Blogger Buzz: Blogger integrates with Amazon Associates ref My review of Nanomaterials by MF Ashby et al

Blogger Buzz: Blogger integrates with Amazon Associates

The book "Nanomaterials, nanotechnologies and design: an introduction for engineers ..." By M. F. Ashby, Daniel L. Schodek, Paulo J. S. G. Ferreira which I strongly recommend for both experienced professionals and teachers in the field as well as or even more so for all new comers to the field is available on Amazon (either on amazon.com or amazon.fr in english)

Blogger Buzz: Blogger integrates with Amazon Associates

Blogger Buzz: Blogger integrates with Amazon Associates

Materials and Environment- Mothers of Inventions

The above title is a declared objective of this blog appearing in first place in site header: "Materials Science and Engineering: Durable Development, Sustainable Development..."

My previous post but one published on 16 March 2010entitled,"Nanoscale, Nanomaterials: Basics - Calculate numbers of surface to volume atoms and much more." included embedding a Google book one of whose authors is by Prof. M.F. Ashby, FRS. whose work I admire greatly.

While researching work by his co-authors in particular by PJ Ferreira of The University of Texas at Austin,with the aim of commenting further on "Nano-things", I spotted not only Ferreira's abundant online publications which included work I had referenced very recently in fact by Carlton and Ferreira on the topic of Inverse Hall-Petch Relationship at the nanoscale (about 10nm)in Nanomaterials. Coincidences... While wondering how come my P.J. Ferreira became associated with Mike Ashby famous particularly for his work in Materials Selection for Engineering Applications a bit of lateral thinking led me to set aside for a moment considerations on how I intend to develop more on "Nano-thing" and focus a new on my blog's first declared focus the Title or Header support punch lines or Tags namely Durable Development, Sustainable Development..." ie. return to Mike F. Ashby.

EUREKA on two counts:

1. "Materials and the Environment – Eco-informed Material Choice" is the title of his second book published in 2009. An embeddable google preview is available for readers to preview in-depth. cf below or via on my RHS menu first entry in new list Materials and Environment.

2. A recent book review by fellow materials professionals appeared on Materials World book reviews I shall quote the reviews introduction "This book is an accessible introduction to environmental issues associated with materials selection. Anyone familiar with Professor Ashby’s other books will recognise his style and, as ever, he excels in presenting information in simple graphical form."...as I tried to convey in my earlier post on M.F.Ashby et al's other 2009 book on Nanotechnology.

The full review MW, Nov 2009, is freely available to all readers:
Materials and the Environment – Eco-informed Material Choice



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30 November 2009

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24 May 2009

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18 May 2009

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Up for review - Top Ten Materials bookmarked to be at the forefront of Technology - Ten Years On

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Create the Future_Design Contest 2010 from COMSOL Start date 01 March 2010.

This appears to be an interesting, helpful and rewarding approach to innovation from one of the leaders in commercial multiphysics modelling.

Comsol also provides a rich selection of freely available resource items, Conference reports on CD, white papers etc. which reminds me, I must pick-up the lastest. CD.

Should readers require a network partner, please check my blog posts for senior experience and multidisciplinary areas of competence.

en référence à : Create the Future Design Contest ::Create the Future (afficher sur Google Sidewiki)

Nanoscale,Nanomaterials_Basics_Calculate numbers of surface to volume atoms and much more.

NB. Embedded Google book (EB) trial, read on and scroll down for relevent pages.
and first experience with Wolfram Alpha. Both postive, a pleasure.

Having "dived in at the deep end" on a couple of recent posts, only just managing to "scratch the surface" in related post 1_ "Multiscale materials modelling" and related post 2 _ "Universal size/shape-dependent law for characteristic temperatures, phase transformation in nanoparticles," I decided to go back to basics.


It is widely known in the nanotechnology field, and as previously mentioned in my earlier post (2) that the ratio of surface area to volume increases as the size of particles size decreases (roughly as the inverse ratio of the characteristic dimension (x). cf graphs above where r is taken for spherical shapes and L for cubic shapes). At small nanosizes this increase in surface is quite dramatic. This surface to volume relationship is the most basic engineering factor in nanoscience and technology. It underpins the surface dependency of most if not all nanoscience and technology fields, eg. where surface properties and effects at low weight are required such as in catalysis or in fuel-cell applications to mention only two.

