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Chung-Yuen Herbert Hui named the 2011 recipient of The Adhesion Society Award for Excellence in Adhesion Science

bio_hui Professor Herbert Hui, of Cornell University, has been named the 2011 recipient of The Adhesion Society Award for Excellence in Adhesion Science, Sponsored by 3M.

The Award will be presented during the 34th Annual Meeting of The Adhesion Society in Savannah, GA, USA, 13-16 February 2011.

The citation reads:  "For his meritorious and creative contributions to the application of fracture mechanics in understanding the problems of adhesion science."

Comments

Zhigang Suo's picture

Dear Herbert:  Heartiest congratulations on receiving this premier award of the Adhesion Society!  This is a truly wonderful news.  Your work on adhesion and soft materials has greatly influenced me and my students.  It has been such a pleasure to learn from reading your papers and discussing with you for all these years.

Mike Ciavarella's picture

 

I add also my congratulations to Prof Herbert Hui.  Adhesion has seen an enormous interest, both from bio-mechanics applications (I remember my friend Nicola Pugno's breakthrough , ---- Physicists Have Found The Formula For A Spiderman Suit said
Physicists have found the formula for a Spiderman suit.



The
tokay gecko, native
to southeast Asia. (©  M. Moffett)

 

Only recently
has man come to understand how spiders and geckos effortlessly scuttle
up walls and hang from ceilings but it was doubted that this natural
form of adhesion would ever be strong enough to hold the weight of real
life Peter Parkers. Recent research concluded that van der Waals forces -- the weak
attraction that molecules have for each other when they are brought
very close together - are responsible for creepy crawlies' amazing
sticking power. It is the tiny hairs on spiders' feet that attract to
the molecules of surfaces, even glass, and keep them
steady. Professor Nicola Pugno, engineer and physicist at Polytechnic of Turin,
Italy, has formulated a hierarchy of adhesive forces that will be
strong enough to suspend a person's full body weight against a wall or
on a ceiling, while also being easy to detach.

which started when I was visiting with Nicola the good friend Huajian Gao in Max Planck -
Stuttgart see
The
Research Group of Prof. Huajian Gao: Home
but also in standard engineering, since we are looking at adhesives for the Ferrari Millechili journal Call for
papers for the Millechili Journal -- weight reduction in vehicle design.
In collaboration with Ferrari SpA

which includes Prof. Tony Kinloch another leader in adhesion.

 

Finally, let me remind you of the sadly deceased Nobel prize winner Prof.
Pierre-Gilles
de Gennes - Biography

Biography
Pierre-Gilles de GennesP.
G. de Gennes was born
in Paris, France, in 1932. He majored from the École Normale
in 1955. From 1955 to 1959, he was a research engineer at the
Atomic Energy Center (Saclay), working mainly on neutron
scattering and magnetism, with advice from A. Herpin, A. Abragam
and J. Friedel (PhD 1957). During 1959 he was a postdoctoral
visitor with C. Kittel at Berkeley, and then served for 27 months
in the French Navy. In 1961, he became assistant professor in
Orsay and soon started the Orsay group on supraconductors.
Later, 1968, he switched to liquid crystals. In 1971, he became
Professor at the Collège de France, and was a participant of
STRASACOL (a joint action of Strasbourg, Saclay and College de
France) on polymer physics.

From 1980, he became interested in interfacial problems, in
particular the dynamics of wetting. Recently, he has been
concerned with the physical chemistry of adhesion.

 

in cholesterol  , in many other areas of cellular mechanics.

 

So let me conclude with the links!

 

Herbert Hui's Research Interests

My current interest is in areas connecting mechanics and
materials. In the past years, I have published in the area of adhesion
science, fracture mechanics of aging aircraft, fracture mechanisms of
polymer/polymer interfaces, fracture mechanics and statistical theory of
failure of composite materials, high temperature creep crack growth in
metals, swelling kinetics and diffusion of organic molecules in polymer
glasses, hypersingular intergrals and boundary element method, sintering
of ceramics, fluid mechanics of aircraft, electronic-packaging and
micro-electo-mechanics systems.

