The Role of Synthesis in Materials Technology

28th April 2008Childrens Club Lecture

And he said unto them, it is not for you to know the times or the seasons, which the Father hath put in his own power.

The Holy Bible (The Acts 1:7)My times are in thy hand.

The Holy Bible (Psalm 31:15)To every thing there is a season, and a time to every purpose under the heaven:A time to be born, and a time to die; a time to plant, and a time to pluck that which is planted;A time to kill, and a time to heal; a time to breakdown, and a time to build up;A time to weep, and a time to laugh; a time to mourn, and a time to dance;A time to cast away stones, and a time to gather stones together; a time to embrace, and a time to refrain from embracing;A time to get, and a time to lose; a time to keep, and a time to cast away;A time to rend, and a time to sew; a time to keep silence, and a time to speak;A time to love, and a time to hate; a time of war, and a time of peace.

The Holy Bible (Ecclesiastes 3:1-8)

13. And God said unto Noah, The end of all flesh is come before me; for the earth is filled with violence through them; and, behold I will destroy them with the earth.

14. Make thee an ark of gopher wood; rooms shalt thou make in the ark, and shalt pitch it within and without with pitch.

15. And this is the fashion which thou shalt make it of: The length of the ark shall be three hundred cubits, the breadth of it fifty cubits, and the height of it thirty cubits.

16. A window shalt thou make to the ark, and in a cubit shalt thou finish it above; and the door of the ark shalt thou set in the side thereof; with lover, second, and third stories shalt thou make it.

The Holy Bible (Genesis 6: 13-16)

Noah’s Ark – The Technological Marvel

http://www.noahsark-naxuan.com/arkmodel.htm

Time line illustrating the use of materials during the past 10, 000 years

Meteorite Iron Use – 4000 BC Bronze Age Begins – 1800 BC Wrought Iron Use – 1500 BC Iron Age Begins – 1000 BC Cast Iron Use – 400 BC Synthetic rubber – 1929/1930 Nylon Introduced – 1939 Teflon Coatings – 1960 Fullerene Production - 1990

Audio tapes, audio tape players, audio tape recorders, calculators, cameras, compact disks (CD’s), CD players, Barcode, Colour Printers, Computers, Digital video disk (DVD), Electronic commerce, E-mail, Internet, Fax machines, Laboratory equipment, Laser printers, Laser pointers, Liquid crystal display, LCD ,

Some Benefits from Materials Technology

Mailing services, Measuring instruments, Modem, Network/cable television, Periodicals, News papers, Over head projectors, Photocopy machines, Play ground equipment, Radio, Refrigerators, Slide Projectors, Scanner, Search Engines, Switching technology, Telephones, Transparencies, Type writers, Video cameras,Vedio conferencing

The Living Cell is the All Time Marvel of Almighty God, The Creator.

Goal of Materials Technology - To design and synthesize the material with artificial intelligence that replicate Living Cell in all aspects. The Living Cell can apparently handle enormous number of unimaginable, uncomprehendable and difficult problems (functions) with ease and spontaneity. multiple functions performed simultaneously by The Living Cell Reproduction, Growth, Defense, Protein synthesis, Transport of nutrients, Information storage, Site directed information transfer, Communication, Energy conversion and Energy storage, SensingAll vital functions for the sustenance of life takes place in the living cells. Thus the Living Cells are self-replicating, self-containing and self-maintaining.

What is new in Materials Technology?

What is the Living Cell? What does a Cell mean? Where does the term ‘Cell’ originate from? How can the Living Cell be multifunctional and versatile? What is the structure of the Cell? What are the dimensions of the Living Cell? What are the constituents of the Cell? Can the Living Cells be mimicked? Can such mimics of the Living Cells act as molecular machines and revolutionize Materials Technology? If so in what way? How cells form complex organisms?

The queries are recurring.

The Living Cell – Some questions to ponder on!

The Living Cells – Some Facts The Cell is the basis of life.

The Cell is the smallest unit of all living organisms

Organism can be unicellular (eg., bacteria) or multicellular (eg., human beings). Human beings have an estimate of 100 trillion (1014) cells.

A typical cell is of 10 μm size and 1 nanogram mass

Latin word ‘Cellula’ means ‘a small room’.

Originator of the term “Cell” - Robert Hooke

Important contribution of Robert Hooke to Biology – His book “Micrographia” published in 1665

Truly, history owes to this industrious scientist and philosopher.

Robert Hooke (18th July 1635 – 3rd March 1703)

(a) Title page of Micrographia (1665) (b) Robert Hooke’s drawings of the cellular structure of cork (plant tissue) and a spring of sensitive plant from Micrographia

(a) (b)

“I could exceedingly, plainly perceive it to be all perforated and porous, much like a honey-comb, but that the pores, or cells, …….. were indeed the first microscopical pores I ever saw, and perhaps, that were ever seen, for I had not met with any Writer or Person, that had made any mention of them before this ….”. Robert Hooke

Mitochondria

Golgi Apparatus

Cell Membrane

Cytoplasm

Lysosome

Chloroplast

Nucleus

Rough Endoplasmic Reticulum

Smooth Endoplasmic Reticulum

Schematic representation of a eukaryotic cell and its compartments

The Living Cell - Compartmentalization

Living Cell – An Inspiration to Advanced Technologies

Can we imagine a data storage device of micrometer (10-6 m) size but can squeez the data equivalent of five high-density floppy disks (5 x 1.44 MB = 7.2 MB) ?