Numerous works mostly from teaching nanomaterials sources approach the subject but the best to my mind is the work by Mike Ashby et al in their book "Nanomaterials, nanotechnologies and design: an introduction for engineers ..." By M. F. Ashby, Daniel L. Schodek, Paulo J. S. G. Ferreira (ref. 1, and relevent pages in the google embedded book, read it below ) (*Prof Mike Ashby, FRS, is famous for his ability to reduce complex engineering materials mechanical properties to their simplest expression and to describe them comparitively in his now well-known Ashby diagrammes. This lead Mike to create Grant Design Ltd., in 1994 with Dr D.Cebon both of Cambridge Univ., UK. cf. Related posts )

Not to give Mike a full clean slate,(although most deserved) I have checked, re-calculated and presented Ashby et al's results in the above graphs using the fairly intuitive Wolfram Alpha's Mathamatical Tool.

To get a better grip on nano-things, their book Ch 6.2 also gives a simple numerical example of the number of increasing number of particle when reducing a particle size from 10µm diametre to a group of 10 nm in diametre particle of identical total volume. (N=V10µ/V10nm). This 10nm group is shown to be comprised of 10^9 particles which in turn is shown to to give a 1000 times increase in surface area. (notice the unit 10 is diametre and not radius)

The graph below right follows Ashby et al's eqn. 6.9 cf. embedded book pages below

Next, the authors treat crystalline nanoparticles. They point out that in addition to shape, structure must be taken into account.

They chose a nanoparticle with a the face centered cubic (FCC) structure, due to its practical importance, eg. Au, Ag, Ni, Al,Cu,Pt have FCC structure. The FCC unit cell, has 14 atoms all on the surface.(cf. image in EB below, ) The general equations for increasing numbers of atoms (n) by increasing unit cell layers are given as:

Total Nos of Surf Atoms Ns=12n^2+2 (eqn 6.10, Ashby et al EB)

Total Nos of Bulk Atoms Nb=4n^3-6n^2+3n-1 (eqn 6.11 Ashbey et al EB)

With (n) as input, resultats are tabulated for n, Ns, Nb, Ns/Nb ratio and percent. in table 6.1 of the EB below and are the so called "structural magic numbers".

There is a brave attempt to show how we get to the above equation by Univ of Wisconsin, Chem 801 Lecture notes (ref 2 below).

No wonder as a student I started to see modulable atomic structures (lego like principle), in the chemistry professors offices or on the lecture hall benches!)

Now thermodynamics imposes a total energy minimisation. For the FCC nanoparticle this given by (surface area X the surface energy), neglecting edge and curvature effects. They present an arguement based on atomic planes of high symmetry; Amoung possible shapes the smallest FCC nanoparticle is the cubo-octohedron. (Ashby fig. 6.20) which is a 14 sided polyhedron (looks almost spherical, doesn't it.) consisting of 12 surface atoms and one bulk atom.

For the cubo-octoherdral nanopartical, the crystal structure is maintained and the eqns giving the structural magic numbers are:

Total nos of surface atoms Ns= 10n2-20n+12 (eqn 6.13 Ashby)

Total nos of bulk atoms Nb= 1/3(10n^3 - 15n^2 + 11n - 3) (eqn 6.13 Ashby)

I have ploted the ratio Ns/Nb from the above eqns with hints on the ease and flexability of wolfram's maths tool. Trial and error is a good guide in this easy to use tool. Enough...

There is more and better in this my first Embedded Google Book.

It is with immense pleasure and priviledge that I am able to present "Nanomaterials, nanotechnologies and design: an introduction for engineers ..." By M. F. Ashby, Daniel L. Schodek, Paulo J. S. G. Ferreira.

More about this book
To get the most out of this book via author authorized limited preview, the reader will find my blog format too small, so take a squint to judge your degree of interest, but whatever, do check the full sized version by clicking the button "More about this book" on the bottom right hand (RH) corner of my embeded version, it's free. A new page opens which allows you to enlarge to suit any level of reading capacity. You can do your own review there and please leave a comment either on the subject of my post or on any of the themes available in the preview. Thanks in advance

Peruse with pleasure and make your own judgement.