Herbert Hui's Selected Publications

  • Modeling the Failure of an Adhesive Layer in a Peel Test PDF
  • Collapse of microchannels during anodic bonding: Theory and
    experiments PDF
  • Crack blunting and the strength of soft elastic solids PDF
  • Bonding of a Viscoelastic Periodic Rough Surface to a Rigid Layer PDF
  • Characterization of a fracture specimen for crack growth in epoxy
    due to thermal fatigue PDF
  • Design of a biomimetic fibrillar interfaces: 1. Making contact PDF
  • Design of a biomimetic fibrillar interfaces: 2. Mechanics of
    enhanced adhesion PDF
  • Investigation of Adhesion Hysteresis in Poly (dimethylsiloxane)
    Networks Using the JKR Technique PDF
  • Constraints on Microcontact Printing Imposed by Stamp Deformation PDF
  • The Mechanics of Tack: Viscoelastic Contact on a Rough Surface PDF

 

 

Adhesion
From Wikipedia, the free encyclopedia

Jump to: navigation, search

This article needs attention from an
expert on the subject
. See the talk
page
for details. WikiProject Physics or the Physics Portal may be able to help recruit an
expert. (November 2008)

Dew drops
adhering to a spider web

For other uses, see Adhesion (disambiguation).

Adhesion is the tendency of certain dissimilar molecules
to cling together due to attractive
forces
. In contrast, cohesion
takes place between similar molecules.

Contents
[hide]

//
[edit] Mechanisms of adhesion

Cohesion
causes water to form drops, surface tension causes them to be nearly spherical, and
adhesion keeps the drops in place.

Water droplets are flatter on a Hibiscus
flower which shows better adhesion.

Five mechanisms of adhesion have been proposed to explain why one
material sticks to another:

[edit] Mechanical adhesion

Adhesive materials fill the voids or pores of the surfaces and hold
surfaces together by interlocking. Sewing forms a large scale mechanical
bond, velcro
forms one on a medium scale, and some textile adhesives form one at a
small scale. This is similar to surface tension.

[edit] Chemical adhesion

Two materials may form a compound at the join. The strongest joins are where atoms
of the two materials swap (ionic bonding) or share (covalent bonding) outer electrons. A
weaker bond is formed if a Hydrogen
atom in one molecule is attracted to an atom of Nitrogen,
Oxygen,
or Fluorine
in another molecule, a phenomenon called Hydrogen bonding.

[edit] Dispersive adhesion

In dispersive adhesion, also known as physisorption,
two materials are held together by van der Waals forces: the attraction between two
molecules, each of which has a regions of slight positive and negative
charge. In the simple case, such molecules are therefore polar with
respect to average charge density, although in larger or more complex
molecules, there may be multiple "poles" or regions of greater positive
or negative charge. These positive and negative poles may be a permanent
property of a molecule (Keesom forces) or a transient effect which can
occur in any molecule, as the random movement of electrons within the
molecules may result in a temporary concentration of electrons in one
region (London forces).

In surface science, the term "adhesion" almost always refers to dispersive adhesion. In a typical
solid-liquid-gas system (such as a drop of liquid on a solid surrounded
by air) the contact angle is used to quantify
adhesiveness. In the cases where the contact angle is low, more adhesion
is present. This is due to a larger surface area between the liquid and
solid and results in higher surface energy. The Work of
Adhesion
explains the interactive force between the liquid and solid
phases and the Young-Dupree equation is used to calculate the Work of
Adhesion. The contact angle of the three-phase system is a function not
only of dispersive adhesion (interaction between the molecules in the
liquid and the molecules in the solid) but also cohesion (interaction between the
liquid molecules themselves). Strong adhesion and weak cohesion results
in a high degree of wetting, a lyophilic condition with low measured
contact angles. Conversely, weak adhesion and strong cohesion results in
lyophobic conditions with high measured contact angles and poor
wetting.

[edit] Electrostatic adhesion

Some conducting materials may pass electrons to form a difference in electrical charge at the join. This
results in a structure similar to a capacitor
and creates an attractive electrostatic force between the materials.

[edit] Diffusive adhesion

Some materials may merge at the joint by diffusion. This may occur when the molecules of both
materials are mobile and soluble in each other. This
would be particularly effective with polymer
chains where one end of the molecule diffuses into the other material.
It is also the mechanism involved in sintering.
When metal
or ceramic
powders are pressed together and heated, atoms diffuse from one
particle to the next. This joins the particles into one.

[edit]
What
makes an adhesive bond strong?

The strength of the adhesion between two materials depends on which
of the above mechanisms occur between the two materials, and the surface
area over which the two materials contact. Materials that wet
against each other tend to have a larger contact area than those that
don't. Wetting depends on the surface energy of the materials. Well-known examples of
adhesion are tape, glue, and stickers.

[edit] See also

[edit] References

  • John Comyn, Adhesion Science, Royal Society of Chemistry
    Paperbacks, 1997
  • A.J. Kinloch, Adhesion and Adhesives: Science and Technology,
    Chapman and Hall, 1987

 

Michele Ciavarella, http://poliba.academia.edu/micheleciavarella
Editor, Italian Science Debate, www.sciencedebate.it
blogs http://rettorevirtuoso.blogspot.com/
YouTube Channel http://www.youtube.com/user/RettoreVirtuoso

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