Can we imagine a motor that is running on and on and on but only of size measuring a few hundredths of a thousandth of a millimeter?

Can we imagine a catalyst capable of converting the inert nitrogen gas from the air into nitrogen fertilizer at room temperature and atmospheric pressure?

Can we dream of the synthesis of natural products with 100 % enantiomeric excess (ee)?

The Lesson – Weak interactions are the best!

Interactions that stabilize the local structures in proteins: (a)Hydrogen bonds (secondary structure), (b) disulfide bridges (tertiary or even Intermolecular, (c) salt bridges, (d) hydrophobic interaction.

The oval shape symbolizes the hydrophobic area from which water is excluded

Information technology Nanotechnology and Biotechnology

Technologies of the New Millennium

Information technology

The Beginning of Information Technology – The Age of the Printed Book Johannes Gutenberg (1397 – 1468) – Printing Technology

A copy of the 42-line Holy Bible

Advent of Computers and Internet – Information Explosion:

But how could this happen? What is the driving force for such a drastic explosion in information technology?

The new synthetic strategies that facilitated miniaturization of electronic elements and circuits Results of Miniaturization of electronic circuits : Saving space Saving materials Enhanced memory capacity Cost effective, Efficient and Faster

NANOTECHNOLOGY:

Nanotechnology - Taniguchi at the University of Tokyo, Japan, in 1974.

On 29th of December, 1959, Richard P. Feynman took the shiny example of the living cell to drive home his point that individual atoms can be arranged in the way we want them to be. With this ultimate degree of miniaturization all the information contained in all the books in the world can be stored in the grain of a sand. Living cell is not only capable of storing enormous amount of information in a very small volume but also equipped with the hard ware to read out the information and retrieve the same when needed and put the same into action. In an analogous way Richard P. Feynman professed that it should be possible to write the entire Encyclopaedia Britannica onto the point of a needle. In those days when computers were huge machines the wiring of which filled the whole room completely, he is genius enough and fore sighted to profess that computers of the future should be made of wires that would only be 10 or 100 atoms in diameter.

Nanoscience refers to the world as it works on the atomic or molecular scale, from one to several hundred nanometers.Nanometer = 10-9 meters: roughly the size of 10 hydrogen atoms lined up or the width of DNA.

Nanotechnology - size matters

Size comparisons of nanocrystals with bacteria, viruses and molecules

Graphite  

More 2D like;  sp2 OrbitalsStrong bonds within layers and weak bond

between layersGood conductor of electricity

Diamond  More 3D like behavior; sp3 orbital

Strong covalent bonding in 3 dimensionsBad electrical conductor 

 

A Schematic representation of the structures of graphite, diamond and fullerenes

Shekar Subramoney, Advanced Materials, 10, 1998, 1157

Simple representation ofNanocarbons withPECULIAR Morphologies

Approaches for the synthesis of Nanostructured Materials

Nanostructured Material

Assemble fromNano-building Blocks

Power/aerosol compactionChemical Synthesis

‘Sculpt’ from BulkMechanical attrition(ball milling)Lithography/etching

bottom-up top-down

(a)A football (the C60 molecule is supposed to have the structure formed when each vertex on the seams of such a ball is replaced by carbon atm, (b) Schematic diagram of the pulsed supersonic nozzle used to generate carbon cluster beams

Synthetic Strategy that lead to the formation of Fullerenes:

Formation of Fullerenes - Synthetic Strategy

Synthetic Strategy for the formation of Fullerenes

Synthesis of Fullerene Derivatives; Exohedral compounds

Endohedral

Intercalation Compounds

Carbon Nanotubes

Challenges ahead (a) Synthesis of carbon nanotubes with desired properties in large

(b) Successful utilization of CNT’s for a variety of Technologies remove the impurities present

(c) Develop synthetic strategies for exclusive production of SWNT’s or MWNT’s

(d) Making nanotubes soluble is also a note worthy problem.