RELATED POSTS:

Multiscale modelling of materials,MMM - Introduction and Explanatory Notes; Refs.,Images, on a Hot Interdisciplinary field

Universal size/shape-dependent law for characteristic temperatures, phase transformation in nanoparticles

Ashby Diagrammes, Granta Design, Materials selection software

It's not HSLA-Bainite"Nanostructured Steels"-Green Light by Irvine-based Materials Science Co-MMFX Tech Corp - Corrosion and Toughness Themes

REFERENCES.

1."Nanomaterials, nanotechnologies and design: an introduction for engineers ..." By M. F. Ashby, Daniel L. Schodek, Paulo J. S. G. Ferreira CH 6 Size effects Surface to volume ratio versus Shape.

2. Chem 801 Lecture Notes, Univ of Wisconsin

Smart material-Super strong gecko insired adhesive gets unstuck is reusable and facilitates recycling components

This invention - innovation appears to have fairly wide spread application potential. As such may well suggest opportunities for the enterprising.

General Motors researchers, led by Tao Xie, a polymer scientist at the GM Research and Development Center in Warren, MI., have made an extremely strong adhesive that comes apart when heated. The adhesive is 10 times stickier than Velcro and the reusable gecko-inspired glues that many research groups have been trying to perfect.

The polymers in the glue bond to each other within minutes when they are initially heated. Thus, when two pieces of the adhesive materials are heated, they stick together strongly, but they come apart easily when heated again.

It is in the class of new materials known as Shape memory materials-here a polymer.

Current Performance:
The researchers were able to attach and pull apart the polymers twice before losing one-third of the adhesive strength (that's still 6.6 times stronger than other adhesives? ) So how many cycles are possible?

Recycling components:

Mark Geoghegan, who studies reversible adhesives at the University of Sheffield in the U.K., says that strong, switchable adhesives could make it easier to recycle computers and electronics, if these adhesives were used to glue them together. "Taking complicated structures apart for reuse at the end of life of the original device is not trivial if their original production involved welding," he says.

The glue could find use in any application requiring a strong but alterable bond, such as furniture, toys, and buildings. Geoghegan envisions offices or hotel rooms that could be tailored to accommodate a handicapped person. Or, he suggests, "Imagine a U2 tour, where sets are assembled and disassembled on a daily basis. It might be easier to use a high-strength reversible adhesive than to use bolts."

This Smart Mat sounds well worth following-up.

Fuller details on MIT's Technology Review Newsletter

REF: (en référence à) : Technology Review: Super Velcro (on (afficher sur) Google Sidewiki.

Universal size/shape-dependent law for characteristic temperatures, phase transformation in nanoparticles,

The Nov. 09 issue of Materials World page 5, has captured my attention for some time. [1]

It's main feature [ref 1]was on multiscale materials modelling (MMM) upon which I finally managed to post recently (9 Feb 2010)[ref 2].

Against the above computationally intensive approach (bottom-up) and on the same page (paper edition only) was a small news snippet relating the claim by physicists Gregory Guisbiers and Lionel Buchaillot, based at the Institute of Electronics, Microelectronics and Nanotechnology (IEMN) Univ of Lille, Villeneuve d’Ascq, to a discovery of a Universal Law for characteristic temperature of nanosized-structures.

The equation, I learned from MW [1] was found by analysing and comparing how the size of nanoparticles affects the temperature at which they melt, become ferromagnetic or become superconductors. It is based upon the surface-to-volume ratio of the nanostructure and the spin of the particles which constitute a material. Surface to volume effect over multiple scales and from melting to superconduction sounded as though I ought to brush up my knowledge.


The description of different effects observed in nature by only one general equation is the “Holy Grail” for all physicists say the authors [best known examples are perhaps Maxwells Unifying Eqns of the Laws of electricity, magnetism and fluid dynamics and Einstein’s famous E=mc^2] Dr Guisbiers considers that this goal has been achieved for characteristic temperatures through a top-down approach that they present as opposed to the bottom-up approach. [3]

To investigate nanomaterials properties, two approaches are available: bottom-up and top-down. The first approach (bottom-up) makes use of computational methods (computer intensive_ fat) like molecular dynamics as in Multiscale Materials Modelling-MMM (earlier post) whereas the second (top-down) relies on classical thermodynamics, (computer lean).

