistry – Dendrimers

Supramolecular Chemistry – Aggregates

Nanoparticle Synthesis

Molecular Beam Epitaxy

SPM Probes

NanotechnologyDown

Top

Ph

ysics

Non-Biological World

Up

Bottom

Ch

emis

try

A Few NANOMETRE Milestones

3.5 billion years ago The first living cells emerge. Cells house nanoscale biomachines that perform such tasks as manipulating genetic material and supplying energy.400 B.C. Democritus coins the word "atom," which means "not cleavable" in ancient Greek.1905 Albert Einstein publishes a paper that estimates the diameter of a sugar molecule as about one nanometer.1931 Max Knoll and Ernst Ruska develop the electron microscope, which enables subnanometer imaging.1959 Richard Feynman gives his famed talk "There's Plenty of Room at the Bottom”, on the prospects for miniaturization.1968 Alfred Y. Cho and John Arthur of Bell Laboratories and their colleagues invent molecular-beam epitaxy, a technique that can deposit single atomic layers on a surface.1974 Norio Taniguchi conceives the word "nanotechnology" to signify machining with tolerances of less than a micron.1981 Gerd Binnig and Heinrich Rohrer create the scanning tunnelling microscope, which can image individual atoms.

A FewA Few NANOMETRE MilestonesNANOMETRE Milestones 1985 Robert F. Curl, Jr., Harold W. Kroto and Richard E. Smalley

discover buckminsterfullerenes, also known as buckyballs, which measure about a nanometer in diameter.

1986 K. Eric Drexler publishes Engines of Creation, a futuristic book that popularizes nanotechnology.

1989 Donald M. Eigler of IBM writes the letters of his company's name using individual xenon atoms.

1991 Sumio Iijima of NEC in Tsukuba, Japan, discovers carbon nanotubes.

1993 Warren Robinett of the University of North Carolina and R. Stanley Williams of the University of California at Los Angeles devise a virtual-reality system connected to a scanning tunneling microscope that lets the user see and touch atoms.

1998 Cees Dekker's group at the Delft University of Technology in the Netherlands creates a transistor from a carbon nanotube.

1999 James M. Tour, now at Rice University, and Mark A. Reed of Yale University demonstrate that single molecules can act as molecular switches.

2000 The Clinton administration announces the National Nanotechnology Initiative, which provides a big boost in funding and gives the field greater visibility.

2000 Eigler and other researchers devise a quantum mirage. Placing a magnetic atom at one focus of an elliptical ring of atoms creates a mirage of the same atom at another focus, a possible means of transmitting information without wires.

The Nobel Prize in Chemistry 1996The Nobel Prize in Chemistry 1996

"for their discovery of fullerenes""for their discovery of fullerenes"

Richard E. Smalley Sir Harold W. Kroto Robert F. Curl Jr.

C60 – Buckminsterfullerene OH

N

O

HH

1 nm 2 nm

1959:1959: Richard P. Feynman; Richard P. Feynman; Plenty of room at the bottomPlenty of room at the bottom

As soon as I mention this, people tell me As soon as I mention this, people tell me about miniaturization, and how far it has about miniaturization, and how far it has progressed today. They tell me about progressed today. They tell me about electric motors that are the size of the nail electric motors that are the size of the nail on your small finger. And there is a device on your small finger. And there is a device on the market, they tell me, by which you on the market, they tell me, by which you can write the Lord's Prayer on the head of can write the Lord's Prayer on the head of a pin. But that's nothing; that's the most a pin. But that's nothing; that's the most primitive, halting step in the direction I primitive, halting step in the direction I intend to discuss. It is a staggeringly small intend to discuss. It is a staggeringly small world that is below. In the year 2000, when world that is below. In the year 2000, when they look back at this age, they will wonder they look back at this age, they will wonder why it was not until the year 1960 that why it was not until the year 1960 that anybody began seriously to move in this anybody began seriously to move in this direction. direction. Why cannot we write the entire 24 volumes Why cannot we write the entire 24 volumes of the Encyclopedia Brittanica on the head of the Encyclopedia Brittanica on the head of a pin?of a pin?

He discussed a "great future" in which "we can arrange the atoms the way we want." Feynman's "great future" arrived in 1989 with the discovery of ways to manipulate atoms with the Scanning Tunneling Microscope.

Nano-CareNano-CareTMTM fabrics sold since Nov. 2001, incorporate “ fabrics sold since Nov. 2001, incorporate “nano-nano-whiskerswhiskers” into the fabric to make” into the fabric to make

it stain-resistant to water-based liquids such as coffee and wine.it stain-resistant to water-based liquids such as coffee and wine.

This Lee Performance Khaki Pant This Lee Performance Khaki Pant features features NanocareNanocare fabric fabric

Product Features: *Product Features: * Nanocare Nanocare fabric fabric repels liquids*repels liquids*

Wrinkle free Lee Wrinkle free Lee NanocareNanocare khaki pant khaki pant fabric * Stain resistant fabric * Stain resistant

Nanocare revolutionizes fabric technology

AUSSIES BASK IN THE SUMMER SUN, AUSSIES BASK IN THE SUMMER SUN, NANOPOWDERSNANOPOWDERS PROTECTING THEIR SKIN PROTECTING THEIR SKIN By Debbi Gardiner By Debbi Gardiner

Small Times Correspondent Small Times Correspondent  Jan. 7, 2003  Jan. 7, 2003

Various sunscreens (Wild Child, Wet Dreams and Bare Various sunscreens (Wild Child, Wet Dreams and Bare Zone) incorporate ZinClearTM, a Zone) incorporate ZinClearTM, a transparenttransparent suspension of nanoscopic zinc oxide particles that are too suspension of nanoscopic zinc oxide particles that are too small to scatter visible light as do products containing small to scatter visible light as do products containing microscopic particles. microscopic particles.

ZinClear allows UV protection without the funny ZinClear allows UV protection without the funny "chalky" look conventional sunscreens give. It's made "chalky" look conventional sunscreens give. It's made with an APT-patented method of processing high quality with an APT-patented method of processing high quality nanopowders. nanopowders.

““Zinc oxide is a natural UV filter but its marketability Zinc oxide is a natural UV filter but its marketability was lacking because of its whiteness. Now we can make it was lacking because of its whiteness. Now we can make it transparent,” said Brian Innes, business development transparent,” said Brian Innes, business development manager at APT. manager at APT.

Nanomaterials in action… Nanomaterials in action…

Wilson Double CoreTM tennis ball has clay Wilson Double CoreTM tennis ball has clay nanoparticles embedded in the polymer lining of its nanoparticles embedded in the polymer lining of its inner wall, which slows the escape of air from the inner wall, which slows the escape of air from the ball making it last twice as long. ball making it last twice as long.

Carbon nanotube stabilizers in Tennis rackets Carbon nanotube stabilizers in Tennis rackets increase torque and flex resistance increase torque and flex resistance


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