Carbon nanotubes are a key component of nanotechnology

Carbon Nano test tube:

The nano sized tubular carbon – Rolled hexagonal graphene sheets with fullerene caps at both ends

Hollow carbon tube - As a nano-scale test tube for doing chemistry As a mold for making nano rods of other materials Storage material Magnetic and Electronic applications

Difficult task - Handling because of size

Graphene Sheet Single walled nano tube

Fig. Hexagonal net work of carbon atoms rolled upto make a seamless cylinder

Nano tube: Seamless cylinders rolled up from graphene sheet

Schematic representation of the relation between nanotube and graphene

Types of carbon nano tubes:

1. Arc-discharge or vaporization process (in the presence of transition metal catalyst)

2. Laser-evaporation of graphite (Laser furnace process)

3. Chemical Vapour Deposition, CVD (Catalytic Pyrolysis of hydrocarbons) or Catalytic Chemical Vapour Deposition (CCVD)

4. Template Carbonization Method

Carbon Nanotubes – An Evolution in Synthetic Strategies

The Arc-Discharge Process

Schematic representation of the apparatus used for the synthesis of CNT’s

The Arc-Discharge Process – Exclusive Synthesis of SWNT’s

Arc – discharge chamber with a web of SWNT’s

TEM images of various CNT’s

Laser Furnace Process

Laser-furnace (vaporization) apparatus

Experimental set up for Chemical Vapour Deposition Synthesis, (b) probable models of CNT growth

Chemical Vapour Deposition

Synthesis of carbon nanotubes by template carbonization method

4. Template Carbonization Method:

impregnation

Polymer solutionALUMINA MEMBRANE

carbonization

48 % HF 24 HRS

CNT

Polymer

Can a carbon source as common as kerosene be used for the synthesis of nanoforms of carbon materials?

(a) (b) (c)

SEM (scanning electron microscope) images of (a) hair like fibers, (b) bitter – gourd - like rough fibers and(c) carbon thin film grown on a stainless steel substrate

Synthesis of loaded (metal(s)) carbon nanotubes

The invention of a very high definition microscope called a scanning tunnelling Microscope by Russell D. Young, in 1971, has revolutionized the field of Nanotechnology.This microscope is an instrument like a blindfolded person feels the surface and scan atom by atom. In this way it is possible to create an image of any particular surface on atomic scale. Not long after this invention it will be possible to manipulate atoms in this Way.

Carbon Nanotubes as STM and AFM Tips:

Carbon Nanotubes as STM and AFM Tips:

STM image of quantum dot formed by self-assembling (Ge “pyramid”)

Scanning tunneling microscope (STM) image of a pyramid of germaniumatoms on top of a silicon surface

Role of Synthesis in Leather Technology

Synthetic strategy for Bronopol

Biomimicking Lotus Leaf Microstructures

Youyang Liu, J. Mater. Chem., 17 (2007) 1071

Dream of human beings – Creation of clothes that clean themselves Self cleaning clothes Two main concepts – Design surfaces that can break down, decompose dust Produce surfaces with repellent properties Common route – Treat target surface with self cleaning coatings Self cleaning coatings – Hydrophilic and hydrophobic Hydrophilic coatings – Window glass Cement Textiles Paints Self cleaning clothes

Self cleaning clothes - Titania nanoparticles Potential hazards with titania nanoparticle films

Surfaces with extreme water repellent properties are known in Nature Super hydrophobic nature of lotus leaves – lotus leaf effect or self cleaning effect

Fig. 10. (a) top view of a lotus leaf (bar = 50 mm). (b) Magnified section of the lotus leaf from (a) (bar = 5 mm). (c) Magnified view of a papilla from (b) (bar = 1 mm). (d) SEM image of the bottom surface of the lotus leaf from (a) (bar = 1 mm).

Morphology of Lotus leaves Vs Carbon nanotube clusters

Fig. 11. (1) Magnified vew of Papilla of Lotus leaf, (2) SEM image of MWNTs depositedon silicon wafer (bar = 1 μm)

(1) (2)

Carbon Nanotubes are ideal candidates for the fabrication of artificial lotus leaves Carbon nanotube clusters with micro-nano binary structures form a good mimic of lotus leaves

Self cleaning coating – Lotus leaf effect

Procedure for coating cotton fibres with carbon nanotubes

Dispersion of CNTs in waterwith ultrasonic treatment

Dip cotton fabricsInto CNTs suspension

Deposit/adsorb CNTs to Cotton faber surface

Self cleaning coating – Lotus leaf effect

Procedure for coating cotton fibres with carbon nanotubes

Dispersion of CNTs in waterwith ultrasonic treatment

Dip cotton fabricsInto CNTs suspension

Deposit/adsorb CNTs to Cotton faber surface

Fuel Cell Applications

Transportation

Industry &Power PlantsResidential

Conclusion: The living cells are versatile in its design and function. They provide all necessary inspiration to design and synthesize new materials with specific functions that bring about revolutionsin Technology and also give birth to Advanced Technologies. Understanding and imitation of natural machinery of the living cells holds great rewards. But such endeavours are not free from barriers and obstacles. For instance, molecular level details of the working of ribosomes (their function of protein synthesis) is unclear even today and remains one of the hardest problems in biology. Therefore our knowledge and understanding of the processes going on in a living cell and also the mechanochemical functions of various cell components is limited. Any improvements in such an understanding facilitate imitation and mimicking of the synthetic strategies involved in life process (a unique network of chemical reactions). This knowledge will in turn bring about drastic changes and advancements in Materials Technology.