Molecular dynamics in MMM often consider fewer than 100 000 atoms, in order to keep calculation time within reasonable values. This factor limits the nanostructure size modelled to a maximum size of tens of nanometres. Therefore, the top-down approach (computer lean) where one can consider bigger particles emerges as a simple complementary method that may provide useful insights in nanotechnology.[4]

Guisbiers and Buchaillot’s general equation is based only on the surface area to volume ratio of nanostructures and statistics (Fermi–Dirac or Bose–Einstein) followed by the particles involved in the considered phenomena (melting, ferromagnetism, vibration and superconduction). From the distinction between fermions and bosons, this equation indicates the universal behaviour of size and shape effects. Theoretical predictions show satisfactory agreement with experimental data taken from literature.[3]

Not having access, as yet, to their paper, I turned to two other summaries 1) by Nanowerk’s Michael Berger [5] and 2) by IOP, Physics World and Nanotechweb’s Belle Dumé. [6] as well
back-up earlier work on dimensional analysis, nano-thermodynamics and use in estimating binary phase diagrams for nanoparticles and calculation approximate melting point depression tendency at very small size (several nanometres) due to Wautelet et al. from the Belgium School at the Univ of Mons-Hainaut, in Mons, Belgium with whom Dr. Guisbiers worked in close collaboration. [7,8 ] (some background information is given below as well as further references to start the readers own enquiries)

Guisbiers and Buchaillot’s general equation is based only on the surface area to volume ratio of nanostructures and statistics (Fermi–Dirac or Bose–Einstein) followed by the particles involved in the considered phenomena (melting, ferromagnetism, vibration and superconduction). From the distinction between fermions and bosons, this equation indicates the universal behaviour of size and shape effects. Theoretical predictions show satisfactory agreement with experimental data taken from literature. [5,6]



The equation (TX/TX,∞ = [1–αshape/D](1/2S)) is based on the diameter of the nanostructure (D); a parameter (αshape) that is related to the surface-to-volume ratio; and the spin (S) of the particles involved in the considered material property. S equals 1/2 or 1 depending on whether the particles are fermions (particles with half-integer spin) or bosons (particles with integer spin). Tx stands for melting, Debye, Curie or superconducting temperature and Tx,∞ is that temperature in a macroscopic sample of the material. The equation has no adjustable parameters and works for all materials, says Guisbiers. In general, the characteristic temperatures decrease as particles become smaller. [6 ]

• The melting temperature is the highest temperature where the solid phase exists under thermodynamical equilibrium.
• The superconductive temperature is the highest temperature for which the material looses all resistance to the flow of electricity and tend to expel any magnetic fields inside it.
• The Curie temperature is the highest temperature for which the ferromagnetic phase is stable.
• The Debye temperature is the temperature corresponding to the maximal energy which can excite lattice vibrations. [ Nanowerk ref5]

Melting and ferromagnetism (which obey Fermi–Dirac statistics laws) are different from superconductivity and lattice vibrations (which follow Bose–Einstein statistics). This difference in behaviour is intimately related to the spin of the particles involved: melting is a solid-liquid phase transition and it occurs when inter-atomic bonds thermally break and a broken bond results in unpaired electrons, each characterized by a half-integer spin. Ferromagnetism, in turn, is a net magnetic moment that appears in the absence of an external magnetic field, and occurs thanks to partially filled shells of electrons. It is again characterized by a half-integer spin. [6 ]

Spin

Lattice vibrations are described by phonons, which, on the other hand, have integer spin. Superconductivity is a state in which conduction electrons are ordered into pairs of electrons, called Cooper pairs, also characterized by integer spin.

Predictions obtained from the equation agree very well with experimental data on melting and superconducting behaviour of nanoparticles – of silicon or lead, for example. The theory agrees fairly well with experimental results for ferromagnetism and lattice vibrations – the discrepancy is less than 10%. "This is an acceptable value because the model is quite simple and only requires knowledge of the size, shape and spin situation of the particles involved," adds Guisbiers” [ 6]


"The work shows that 19th century physics can still provide useful insights into 21st century nanotechnology, and all this can be done with just a pencil and paper – no supercomputers involved!" [6 ]



Back-ground material: [7,8,9, 10]
Understanding how materials behave at tiny length scales is crucial for developing future nanotechnologies and continues to be a great challenge for both theoretical and experimental physicists alike. Wautelet likes to reminds us that particles in the range 1-100 nm occupy an intermediary state between solid and molecular states. These nanoparticles range from particles made-up from a few atoms to so called ‘clusters up to the 100 nm range.(ref.x) from When the number of atoms in the particle lies in the range of 1000 or more, (factor of 10 or more) properties evolve from molecular to bulk solid in nature. Such particles are characterised by the fact that the ratio of the number of surface to volume atoms is not small. Eg. For a particle containing about 4000 atoms of radius R = 2nm approx., the ratio S/V =0.3 approx. ie. One third of the atoms are surface atoms. Therefore it is to be expected that surface effects will greatly influence cohesive properties of particles and must not be neglected. Theoretical work, on size dependant melting point depression goes as far back as 1909 to Pawlow (1909)[ref x]. Wautelet [ ] or in more detail P. Cheyssac [10 ] point out that for inorganic particles, it has been show experimentally in several studies notably by Buffet and Borel Phys Rev A 13 2287., 1976. that the melting point temperature (Tmpt.) decreases with decreasing particle radius (Tmpt decreases linearly with R^-1 (1/R).

Wautelet et al[ 7] outline the classical thermodynamics approach and extensions required to describe nanosystems with example published on binary systems such as (Se-Ge) first assuming particles are spherical (close packed) and non-spherical, [Wautelet et al. 8 ] They consider that the thermodynamical treatment remains valid for nanoparticles > 3nm. Further Wautelet et al [8 ] show that these size dependent effects are always larger for non-spherical shapes than for the spherical hypothesis, owing to the fact that the determining factor is the ratio of numbers of surface to volume atoms.

Note on high temperature superconductors for future reference:

The universal scaling law in magnetic phase diagram of high temperature superconductors (HTSC) K. Kitazawa, J. Shimoyama, H. Ikuta, T. Sasagawa and K. Kishio, Physica C: Superconductivity Volumes 282-287, Part 1, August 1997, Pages 335-338 online March 1999.
NB. Phase changes, Characteristic temperatures, T/Tc...

Abstract
An empirical scaling law γ2B = F(T/Tc) is proposed to successfully describe the three phase boundary lines; flux lattice melting , decoupling, and irreversibility lines in the magnetic phase diagram of the high temperature superconductors. The characteristic field of the three boundary lines changes by orders of magnitude, depending upon the material system; YBCO, LSCO and Bi2212. However, it was found that all the three lines could be scaled by a single material parameter, the electromagnetic anisotropy factor γ2 of each material. It is proposed that the three phase boundaries can be predicted for any HTSC system provided that its anisotropy factor is given.

Superconductors on Wikipedia

High-temperature superconductivity

Explaining high-Tc superconductors, M. Rice,Institute for Theoretical Physics, ETH Zürich in Physics World LINK Sign in to Physics World for free access to aricles and news letters.

References.

1. Model behaviour of ceramic and intermetallic alloys
(NB*** also IOM3 runs a Member-get-member scheme.
If you like my blog and references to the IOM3 and its resources, let me introduce you to the scheme. Visit the link at no cost to readers.)

2. Multiscale modelling of materials,MMM - Introduction and Explanatory Notes; Refs.,Images, on a Hot Interdisciplinary field

3. Universal size/shape-dependent law for characteristic temperatures, Abstract,
G. Guisbiers and L. Buchaillot,Physics Letters A Volume 374, Issue 2, 28 December 2009, Pages 305-308. doi:10.1016/j.physleta.2009.10.054

4. “Investigation on the nanomaterials properties”, Gregory Guisbiers,Seminar of The Microsystems Chair of the Louvain School of Engineering, 27 Nov. 2008. [LINK]

5. A universal law for characteristic temperatures at the nanoscale in Nanowerk 3 Nov 09

6. 'Universal' equation describes how materials behave at nanoscale,Physics World 5Nov09

7. Wautelet et al., Phase diagrams of small particles of binary systems: a theoretical approach.
Nanotechnology 11 (2000) 6-9. [LINK]

8. Wautelet et al, On the phase diagram of non-spherical nanoparticles, IOP pub, J. Phys.:Condens Matter 15 (2003) 3651-3655. [LINK].

9. Wautelet,M. Phase stability of electronically excited Si nanoparticles 2004 J. Phys.: Condens. Matter 16 L163-L166, download pdf free online from IOP Institute of Physics.

10 Phase transformation of metallic nanoparticles, P. Cheyssac, CNRS, Cargese Workshop Mai 2003 [LINK]